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Biology and Taxonomy

of Nematode Parasites

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U.S. Department of Agriculture

Forest Service

Agriculture Handbook No. 446
ÜSDA. National Agricüttural-Libraöf

NAL^ÍÍ ^ ß. ^

10301 Baltimore Bwa

Biology and Taxonomy

of

Nematode Parasites and Associates

of Bark Beetles in the United States

by

Calvin L. Massey, Chief Nematologist

Rocky Mountain Forest and Range Experiment Station

Agriculture Handbook No. 446

Library of Congress Catalog Card Number 73—600071

Forest Service

United States Department of Agriculture March 1974

Washington, D.C.

For sale by the Superintendent of Documents, U.S. Government Printing Office,

Washington, D.C. 20402—Price $3.60

Stock Number 0100-02836
ACKNOWLEDGMENTS

I am greatly indebted to many people who significantly contributed to the subject matter accuracy of this publication. Outstanding among them is Professor Gerald Thorne, Professor

Emeritus, Department of Plant Pathology, University of Wisconsin, and former nematologist with the U.S. Department of

Agriculture. In addition to Professor Thorne, Dr. 0. J. Dickerson, Associate Professor of Nematology, Kansas State University, and Dr. C. Clayton Hoif, Professor of Biology, University

of New Mexico, reviewed the manuscript.

n
SUMMARY

Bark beetles are the most important insect pests of forest trees

in the United States. Nematodes are one of many biotic factors

affecting bark beetle populations.

Research into methods for controlling bark beetle populations

is mostly centered on manipulation of beetle environment through

silvicultural or biological control. Nematodes are one of the major

biotic factors affecting bark beetle populations. For the most part,

life histories of the parasites are synchronized with their host.

Adult parasites are usually produced in adult beetles. Many of

the parasites sterilize their host. It may be possible to sterilize one

or both sexes of a given beetle population by the planned introduction of infested beetles, or by altering the life history of a

parasite so that mature nematodes are produced in immature

beetles. In the laboratory, Contortylenchus reversus, parasitizing

host larvae growing under stress, develop to maturity within the

larvae and cause its death.

Egg galleries of beetles infected with nematodes may be used

in biological evaluations of beetle infestations. Scolytus ventralis

infestations can be evaluated simply by the presence or absence

of short galleries produced by infected beetles.

This publication includes descriptions and drawings of 32 parasites and 112 associates, many of which are new to science. It also

summarizes available information on the biology and ecology of

nematode parasites, and includes a historical review of parasite

study, a discussion of research problems, a list of parasites according to beetle species, and an index to the genera.

Ill
CONTENTS

Page

INTRODUCTION 1

HISTORICAL REVIEW 2

MATERIALS AND METHODS 3

BIOLOGY OF PARASITES . . . 4

Life History 4

Percentage of Various Bark Beetle Species

Infected by Internal Nematode Parasites 9

Effect on Host 13

BIOLOGICAL NOTES ON ASSOCIATES 16

DISCUSSION 17

TAXONOMY 18

Parasites 19

Neotylenchoidea 19

Aphelenchoidea 53

Associates 63

Rhabditoidea 63

Tylenchoidea 135

Neotylenchoidea 154

Aphelenchoidea 173

LITERATURE CITED 223

APPENDIX 229

Nematode Parasites and Associates by Bark

Beetle Species 229

Index to Genera 233
BIOLOGY AND TAXONOMY OF NEMATODE PARASITES

AND ASSOCIATES OF BARK BEETLES IN

THE UNITED STATES

by

Calvin L. Massey ^

INTRODUCTION

Bark beetles are the most important insect

pests of forest trees in the United States. Mortality caused by beetles exceeds that of all other

natural agents combined, including fire.

Many of our most important bark beetle

speci€s are cyclical in nature in that the pests

remain endemic until a combination of factors

favorable to their development occurs; then

populations expand rapidly. Millions of board

feet of valuable timber are destroyed in a relatively short period. Dendroctomts rufipennis

(Kby ), a pest of Engelmann spruce; Dendroctonus ponderosae Hopk., a pest of ponderosa

and lodgepole pine ; Dendroctonus frontalis

Zimm., a pest of southern pines; and Dendroctonus adjunctus Bland., a pest of ponderosa

pine in the Southwest, are prime examples of

such species.

Research into methods by which bark beetle

populations can be held in check is for the most

part pointed toward the manipulation of beetle

1 Formerly chief nematologist, Rocky Mountain

Foresl and Range Experiment Station, Forest Service,

U.S. Department of Agriculture, with central headquarters maintained at Fort Collins in cooperation with

Colorado State University; Massey was permanently

assigned to the Forest Insect Laboratory at Albuquerque, in cooperation with University of New Mexico,

until his retirement in May 1972.

environment, either through the host tree, i.e.

silvicultural control ; through factors which are

concerned primarily with the insect, i.e. biological control ; or both.

Although little is known of factors responsible for the rise and decline of bark beetle populations, nematodes are thought to be one of

the major biotic factors. Of considerable importance are nematodes belonging to the superfamily Neotylenchoidea, including the genera

Parasitylenchus, Contortylenchu^, Sphaerularia, and Allantonema.

The purpose of this volume is to bring together the information available on the biology,

ecology, life history, and taxonomy of nematode

parasites. In addition, a discussion of research

methods and possibilities is presented, and an

index to the genera is provided.

The line drawings in the text are designed to

provide diagnostic characteristics of the respective nematode species. Scales to illustrate size

of most of the drawings were determined by

the author. Study material was not available

for a few species and the reader is encouraged

to determine the size from the text description.

The information presented here should provide

a basis for extensive research on all factors

affecting the ecology of the beetles.
HISTORICAL REVIEW

The study of nematode parasites of bark

beetles originated in Europe. One of the earliest

papers on this group of animals and their relationship to bark beetles was published in

1890 by von Linstow. He identified Contortylenchus diplogaster (Linstow, 1890) Rühm,

1956, the type species of Contortylenchtis, as

Allantonema diplogaster Linstow, 1890; the

host was Tomicus typographus = Ips typographus L. In his paper, he appears to have

misidentified a diplogasterid as the free-living

sexual forms of the parasite. Roux (1906) recovered Anguillonema xylebori (Roux, 1906),

Rühm, 1955 (Tylenchus xylebori Roux, 1906)

from the tunnels of Xyleborus saxesensi Ratz.

Probably the most comprehensive work in

the field of bark beetle nematode relationships

was initiated by Fuchs (1915) who studied the

nematode parasites of Ips typographus and

Hylobius abietis L. Two internal parasites and

eight associates, some of which were phoretics,

were described. His publications, many of

which are landmarks in the field, continued

through 1938. Some major taxonomic designations in both the superfamilies Aphelenchoidea

and Tylenchoidea were directly affected by his

investigations. His studies indicated that nematodes (1) killed or weakened bark beetles, (2)

reduced egg-laying in beetles by 40 percent, and

(3) prevented multiple generations in a given

year.

J. N. Oldham (1930), a British scientist,

published on a nematode parasite of Scolytus

midtistriatus (Marsh) and Scolytus scolytus F.

He observed that approximately 60 percent of

the beetle population was infested with a

species of Parasitylenchus of which 40 percent

were sterilized.

Yatsenkowsky (1924), in Russia, noted that

bark beetles infected with small numbers of

nematodes were castrated; those with larger

numbers were killed. More recently. Rühm

(1956) made a comprehensive study of the

nematode parasites and associates of bark

beetles in Germany. He discussed the effect of

environment on nematodes' life histories and

effect on their hosts. In the study, he described

10 new internal parasites and 50 new associates.

Of considerable interest is the work of

Prosper Bovien (1937), a Belgian studying

nematode parasites of a large group of coleopterous insects, Psychodids and Diptera. He

hypothesized that nematodes infesting the gut

of wood-eating insects were in a transitional

stage between phoresis and true parasitism.

Two Russian nematologists, S. L. Lazarevskaya (1965) and A. Slankis (1967), have published papers of note during the past decade.

The first published on associated insects,

Slankis on internal nematode parasites belonging to the genera Contortylenchus and Parasitylenchus.

The study of nematodes and their relation to

bark beetles is of rather recent origin in North

America. Thorne (1935) published on the

nematode parasites and associates of the mountain pine beetle, Dendroctonus ponderosae

Hopk., and Nickle (1963) has published on the

taxonomy and life history of several species of

Contortylenchus. Reid (1958) noted several

nematode associates of the mountain pine beetle

and determined that an internal nematode parasite, Sphaeridaria hastata Khan 1957, drastically affected the egg production of infested

females.

Other studies of considerable importance,

while not directly related to parasites and associates of bark beetles, are noteworthy in that

they concern groups of nematodes that are

parasitic in or associated with the insects.

Wülker (1923) made an extensive study of the

development of Allantonema. Wachek (1955)

reviewed nematode genera of the superfamily

Tylenchoidea known to be parasitic in insects,

many of these genera being parasitic in bark

beetles.
MATERIALS AND METHODS

To determine the nematode parasites and

associates of a given bark beetle species, beetles

were collected nationwide. Beetles collected in

distant areas were shipped by airmail, special

delivery, to the Forest Insect Laboratory at

Albuquerque and stored at 40° F until they

could be examined. All stages of beetles were

dissected in physiological saline solution and

examined for internal nematode parasites. The

salino solution prevents bursting of the parasites when removed from the body cavity of the

host. The bark from which they were collected

was soaked in water for 24 hours, the residues

screened, and the free-living forms of the parasites and associated nematodes were retrieved

by the Baermann funnel technique developed

by Christie and Perry (1951).

Nematodes were processed for species determination by the following method: fixation

in FAA for 24 hours. The FAA is composed of :

distilled water—120 cc, ethyl alcohol (95 percent)—60 cc, formaldehyde solution (36.6 percent) 18 cc, glacial acetic acid—3 cc, and glycerin—2 cc. Specimens were then processed to

pure glycerin by placing them in a solution of

20 percent ethyl alcohol, 1 percent glycerin contained separately in a saturated atmosphere of

95 percent ethyl alcohol for 24 hours. The nematodes were then removed from the resulting

solution and placed in 95 percent ethyl alcohol

and 5 percent glycerin and allowed to remain

until the solution had evaporated to pure glycerin. Glycerin mounts were then made and the

nem^itodes were established in a permanent

colle<*tion at the Rocky Mountain Forest and

Range Experiment Station.

Life history studies were for the most part

conducted in the laboratory. To determine life

history and effect of the parasite on the host,

pairs of beetles were usually introduced into

their plant host material (wood bolts or slabs)

which were enclosed in individual containers.

These were opened at periodic intervals, and

numbers of progeny produced by infested female beetles were compared to those produced

by noninfested beetles. Free-living stages of the

nematode parasites were obtained by washing

the nematodes from egg and larval galleries

made by the infested females. Life histories of

the parasites were determined by examining

the immature stages of the beetles at intervals

from the time of egg deposition to adulthood.

This was accomplished by examining progeny

from pairs of beetles in series. Habits of the

nematodes were also determined by placing

individual infested larvae in vials containing

fresh phloem and following the development of

host and parasite daily. Percentage of infested

beetles in a given population was determined

by direct examination following dissection.

Nematode measurements preceding each description were derived in the following manner :

a = Total length divided by greatest

width

b = Total length divided by neck length

c= Total length divided by tail length

v= Position of vulva in relation to total

body length.

Measurements include ranges for the most part,

only when variations were distinctly observable.
BIOLOGY OF PARASITES

Life History

Most nematode parasites of bark beetles are

obligate parasites, and, with few exceptions,

all are true parasites and do not kill their host.

None except Parasitorhabditis and the occasionally parasitic Ektaphelenchus are capable

of completing an individual generation in a

free-living state.

In general, the life histories of nematodes

belonging to the superfamily Neotylenchoidea

infecting bark beetles are the same. The life

history of parasites belonging to the genus

Parasitylenchus is the same as that of the

genus Contortylenchtts, with the exception that

members of the genus Parasitylenchus are

ovoviviparous, and Contortylenchus oviparous.

Immature forms of the nematode parasites

are deposited in egg galleries by infested

beetles. Males develop to maturity in egg galleries and impregnate immature free-living

females. Impregnated females immediately

penetrate through the cuticle into the body

cavity of the host, usually a first or second stage

host larva, although older larvae may also become infected. Infection of late stage larvae

seems to be dependent on the time of nematode

deposition by infected host adults.

The development of the parasite is in general

synchronized with its host, parasitic females

reaching sexual maturity when the host beetle

has attained the same stage of development

(fig. 1). Eggs or larvae are then deposited in

the body cavity of the host, the young larvae

penetrate the gut and are deposited in the egg

gallery of the host with the fecal material to

complete the generation. The number of generations produced per year by the parasite

under normal conditions is the same as for the

host. Contortylenchus elongattis (Massey,

1960) Nickle, 1963 has three and a partial generation when infecting Ips confustis (Lee.)

under field conditions. The same nematode will

produce as many as 12 generations per year

when reared in the insect under controlled

laboratory conditions. Contortylenchus reversus (Thorne, 1935) Rühm, 1956 may take

as long as 2 years to complete its development

in the spruce beetle, Dendroctonus rufipennis,

a bark beetle which in general requires 2 years

to complete a generation.

The life history of Contortylenchus can be

altered under certain conditions of stress. Life

history studies conducted in the laboratory

reveal that, when host larvae are reared under

abnormal nutritional conditions, development

of the parasite may be changed. Twenty-five

larvae of Z). rufipennis infested with C. reversus were reared on partially dried phloem.

Ten of the larvae were killed by accelerated

development of the nematode, which produced

young in the body cavity of its host. Under

these conditions, individual host larvae may be

reinfected by infective-stage females which

they have deposited.

Studies indicate that free-living forms persist for only a short time in the gallery of the

host, and that a greater proportion of the host

may be infected when the immature forms of

the parasite are deposited in the gallery while

host eggs are hatching. Infective-stage females

are nonselective. As many as 75 developing

parasitic females of Contortylenchus reversus

have been found in one half-grown larva (fig.

2) while other individuals of the same brood

were not yet infected. Multiple infections are

common. The average number of parasitic females in a study involving 20 adult D. rufipennis infested with C, reversus ranged between

1 and 20 and averaged 5.5. The deposition of

masses of infective-stage females and developing males in the egg galleries is probably the

determining factor.

An individual bark beetle may be infected

with more than one genus or species of parasitic females. Individual Scolytus ventralis Lee.

are commonly infected with Parasitylenchus

elongatus Massey, 1958 and Parasitylenchus

scrutillus Massey, 1964. Massey (1956) found

that 2 percent of the adult D. rufipennis ex-
F-saisis

Figure 1.—Ips confusus infected with adults of Contortylenchus elongatus.

amined were infected with both C. reversus and

Sphaerularia dendroctoni Massey, 1956 (fig. 3).

The same two nematodes have been recovered

from individuals of D. pseudotsugae Furniss

(1967).

Although the life history of Sphaerularia

dendroctoni is little known, examination of

parasitic larvae from the body cavity of adult

beetles suggests that it may vary from the

typical life cycle of Parasitylenchus and Contortylenchus. Males attain sexual maturity

within the body cavity of the host. The significance of this is not known. Members of the

genus Polymorphotylenchus also produce sexually mature males in the body cavity of their

host and the life cycle proceeds in the same

manner as members of the genus Parasitylenchus. Whether this will prove to be the case

with S. dendroctoni remains to be determined.

The life cycle of Allantonema, the other important bark beetle parasite, was not studied.

It appears to be relatively rare in the United

States. Two species have been collected, one

from Orthotomicus ornatus Sw., the other from

Hylastes sp., both in New Mexico. Rühm

(1956) states that Allantonema morosum

(Fuchs, 1929) Filipjev, 1934, a parasite of

Hylastes ater Payk, has a life cycle similar to

Parasitylenchus and Contortylenchus, with the

exception that larvae and eggs are produced in

the immature stages of the host and are subsequently deposited in the galleries. Rühm also

notes that A. morosum is the only member of

this genus in which such a habit has been

reported. His studies were cursory, and it is
F-521849

Figure 2.—Larva of Ips confusus with juvenile female of Contortylenchus elongatus immediately beneath cuticle.

possible that other factors were responsible for

the deviation.

The number of molts required by the various

parasitic nematode larvae was not determined

by the writer. Rühm (1956) reports that

larvae of Contortylenchus and Parasitylenchus

molt twice within the host and once in the host

gallery.

The life history of three nematode parasites

occurring in the United States—Parasitylenchus elongatus, a parasite of Scolytus ventralis;

Contortylenchus elongatus, a parasite of Ips

confusus and Ips lecontei Sw. ; and Parasitaphelenchus dendroctoni Massey 1966, a parasite

of Dendroctonus adjunctus Bland.—are herein

presented as typical examples of the development of nematode parasites of bark beetles.

Parasitylenchus elongatus: Infective-stage

larvae, approximately 1.0 mm in length, are

impregnated by sexually mature males in egg

galleries of the host. These impregnated females penetrate the cuticle or the oral or anal

opening, and enter the body cavities of larvae

which are approximately one-third grown.

They also have been recovered from nearly

mature larvae indicating that infective-stage

females are deposited over a considerable period of time or that infective-stage females

migrate from newly formed egg galleries to

infect larvae from adjacent larval galleries.

Development in general proceeds with the

growth of the host :

Nematody body length (mm)

Host j j

^^' Ov.. ^ ,

development Range Mean

Larvae

Vs grown 1.0-3.4 1.6

V2 grown 1.0-4.4 2.5

% grown 1.0-5.9 4.1

Pupae 3.4-6.9 4.6

Mature adults 4.3-7.6 6.2

After the nematodes enter their host, the lip

region degenerates rapidly and the stylet becomes nonfunctional and displaced, and food

apparently is absorbed through the body wall

of the parasite.

Although the parasite approaches its mature

length in the host pupal stage, young are produced only in the adult beetle. Eggs are hatched

in the uterus and the parasite gives birth to

living young. Mature nemas are little more

than egg sacs. Ovary walls are not discernible

and the body cavity is filled with eggs and

first-instar larvae.

Host infections are generally multiple. Up to

eight individual parasites have been recovered

from the body cavity of an infected host larva.
F-521850

Figure 3.—^Adults, eggs, and larvae of Contortrlenchus reversas and Sphaerularia dendroctoni from the body cavity

of adult Dendroctonus rufipennis.

The body cavity of an infected adult beetle can

be packed with living larvae, approximately

2,500 having been counted from one individual.

The nema larvae penetrate the gut of the host

and are deposited with the feces in the egg

galleries within 10 days after beetle attack.

Infective-stage larvae travel considerable

distances to infect host larvae produced by

nematode-free beetles. In the laboratory they

were collected up to 3 inches from the place of

original deposition ; evidence indicates that they

are capable of traveling twice that distance.

Male parasites occur only in the egg gallery

of the host where they fertilize the infectivestage females. The life cycle in the laboratory

is completed in approximately 2 months at a

temperature of 24°C and a relative humidity of

70 percent. Under field conditions, there is one

generation annually.

Contortylenchus elongattis: Infective-stage

females are approximately 0.7 mm in length

and are impregnated by sexually mature males

in the egg galleries of the host. The impregnated females are thought to penetrate the

cuticle or oral or anal opening, and enter the

body cavity of the host. They usually enter

second- or third-instar larvae, although all

immature stages may be infected. Development

progresses with the development of the insect.

Eggs are deposited only in the abdominal cavity

of the host. Upon hatching, the nema larvae

penetrate the gut and are passed into the egg

gallery with the fecal material throughout the

egg-laying period of the adult beetle beginning

as early as 4 days after beetle attack and as

late as 12 days. The nematodes apparently

molt twice in the galleries before the sexual

characters of the male are observed.

According to Nickle (1963), the nematode

larva molts once in the egg and hatches in the
body of the insect as a second-stage larva. It

is deposited as a fourth-stage larva in the egg

gallery, then molts once more.

Development within the host is rapid :

Nematode body length (mm)

Host

^, v.-^*»^v.w^^ ^^^J o \ /

development Range Mean

Larvae

%-^^ grown 0.7-0.9 0.8

% grown .9-3.0 2.4

Pupae .9-3.8 2.4

Mature adults 2.1-6.3 4.3

Head characteristics change immediately

after the nema larva has entered the body

cavity of the host and the body broadens and

elongates.

Young females are often found in the body

cavity of insect pupae, with fully developed eggs

in the uterus. Under normal conditions, however, no eggs have been found in pupae. Nematode eggs are found immediately after the host

has attained adulthood and these eggs hatch

immediately after deposition. As with Parasitylenchus elongatus, the body cavity of infected

beetles is filled with adults and larvae of the

parasite; the maximum number of larvae

and eggs observed in an individual beetle was

5,775, the maximum number per parasite was

1,375. Because the parasites deposit eggs continuously, the exact number of individuals produced is not known.

The life cycle of C, elongatus may vary from

4 weeks to 8 months depending upon the generation of beetles infested. During the summer

months, development is complete in approximately 4 weeks while in the overwintering

generation, development is not completed for

8 months. Under laboratory conditions, the

parasites developed from egg to adult in 23

days.

Internal parasitism of bark beetles by members of the superfamily Aphelenchoidea is

confined exclusively to two genera, Parasitaphelenchiis and Ektaphelenchus, Internal parasitism by the latter appears to be accidental and

occurs rarely. Members of this genus are typically phoretics, and are carried in small cocoons

beneath the wing covers of adult beetles.

Members of the genus Parasitaphelenchus

are obligate parasites of bark beetles. Little is

known of their life history. Of the species

occurring in the United States, the biology of

Parasitaphelenchus dendroctoni Massey 1966,

a parasite of Dendroctonus adjunctuSy is best

documented. The nematode has a single generation each year. It is a dimorphic species, the

free-living form bearing little resemblance to

the parasitic form. Free-living forms may be

found in egg galleries of D. adjunctus in October and in May of the following year. Since

the free-living form is comparatively shortlived, individuals found in the egg galleries in

May probably overwintered as parasites within

the host.

Free-living females deposit eggs in the host

egg gallery where the larvae hatch, enter the

beetle, and develop as the beetle develops. Infections are multiple ; as many of 25 nematodes

have been found in one beetle. Effects on the

host are not known but observations indicate

that infection may not be detrimental unless a

large number of parasites enter a single individual. Young nematodes are not produced

within the body cavity of the insect. Sex of

parasitic, immature forms could not be determined. Parasitic larvae reenter the gut and are

deposited in the egg gallery where they become

sexually mature.

Rühm (1956), in discussing the life history

of members of the genus Parasitaphelenchus,

notes that after entering a host larva, the

nematode molts only once. It molts again in

the egg gallery before sexual maturity is

attained. The second molt is accompanied by

considerable stretching of the entire body.

Rühm notes that sexual development is more

advanced in males than in females and that

the number of females exceeds the number of

males. Nematode larvae produced from eggs

within the gallery molt twice before entering

their host.

In the superfamily Rhabditoidea, one genus,

Parasitorhabditis, is an internal parasite of

bark beetles. The immature nematodes are

usually found parasitic in the gut of various

species of scolytids in the United States. Adults

are abundantly associated in the galleries with

most bark beetle species.

A Parasitorhabditis sp. associated with D.

rufipennis has been easily reared on malt agar.

Rühm (1956) records Parasitorhabditis piniperda (Fuchs, 1937) Rühm 1954 as a parasite

in the body cavity of Myelophilus piniperda L.,

where its mode of infection and parasitic characteristics appear to be similar to that of Parasitaphelenchus. The nematode larvae, however,

infest only the cavity of immature stages of the

beetle. Hunt and Poinar (1971) have success-
fully reared several generations of an undescribed Parasitorhahditis from Dendroctonus

Valens Lee. on sporulating cultures of Ceratocystis minor (Hedg.) Hunt. Their research

indicates that at least some species of the genus

can reproduce satisfactorily without passing

through an insect host.

Percentage of Various Bark Beetle

Species Infected by Internal

Nematode Parasites

The percentage of individual bark beetles

of a species infected by internal nematode parasites are quite variable. Only two scolytids

which have been examined in large numbers

have been without them. They are Dryocoetes

confusMs and Ips integer. The percentages of

infected beetles of a given species in given

populations may vary from 0 to 90 percent and

may fluctuate drastically from year to year.

For example, 15 percent of the roundheaded

pine beetle, D. adjiincttis, examined in 1952

were infected with Parasitaphelenchus dendroctoni; in 1963, 80 percent of the beetles

from the same area were infected. In 1957, 41

percent of Ips confiisiis adults from 17 trees

were infected with C. elongatus. In 1958, 29

percent of the beetles from the same area were

examined and were infected. The number varied

considerably from generation to generation.

In 1958, 34 percent of generation I was infected

compared to 17 percent of generation IV.

Reasons for the variation are not known.

Environmental factors, of which moisture

probably is the most important, evidently play

a large role in determining nematode abundance. Nematode populations are extremely

high and varied as to species in bark beetle

infested spruce and fir, and are correspondingly

low and less varied in ponderosa pine (Pimis

ponderosa Laws.) and pinyon (Pinus edidis

Engelm.) where moisture required for survival

of the tree is much lower. Dendroctonus ponderosae and Dendroctonus hrevicomis Lee,

pests of ponderosa pine, are generally less

heavily parasitized by internal nematode parasites than Dendroctonus rufipennis and Scolytus

ventralis, pests of Engelmann spruce {Picea

engelmanni Parry) and white fir {Ahies concolor (Gord. and Glend.) Lindl.), respectively.

During studies on various bark beetle species,

the numbers infected were recorded when collections were large enough to be meaningful.

Table 1 shows the variation in numbers infected within a given bark beetle species, and

among the various host genera and species.

Table 1.—Percentages of various hark beetle species infected with internal nematode parasites

Bark beetle Nematode

species

Beetles

species Examined Infected Locality Date

Number Numher Percent

Conopthorus 57 0 0 Hamden, Conn. 1968

coniperda

Dendroctonus Parasitylenchus 212 123 58 Lincoln NF, N.M. 1962

adjunctus stipatus

Dendroctonus Parasitylenchus 212 25 12 Lincoln NF, N.M. 1963

adj tîictus stipatus

Dendroctonus Parasitylenchus 104 13 12 Lincoln NF, N.M. 1969

adjmctus stipatus

Dendroctonus Parasitylenchus 35 23 m Lincoln NF, N.M. 1970

adjunctus stipatus

Dendroctonus Parasitaphelenchus 212 32 15 Lincoln NF, N.M. 1962

adjunctus dendroctoni

Dendroctonus Parasitaphelenchus 212 170 80 Lincoln NF, N.M. 1963

adjunctus dendroctoni

Dendroctonus Parasitaphelenchus 104 72 70 Lincoln NF, N.M. 1969

adjunctus dendroctoni
Table 1. Percentages of various bark beetle species infected with internal nematode parasites-

(Continued)

Bark beetle Nematode

species

Beetles

species Examined Infected Locality Date

Number Number Percent

Dendroctonus

brevicomis

Contortylenchus

brevicomi

346 10 3 Bandelier Nati. M., N.M. 1958

Dendroctonus

frontalis

Contortylenchus

brevicomi

611 112 18 Talladega NF, Ala. 1954

Dendroctonus

frontalis

Contortylenchus

brevicomi

192 34 18 Jonesville, La. 1969

Dendroctonus

frontalis

Contortylenchus

brevicomi

116 3 2.5 Beaumont, Texas 1969

De7idroctonus

frontalis

Dendroctonus

parellelicollis

Dendroctonus

ponderosae

236 0 0 Keysville, Va. 1968

42 0 0 Santa Fe, N.M. 1957

Contortylenchus

reversus

50 1 2.0 Roosevelt NF, Colo. 1971

Dendroctonus

pseudotsugae

Contortylenchus

reversus

296 106 36 Santa Fe NF, N.M. 1959

Dendroctonus

pseudotsugae

Contortylenchus

reversus

541 175 32 Santa Fe NF, N.M. 1960

Dendroctonus

pseudotsugae

Contortylenchus

reversus

323 173 54 Santa Fe NF, N.M. 1961

Dendroctonus

pseudotsugae

Contortylenchus

reversus

136 56 41 Santa Fe NF, N.M. 1962

Dendroctonus

pseudotsugae

Parasitaphelenchus

beccus

301 227 75 Santa Fe NF, N.M. 1959

Dendroctonus

pseudotsugae

Parasitaphelenchus

beccus

542 407 75 Santa Fe NF, N.M. 1960

Dendroctonus

pseudotsugae

Parasitaphelenchus

beccus

323 276 85 Santa Fe NF, N.M. 1961

Dendroctonus

pseudotsugae

Parasitaphelenchus

beccus

174 152 87 Santa Fe NF, N.M. 1962

Dendroctonus

rufipennis

Sphaerularia

dendroctoni

625 m 11 White River NF, Colo. 1952

Dendroctonus

rufipennis

Sphaerularia

dendroctoni

625 221 35 White River NF, Colo. 1953

Dendroctonus

rufipeyinis

Sphaerularia

dendroctoni

625 6 1.0 Routt NF, Colo. 1952

Dendroctonus

rufipennis

Sphaerularia

dendroctoni

625 35 6.0 Routt NF, Colo. 1953

Dendroctonus

rufipennis

Sphaerularia

dendroctoni

50 1 2.0 Mt. Taylor, N.M. 1965

10
Table 1. Percentages of various hark beetle species infected with internal nematode parasites-

(Continued)

Bark beetle Nematode

species

Beetles

species Examined Infected Locality Date

Dendrcctonus

rufipennis

Contortylenchus

reversus

Numher

625

Numher

53

Percent

8.0 White River NF, Colo. 1952

Dendroctonus

rufipennis

Contortylenchus

reversas

625 115 18.4 White River NF, Colo. 1953

Dendroctonus

rufipennis

Contortylenchus

reversus

625 115 18.4 Routt NF, Colo. 1952

Dendroctonus

rufipennis

Contortylenchus

reversus

625 147 23.6 Routt NF, Colo. 1953

Dendroctonus

rufipennis

Contortylenchus

reversus

174 ^ 68 39.0 Mt. Taylor, N.M. 1965

Dendroctonus

terehrans

Dendroctonus

terehrans

96 0 0 Oakdale, La. 1970

Contortylenchus

terehranus

48 4 8 Spurger, Texas 1970

Dendroctonus

terehrans

Contortylenchus

terehranus

38 1 2.6 Nacogdoches, Texas 1970

Dendroctonus

Valens

Contortylenchus

sp.

18 7 39.0 Prescott NF, Ariz. 1966

Ips

avulsus

Parasitylenchus

avulsi

83 18 22.0 Talladega NF, Ala. 1954

Ips

avu Isus

Parasitylenchus

avulsi

25 5 20.0 Henderson, N.C. 1968

Ips

avu Isus

Parasitylenchus

avulsi

Q>ß 15 22.7 Oakdale, La. 1969

Ips

calligraphus

Contortylenchus

grayidicolli

108 7 6.5 Weed, N.M. 1969

Ips

con fUSUS

Contortylenchus

elongatus

615 254 41.3 Bandelier Nat'l. M., N.M. 1957

Ips

confUSUS

Contortylenchus

elongatus

568 163 28.7 Bandelier Nati. M., N.M. 1958

Ips

crincollis

Contortylenchus

cribicolli

50 9 18 Ruidoso, N.M. 1968

Ips

grvndicollis

Contortylenchus

grandicolli

36 6 16.7 Beaumont, Texas 1969

Ips

grvndicollis

Contortylenchus

grandicolli

83 11 13.3 Oakdale, La. 1969

Ips

integer

212 0 0 Prescott, Ariz. 1966

Ips

kn lusi

50 0 0 Weed, N.M. 1969

11
Table 1. Percentages of various bark beetle species infected with internal nematode parasites^

(Continued)

Bark beetle Nematode

species

Beetles

species Examined Infected Locality Date

Number Numher Percent

Ips Contortylenchus 78 14 18.0 Red Feather Lakes, Colo. 1966

pilifroiis spirits

Ips Parasitylenchiis 50 24 48.0 Gorham, Maine 1968

pini ipinius

Ips Parasitylenchus 48 2 4.1 Neola, W. Va. 1968

pini ovarius

Ips Contortylenchus 48 1 2.0 Neola, W. Va. 1968

pini spirus

Ips Contortylenchus 50 7 14.0 Gorham, Maine 1968

pini spirus

Hylurgops Parasitylenchus 25 15 60.0 Gorham, Maine 1968

pinifex coronatus

Hylurgops Contortylenchus 25 1 4.0 Gorham, Maine 1968

pinifex sp.

Hylurgops Parasitylenchus 35 8 22.8 Caroline Co., N.Y. 1968

pinifex coronatus

Leperisinus Parasitylenchus 105 3 2.8 Chillicothe, Ohio 1970

aculeatus lepersini

Leperisinus 21 0 0 Bottineau, N.D. 1969

aculeatus

Leperisinus 120 0 0 Bottineau, N.D. & 1970

californicus Rugby, N.D.

Leperisinus 386 0 0 Rugby, N.D. 1971

criddlei

Orthotornicus Parasitylenchus 92 3 3.2 Freeport, Maine 1968

caelatus oriundus

Phloeosinus 25 0 0 Keysville, Va. 1968

dentatus

Pityokteines

elegans

225 0 0 Sandia Mtns., N.M. 1968

Pityogenes

carinulatus

78 0 0 Sandia Mtns., N.M. 1968

Pityophthorus Contortylenchus 53 15 28.3 Neola, W. Va. 1968

sp. pityophthori

Pityophtho'ï^is Parasitaphelenchus 35 5 14.3 Hamden, Conn. 1968

sp. sp.

Pityophthorus Parasitaphelenchus 100 2 2.0 Coconino NF, Ariz. 1969

sp. sp.

Pityophthorus Parasitylenchus 100 1 1.0 Coconino NF, Ariz. 1969

sp. sp.

Polygraphus Parasitylenchus 225 7 3.1 Flagstaff, Ariz. 1968

hoppingi parasiUis

12
Table 1. Percentages of various bark beetle species infected with internal nematode parasites-

(Continued)

Bark beetle Nematode

species

Beetles

species Examined Infected Locality Date

Niimber Number Percent

Pseudohylesinus

grandis

167 0 0 Grand Canyon, Ariz. 1968

Pseudopityophthorus 50 0 0 Zaleski SF, Ohio 1970

Scolyius

muiicus

Scolyius

muliistriatus

Scolytus

muliistriatus

100 0 0 Delaware, Ohio 1970

58 0 0 Chillicothe, Ohio 1970

Parasitaphelenchus

sp.

100 17 17 Albuquerque, N.M. 1963

Scolytus

veniralis

Parasiiylenchus

elongaius

215 56 26.0 Sandia Mtns., N.M. 1961

Scolyius

veniralis

Parasiiylenchus

elongaius

191 46 24.0 Sandia Mtns., N.M. 1962

Effect on Host

In the United States, extensive nematode

studies have been made on only a fev^ scolytid

species to determine their effect on the beetles

they infect. The author's studies have been

confined to the effect of Contortylenchus reversus and Sphaerularia dendroctoni on Dendroctonus rufipennis; Parasiiylenchus elongaius

on Scolytus veniralis; C. reversus on D, pseudoisugae, C. reversus and Parasiiylenchus sp.

on Ips pilifrons; and Conioriylenchus elongaius

on Ips confusus and /. leconiei. In addition to

these studies, Ashraf (1969) and Ashraf and

Berryman (1970) determined the effect of

P. elongaius on S. veniralis and in Canada,

Reid (1958) studied the effect of Sphaerularia

hastata on D. ponderosae. While the effect of

parasitism has been determined on only a few

beetles, it is logical to assume that similar

parasites have a similar effect on the various

bark beetles from v^hich they have been collected.

The most pronounced effect of internal nematode parasites of bark beetles is in limiting egg

production. Massey (1956) shov^ed that female

spruce beetles (Z). rufipennis) infected with S.

dendrocioni laid an average of 28.8 eggs per

female while noninfected females laid an average of 76.5. Male insects did not appear to be

advei'sely affected, although they did carry

nematodes and aided in their dissemination. In

the same study, it was determined that females

infected with C. reversus laid about 35 eggs

per female while noninfected females laid an

average of 65. In this study, it was also determined that 22 percent of the beetle larvae from

parents infected with C. reversus were also

infected.

Massey (1964), reporting on the effect of

P. elongaius on the fir engraver, noted that

unlike other tylenchs parasitizing bark beetles,

P. elongaius killed its host. Infected females

constructed very short galleries, seldom over

an inch in length (fig. 4). The beetles died

within a short time after larval nematodes

were deposited in the galleries. The study

showed that no eggs were produced in short

galleries made by 39 infected females, and that

29 noninfected females constructed 66 inches

of gallery and deposited 21 eggs per inch.

Studies in New Mexico indicate that P.

elongaius was responsible for the decline of an

infestation of the beetle at Ruidoso. A biological evaluation of the infestation shortly before

its termination revealed trees in which the

majority of the galleries were very short and

eggs had not been deposited. Duplicate conditions were produced in the laboratory by inoculating green logs with beetles infected with

the parasite. Ashraf (1969) studied the effect

of P. elongaius in the fir engraver beetle. He

13
líBi^l

F-521847

Figure 4.—A. Galleries produced by females of Scolytus

ventralis infected by Parasitylenchus elongatus; B.

galleries produced by noninfected females.

determined that the nematode caused up to 9

percent egg mortality in Scolytus ventralis.

Larval parasitism increased over the course of

the study and resulted in 1-4 percent larval

mortality. Adults were parasitized 63 and 76

percent in 1967 and 1968. Emergence of parasitized adults was delayed. Flight potential of

nematode-infected adults was seriously impaired, particularly when parasitism was

heavy. Heavy nematode infection sterilized S.

ventralis females. Ovaries of infected females

were rudimentary, while testes of infected

males were normal in all except heavily infected

individuals.

A study to determine the effect of C. reversus

on the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., involved 24 pairs of beetles isolated in green Douglas-fir slabs. Five noninfected females laid an average of 72.2 eggs per

gallery, while 9 infected females laid an average

of 48.4 eggs per gallery. The average length of

egg galleries constructed by noninfected females was 13.8 inches, by infected females, 8.2

inches. The other 10 females died of unknown

causes.

Similar studies involving Ips pilifrons Sw.

infected by C. reversus revealed that noninfected female beetles laid an average of 40.2

eggs per gallery, infected females an average of

10.5, a reduction of 74 percent. In this study,

5 infected females produced 43 larvae of which

27 were infected. Parasites per larvae averaged

12, although 3 larvae contained 56, 75, and 100

parasites, respectively. Galleries constructed by

the infected beetles were considerably shorter

than those constructed by noninfected females

(fig. 5).

Separate studies were made on the same insect which involved C. reversus and Parasitylenchus sp., together with an entomophagous

parasite, Tomicobia tibialis Ashm., a parasite

of the adult beetle. C. reversus was superior to

both Parasitylenchus sp. and the insect parasite in reducing brood production. Female

beetles infected with C. reversus produced an

average of 4.7 individuals, females infected

with T. tibialis produced an average of 7.3 individuals, and those infected with Parasitylenchus sp. produced 22.5; noninfected beetles

produced an average of 40.6. All beetles infected with T. tibialis ultimately died but only

after broods had been produced. The insect

parasite appeared to have little effect on male

beetles. Nonparasitized females mated to parasitized males produced a normal number of offspring.

Contortylenchus elongatus, a nematode parasite of Ips confv^us and /. lecontei, is an effective agent in reducing the brood produced by

both beetles. Massey (1960), working with

I. confusus, determined that the average number of eggs produced in a 2-week period by

infected females of paired beetles was 12.5,

by noninfected females, 26.0. Brood produced

in a 4-week period by infected females averaged 24.3, while noninfected females averaged

57.9, a 58 percent' reduction due to infection.

Maximum number of larvae, pupae, and adults

14
f^f^ \

\

.< ,.:i^

• ^ 'it?

B

F-521846

Figure 5 A. Galleries produced by noninfected females, /ps pilifrons; B. galleries produced by females infected

with Contortylenchus reversus.

produced by an infected female was 49 compared with 108 by noninfected females. The

beetle progeny also were more likely to be infected with the nematode parasite when the

female or both sexes were parasitized than

when the male alone was infected. Forty-seven

percent of the brood was infected when the

adult female was parasitized, 53 percent when

both adults were infected, and 6.2 percent when

males were infected. Beetles parasitized by the

nematode constructed egg galleries that averaged only 4.5 inches as compared with 7.1

inches for noninfected females. C. elongatus

has a similar effect on /. lecontei.

Reid (1958) studied the effect of Sphaerularia hastata on the mountain pine beetle in

the East Kootenay region of British Columbia

and found that 33 infected females laid an

average of 38.4 eggs per gallery while 88 noninfected females laid an average of 56.9. Infected beetles moved very lethargically and did

not attempt to escape when removed from their

galleries. Antennae and legs often trembled

noticeably.

15
BIOLOGICAL NOTES ON ASSOCIATES

The majority of nematodes found associated

with bark beetles are, in a strict sense of the

word, phoretics. They are carried from gallery

to gallery, tree to tree, beneath the wing covers

of the beetles, in the intersegmental folds of the

abdomen, and on the various tarsal and tibial

joints of the legs. Particularly interesting is

the habit of members of the genus Ektaphelenchus. The nematodes form small, leathery cocoons beneath the wing covers of adult beetles

and are transported in this manner. Cocoons

made by Ektaphelenchus ohtusus Massey, 1956

beneath the wing covers of D. rufipennis may

contain as many as 75 females and a single

male. The cocoons evidently burst after or during construction of the egg gallery as the galleries contain numerous mature and immature

individuals of the species. On rare occasions,

E. ohtusus has been recovered from the body

cavity of the spruce beetle. Infections are relatively light—at the most, 6 or 7 individuals in

the hemocele. It is possible that in time the

nematode will became a true parasite.

In the Aphelenchoidea, other than EktaphelenchuSy Cryptaphelenchus, and Bursaphelenchus are commonly phoretic and depend on

fungal growth in bark beetle galleries for their

survival. Members of the genus Laimaphelenchus are commonly associated with bark beetles,

although they have never been observed either

in adult or immature form as actual bark beetle

phoretics. McBeth (1937) observed Laimaphelenchus penardi (Steiner, 1914) Filipjev and

Schuurmans Stekhoven, 1941 feeding on a larva

of Parasitorhabditis sp. Members of the genus

Seinura, according to Hechler (1963) and Linford and Oliveira (1937), are commonly predaceous on other nematodes.

In the Rhabditoidea, members of the genera

Mikoletzkya, Neocephalobus, Diplogasteroides,

Rhabdontolaimus, Cylindrocorpus, and Acrostichus are commonly carried by the beetles.

Macrolaimiis and Santafea, along with Geraldius and Plectiis, are commonly recovered from

bark infested with beetles, but they may be inhabitants of the outer bark and its associated

growth, such as lichens and Spanish moss

rather than true inhabitants of bark beetle

galleries since they have been collected from

bark of noninfested trees. It is possible that

they may be carried by other insects.

Evidence indicates that members of the genus

Mikoletzkya prey on the eggs of bark beetles.

Eggs in galleries of the mountain pine beetle

with dense populations of Mikoletzkya pinicola

(Thorne 1935) Baker 1962 fail to hatch while

those which are lightly infested by the nematode produce a normal population. This predatory habit is mentioned elsewhere in the literature as it concerns diplogasterids. Cobb, in

Merrill and Ford (1916), observed Mikoletzkya

aerivora (Cobb, 1916) Baker, 1962 feeding on

grasshopper eggs. Steiner (1930) felt that

Neodiplogaster pinicola Steiner, 1930 was predaceous on the eggs and small larvae of Pissodesstrobi (Peck.).

Parasitorhabditis is abundantly associated

with various scolytid species. Members of this

genus, while parasitic in the gut of their host,

are able to produce successive sexual generations in bark beetle galleries.

The superfamily Tylenchoidea is represented

by two genera that are abundantly associated

with bark beetles. They are Neoditylenchus and

Sychnotylenchus. Both apparently depend on

fungal growth occurring in scolytid galleries

for survival. They are insect phoretics.

Several genera belonging to the superfamily

Neotylenchoidea have been recovered in association with bark beetles. Probably most common are members of the Nothotylenchus; however, all members of this large group are

relatively few in comparison to members of the

Rhabditoidea and Aphelenchoidea. Their lack

of abundance is somewhat anomalous when one

considers that all the important internal parasitic nematodes of bark beetles belong to the

superfamily Neotylenchoidea.

16
DISCUSSION

Much remains to be learned on the biology,

ecology, and life histories of nematode parasites of bark beetles ; only the surface has been

scratched. While the basic life histories and

host relationship of many of the important

species have been established, little is known of

their ecology. Much information is needed on

the effect of environmental conditions such as

moisture, drought, and biotic factors on the

free-living forms. Additional knov^ledge is

essential on the effect of beetle vigor and beetle

nutrition on the parasitic stages of the nematodes.

All efforts to rear the parasites on artificial

media have failed. At present they can be

reared only in their host. Research should be

expanded to develop methods for artificial

rearing. Once this door is opened, possibilities

for research on the animals in relation to their

host are infinite.

While the animals offer interesting possibilities in the biological control of bark beetle

populations, extensive research will be essential before their use in such a manner can be

forecast.

It may be possible to increase the lethal

potential of the parasites by cross inoculating

them to host species of the same genus or

closely related genera.

It has been demonstrated that many of the

parasites sterilize their host. It may be possible

to sterilize one or both sexes of a given beetle

population by the planned introduction of infected beetles.

Research has revealed that, for the most

part, life histories of the parasites are synchronized with their host. Adult parasites are

usually produced in adult beetles. It may be

possible to enhance the effect of the parasite by

altering its life history so that mature nematodes are produced in immature beetles. It has

been demonstrated in the laboratory that Contortylenchiis reversus, parasitizing host larvae

growing under stress, develop to maturity

within the larvae and cause its death.

Under laboratory conditions, populations of

beetles can be eradicated by breeding infected

males and females, or infected females to noninfected males. It is possible that such a system

would be even more successful under field conditions where other assisting biotic factors such

as entomophagus parasites and mites are more

prevalent.

Egg galleries of beetles infected with nematodes may be used in the biological evaluation

of bark beetle infestations. Scolytus ventralis

infestations, at present, can be evaluated

simply by the presence or absence of short

galleries produced by infected beetles.

Many biotic factors affect bark beetle populations. Nematodes are one of the factors. It

is hoped that the information contained in this

bulletin will provide for extensive research on

all factors affecting the ecology of the beetles.

17
TAXONOMY

Classification of nematodes belonging to the

superfamily Neotylenchoidea, parasitic in bark

beetles, is considerably confused. The confusion

is brought about for the most part by the dearth

of morphological characters that can be applied

to the parasites and to their free-living counterparts and to the lack of research both taxonomically and biologically on the group as a

whole. As noted in the historical review, very

little work has been done in the United States.

Europeans have studied the worms both systematically and biologically in considerable

detail but their research has been confined to

the relatively few bark beetle species which

occur on that continent. In the United States,

only a few taxonomic studies are available to

the researcher. In 1967, Nickle proposed a classification in which all insect parasitic nematodes would be placed in the family Sphaerulariidae (Lubbock, 1861) Skarbilovich, 1947.

He proposed reducing the family Allantonematidae (Periera, 1931) Chitwood and Chitwood, 1937 to subfamily rank on the assumption that Sphaerulariidae was an older family

name and therefore predated the family Allantonematidae. Nickle assumed, however, that

Sphaerularia type genus of the family Sphaerulariidae and Allantonema type genus for the

family Allantonematidae are so closely related

that they can be adequately included under one

family Sphaerulariidae. I do not agree with this

proposal. The habits of Sphaerularia and morphological characters of the parasitic females

preclude their placement in the same family as

Allantonema and closely related genera.

Nor do I agree with Nickle's reducing the

family Contortylenchidae to subfamily rank.

The nematodes exhibit sufficient morphological

characters to deserve family ranking. These

characters, such as the deeply cleft vulva, body

form, structure of stylet and other internal

organs, and homomorphic body shape easily

separate the animals from Allantonema and

Parasitylenchus, The parasitic females of the

last named genera quite often are amorphous

in shape and structure.

Nickle also proposed the separation of the

genus Parasitylenchus into several new genera

through the erection of one new genus

Neoparasitylenchus and the raising of the subgenera Sulphuretylenchus Rühm, 1956, Metaparasitylenchus Wachek, 1955 and Proparasitylenchus Wachek, 1955 to generic rank. I am

very familiar with nematodes included in the

changes, and do not agree with the new generic

proposal nor the raising of the subgenus Sulphuretylenchus to generic rank on the basis of

body form only. As previously stated, body

shape in the parasitic females of Parasitylenchus may be quite amorphous. This amorphism

could be related to host and related environmental factors. In addition, it is very difficult to

distinguish morphological characters other than

those variables for specific designation in the

free-living forms. Males develop to sexual maturity in bark beetle galleries and infectivestage females are impregnated as immatures in

the egg tunnels. Neither sex exhibits characters

of sufficient importance to require generic rank.

Internal parasites of bark beetles of the

superfamily Aphelenchoidea are included in

only one genus, Parasitaphelenchus. The genus

Sphaerularia, family Sphaerulariidae, originally included in this superfamily, has been

rightfully transferred to the superfamily Neotylenchoidea by Jairajpuri and Siddiqi (1969).

For the most part, nematode associates of

bark beetles are closely related taxonomically

to soil and free-living forms. Many of the

groups, however, are known only as insect associates. The majority of members of the aphelenchoid genera Bursaphelenchus, Ektaphelenchus, Cryptaphelenchus, and Laimaphelenchus

are bark beetle or tree-infesting weevil associates. The same can be said of the tylenchoid

genera Neoditylenchüs, Sychnotylenchus,

StictyluSy Deladenus, and Anguillonema, All

are morphologically related to free-living

18
counterparts but have adapted themselves to a

bark beetle related environment.

By far the greatest number of species associated with bark beetles are included in genera

belonging to the superfamily Rhabditoidea. The

genera Mikoletzkya, Parasitorhabditis, Rhabdontolaimus, Diplogasteroides, and Acrostichus

are quite prominently associated v^ith bark

beetles and for the most part are taxonomically

distinct. Their classification has been properly

portrayed with free-living and plant parasitic

forms from which they have probably developed. The system of classification of associated

nematodes used in this bulletin has been adapted

from Baker (1962) and Golden (1971).

Parasites

Neotylenchoidea (Thorne, 1941) Jairajpuri

and Siddiqi, 1969

Allantonematidae (Pereira, 1931) Chitwood

and Chitwood, 1937

Allantonematinae Pereira, 1931 (Chitwood

and Chitwood, 1937)

Allantonema Leuckart, 1884

A. orthotomici n. sp.

A. paramorosum n. sp.

Parasitylenchus Micoletzky, 1922

P. avulsi Massey, 1958

P. coronatus n. sp.

P. elongatus Massey, 1958

P. ipinius n. sp.

P. leperisini n. sp.

P. oriundus n. sp.

P. ovarius n. sp.

P. parasitus n. sp.

P. pilifronus Massey, 1958

P. scrutillus Massey, 1964

P. senicus n. sp.

P. stipatus Massey, 1966

P. undulattts n. sp.

Contortylenchidae Rühm, 1956

Contortylenchus Rühm, 1956

C. brevicomi (Massey, 1957)

Rühm, 1960

C. bullus n. sp.

C cribicolli n. sp.

C. elongatus (Massey, 1960)

Nickle, 1963

C. grandicolli (Massey, 1957)

Rühm, 1960

C. orthotomici n. sp.

C. pityophthori n. sp.

C. reversus (Thorne, 1935)

Rühm, 1956

C. spirus (Massey, 1957) Rühm,

1960

C. terebranus n. sp.

Sphaerulariidae (Lubbock, 1861) Skarbilovich,

1947

Sphaerulariinae (Lubbock, 1861) Pereira,

1931

Sphaerularia Dufour, 1837

S, dendroctoni Massey, 1956

Genus Allantonema Leuckart, 1884

Synonym : Tylenchomorphus Fuchs, 1915

Type species : Allantonema mirabile Leuckart, 1884

Free-living forms : Cuticle smooth or with

transverse striae. Lips distinct. Stylet well

developed. Dorsal esophageal gland opening

relatively far posterior to base of stylet. Vulva

posterior, lips continuous with body contour.

Anal opening distinct. Spicules paired, tylenchoid. Bursa peloderan. Tail conoid to a subacute terminus.

Parasitic form bean shaped, cuticle smooth or

with transverse striae. Lip region overgrown

by body expansion. Stylet obscure. Lumen of

esophagus usually visible for short distance

from base of lips. Body growth usually obscuring vulval opening. Ovary appearing to float

free in body cavity. Ovoviviparous.

Allantonema orthotomici n, sp

Parasitic females : Length

0.61 mm

0.83 mm

Width

0.18 mm

0.16 mm

Figure 6

V

90%

Body bean shaped. Cuticle smooth. Lip region

not set off, conical in young specimens, broadly

rounded in older specimens. Spear not visible in

specimens examined. Portions of esophagus

traceable a short distance posterior to lip

region. Vulva prominent in young females, lips

continuous with body wall. Vagina oblique,

very short. Ovary reflexed many times together

with uterus, filling body cavity. Posterior portion of body cavity filled with developing eggs

and larvae. Anal opening distinct in young

females. Both vulva and anus are obscure in old

parasitic females. Terminus broadly rounded.

Larvae from body cavity of host: body

straight, cylindroid. Cuticle with coarse transverse striae. Lip region broadly rounded with

definite constriction. Cephalic framework mod19
Il i

f il fi

ÎVlirii:

1-/ v;

'iß

1 / ¡M

ll;;l \.B

.01mm

I I

.01mm

Figure 6.—Allantonema orthotomici n. sp.: A. Young, parasitic female; B. old, parasitic female; C. larva, head, and

neck; D. larva, head; E. larva, tail.

20
erately sclerotized. Spear 10 /x in length, slender

with distinct basal knobs. Esophageal glands

extending 4 body widths posterior to nerve

ring. Elxcretory pore passes through hemizonid,

opposite nerve ring. Genital primordia positioned in posterior one-third of body. Anal

opening rudimentary. Tail conoid to a broadly

rounded terminus.

Diagnosis.—Related to Allantonema philonthi

Wachek, 1955. Parasitic females are generally

smaller. Differs in the apparent absence of a

stylet in the parasitic forms and in their generally smaller size.

Tyjje host.—Parasitic in body cavity of Orthoto7fiiciis ornatus Swaine.

Type locality.—Bandelier National Monument, New Mexico.

Type specimens.—Collection No. 15-Z.

Allantonema paraniorosuni n. sp.

Mature parasitic females :

nine measured from four beetles.

Figure 7

Length Width

0.65 mm 0.28 mm

0.67 mm 0.25 mm

0.68 mm 0.24 mm

0.76 mm 0.36 mm

0.88 mm 0.19 mm

0.98 mm 0.33 mm

1.05 mm 0.27 mm

1.12 mm 0.27 mm

1.30 mm 0.30 mm

Average 0.89 mm 0.27 mm

Body usually bean shaped, approximately

3 times longer than wide; however, length of

some specimens may be 5 times width. Cuticle

with moderately fine transverse striae. Fat

globules intermittently attached to cuticle over

entire body surface. Lip region broadly rounded

and overgrown by body expansion. Stylet not

discernible in 12 specimens available. Rudiments of esophagus visible for a short distance

posterior to lip region. Vulva terminal, in some

specimens not discernible because of overgrowth

of body. Ovary reflexed numerous times, together with uterus filling body cavity. Posterior

portion of body occupied entirely by uterus and

developing eggs and larvae. Terminus broadly

rounded. Ovoviviparous.

Larvae from body cavity of host: Body

straight, cylindroid. Cuticle with moderately

coarse transverse and longitudinal striations.

Lip region not set off, rather broadly rounded.

Framework moderately distinct. Stylet exceedingly fine without basal knobs or thickenings.

Esophageal glands indistinct. Nerve ring very

prominent. Excretory pore slightly posterior to

nerve ring. Genital primordia prominent and

located in posterior one-half of body. Anal

opening distinct. Tail conoid to semiacute terminus.

Diagnosis.—Related to Allantonema morosum (Fuchs, 1929) Filipjev, 1934; differs from

that species in the much smaller average size of

parasitic females. Cuticle of the parasitic

females with transverse striations. Cuticle of

larvae with coarse longitudinal and transverse

striae. Parasitic females also differ from A.

morosnm in apparent absence of a stylet.

Type host.—Body cavity of Hylastes sp.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 69.

Genus Parasitylenchus Micoletzky, 1922

Synonyms : Metaparasitylenchiis Nickle, 1967

Sulphuretylenchus Nickle, 1967

Proparasitylenchus Nickle, 1967

Neoparasitylenchus Nickle, 1967

Type species : Parasitylenchus dispar (Fuchs,

1914) Micoletzky, 1922

Parasitic females : Ranging in size from short

stout to long thick bodied. Cuticle smooth or

with transverse striae of varying coarseness.

Lip region usually overgrown by body growth.

Stylet usually visible, short, stout, with or without basal knobs or thickenings, often displaced

by developing ovary. Esophagus traceable for

only a short distance from base of spear. Excretory pore and nerve ring both becoming

obscure with body development. Vulva far

posterior, at times terminal, usually visible only

on younger specimens. Ovary, together with

uterus, filling entire body cavity when fully

developed. Anus closely associated with vulva,

at times terminal. Terminus usually broadly

rounded.

Free-living forms: Lip region continuous

with body contour. Cephalic framework lightly

sclerotized. Stylet usually stout, with or without

basal knobs or thickenings. Dorsal esophageal

glands prominent to obscure in some species.

Esophagus appearing to join directly with gut.

Vulva continuous with body wall. Vagina short,

very narrow. Posterior portion of developing

ovary filled with sperm cells. Anal opening

usually obscure. Terminus variable in shape.

21
îèM

0.1mm

Figure 7.—Allantonema paramorosum n. sp.: A. Parasitic female; B. larva, head, and neck; C. larva, tail.

22
Male : Stylet very slender, with or without basal

thickenings or knobs. Spicules paired and

gubernaculum typically tylenchoid. Bursa peloderan.

Parasitylenchus avulsi Massey, 1958 Figure 8

First-stage larvae: Length = 0.29 mm; Width

= 0.016 mm; a = 17; b=?; c=?; lip region

flatly rounded ; spear slender, faintly knobbed ;

esophagus a narrow tube, narrowing even more

as it passes through the prominent nerve ring;

excretory pore not visible, body cavity filled

with large vacuolelike inclusions; anal opening

not visible ; tail narrowly rounded.

Parasitic females: Length=1.2-1.55 mm;

Width = 0.10-0.12 mm; a = ll; b=?; c=54;

Y = 9Sfc, Body sausage shaped, narrowing only

slightly at anterior and posterior ends, assuming circular shape when reflexed; cuticle

smooth, regular, hypodermis composed of cells

with arge nuclei; lip region crown shaped,

broad:y rounded; spear moderately slender

with prominent knobs, 13 fx in length ; lumen of

the esophagus traceable for a short distance

from the base of the spear; ovary reaching

almost to the base of the spear, reflexed one to

several times in mature specimens; uterus occupying a prominent part of the body cavity;

vagina a narrow slit ; anal opening subterminal,

only slightly separated from the vulva; terminus obtuse. Free-living forms unknown.

Diagnosis.—Parasitylenchus with crownshaped lip region. Differs from Parasitylenchus

cossoni Wülker, 1929 in shape of lip region and

subterminal location of vulva. It differs from P.

scolyti in its larger size and shape of terminus.

Type host.—Ips avulsus (Eichh.).

Type locality.—Tsllsidegsi National Forest,

Alabama.

Type specimens.—Collection No. 15-J.

P. avulsi was taken from the body cavity of

adult Ips avulsus found associated with Dendroctonus frontalis Zimm. and Ips grandicollis

(Eichh.).

Figure S.—Parasitylenchus avulsi Massey, 1958: A. Head; B. tail; C. parasite female.

23
Parasitylenchus coronatus n. sp. Figure 9

Parasitic females: Length = 2.1-2.3 mmWidth-185-200 ^; ¥= 99-100%.

Body ventrally arcuate, at times forming a

complete circle. Cuticle relatively thick with

distinct transverse striae visible over entire

body length. Lip region distinct, overgrown by

body and appearing nipplelike in lateral view.

Stoma and stylet readily visible. Stylet slender,

13^ in length, with small basal thickenings, at

times displaced by growth of ovary. Esophagus

distinct, lumen visible for a short distance.

Excretory pore, hemizonid, and nerve ring not

visible. Vulva opening at terminus or slightly

anterior to it, obscure in older specimens. Ovary

single, reflexed many times, together with

uterus filling entire body cavity. Anal opening

and rectum not distinguishable. Tail broadly

rounded, with a titlike terminus in some specimens. Ovoviviparous. Free-living forms unknown.

2)mi/nom\—Related to Parasitylenchus

aviilsi; differs from that species in its much

larger size, in the presence of transverse striae,

and in absence of a discernible anal opening.

Type /^os¿.—Parasitic in body cavity of Hyhirgopspinifex (Fitch).

Type locality,—Gorham, Maine.

Ttjpe specimens,—Collection No. 35-Y.

Parasitylenchus elongatus Massey, 1958 Figure 10

Eggs : Hatch within uterus of living female.

^ First-stage larvae: Length = 0.30 mm; Width

= 0.03 mm; spear not visible; lip region

rounded; anal opening not visible; tail obtuse.

Infective-stage females: Length^ 1.16-1 20

mm; a = 78.8-79.2; b=?; c=?; V = 95%.

Cylindroid, elongate. Cuticle without lateral

mcisures, transverse striae fine. Lip region not

set off. Cephalic framework lightly sclerotized.

Stylet coarse, with distinct basal thickenings,

10-11 /x in length. Dorsal esophageal gland outlet obscure. Extended esophageal glands indistinct. Nerve ring prominent. Excretory pore

immediately posterior to nerve ring, passing

through hemizonid. Lips of vulva at times

slightly protuberant. Vagina short, indistinct.

Ovary single, outstretched, posterior portion

Figure 9,—Parasitylenchus coronatus n. sp.: A. Head; B. tail; C. parasitic female.

24
Figure 10.—Parasitylenchus elongatus Massey, 1958: A. Parasitic female; B. infective-stage female, head and neck;

C. infective-stage female, tail; D. male, head and neck; E. ventral view, male tail; F. lateral view, male tail.

25
packed with sperm cells. Anus and rectum

obscure. Tail cylindroid to an obtuse terminus.

Immature parasitic females from larval insects: Length = 1.6-2.7 mm; Width = 0.18 mm;

cuticle very finely striated, hypodermal cells

with large nuclei; lip region rounded; spear

moderately coarse, knobbed; lumen of esophagus visible for a considerable distance from

base of spear; genital primordium apparent

over approximately one-half body length ; vulva

and anal opening not visible.

Immature parasitic females from adult

beetles : Length = 4.7-4.9 mm ; Width = 0.25

mm ; body elongate, becoming reduced in length

because of distortion of body wall ; cuticle thick,

wrinkled, appearing to be almost annulated;

lip region flattened, in many specimens distorted and misshapen ; spear moderately coarse,

11 ^ in length, often displaced by developing

ovary; ovary reflexed several times; uterus

occupying a major portion of body cavity and

becoming distended with larvae as eggs hatch;

vulva protuberant; anal opening invisible; tail

obtuse.

Male: 1.20-1.25 mm; a = 53; b=?; c = 26.

Body straight. Cylindroid, slender. Cuticle

with exceedingly fine transverse striae. Lip

region rounded, set off by constriction. Cephalic

framework indistinct. Stylet 8-9 ^i long, exceedingly slender, with very small basal thickenings.

Dorsal esophageal gland outlet obscure. Extended esophageal glands obscure, although

visible in some specimens. Excretory pore

adjacent to nerve ring and passing through

hemizonid. Testis single, outstretched, at times

reaching to within body width of nerve ring.

Spicules and gubernaculum typically tylenchoid.

Bursa enveloping tail and joining body wall

one body width anterior to proximal end of

spicules. Tail conoid to acute terminus.

Diagnosis.—Elongate Parasitylenchus with

broadly rounded lip region and obtuse tail.

Differs from other species of the genus in its

greater length and width.

Type host.—Scolytus ventralis Lee.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 12-D (Holotype),35-B (Allotype).

Parasitylenchus ipinius n. sp. Figure 11

Mature parasitic females: Lengths 1.5-1.6

mm; Width = 102-114/x;V = 96-97%.

Body ventrally arcuate. Cylindroid. Cuticle

relatively thin. Lip region not set off, with convolutions as figured. Stylet slender, 13 fx in

length, with small basal thickenings, shaft only

slightly tapering, at times slightly displaced by

ovary. Lumen of esophagus traceable for a

short distance from base of spear. Excretory

pore, hemizonid, and nerve ring not discernible.

Vulva distinct, vagina very short. Ovary single,

reflexed several times. Oocytes arranged anteriorly in three rows; in mature specimens,

ovary, eggs, and larvae filling entire body cav-

.02mm

Juvenile parasitic females: Length = 0.70-

0.88 mm ; Width = 58 /x; V = 94-95%.

Figure 11.—Parasitylenchus ipinius n. sp. : A. Parasitic

female; B, parasitic female, head.

26
ity. Anus distinct, at times opening at terminus.

Terminus usually rounded, at times with convolutions. Oviparous or ovoviviparous. Sexual

stages unknov^n.

Diagnosis,—Related to Parasitylenchus ovarius. Eiflfers in more slender stylet, smaller size,

and convolutions of lip region.

Type host,—Body cavity of Ips pini (Say).

Tyjte locality,—Gorham, Maine.

Ty2^e specimens.—Collection No. 35-V.

Parasitylenchus leperisini n. sp. Figure 12

Free-living infective-stage females: Length

= 0.7(1' mm; a = 60; b=?; c=?; V = 90%.

Body cylindroid, slender. Cuticle v^ithout

lateral incisures, transverse striae moderately

coars(i. Lip region continuous v^ith body contour, rounded. Cephalic framev^ork lightly

sclerotized. Stylet relatively stout with prominent basal knobs, 10-11 ¡JL in length. Dorsal

esophageal gland outlet obscure. Extended

esophageal glands obscure. Excretory pore anterior to nerve ring. Lips of vulva slightly protuber,mt. Vagina very short. Ovary single, posterior seven-eighths filled with spermatozoa,

anteror portion consisting of 4-8 oocytes

arranged in a single row. Anus and rectum

obscure. Tail conoid to subacute terminus.

Free-living males: Length = 0.70-0.72 mm;

a = 40-48 ; b =?; c = 26.4-26.7.

Body cylindroid, slender. Cuticle with moderately coarse transverse striations. Lip region

continuous with body contour broadly rounded.

Cephalic framework lightly sclerotized. Stylet

very slender, 9-10 /x in length, with prominent

basal knobs. Dorsal esophageal glands obscure.

Excretory pore anterior to nerve ring. Testis

single, outstretched, short, posterior portion

filled with small, highly refractive sperm cells.

Spicules and gubernaculum tylenchoid. Spicules

short, delicately developed. Bursa peloderan.

Tail conoid to subacute terminus.

Paiasitic juvenile females: Length = 0.76-

0.90 mm; a = 18-23; b=?; c=?; V=92-95%.

Body cylindroid. Cuticle with transverse

striae being obliterated by body development,

except at lip region and caudal area. Lip region

continuous with body contour, rounded, body

expanded immediately posterior to lips. Cephalic framework lightly sclerotized. Stylet

10-11 /x in length, with prominent basal knobs.

Dorsal esophageal gland outlet obscure. Corpus

of esophagus and its lumen traceable only a

short distance posterior from base of spear.

Excretory pore prominent, far anterior, placement due to body development. Lips of vulva

slightly protuberant, vagina short. Ovary

single, posterior portion packed with spermatozoa, anterior portion becoming multiplecelled, reflexed. Anus and rectum visible, but

indistinct. Tail conoid to narrowly rounded

terminus.

Mature parasitic females : Length Width V

1.35 mm 60^ 98%

1.20 mm 60 fi 96%

0.91mm bO fi 94%

Body cylindroid. Cuticle smooth, with irregular annulation in head and caudal regions. Lip

region overgrown by body development. Stylet

stout, with prominent basal knobs, 10-11 /x in

length, not displaced by developing ovary.

Corpus of esophagus and its lumen visible for

only a short distance from base of spear. Excretory pore prominent, its outlet at stylet level,

seeming change in position caused by body

development. Lips of vulva slightly protuberant.

Ovary single, reflexed many times, the oocytes

for most part arranged in a double row. Anus

and rectum visible but indistinct. Tail broadly

rounded with a distinct titlike terminus.

Diagnosis,—Distinct because of the prominent excretory pore visible in all stages and

because of its anterior location.

Type host,—Parasitic in body cavity of

Leperisinus aculeatus (Say).

Tijpe locality,—Chillicothe, Ohio.

Type specimens,—Collection No. 86-B.

irasitylenchus oriundas n. sp. Figure 13

Parasitic females : Length Width V

0.67 mm 60^

0.72 mm 50/.

0.75 mm 50/x 93-97%

Body ventrally arcuate, cylindroid. Cuticle

with coarse transverse striations, not undulate.

Lip region not set off, usually narrowly rounded,

may be overgrown by body expansion in older

specimens. Stylet 7-8 ¡x in length, slender, with

small basal thickenings. Stoma obscure. Lumen

of esophagus traceable for only a short distance

from base of spear. Vulva strongly developed,

vagina oblique. Ovary single, reflexed several

times. Anus and rectum not discernible. Tail

broadly rounded, usually terminating with a

nipplelike muero.

27
Figure 12.—Parasitylenchus leperisini n. sp.: A, Male, head and neck; B,

male, tail; C» female infective-stage, head and neck; D. female infectivestage, tail; E. parasitic female, head; F, parasitic female tail; G. juvenile

parasitic female, head; H. juvenile parasitic female, tail; /. mature parasitic female.

28
c IP

Figure 13.—Parasitylenchus oriundus n. sp.: A, Parasitic female, head; B, mature parasitic female; C. parasitic

female, tail; D. parasitic female, head; E. parasitic female, tail.

29
Diagnosis,—Related to Parasitylenchus ovarius. Differs in its smaller size and character

of lip region and in cuticular characteristics.

Type host.—Body cavity of Orthotomicus

caelatus (Eichh.).

Type locality.—Freeport, Maine.

Type specimens.—Collection No. 35-W.

Parasitylenchus ovarius Massey, 1958 Figure 14

Eggs : Hatch within uterus of adult females.

First-stage larvae: Length = 0.7 mm; Width

= 0.03 mm; cuticle with faint striations; lip

region flattened to very slightly rounded ; spear

10 fjL in length, slender, minutely knobbed;

esophagus a narrow tube, becoming constricted

as it passes through the nerve ring; nerve

ring prominent; excretory pore not visible in

specimens examined; genital primordia apparent; anal opening not visible; body cavity

filled with vacuolelike inclusions.

Parasitic female: Length = 1.7 mm; Width

= 0.16 mm; a = ll; b=?; c = 8; body when

relaxed assumes semicircular position, saclike

in shape, broadest at middle, narrowing at

anterior and posterior ends ; lip region broadly

rounded; spear slender, 14 ¡JL in length, with

prominent knobs, often displaced by growth

of ovaries, becoming nonfunctional in older

specimens; lumen of esophagus visible for

only a short distance from base of spear ; ovary

single, reflexed ; uterus filling a large portion of

body cavity in mature specimens; vulva and

anal opening closely separated; tail narrowly

obtuse. Males unknown.

Diagnosis.—Parasitylenchus ovarius is closely

related to P. dispar and P. grossmannxie Rühm,

Figure 14.—Parasitylenchus ovarius Massey, 1958: A. Parasitic female.

30
1954. It differs from P. dispar in its larger size

and terminal location of anal opening; from P.

grossniannae in presence of discernible anal

opening and more narrowly rounded lip region.

Type host.—Ips pilifrons Sw.

Type locality.—Uncompahgre National Forest, Norwood, Colorado. Only adult beetles were

parasitized.

Ty%e specimens.—Collection No. 15-E.

Parasit'lenchus parasitus n. sp.

Para sitie females : Length

2.0 mm

3.2 mm

Width

200 fi

Figure 15

V

98%

Body sinuous to straight. Cuticle thick, without undulation, very faint transverse striae.

Lip region rounded. Stylet slender, 12-13 /x,

with l)asal thickenings. Stoma not discernible.

Vulva slightly anterior to terminus. Ovary

reflex(id several times. Anus and rectum not

discernible. Terminus broadly rounded.

Diagnosis.—Related to Parasitylenchus ovarius. Differs in cuticular characteristics and

placement of the vulva.

Ty%)e host.—Body cavity of Polygraphus

hoppvrigi Sw.

Type locality.—Flagstaff, Arizona.

Type specimens.—Collection No. 35-X.

Parasitylenchus pilifronus Massey, 1958 Figure 16

Parasitic female : Length = 3.8-5.4 mm ;

Width = 0.23 mm; body elongate, anterior onethird of body widest, tapering toward posterior

end, cuticle translucent, hypodermis composed

of large irregular transparent cells as figured;

lip region broadly rounded; spear 13 /x long,

slender, with prominent knobs; ovary single,

reñexed one to several times, often almost

reaching base of spear; vulva and anal openings not apparent. Males unknown.

Diagnosis.—Parasitylenchus with transparent cuticle; differs from other species in the

genus in peculiar arrangement of hypodermal

cells and in their lack of color.

Type host.—Ips pilifrons.

Type locality.—Uncompahgre National Forest, Norwood, Colorado.

Type specimens.—Collection No. 15-M.

Parasitylenchus scrutillus Massey, 1964 Figure 17

Egg: Oval. 47 x 23 /x. Hatch within uterus of

parasitic females.

First-stage larvae: 0.22 mm; a = 21; b=?;

c=?

Cuticle moderately thick with fine transverse

striations. Head broadly rounded, almost flat.

Spear not observed. Body cavity filled with

large vacuoles. Esophagus, nerve ring, excretory pore, and anal openings not seen. Terminus

broadly rounded.

Young parasitic females: Length = 2.0-2.4

mm; Width = 0.35 mm.

Cuticle thick with fine transverse striations.

Head broadly rounded. Spear short, thick, with

prominent knobs. Esophagus well developed,

occupying three-fourths of body cavity in region

of neck. Nerve ring and excretory pore not

apparent. Ovary single, reflexed several times,

reaching almost to base of spear in some specimens. First-stage larvae present in uterus.

Vulva and anal opening not apparent. Terminus

broadly rounded, similar to shape of head.

Mature parasitic females: Length = 2.0-2.4

mm ; Width = 0.35-0.40 mm.

Cuticle thick with fine transverse striations,

wrinkled. Head broadly rounded. Spear short,

prominently knobbed, in many specimens displaced, evidently nonfunctional. Esophagus

traceable for only a short distance from base of

spear. Nerve ring and excretory pore not apparent. Walls of the ovary not apparent.

Developing eggs present only one body width

from anterior end. First-instar larvae present

in posterior portion of body cavity. Vulva and

anal opening not apparent. Terminus broadly

rounded, approximately size and shape of head.

Males : Unknown.

Diagnosis.—Similar in shape to Parasitylenchus ovarius Massey, 1958; differs in length

and absence of discernible vulva and anal

opening.

Type host.—Scolytus ventralis.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 12-P.

Parasitylenchus senicus ii. sp.

Parasitic females : Length

0.62 mm

0.70 mm

0.80 mm

0.92 mm

Figure 18

Width

88 At

117 fi

110/i

80 A

Body relatively straight. Cuticle thick, with

31
Figure 15.—Parasitylenchus parasitus n. sp.: A. Parasitic female, head; B. parasitic female, tail;

C, mature parasitic female.

32
Figure 16.—Parasitylenchus pilifronus Massey, 1958: A. Mature parasitic female; B. hypodermal pattern; C. stylet.

33
' I

.05 m m

Figure 17.—Parasitylenchus scrutillus Massey, 1964: A. Mature parasitic female; B. juvenile parasitic female; C.

developing parasitic female; D. first-stage larvae, head and neck; E, first-stage larvae, tail.

34
a

0.1 mm

B

coarse transverse striations, undulant. Lip

region partially enveloped by body expansion.

Stylet coarse, without basal knobs, 10-11 fx in

length, often displaced by development of sexual

organs. Stoma obscure. Esophagus traceable

for only a short distance from base of stylet.

Vulva slightly anterior to terminus. Ovary

single, reflexed several times. Anus and rectum

not discernible. Terminus broadly rounded.

Ovoviviparous.

Newly hatched larvae : Length

0.25 mm

0.29 mm

Width

20 At

Body straight, cylindroid, filled v^ith fat

bodies. Cuticle v^ith very fine transverse striations. Lip regions distinguished by 4 cuticular

folds. Cephalic framework indistinct. Stylet

fine, without basal knobs, 6 /x in length. Neck

set off by slight constriction. Excretory pore

3-4 body widths posterior to head. Anus and

rectum not discernible. Tail conoid to broadly

rounded terminus.

Diagnosis.—Distinguished from other members of the genus by its very small size and

cuticular folds at lip region of newly hatched

larvae.

Type host,—Body cavity of Pityophthorus sp.

Type locality.—Mt. Taylor, New Mexico.

Type specimens.—Collection No. 35-L.

Parasitylenchus stipatus Massey, 1966 Figure 19

Mature parasitic females: Length = 5.0-7.25

mm ; Width = 0.25-0.28 mm.

Cuticle smooth, thick. Head rounded in some

specimens, flattened in others. Stylet 15-16 /x

in length, with prominent knobs, displaced and

evidently nonfunctional. Esophagus a straight

tube, the lumen traceable for only a short distance from base of spear. Ovary single, reflexed

several times, in many specimens occupying

most of body cavity, the posterior end filled

with first-instar larvae. Vagina a faintly visible

transverse slit only 1 body width anterior to

terminus. Anal opening at terminus.

Free-living males: 1.25-1.41 mm; a = 44-47;

b = 5.0;c = 13.0-13.8.

Cuticle with very faint transverse striations.

Figure 18.—Parasitylenchus senicus ii. sp.: A, Mature

parasitic female; B, newly hatched larva, head; C,

stylet.

35
Figure 19.—Parasitylenchus stipatus Massey, 1966: A. Mature parasitic female; B. parasitic female, head; C.

parasitic female, tail; D, male, head and neck; E, male, tail.

36
interrupted by 2 widely spaced lateral incisures.

Lip region hardly set off, lips distinct. Stylet

12 fx in length, slender, with prominent basal

knobs. Dorsal esophageal gland 5 body diameters long, joining esophagus at nerve ring.

Nerve ring 5 body diameters behind base of lips.

Excretory pore 3 body diameters posterior to

nerve ring. Hemizonid immediately anterior to

excretory pore. Testis single, outstretched.

Spicules paired, arcuate. Gubernaculum platelike, slightly more than one-third length of

spicules. Bursa envelops tail. Terminus finely

rounded.

Diagnosis.—Parasitic females are similar in

character to Parasitylenchus elongatus Massey,

1958, but differs in the discernible vulval and

anal opening and greater length and width of

P. stipatus. Free-living males of P. stipatus

differ from males of P. elongatus in length and

shape of tail, greater body width, and prominence of dorsal esophageal gland.

Type host.—Dendroctonus adjunctus Blandford.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 35-C (Allotype) ;35-E (Holotype).

Parasitylenchus undulatus n. sp. Figure 20

Length Width

1.59 mm 82/x

1.48 mm 91M

1.68 mm 132/^

1.75 mm 14. IX

Parasitic females :

Body cylindroid. Cuticle relatively thick,

smooth, undulant. Lip region variable in shape,

ñat to rounded in some specimens, partially

overgrown by body expansion. Stylet exceedingly slender, with small basal knobs, at times

displaced by growth of internal organs, 9 /x in

length. Stoma obscure but visible in most specimens. Esophagus visible for only short distance

posterior to stylet attachment. Vulva approximately 1 body width anterior to terminus.

Ovary single, reñexed many times. Anal opening terminal. Tail with a titlike terminus in

most specimens. Oviparous.

Diagnosis.—Differs from other species in the

genus in the exceedingly fine stylet and the

distinctive undulant cuticle.

Type host.—Body cavity of Pseudohylesinus

nebulosus (Lee).

Type locality.—Cibola National Forest, New

Mexico.

Type specimens.—Collection No. 35.

Genus Contortylenchus Rühm, 1956

Type species : Contortylenchus diplogaster

(Linstow, 1890) Rühm, 1956

Free-living males and females: Body cylindroid, usually slender. Lips usually continuous

with body contour. Cuticle smooth or with

transverse striae, with or without lateral incisures. Stylet well developed, with or without

basal knobs or thickenings, male stylet usually

more slender than female. Esophagus with or

without extended glands, when present obscure.

Vulva distinct. Ovary single, posterior portion

packed with refractive spermatozoa. Anus and

rectum obscure. Tail conoid to a variable-shaped

terminus. Males: Testis single, posterior portion packed with developing spermatozoa.

Spicules and gubernaculum tylenchoid. Bursa

peloderan. Tail conoid to acute or subacute

terminus.

Parasitic females: Large bodied, short and

stout or long and sinuous. Cuticle with or without transverse striations. Lip region usually

conical, but may be broadly rounded with lips

actually overgrown by body development. Stylet

relatively stout, with or without basal knobs,

never displaced by ovarial development. Esophagus usually traceable through entire length,

juncture with intestine obscure. Ovary single,

reflexed many times. Oocytes arranged in from

2-3 rows. Uterus long, containing many eggs

in mature specimens, anterior portion acting as

spermatheca. Tail dorsally arcuate. Vulva

usually a deep depression. Vagina comparatively short. Anus and rectum usually visible

but obscure. Terminus with or without muero.

Oviparous.

Tail conformation in parasitic females are

of considerable aid in distinguishing the various

species occurring in the United States. Tails

for each species are illustrated in figure 21.

A. Contortylenchus elongatus

B. C. grandieolli

C. C. terebranus

D. C. brevicomi

E. C. cribicolli

F. C. reversus

G. C. spirus

H. C. orthotomici

I. C. pityophthori

J. C. bullus

37
Figure 20.—Parasitylenchus undulatus n. sp.: A, Parasitic female; B, parasitic

female, head.

38
Figure 21.—Tails for each species: A, Contortylenchus elongatus; B, C. grandicolli; C,

C, terebranus; D. C, brevicomi; E, C. cribicolli; F. C, reversas; G, C. spirus; H, C. orthotoinici; I. C, pityophthori ; J. C. bullus.

39
Contortylenchus brevicotni (Massey, 1957) Rühm, 1960

Figure 22

Synonym: Contortylenchus harherus (Massey, 1957) Rühm, 1960.

Eggs deposited before segmentation, 20 x

50 /x, laid in body cavity of infected beetles.

First-stage larvae : Length = 0.4-0.5 mm ;

Width = 20/x;a = 17;b = 4.8;c=?

Cuticle very finely striated, lip region rounded

and expanded. Spear very slender, minutely

knobbed. Esophagus a narrov^ tube. Nerve ring

prominent. Excretory pore slightly posterior

to nerve ring. Genital primordia apparent.

Anal opening not discernible.

Parasitic females : Length = 2.1-3.9 mm ;

Width = 70-120/x.

Body bent dorsally, tapering conspicuously

tow^ard head. Cuticle thick, moderately to

coarsely striated, becoming annulated at the

anterior end, annules more apparent in some

specimens. Body ventrally constricted at vulva.

Tail broad, obtuse v^ith a distinct muero. Length

from posterior end to vulva 70 /x. Spear slender,

short, v^ith or v^ithout knobs. Esophagus a

straight tube. Lumen of the esophagus distinct

for only a short distance from the spear. Ovary

outstretched, about three-fourths as long as

body. Vagina a broad transverse slit. Spermatheca present, filled v^^ith spermatozoa. Anal

opening obscure.

Male: Length = 0.65-0.85 mm; Width = 10 /x;

a = 56;b=?;c = 21;T = 56-72.

Body much more slender than that of female,

tapering slightly tov^ard anterior end. Cuticle

finely to moderately striated. Spear slender,

approximately as long as body at its greatest

v^idth, knobs distinct. Esophagus a straight

tube v^ithout bulb, narrov^ing as it passes

through the prominent nerve ring. Excretory

pore slightly posterior to nerve ring. Testis

outstretched. Vas deferens distended with

spermatozoa. Spicula curved, about one-half as

long as tail. Gubernaculum thin, troughlike,

slightly curved. Bursa enveloping tail, extending forvv^ard to a point slightly anterior to

spicula.

Males are not parasitic and are found only

in galleries of the host.

Diagnosis.—Contortylenchus v^ith dorsally

bent body, distinct muero, moderately to

coarsely striated cuticle, cuticle thick.

Tyjje host.—Dendroctonus brevicomis Lee.

Parasitic females also collected from Dendroctonus frontalis.

Type locality.—Salmon National Forest,

Idaho.

Tijpe specimens.—Collection No. 7A-2.

Contortylenchus bullus n. sp.

Parasitic females : Length Width

Figure 23

VulvaV Terminus

1.09 mm

1.21 mm

1.22 mm

1.27 mm

1.58 mm

1.67 mm

79 M

82/x

70 fi

94 fM

97 fi

82^

92%

92%

91%

92%

92%

91%

82/.

88 fjL

102^

97/.

120^

138 M

Body posture circular. Cylindroid. Cuticle

moderately thick, with moderate to coarse

transverse striations. Lip region conelike. Cephalic framework indistinct. Stylet coarse, 12 /x

in length, with distinct basal knobs. Lumen of

esophagus traceable for a short distance from

the base of spear. Vulva moderate to shallow

constriction. Vagina transverse. Ovary single,

reflexed several times. Anus one-half body width

anterior to terminus. Tail broadly rounded to a

short, nipplelike mucronate terminus.

Diagnosis.—Distinctive shallow vulval depression and characteristic obtuse nipplelike

muero distinguish this species from other members of the genus.

Type host.—Parasitic in body cavity of Hylurgops pinifex.

Type locality.—Caroline County, New York.

Type specimens.—Collection No. 35-Q.

Contortylenchus cribicolli n. sp. Figure 24

Parasitic females : Length Width V V-T

1.56 mm

1.73 mm

1.97 mm

2.16 mm

79 M

108 fi

108 lii

88 fi

94%

93%

94%

94%

91 fi

111/i,

117 A^

120 yU

Body dorsally arcuate, usually forming a

near complete circle. Cylindroid. Lateral striae

moderately fine to coarse. Lip region conical,

not set off. Cephalic framework indistinct, but

visible. Usually visible spear relatively slender,

with distinct basal knobs or thickenings, 9 /x in

length. Lumen of esophagus visible for a short

distance from base of spear. Dorsal esophageal

gland outlet not observed. Vulva forming a

shallow cleft, almost continuous with body wall.

Vagina slightly oblique. Ovary single, reñexed

40
.02 mm

,03 mm

22.—Contortylenchus breviconii (Massey, 1957) Rühm,

: A. Parasitic female, head; B. parasitic female; C. male,

D, male, head and neck; E. male, tail; F. larva, head and

G, larva, tail.

41
Figure 23.—Contortylenchus bullus n. sp.: A. Parasitic female; B. head.

several times in some specimens. Anal opening

slightly anterior to terminus. Rectum obscure.

Tail conoid to a broadly rounded terminus with

a small dorsally located muero.

Diagnosis,—Related to Contortylenchus reversus; differs in the shallow vulva opening,

shape of tail from vulva to terminus, and its

generally larger size.

Type host.—Body cavity of Ips cribicollis

(Eichh.).

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 35-0.

42
Figure 24.—Contortylenchus cribicolli n. sp.: A, Parasitic female; B. head; C. head.

Contortylenchus elongatus (Massey, 1960) Nickle, 1963

Figure 25

Immature females : Length = 0.78 mm; Width

= 43 a.

Cuticle very finely striate, becoming almost

annulate in head region. Body tapering only

slightly toward head, beginning to constrict

ventrally and bend slightly dorsally near vulva.

A series of cells with very large nuclei at times

extending the entire length of the body. Lip

region narrowly rounded. Spear 14 ¡x in length,

finely knobbed. Esophagus a narrow tube;

lumen of esophagus traceable, posterior to

prominent nerve ring. Genital primordia extending halfway to anterior end. Vagina a

43
Figure 25.—Contortylenchus elongatus (Massey, 1960) Nickle, 1963.

44
prominent broad transverse slit; terminus to

vulva 70 ¡JL, Anal opening not discernible.

Terminus narrowly rounded.

Mature parasitic females: Length = 4.25-6.3

mm; Vv^idth = 0.12-0.14mm.

Cuticle moderately thick, transversely

striated, the striations coarser in head region.

Body tapering slightly toward head, bent dorsally near vulva. Body tends to coil when nema

is killed by heat. Spear 14 fx in length. Lumen of

esophagus visible for only a short distance from

spear. Ovary reflexed at times one-half body

length. Vagina a broad transverse slit. Anal

opening not discernible. Tail broad, obtuse with

distinct muero. Length from terminus to vulva

360-450 /x.

Male: Length=:0.68 mm; a = 26; b = 6; c = 18.

Head as figured. Lip region rounded. Cuticle

with fine transverse striations. Spear moderately coarse, knobbed, 14 /x in length. Esophagus

beginning as a straight tube, narrowing as it

passes through nerve ring, broadening into a

ventrally lobed nonvalvular bulb. Excretory

pore adjacent to bulb. Testis outstretched, at

times almost reaching bulb of esophagus.

Spicules paired, tylenchoid. Gubernaculum thin,

troughlike, almost straight. Tail with a sharp

mucronato tip, bursa enveloping tail and extending forward well beyond anterior end of

spicuLi.

Type host.—Ips confusus (Lee.).

Type locality.—Bandolier National Monument, New Mexico.

Type specimens.—Collectio

posterior to nerve ring. Genital primordia as

figured. Anal opening discernible. Rectum usually obscure. Tail conoid to rounded terminus.

Parasitic females : Length = 1.7-2.3 mm ;

Width = 90-120/x.

Body cylindroid, strongly bent dorsally until

almost circular in some specimens. Neck tapering gradually to the broadly rounded lip

region. Body cylindrical throughout, narrowing

only slightly at extremities. Tail broadly

rounded with small muero. Cuticle thick, with

moderate to coarse transverse striations. Some

specimens with annules in head region. Four

large glands present in head, their outlets not

discernible. Spear slender, variably knobbed.

Stylet length 11 /x. Esophagus a straight tube,

lumen traceable for only a short distance from

spear. Gut visible for entire length. Anal opening not discernible. Ovary usually outstretched

but occasionally reflexed, occupying approximately two-thirds of body length. Spermatheca

present, filled with spermatozoa. Vagina a

broad transverse slit. Distance from posterior

end to vulva 190-260 /x.

Diagnosis.—Contortylenchus with body

strongly bent dorsally. Lip region broadly

rounded. Tail with small muero. Cuticle thick,

strongly striated.

Type host.—Ips grandicollis (Eichh.).

Type locality.—Talladega National Forest,

Alabama.

Type specimens.—Collection No. 26-F.

I960

Larvae from body cavity:

0.54 nr m.

Body with slight ventral arcuation or

straight, cylindroid. Cuticle relatively thick

with noderately coarse transverse striations.

Lip region rounded, not set off. Cephalic framework sclerotized. Stylet very slender, with or

without basal thickenings, ca 10 /x long. Dorsal

esophageal gland outlet not discernible. Several

large glandular structures, variable in length,

extending posteriorly from base of stylet, extended esophageal glands prominent and

terminating ca II/2 body widths posterior to

nerve ring. Nerve ring very prominent. Excretory pore not observed. Hemizonid immediately

. 26-R. Contortylenchus orthotomici n. sp. Figure 27

1957) Rühm,

Figure 26

Parasitic females : Length

1.00 mm

1.02 mm

Width

64/.

83 A.

V V-T

93% 67/x

93% 67/.

.ength = 0.49- 1.07 mm 79/x 93% 64/1

1.13 mm 79/. 92% 68 /.

Body posture a complete circle, cylindroid.

Cuticle relatively thin with fine transverse

striae, especially visible at head and neck. Lip

region not set off, conical. Cephalic framev^ork

indistinct. Stylet moderately slender, 10 /x in

length, v^ith distinct basal knobs. Dorsal esophageal gland outlet obscure. Esophagus traceable for approximately a body v^idth posterior

to base of spear. Vagina prominent and transverse, one-half body v^idth in length. Ovary

single, reflexed in some specimens several times.

Anal opening slightly posterior to terminus.

Rectum obscure. Tail broadly rounded and

45
I'll

Ili'- )

I / /

11/

I I

.02mm !

I y:

Figure 26.—Contortylenchus grandicolli (Massey, 1957) Rühm, 1960: A. Parasitic female; B. female, head; C.

larva, head; D, larva, head and neck; E, larva, tail.

terminating in a small buttonlike muero, in

some specimens muero absent. Oviparous.

Free-living sexual stages unknov^n.

Diagnosis.—Contortylenchus v^ith slender

stylet and deeply cleft vulva.

Type host,—Body cavity of Orthotomicus

caelatus.

Type locality,—Hamden, Connecticut.

Type specimens,—Collection No. 35-S.

Parasitic females :

hori n. sp. Figure 28

Length Width V V-T

0.44 mm 58/. 91% 38/.

0.47 mm 64/. 90% 47/.

0.50 mm 76/. 90% 50/c

0.51 mm 58/. 92% 38/.

0.53 mm 64/. 91% 42/.

0.62 mm 91/. 90% 58/.

Body posture circular, cylindroid. Head and

neck considerably narrov^er than body proper,

with coarse transverse striae. Lip region narrowly rounded, cone-like. Cephalic framework

indistinct. Spear 9 /x in length, with well developed basal knobs. Vagina a deep slit. Vagina

oblique. Ovary single, reflexed several times,

filling body cavity. Anal opening slightly anterior to terminus. Tail terminating in a large

bluntly pointed muero.

Larvae from body cavity: Length = 0.26-0.29

mm.

Body straight, cylindroid. Cuticle with fine

transverse striations. Lip region rounded,

slightly expanded. Cephalic framework lightly

sclerotized. Stylet 9 /x in length, with distinct

basal knobs. Extended esophageal glands

terminating approximately 2 body widths posterior to nerve ring. Nerve ring prominent.

46
iD2mm

Figure 27.—Contortylenchus orthotomici n. sp.: A. Parasitic female; ß. head.

47
LL

^

et

T3

es

es

0

48
Genital primordia visible in posterior one-third

of body cavity. Anal opening not observed.

Tail conoid to a narrowly rounded terminus.

Males: Length = 0.29 mm; a = 19.53; b=:3.47;

c = 23.1.

Body straight. Cylindroid. Lip region

rounded, slightly expanded. Cephalic framework lightly sclerotized. Stylet 8 /x in length,

with basal thickenings. Nerve ring prominent.

Esophageal glands terminating 1-2 body widths

posterior to nerve ring. Excretory pore not

observed. Testis single, outstretched. Spicules

and gubernaculum typically tylenchoid. Bursa

joining body wall, slightly anterior to proximal

end of spicules. Tail conoid to a heavily sclerotized mucronate terminus.

Males were taken from the body cavity of the

host indicating that sexual development is complete before deposition in the host's gallery.

Diagnosis.—Differs from Contortylenchus

tomici (Bovien, 1937) Rühm, 1956 in its generally smaller size and in shape and length of

mucronate terminus.

Type host.—Body cavity of Pityophthorus sp.

Type locality.—Neola, West Virginia.

Type specimens.—Collection No. 35-N.

Contortylenchus reversas (Thorne, 1935) Rühm, 1956

Figure 29

The following is Thome's original description:

''Eggs: Deposited before segmentation. Size

variable, 30 x 60 /x to 42 x 90 /x. Several hundred

deposited by each female in the body cavity of

the grub or adult beetle. Segmentation and

hatching occur immediately after deposition.

''Newly hatched larvae: Length = 0.22-0.30

mm; Width = 12-16/x.

"Cuticle finely striated. Lip region rounded

and expanded. Tail conoid to the small blunt

terminus. Spear exceedingly slender, without

basal knobs. Esophagus a slender tube, narrowing as it passes through the nerve ring, then

gradually expanding and merging with intestine. Excretory pore a little posterior to

nerve ring.

"Second-stage larvae : Similar in appearance

to young larvae except for uniformly tapering

anterior end and developing gonads. Genital

primordium visible at beginning of first molt,

from which single ovary develops forward until

it is about half as long as body, its terminus

reflexed a distance equal to 3-5 body widths.

A prominent gland usually is visible just back

of nerve ring. During this stage little or no

increase in body length but marked development in width.

"Intermediate forms between this stage and

adults were not found. Apparently it is during

this portion of the life cycle that the nemas

leave their hosts and transfer to other beetles

or grubs. However, none was found outside the

bodies of the hosts and the method of transfer

remains unknown.

"Females from grubs and adult beetles:

Length = 1.0-1.8 mm; Width = 50-180 /x; V = 94-

96%.

"Body bent dorsally, more or less cylindrical

throughout greater part of its length, but tapering conspicuously to the very narrow lip region,

which is not set off in any manner. Cuticle annulated near head and at terminus; on some

specimens annules conspicuous, on others almost invisible. Body constricted at vulva, especially ventrally. Tail broad, bearing dorsal,

hornlike, annulated terminal projection which

actually is the upturned original tail of the immature nema. This "horn'' apparently becomes

upturned as body distends with growth of the

internal organs, and pressure is relieved on the

^rentrai side when the broad vulvar opening is

formed at the last molt. Four labial papillae

almost invisible even from a face view. Amphids lie close to oral opening. Four large

glands are prominent features of head region.

Spear 12-14 fx long, slender, with short ventrally located aperture. Knobs of spear vary

from obscure to distinct. Lumen of esophagus

visible only a short distance from spear. A

series of 15-18 pairs of conspicuous lateral

structures distributed throughout body. Vulva

a broad transverse slit. Three glands lie opposite vulva, causing constriction of the organs.

Anus and rectum obscure. Ovary extending forward about three-fourths length of body, then

reflexed a distance equal to 1-2 body widths.

Oviparous. Females generally burst when removed from the host.

''Diagnosis.—Oviparous. Contortylenchus

with dorsally bent body bearing a prominent

upright terminal "horn.'' A series of 15-18

pairs of conspicuous lateral structures distributed throughout the body."

Host.—Parasitic in the body cavity of Dendroctonus ponderosae Hopk.

49
Contortylenchus spirus (Massey, 1957) Rühm, 1960

Figure 30

Parasitic females: Length = 2.70-2.75 mm;

Width = 100/x.

Body assumes spiral shape when killed by

heat, more or less cylindrical throughout but

narrowing conspicuously in head region. Lip

region narrowly rounded. Tail broadly rounded

without muero. Cuticle finely striated, annulated at anterior end in some specimens. Four

large glands occupy large portion of head region, their outlets not traceable. Spear length

10 /A, slender, knobbed. Esophagus a straight

tube, lumen traceable for only a short distance.

Gut visible for entire length. Anal opening

obscure. Ovary occupying three-fourths of body

cavity, reflexed one to several times. Spermatheca not present and spermatozoa not observed in uterus. Vagina a broad transverse

slit. Distance from posterior end to vulva

130/x.

Eggs: 16x35/..

Dia g nosis.—Contortylenchus with body

formed in a springlike or spirallike shape. Four

large glands prominent feature of head region.

Lip region narrowly rounded. Tail broadly

rounded without muero. Apparently similar to

Contortylenchus diplogaster (Linstow, 1890)

Rühm, 1956 but differs in its larger size and

absence of a caudal muero.

Type host.—Ips pini. Some specimens of this

species also have been collected from Ips spp.

in New Mexico.

Type locality.—Uncompahgre National Forest, Norwood, Colorado.

Type specimens.—Collection No. 7-Q.

tiitortylenchus terebranus n, sp. Figure 31

Parasitic females : Length Width V V-T

1.91 mm 10 ß 95% 114/x

2.07 mm 73/. 94% 111/.

2.32 mm 64 fM 95% 108^1

2.38 mm 70/. 95% 111/.

Figure 29.—Contortylenchus reversus (Thorne, 1935)

Rühm, 1956: A, Parasitic female; B. head; C. tail.

Body posture in semicircle or coiled, cylindroid except at extremities. Cuticle thick with

very coarse transverse striae. Lip region not

set off, conical, in older specimens nose cone

enveloped by body growth. Cephalic framework

indistinct. Spear 10-11 /x in length, relatively

coarse with distinct basal knobs or thickenings,

becoming obscure in older specimens. Esophagus traceable for one to two body widths

50
.02 mm

Figure 30.—Contoríríenc/t«s spirus (Massey, 1957) Rühm, 1960: A. Parasitic female; B. head.

51
from base of spear. Vulva very prominent;

vagina oblique, approximately one-half body

width in depth. Ovary single, outstretched and

occupying most of body cavity in older specimens. Anus terminal, opening on dorsal side

of muero. Rectum indistinct. Tail broadly

rounded with a heavily sclerotized, strongly

developed muero.

Infective-stage females : Length = 0.48-0.52

mm; Width = 15-16/x.

Body posture straight, cylindroid. Cuticle

comparatively thick, with very fine transverse

striae. Lip region continuous with body contour, broadly rounded. Cephalic framework

lightly sclerotized. Spear 13 ¡JL in length, coarse,

with well developed basal knobs. Dorsal esophageal gland outlet obscure. Excretory pore

not observed. Nerve ring very prominent.

Hemizonid not observed. Developing uterus

filled with spermatoza. Anus and rectum obscure. Tail conoid to a narrowly rounded terminus.

Males: Length = 0.49-0.61 mm; a = 28-30;

b=?;c = 16.8-21.

Body posture straight, cylindroid. Cuticle

relatively thick. Lateral striae very fine. Lip

region continuous with body contour. Cephalic

framework distinct, but lightly sclerotized.

Stylet very slender, with or without basal

thickenings, 10 /x in length. Esophageal glands

obscure. Nerve ring very prominent. Excretory

pore one-half body width posterior to nerve

ring. Hemizonid not observed. Testis single,

reflexed, posterior three-fourths filled with

sperm cells. Spicules and gubernaculum typically tylenchoid. Bursa encompassing tail. Tail

conoid, narrowly rounded to heavily sclerotized

mucronate terminus.

Diagnosis,—Contortylenchus with distinctive

lip region and with anal opening on dorsal side

of mucronate terminus.

Type host.—Body cavity of Dendroctonus

terebrans (Oliv.).

Type locality,—Lake City, Florida.

Type specimens.—Collection Nos. 7-V and

7-V-l.

Genus Sphaerularia Dufour, 1837

Type species: Sphaerularia bombi Dufour,

1837

Free-living forms: Cuticle with transverse

striae. Lips continuous with neck region.

Figure 31.—Contortylenchus terebranus n. sp.: A, Parasitic female; B. head; C. head; D, male, head and

neck; E, male, head; F. male, tail; G. infective-stage

female, head and neck; H. infective-stage female,

head; /. infective-stage female, tail.

52
Cephalic framework indistinct. Stylet usually

with basal knobs. Dorsal esophageal gland outlet discernible. Tail cylindroid to a narrowly

rounded terminus. Spicules and gubernaculum

tylenchoid. Bursa peloderan.

Parasitic females : Evaginated uterus is most

prominent part of individual. As it protrudes

from body wall cells enlarge and each contains

prominent nucleus. Ovary is extruded with

uterus and floats free in lumen. Females change

little in size. However, as reproductive system

extrudes, cuticle becomes wrinkled.

Sphaerularia dendroctoui Massey, 1956 Figure 32

Synonym : Sphaeriilariopsis dendroctoui

(Massey, 1956) Nickle, 1963

Eggs: Deposited after segmentation, size 40

x80 fxy developed in uterus outside body wall.

Hatching occurs immediately after deposition.

First-stage larvae: Length = 0.48-0.67 mm;

Width = 20-25/x.

Cuticle very finely annulated; tail conoid,

rounded at the terminus ; spear moderately fine

with basal knobs.

Second-stage larvae: Similar in appearance

to first-stage larvae. Length = 0.64-0.70 mm;

Width = 20-25 /x; genital primordia becomes

apparent in this stage. Female larvae can be

determined by enlargement of vagina.

Male: Length = 0.70-0.78 mm; Width = 20 /x;

a = 43.3;b = 6;c = 48.7;T = 75.

Cuticle very finely annulated; lip region flat

to slightly rounded, set off by a very slight

constriction, or rather a narrowing of the neck

region, a little wider than high. Spear moderately fine with basal knobs, slightly longer than

width of lip region; excretory pore slightly

posterior to nerve ring and located approximately one-fifteenth of body length from anterior end ; hemizonid adjacent to excretory pore ;

esophagus without median bulb, constricted as

it passes through nerve ring, ending in a cylindroid basal bulb which slightly overlaps the

intestine on dorsal side. Bulb with 3 prominent

nuclei generally visible; testis outstretched or

reflexed, at times almost reaching excretory

pore, the lower third distended with spermatheca; spicula curved, three-fourths as long as

tail; gubernaculum thin, troughlike, almost

straight, about one-fourth as long as spicula;

tail conical with a small, rounded terminus;

bursa enveloping tail, extending a short distance anterior to proximal end of spicules.

Immature females: Length = 0.80 mm;

Width = 32/x.

Cuticle finely annulated in younger specimens, becoming strongly wrinkled with age,

very deep wrinkles at variable regions on

cuticle giving the appearance of segmentation.

Lip region similar to that of male; ovary reflexed nearly half its length in some individuals ;

vulva narrow transverse slit, becoming greatly

distended as genital organs descend within body

cavity. Vagina protrudes as figured. Tail conical

with small, rounded terminus.

Mature females: Uterus in this stage is the

most prominent part of the individual. As it

protrudes from the body wall, the cells enlarge

to tremendous size, each with a prominent

nucleus. Size of the uterus may reach a length

of 1.6 mm and a width of 0.25 mm. Growth

occurring outside body wall. Cells of the uterine

wall, while more or less globular in juvenile

females, becomes elongate with maturity, giving the uterine sac a smooth appearance. Size

of female changes but little, but as the reproductive system extrudes, cuticle of the female

becomes wrinkled. The spear becomes obscure

and nonfunctional; anal opening disappears.

As the uterus enlarges and protrudes from

the body of the female, it evidently turns inside out, carrying the ovary and vagina with

it, so that the uterus remains attached to the

anterior end of the extruded vagina. The anterior end of the ovary floats more or less freely

in the lumen of the uterus, adjacent to the

posterior end of the female. The uterus remains

attached to the anterior end of the vagina and

the eggs are deposited through a small opening

at that end.

Type host.—Dendroctonus riifipennis

(Kirby).

Type locality.—Red Table Mountain, Eagle

County, Colorado.

Type specimens.—Catalog numbers 18 E,Z,

and Y, Allotype 17.

Aphelenchoidea (Fuchs, 1937) Thorne, 1949

Aphelenchoididae (Skarbilovich, 1947) Paramonov, 1953

Aphelenchoidinae Skarbilovich, 1947

Parasitaphelenchus Fuchs, 1929

53
Figure 32.—Sphaerularia dendroctoni Massey, 1956: A, B, C, Female with uterus in

initial stage of prolapse; D, E. females with prolapsed uterus; F. female, head; G.

male, head and neck; H, male, head; /, male, tail.

54
p. acroposthion (Steiner, 1932) Rühm,

1956

P. becus n. sp.

P. dendroctoni Massey, 1966

P, gallagheri (Massey, 1960) J. B.

Goodey, 1960

P. procerus n. sp.

Genus Parasitaphelenchus Fuchs, 1929

Type species: Parasitaphelenchus uncinatus

(Fuch;, 1929) Fuchs, 1929

Body long and slender. Lips offset. Spear

long, comparatively slender, with or without

basal knobs or swellings. Metacorpus oblong,

ovate, with well developed valve plates. Dorsal

esophageal glands slender, elongate. Excretory

pore may occur either anterior or posterior

to metacorpus. Vulva far posterior, usually

with v/ell developed posterior uterine branch.

Tail almost cylindroid from vulva to anus. Anal

opening at times obscure. Spicules paired and

fused along ventral shaft, usually with well

developed ventral rostra. One to three pairs of

subveiitral caudal papillae. Terminus mucronate.

Parasitic larvae: Lips obscure. Stylet obscure; however, vestibule apparent in many

species. Metacorpus usually well developed,

usuall;/ with apical and caudal cuticular projections.

Parasitaphelenchus acroposthion (Steiner, 1932) Rühm,

1956 Figure 33

Steiner's measurements except for length are

inadeciuate. Lengths are : female = 2.4 mm; male

= 1.6 mm. His original description follows:

*^Bcdy is very slender and elongate. Tail of

female short and bluntly rounded ; that of male

also short, and its base similar to that of female

but eiids in a short horn-like process. Cuticle

finely annulated, but no lateral membrane was

seen. Lip region distinctly set off, exhibiting in

a froit view rounded well-separated lips. A

cuticularized ring with six short rays encircles

the oral opening. Structures of head end rather

obscure, but amphids believed to be in position

shown. This species, like other members of the

genus, has four submedial papillae. The spear

is extremely fine and appears to be composed

of three different portions—an anterior conical

portion rather well cuticularized, a succeeding

short cylindrical portion rather well cuticularized, and then a long cylindrical portion

which is hardly cuticularized and which,

posteriorly, is set off from the esophageal canal

only by the attachment of the protruding spear

muscles. No basal swellings were seen. The

esophageal bulb is well developed and of oval

shape; it has rather long but thin valvulae.

The radial muscles attached to the valvulae

exclude a more glandular portion at the anterior and posterior ends of the bulb. The connection of the intestine with this bulb is much the

same as in other forms of Aphelenchoidea. The

nerve ring occurs a short distance behind the

bulb. The intestine is of somewhat degenerate

character; its cell walls can hardly be recognized, the whole organ being filled with reserve material. The rectum and anal opening

are extremely fine and obscure. No excretory

pore was seen. The vulvar opening is well

marked because the body narrows just behind

it. The female sexual apparatus is prodelphic;

there is, however, a well-developed posterior

branch of the uterus, and attached to it there

appears to be a vestigial ovary extending

nearly to the anus. The anterior ovary extends

forward nearly to the nerve ring. The very

short sexual apparatus of the male is of the

proorchid type, with the end of the testis reflexed. It seems that the two spicula are

amalgamated, forming a single spiculum,

pointed at the outer end, but very wide at the

inner end. The ventral apophysis is somewhat

swollen proximally. Only one male was studied

in ventral view ; it showed in the anal region a

peculiar lateral expansion somewhat resembling a vestigial bursa. Two papillae were distinctly seen on the inside of this expansion,

one in the anal region and the other at the base

of the horn-like process. It is doubtful whether

these males are fully functional.

''Diagnosis.—Parasitaphelenchus of long,

slender shape. Tail of female short, obtusely

rounded; that of the male broadly conical at

the base, mucronate. Spear rather narrow, of

average length, without basal swellings. Esophageal bulb ovoid. Vulva well marked because

the body narrows abruptly behind it. Male with

slightly sublateral papilla in latitude of the

anus, and another somewhat in front of terminal process."

Habitat,—Egg galleries of Dendroctonus

ponderosae.

Locality.—Steiner collected the nematodes in

Utah.

55
im...op

post brut

-CUtStCt

m

B

Jatexp

post cop ppl

i\\\

) !ll

uU

r.'is

9/

Y

Figure 33.—Parasitaphelenchus acroposthion (Stc

, . ., ^ , . . . '•^"e'"' 1932) Rühm, 1956: A. Female, tail; B. face view; C. ventral

view, male tail; D. lateral view, male tail; E. stylet; F. head and neck. (After Steiner, 1932).

56
Pítrasitaphelenchus beccus ii. sp. Figure 34

Femule: 1.79-2.0 mm; a^^^76.3-85.1 ; b = 20.4-

21.3;c-=?;V = 89-92%.

Male: 1.12-1.22 mm; a==63.6-69.3; b = 12.7-

13.9; c:^69.3-76.4.

Body sinuous, cylindroid. Cuticle without

lateral incisures. Transverse striae very fine.

Lip region rounded, set off, lips distinct. Cephalic framew^ork sclerotized. Stylet relatively

fine, 18 fx in length, with small basal thickenings.

Retractor muscles prominent. Dorsal esophageal gland outlet obscure. Metacorpus oval,

two-thirds as wide as long. Dorsal esophageal

glands prominent, ca 5 body widths in length.

Excretory pore over a body width anterior

to metacorpus. Nerve ring one-half body width

posterior to metacorpus. Hemizonid not observed. Body narrowing sharply at vulva, lips

of which may or may not be protuberant.

Vagina slightly oblique. Ovary outstretched,

oocytes arranged in 3 rows at its anterior,

oocytes in posterior portion in a single row.

Posterior uterine branch ca 5 body widths in

length. Anus and rectum obscure. Tail conoid

to a broadly rounded or mucronate terminus.

Male : Testis single, outstretched. Spicules

paired, typically parasitaphelenchoid. Two

pairs of caudal papillae, 1 pair immediately

preanal, 1 pair immediately anterior to a

mucronate terminus.

Parasitic larvae: 0.61-0.70 mm; a = 19.0-

21.7;b = 8.7-8.8;c=?

Body with slight ventral arcuation. Cuticle

apparently smooth, without lateral incisures.

Lip region rounded, not offset, with a hornlike

muero. Spear not visible, vestibule apparent.

Metacorpus distinct. Excretory pore anterior

to metacorpus. Nerve ring one-half body width

posterior to metacorpus. Dorsal esophageal

glands not observed. Body cavity filled with

fat globules. Tail conoid to a fine hornlike

mucronate terminus.

Diaijnosis.—Related to Parasitaphelenchus

gallagiieri. Free-living sexual forms differ in

the position of excretory pore, shape of metacorpus, and in length and coarseness of stylet.

Parasitic larvae differ in the shape of the lip

region and in the shape of head and tail

muero,

Type host and habitat.—Associated with and

parasitizing the Douglas-fir beetle. Dendroctonus pseiidotsiigae Hopk., in Douglas-fir,

Pseudotsugae mensiesii (Mirb.) Franco. Collected by Malcolm M. Furniss.

Type specimens,—Collection No. 59-E and

59-E-l.

Parasitaphelenchus dendroctoni Massey, 1966 Figure 35

Parasitic form: 1.5 mm; a = 23; b = 25; c=?

Cuticle smooth. Lips not discernible. Anterior

and posterior ends of nema armed with cuticular flaps or mucros. Stylet without knobs, not

visible in many specimens. Median bulb of

esophagus ovate. Esophageal glands, excretory

pore, nerve ring, hemizonid, and anal opening

not discernible. Body cavity of most specimens

examined filled with fat bodies that masked the

presence of many diagnostic characters. Male

and female specimens cannot be separated with

any degree of certainty.

Type host,—Dendy^octonus adjunctus.

Type locality.—Ruidoso, New Mexico.

Type specimens,—Collection No. 14-E.

Free-living form: Females: 2.5-3.7 mm;

a = 64-75;b = 24-28;c=? V=::90%. Males: 1.7-

2.4 mm ; a = 74-82 ; b=:21 ; c = 96-119.

Cuticle smooth with no discernible transverse

striations. Lip region only slightly set off.

Stylet 15 /x long without basal knobs or thickenings. Median bulb of esophagus ovate; esophageal glands short, stout, extending approximately 3 body widths posterior to median bulb.

Nerve ring approximately three-fourths body

width behind median bulb. Excretory pore two

and one-half body widths posterior to median

bulb. Hemizonid one-half body width forward

of excretory pore. Ovary outstretched, massive.

Posterior uterine branch extending at times to

within one body width of terminus. Two specimens examined had mature eggs in the posterior uterine branch. Vagina transverse. Body

cylindroid posterior to vulva, ending in a

broadly rounded, mucronate tail. Anal opening

not discernible.

Male: Testis single, outstretched. Spicula

elaborate as illustrated, less than a body width

anterior to terminus. One pair of postanal

caudal papillae immediately anterior to terminus. Tail broadly rounded, with mucronate

tip.

Diagnosis.—Differs from all other species

of the genus in its greater length, number of

caudal papillae, and in shape and size of

spicula.

57
Figure 34.—Parasitaphelenchus beccus n. sp.: A, Head and neck; B, head; C.

male, tail; D, female, tail; E, larva, head and neck; F. larva, tail.

58
/// / / /Il II! 11 al

Figure 35.—Parasitaphelenchus dendroctoni Massey, 1966: A, Head and neck; B. female, tail;

C. male tail; D. parasitic larva, head and neck; E. parasitic larva, tail.

59
Type habitat.—Ponderosa pine, Pinus ponderosa Laws.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 37-R.

Parasitaphelenchus gallagheri (Massey, 1960) J. B.

Goodey, 1960 ( redescribed ) Figure 36

Synonym : Aphelenchoides gallagheri Massey,

1960

Females: 1.42-1.73 mm; a = 47.0-70.3; b =

16.6-24.7; c = 48.3-56.0;V = 90%.

Males: 0.98-1.07 mm; a = 39.0-60.6; b =

12.8-14.5; c = 51.8-55.3.

Body posture straight to sinuous, cylindroid.

Cuticle without lateral incisures. Transverse

striae moderately fine. Lip region slightly set

off over 2 times wider than deep. Lips distinct.

Cephalic framework lightly sclerotized. Spear

15 fjL long, with distinct basal thickenings.

Stylet muscles well defined. Dorsal esophageal

gland outlet obscure. Metacorpus oblong, twice

as long as wide. Dorsal esophageal gland over 4

body widths in length. Nerve ring one-half

body width posterior to metacorpus. Excretory

pore opposite hemizonid. Lips of vulva only

slightly protuberant. Vagina oblique. Ovary

outstretched. Oocytes arranged posteriorly in a

single row, anteriorly in a double row. Posterior uterine branch 5-7 body widths in length,

usually containing sperm cells. Anus and rectum visible but not prominent. Tail conoid,

broadly rounded, with or without a terminal

muero.

Male: Testis single, outstretched. Spicules

paired and generally distinct. The dorsal shaft

usually more heavily sclerotized than the ventral shaft. Ventral rostrum finely produced.

There are two pairs of caudal papillae, one pair

immediately preanal, one pair immediately

anterior to a relatively large, mucronato terminus.

Parasitic larvae: The following description

is of larvae that are most commonly found in

active adult beetles during the summer months.

The exact instar was not determined.

Length=0.63-0.69 mm; a = 26.8-33.7; b =

7.9-8.4; c = 18.1-19.5.

Body posture ventrally arcuate. Cuticle without lateral incisures or apparent striae. Lip

region not set off. Hornlike apical and caudal

cuticular projections. Cephalic framework indistinct. Stylet absent. Vestibule apparent in

most specimens. Median bulb prominent, twice

as long as wide. Nerve ring almost a body width

posterior to metacorpus. Excretory pore opposite nerve ring, and at times passing through

hemizonid. Genital primordia distinct. Anus

and rectum obscure. Tail conoid with a prominent horn-like, mucronato terminus.

Larval forms in the genus bear definitive

characters that at times are lacking in freeliving adults. Parasitaphelenchus gallagheri

larvae are distinctive in the small cephalic

projections observed in lateral view.

Type habitat and host.—Free-living males

and females associated with Ips confusus in

pinyon, Pinus edulis Engelm. Parasitic larvae

from body cavity of Ips confusus.

Type locality.—Bandolier National Monument, New Mexico.

Type specimens.—Collection No. 13-G (Allotype),8-N (Holotype).

Parasitaphelenchus procerus n. sp. Figure 37

Female: 1.76-1.94 mm; a = 75.12-82.5; b =

24.0-28.7; c=?;V= 90-91%.

Male: 1.10-1.21 mm; a = 75.2-82.6; b = 14.5-

15.2;c = 75.2-82.6.

Body sinuous, cylindroid. Cuticle without

lateral incisures. Transverse striae fine. Lips

rounded, continuous with neck region. Cephalic

framework lightly sclerotized. Spear slender,

11 /x in length, with very small basal thickenings, retractor muscles prominent. Metacorpus

oblong, ovate, twice as long as wide. Dorsal

esophageal gland outlet distinct, the gland 5-6

body widths long. Excretory pore a body width

posterior to nerve ring. Hemizonid slightly

anterior to excretory pore. Ovary single, outstretched. Lips of vulva continuous with body

wall. Vagina oblique. Posterior uterine branch

ca 5 body widths in length. Anus and rectum

not discernible. Tail conoid to an acute mucronato terminus.

Male: Testis single, outstretched. Spicules

paired with a finely produced curved ventral

rostrum. There are two pairs of caudal papillae,

one pair preanal, one pair immediately anterior

to terminus. Tail conoid to an acute mucronato

terminus.

Diagnosis.—Related to Parasitaphelenchus

dendroctoni. Varies in structure of lip region.

60
Figure 36.—Parasitaphelenchus gallagheri (Massey, 1960) Goodey, 1960: A. Head and neck; B. head; C.

female, tail; D. larva, head; E, larva, midbody; F. male, tail; G, body showing vulva and postuterine

brjinch; H, larva head and neck; /. larva, tail.

61
i::v9;;'/;li:>i3".

;^M

. ',íil

im

fiMM

•*••' i;.-..'v:|'.".| -I/-'::

mm

mm w

.01 mm

ac

,03 mm

cl

03 mm

mi

c

j-;:>;

::t ■■:

¡mm--

mil mm

mm:

•.'i :•;

?1:

•'^^iS;;

bS:^

m

Wm

Figure 37.—Parasitaphelenchus procerus n, sp.: A. Head and neck; B. head; C female, tail; D. male, tail.

62
in shorter length of stylet, and in general

body proportions.

Type habitat.—Associated with Ips calligraphus (Germ.) in slash pine, Pinus elliottii

Engelm.

Type locality,—Patrick, South Carolina.

Type specimens,—Holotype and Allotype Collection No. 59-F.

Associates

Rhabditoidea (Örley, 1880) Travassos, 1920

Rhabditidae Örley, 1880

Rhabditinae (Örley, 1880) Micoletzky, 1922

Cephaloboides Rahm, 1928 n. rank

C. rotundus n. sp.

Mesorhabditis (Osche, 1952) Dougherty, 1953

M, longistomis n. sp.

Protorhabditinae Dougherty, 1955

Parasitorhabditis (Fuchs, 1937) Chitwood and Chitwood, 1950

Syn. Rhabditis (Parasitorhabditis)

Fuchs, 1937

P. cluniculus n. sp.

P, gracilis n. sp.

P. hastulus n. sp.

P. hylurgi n. sp.

P. ipini n. sp.

P. terebranus n. sp.

Bunonematinae Micoletzky, 1922 (Chitwood, 1935)

Bunonema Jägerskiöld, 1905

B, newmexicana Massey, 1964

Cylindrocorporidae Goodey, 1939

Cylindrocorpus Goodey, 1939

C, erectus Massey, 1960

Diplogastridae (Micoletzky, 1922) Steiner,

1919 2

Diplogastrinae Micoletzky, 1922

Acrostichus Rahm, 1928

A, concolor (Massey, 1962)

Massey, 1970

A, gubernatus n. sp.

A. ponderosus Massey, 1962

A. taedus Massey, 1962

2 According to Baker and Sanwal, 1960, the genitive

singular of the termination gaster would appear to be

gastros and the latinizing of a family name with this

termination would be gastridae and not gasteridae. The

same spelling would also apply to Diplogasterinae and

Neodiplogasterinae ; accordingly the correct spellings

are herein applied (page 133, Code of Zoological Nomenclature) .

Gerthornus Massey, 1966

G, balaenus Massey, 1966

Mikoletzkya (Weingärtner, 1955) Rühm,

1960

M, bandelieri (Massey, 1960) Massey,

1966

M. calligraphi n. sp.

M, cervicula Massey, 1966

M, diluta Massey, 1966

M, inedia Massey, 1966

M, langcauda n. sp.

M, pinicola (Thorne, 1935) Baker,

1962

M, pugnea Massey, 1970

M, ruminis Massey, 1966

M, tornea Massey, 1966

Mononchoides Rahm, 1928

M, adjunctus Massey, 1966

Neodiplogastrinae Paramonov, 1952

Neodiplogaster Cobb, 1924

N, magulum n. sp.

Diplogasteroidinae Filipjev and Schuurmans Stekhoven, 1941

Diplogasteroides deMan, 1912

D, bibrochus n. sp.

D, dimidius n. sp.

D, ipini n. sp.

D, marshalli Massey, 1962

Dirhabdilaimus Paramonov and Turlygina, 1955

D, nacogdochensis n. sp.

Rhabdontolaimus (Fuchs, 1931) Filipjev and Schuurmans Stekhoven, 1941

R, adephagus n. sp.

R, frontali n. sp.

R, janae (Massey, 1962) n. comb.

Cephalobidae (Filipjev, 1934) Chitwood and

Chitwood, 1934

Panagrolaiminae Thorne, 1937

Panagrolaimus Fuchs, 1930

P, concolor Massey, 1964

P, conophthori n. sp.

P. leperisini n. sp.

Neocephalobus (Steiner, 1929)

Steiner, 1934

N, judithae (Massey, 1964) n.

comb.

Panagrodontus Thorne, 1935

P, dentatus Thorne, 1935

Plectonchus Fuchs, 1930

P, molgos n. sp.

P, wyganti Massey, 1964

Panagromacra Massey, 1964

P. nfiargaretae Massey, 1964

63
Pa7iagrohelus Thorne, 1939

P. phloeosini n. sp.

P. scolyti Massey, 1964

Turbatricinae T. Goodey, 1943

Panagrellus Thorne, 1938

P. leperisini n. sp.

Teratocephalidae Andrassy, 1958

Teratocephalus deMan, 1876

r. angustus n. sp.

Chambersiellidae (Thorne, 1937) Sanwal, 1957,

1971

Chambersiellinae Thorne, 1937

Geraldiits Sanwal, 1971

G, bakeri (Sanwal, 1957) Sanwal,

1971

Santafea Massey, 1963

S, croca Massey, 1963

S. damalis Massey, 1966

Macrolaiminae Sanwal, 1971

Macrolaimus Maupas, 1900

M. canadensis Sanwal, 1960

M. taiirus Thorne, 1937

Genus Cephaloboides (Rahm, 1928) n. rank

Synonyms : Rhabditis (Cephaloboides) Rahm,

1928

Cuticuleria van der Linde, 1938

Type species : Cephaloboides musicola Rahm,

1928

Lips at times offset, with or without papillae,

stoma 2-3 times deeper than wide. Cheilorhabdions rudimentary or absent. Esophagus with

prominent median bulb. Ovaries paired. Spicules paired. Bursa leptoderan. Rays radially

arranged. Tail in both sexes dome shaped with

spicate terminus.

Cephaloboides rotundas n. sp. Figure 38

Females: 0.82-1.0 mm; a = 20-22; b = 4.4-

5.0; c = 20.2-30.8;V = 55-56%.

Males: 0.81 mm; a = 18.4-19.7; b=:4.1-4.5;

c = 15-25.

Body straight, cylindroid, cuticle with very

fine transverse and longitudinal striations. Lips

rounded, with fine setose papillae. Cheilorhabdions absent. Prorhabdions make up major part

of stoma which is 20 fx in depth; meso, metarhabdions with two prominent teeth, the

ventral tooth slightly anterior to dorsal tooth.

Anterior part of esophagus forming a stomatal

collar, corpus muscular, the posterior portion

expanded into a prominent median bulb.

Corpus and median bulb equal in length to

isthmus and basal bulb. Nerve ring at midisthmus. Hemizonid not observed. Excretory

pore opposite anterior end of basal bulb. Cardia

conspicuous. Lips of vulva at times protuberant.

Vagina transverse. Ovaries paired, at times

reflexed their entire length. Uterus in each

ovary serving as spermatheca. Anus and rectum

conspicuous. Tail broadly rounded with a

spicate terminus.

Male: Testis single, reflexed at times onethird its length. Spicules paired and separate,

slightly ventrally arcuate capitate, 32-35 /x in

length. Gubernaculum more or less linéate. Tail

as in female. Bursa leptoderan, reduced. There

are 7 pair of bursal rays.

Diagnosis.—Differs from C. musicola in

shape of lips and its much smaller size.

Type habitat.—Associated with Dendroctonus

adjunctus in ponderosa pine.

Type locality.—Oak Creek Canyon, Arizona.

Type specimens.—Collection No. 61.

Genus Mesorhabditis (Osche, 1952) Dougherty, 1953

Synonym: Rhabditis (Mesorhabditis) Osche,

1952

Type species : Mesorhabditis spiculigera

(Steiner, 1936) Dougherty, 1953.

Lips prominent, set off by constriction. Stoma

cylindroid with short glottoid apparatus. Metarhabdions toothed. Vulva posterior. Ovary

single. Bursa peloderan. Spicules slender,

elongate, capitate amalgamated.

Mesorhabditis longistotnis n. sp. Figure 39

Females: 0.44-0.52 mm; a = 24-26; b = 3.6;

c = 8.7-10.3 ;V = 75%.

Males : unknown.

Cuticle transversely striate, lateral ñeld

marked by three incisures. Lips set off by constriction, cephalic papillae prominent. Pharynx

cylindroid, three times as long as width of head

at base of lips. Prorhabdions composing

approximately three-fourths of the stoma.

Meso, meta, and telorhabdions fused into a

glottoid apparatus, 2 conspicuous inward-pointing teeth above base of the pharynx. Amphids

prominent, located at base of lateral lips.

Corpus of esophagus about equal in length to

isthmus and terminal bulb combined; terminal

64
B

•fc-'.l|-<^>V

abd

,03 mm

Figure 38.—Cephaloboides rotundus n. sp.: A.

male, tail.

VÉk

m

*!

:. : • /••//.••V.-. • ...'-r/l'.Y. J

Iftifiif

ïïmamm ..::àîN^. ^*^;

■■/I--':

üííí;

I

Head and neck; B. female, tail; C. female, midbody; D.

65
'\^^\h'^

.01mm

.03 mm

IM I //

.'rP^'^^V

'/Co;.//

- r ;•

I '!

Figure 39.—Mesorhabiditis longistomis n. sp.: ^. Head and neck; B. head; C.

female, midbody and tail D. ventral view, female tail.

66
bulb valvate. Nerve ring at middle of isthmus. with the spruce beetle and the specimen is given

Excretory pore slightly posterior to nerve ring. the specific designation of M, longistomis.

Hemizonid immediately anterior to excretory

pore. Ovary single, short, reflexed. Lips of vulva ^enus Parasitorhabditis (Fuchs, 1937) CMtwood

protuberant. Vagina transverse. Length of tail and Chitwood, 1950 Emended

about equal to distance between vulva and anal

opening. Tail conoid to acute terminus. Synonym: Rhabditis (Parasitorhabditis)

Diagnosis—This species is closely related to Fuchs, 1937

Mesorhabditis spiculigera (Steiner, 1936) m . D V ? Z.^U- Z.^

Dougherty, 1953. It differs from that species in ,JT loT.Tn ' ParasztorhabdzUs obtusa

the number of lateral incisures and its very ^F^^*«' ^^IS) Dougherty, 1953.

short ovary. Lips angular to rounded. Stoma consisting of

Type habitat.—Associated with Scolytus ven- elongate prorhabdions. Meso, meta, and telortralis in white fir, Abies concolor (Gord. and habdions rudimentary or absent with or withGlend.) Lindl. out slender teeth. Esophagus with or without

Type locality.—Sandia Mountains, Cibola median bulb, basal bulb valvate. Ovary single.

National Forest, New Mexico. reflexed, vulva at 90% or more. Anus and

Type specimens.—Collection No. 23-H. rectum conspicuous. Terminus obtuse to filaThis nematode was noted as sp. inquirenda mentous. Testis single, spicules spicate, fused

Massey, 1964. Since that time, several addi- at distal end. Gubernaculum variable in shape,

tional specimens were collected in association Bursa peloderan with 8-12 pair of bursal rays.

Key to Species of Parasitorhabditis occurring in

the United States

1. Vulva at 95% or more 2

Vulva at less than 95% 4

2. Remnants of metarhabdions with 2 teeth,

subdorsal and subventral cluniculiis n. sp.

Remnants of metarhabdions without teeth 3

3. Gubernaculum with distal prong hastulus n. sp.

Gubernaculum without distal prong .... ipini n. sp.

4. Esophagus of female with median bulb, remnants of dorsal metarhabdion with a

slender tooth, cuticle with regular punctation hylurgi n. sp.

Esophagus without median bulb 5

5. Remnants of metarhabdions without teeth,

terminus of female sharply rounded .... gracilis n. sp.

Remnants of metarhabdions with 4 teeth,

terminus of female with short filament . . terebranus n. sp,

Parasitorhabditis cluniculus n. sp. Figure 40 and median bulb. Ncrvo ring at midisthmus.

Female: 0.99-1.0 mm; a = 20.5-22.4; b=5.1- Excretory pore slightly posterior to nerve ring

5.4; c = 56-58; V = 95%. and hemizonid. Lips of vulva protuberant. VaMale: 0.78-0.81 mm; a = 23-24.4;b = 4.5-4.8; gi^a oblique. Ovary single and reflexed twoc = 17.8-21.2. thirds its length. Quadricolumella conspicuous

^, ,. - ., ^ ^.,,,., ^ , . and of variable length, at times 4-5 body widths

Cylmdroid. Cuticle thick. Transverse striae j^^g. Uterus thick-walled and muscular. Anus

coarse, especially forward from anterior end ^^^ ^^^^^^ conspicuous. Phasmid obscure. Tail

of esophagus. Lips rounded to angular. Stoma ^^^^^^ ^o a narrowly rounded terminus.

20 ^ m depth. Remnants of metarhabdions with

2 small teeth. Corpus muscular, only slightly Male: Testis single, reflexed one-third its

widened at base to form an obscure median length. Spicules spike-like, 33 /x in length. Gubulb. Isthmus slender. Basal bulb valvate, basal bernaculum shaped as figured, 17 ¡x in length,

bulb and isthmus one-third longer than corpus Tail conoid to an acute terminus. Bursa pelo67
L

-^m

'^m

- l-p

?-A -A'

W:. Mi

¡»ill

.03 mm

CB

■■m0êmt ■■

i^b'

si;i ii

mmmilm-i

.01 mm

m. i

1/

lililí

m mf^

/

.03 mm rFigure 40.—Parasitorhabditis cluniculus n.

gubernaciilnm.

w

m

'.#^^

'm

sp.: A. Head and neck; B. female,

W

tail; C. male, tail; D.

68
deran. There are 11 pair of bursal rays arranged as illustrated.

Diagnosis,—Closely related to Parasitorhabditis bidentati Rühm, 1954. Differs in shape

of female tail and in the shape of the gubernacalum. P. bidentati has only 10 pair of bursal

rays.

Type habitat.—Associated with Polygraphus

hojpingi in Engelmann spruce, Picea engelmanni Parry.

Type locality,—Flagstaff, Arizona.

Type specimens,—Collection No. 84-E.

Parasitorhabditis gracilis n. sp. Figure 41

Female: 0.80 mm; a = 24.9; b = 5.0; c = 27.4;

V=93%.

Male: 0.76 mm; a=:29; b = 5.1; c = 29.

Cylindroid, cuticle moderately thick with

rather coarse, transverse striae. Lips angular.

Stoma 14 ¡x deep. Pharynx without teeth, corpus

muscular without median bulb, lumen heavily

sclerotized, serrated. Isthmus very slender,

isthmus and median bulb one-third longer than

corpus. Nerve ring at midisthmus. Excretory

pore and hemizonid slightly anterior to nerve

ring. Hemizonid immediately anterior to excretory pore. Vulva with protuberant lips. Vagina

oblique. Ovary single, reflexed two-thirds its

length. Quadricolumella elongate, in some specimens, several body widths in length. Anus and

rectum conspicuous. Phasmid conspicuous,

op])osite anal opening. Tail conoid to sharply

rounded terminus.

Male: Testis single, reflexed. Spicules spicate, 34 ¡JL in length. Gubernaculum as figured,

18 /x in length. Tail conoid to an acute terminus.

Bursa peloderan. Nine pairs of bursal rays.

Diagnosis,—Related to Parasitorhabditis

hylurgi n. sp., varies in its more slender shape,

absence of cuticular punctation, and in size and

shape of the spicules and gubernaculum.

Type habitat,—Associated with Pseudohylesinus grandis Sw. in white fir.

Type locality,—Grand Canyon, Arizona.

Type specimens,—Collection No. 84-J.

Parasitorhabditis hastulus n. sp. Figure 42

Female: 0.67-0.75 mm; a = 19-21; b = 4.4-

4.8; c = 42.2-45.8 ;V=:95%.

Male: 0.62-0.67 mm; a = 25-26; b = 4.2-4.6;

c = 20.8-23.7.

Body straight, cylindroid. Cuticle thick.

Transverse striae fine. Lips open, angular without visible cephalic papillae. Stoma 5 times

deeper than wide, rhabdions without teeth.

Corpus and median bulb muscular. Lumen of

corpus heavily sclerotized, serrate for threefourths of its length. Basal bulb valvate,

muscular. Basal bulb and isthmus longer than

corpus and median bulb. Nerve ring at midisthmus. Excretory pore at anterior end of

basal bulb. Hemizonid immediately anterior to

excretory pore. Vulval lips protuberant. Vagina

oblique. Ovary single, reflexed two-thirds its

length. Quadricolumella 5-6 body widths in

length. Uterus distinctive, thick walled, anterior portion very muscular. Anus and rectum

conspicuous. Tail conoid to a bluntly rounded

terminus.

Male: Testis single, reflexed one-third its

length. Spicules paired, distally fused, spikelike, 39 fx in length. Gubernaculum with a distal

prong, 19 /x in length. Bursa peloderan. Ten

pairs of bursal rays. Tail conoid to an acute

terminus.

Diagnosis,—Differs from other species in the

genus in the shape of the gubernaculum and

in the relatively long spicules.

Type habitat,—Associated with Ips grandicollis in loblolly pine, Pinus taeda L.

Type locality,—Beaumont, Texas.

Type specimens,—Collection No. 84-C.

Parasitorhabditis hylurgi n. sp. Figure 43

Female: 0.89-0.90 mm; a = 16.8-19; b = 4.8-

5.3;c = 24.5-25.3;V=92%.

Male: 0.77-0.83 mm; a= 18.9-21.9; b = 4.4;

c = 21.9-29.4.

Cylindroid. Cuticle thick with coarse transverse striae. Punctations in symmetrical rows

on head as figured. Stoma 20 /x deep. Remnants

of dorsal metarhabdion with a very fine tooth.

Corpus muscular, widened at its base into a

median bulb, lumen heavily sclerotized, serrate.

Basal bulb valvate, together with isthmus

longer than corpus and median bulb. Nerve

ring at midisthmus. Excretory pore opposite

nerve ring. Hemizonid immediately anterior to

excretory pore. Lips of vulva protuberant. Vagina oblique. Ovary single, in some specimens

reflexed three-fourths its length. Quadricolumella well developed, variable in length. Uterus

elongate. Anus and rectum conspicuous. Phas69
¡Ai

03mm

1:-;'^^

;::Ns¿^^^Av.-¿:>.;:;

«pa

'•y^:

ï»«$?^?:

1^

SA

i^^?;=?^v:i*:-

11^ÍSniíS:-=:á:

:i)¿^?i:

^^i:-

N^Si-v^;'

mt{^,

Mi:

::/â >i^-¿^

Í /'^

^^^•:;;íí

l-W

i f. Í7a

Il I :••:•:?

fè:\ "^^^

/.•^::

:^. i

íiW^i^. ri Äsjj

m.

.\\v

^

Figure 4.l.—Parasitorhabditis gracilis n. sp.: ^. Head and neck; B. female, tail; C. maie, tail;

D. gubernaculum.

70
li:í\

WT-W émm il \m .03 mm

Ma

^m' tíiííí

%m m-iñ

m¿^:

¡

imm

mE&m

\Uy:Ñ

: :;av:^ •:'. • MUSIB '"*

I

14

.01 mm.

IM

:: •.•( ;. • ;••. 1/,;. ..>-:-.\:-;.;:fv-:. .•;

»^taai :/v^; â/

feil I»fi

/Ä?;#^

v\=à^>^

^

:^' ^%'

v\^::

lv..-

;i^

Figure 42.—Parasitorhabditis hastulus n. sp.

D. gubernaculum.

y4. Head and neck; B, male, tail; C, female, tail;

71
í><®- ¿í? V^§|^p¿^?^

.V;

"^ ' 'É' '

:/|ií;

..K

D3mm

Figure 43.—Parasitorhabdids hylurgi n.

tail; D. male, tail; E. gubernaculum.

sp.: ^. Head and neck; B, cuticular pattern; C. female,

72
mid prominent, located opposite anal opening.

Tail conoid to an acute terminus.

Male: Cylindroid, body posture straight.

Testis single, reflexed one-third its length.

Spicules spike-like, 40 /x in length. Gubernaculum as figured, 21 /x in length. Tail conoid

to an acute terminus. Bursa peloderan. There

are 9 pairs of bursal rays.

Diagnosis.—Differs from other species in the

genus in the unique cuticular pattern and shape

of female tail. Gubernaculum distinctive.

Type habitat,—Associated with Hylurgops

pinifex in red pine, Pinus resinosa Ait.

Type locality.—Caroline County, New York.

Type specimens.—Collection No. 84-F.

Parasitorhabditis ipini n. sp. Figure 44

Female: 0.66-0.95 mm; a = 20.3-22.6; b =

4.4-5.1; c = 75.3-108;V = 95%.

Male: 0.61-0.75 mm; a = 21; b = 3.9-5.0; c =

18.9-22.7.

Body straight, cylindroid, cuticle thick.

Transverse striae fine to moderately fine. Lips

angular to rounded. Stoma 19 /x in depth.

Rhabdions without teeth. Corpus muscular

without median bulb, the lumen heavily sclerotized, serrated. Isthmus and basal bulb much

longer than corpus. Basal bulb muscular.

Cardia prominent. Nerve ring approximately at

midisthmus. Excretory pore and hemizonid

variable in position from nerve ring to anterior

portion of basal bulb. Excretory pore on some

specimens passing through hemizonid. Lips of

vulva protuberant. Vagina oblique. Ovary

single, reflexed two-thirds its length. Quadricolumella short, less than a body width in

length in some specimens. Uterus narrow, thin

walled. Anal opening and rectum conspicuous.

Phasmid obscure. Tail conoid to broadly

roimded dome-shaped terminus, sometimes

mucronate.

Male : Testis single, reflexed as much as onethrd its length. Spicules paired, joined, spikelike, 35 /x in length. Gubernaculum as figured,

19 /x in length. Tail conoid to an acute terminus.

Bursa peloderan. Nine pair of bursal rays,

arranged as figured.

Diagnosis.—Related to Parasitorhabditis obtusa (Fuchs, 1915) Dougherty, 1953. Varies

from that species in cuticular characteristics

and in the length of tail of female, in the shape

of gubernaculum, and in number of bursal rays.

Type habitat.—Associated with Ips pini in

red pine.

Type locality.—Caroline County, New York.

Type specimens.—Collection No. 84.

Parasitorhabilitis terebranus n. sp. Figure 45

Female: 0.77-0.81 mm; a = 19.7-20.1; b =

4.2-4.3; c = 26.2-27.3 ;V= 93%.

Male: 0.75 mm; a = 19.5; b = 4.1; c = 27.3.

Cylindroid. Transverse striae moderately

fine. Lips angular to rounded with moderately

prominent papillae. Stoma 21 /x in depth.

Prorhabdions unique in that the anterior tips

are bent. Remnants of metarhabdions with 4

teeth, 2 subventral, 2 subdorsal, only distinct

in lateral view. Esophagus without median

bulb, muscular, lumen of corpus heavily sclerotized, serrate. Isthmus and basal bulb muscular throughout, length of corpus equal in length

to isthmus and basal bulb. Cardia very conspicuous. Nerve ring at midisthmus. Excretory

pore slightly anterior to nerve ring. Lips of

vulva protuberant. Vagina oblique. Ovary reflexed up to three-fourths its length. Quadricolumella variable in length, up to several body

widths long. Phasmid, anus, and rectum conspicuous. Tail conoid to a short filamentous

terminus.

Male: Testis single, reflexed. Spicules very

slender. Spicate capitate, 34 /x in length. Gubernaculum as figured, 17 /x in length. Tail

conoid to an acute terminus. Bursa peloderan.

There are 9 pair of bursal rays.

Diagnosis.—Differs from all other species in

genus in the short spicate terminus. Also distinctive as to the length of isthmus and basal

bulb in relation to length of corpus of esophagus and in the unique prorhabdions.

Type habitat.—Associated with Dendroctonus terebrans in loblolly pine.

Type locality.—Nacogdoches, Texas.

Type specimens.—Collection No. 45-C.

Genus Bunonema Jägerskiöld, 1905

Synonyms : Craspedonema Richters, 1908

Rhodolaimus Fuchs, 1930

Type species: B. richtersi Jägerskiöld, 1905

Body spindle shaped, tapering to a sharply

pointed tail. Cuticle with dorsal and ventral

73
WM

I::-:

•:-:7 ■■

:••/ .

^S:--:-^:ifeii^ •V:îV::

D3mnn

::--..\v, • .•;; •.-. .;•;

IB ím

II -i::-'

#"m

!yí;-ihk

.03 mm

;;•.:: ::•_ ;• : : c.¡ !:• -3 •..•.• ;v

Figure 44.—Parasitorhabditis ipini n. sp.: À. Head and neck; ß. female, tail; C. female, tail; D. male,

tail.

74
.03 mm

¡m

ií

B

■■:^'-y'^ ^¡vMmMi ...

:-;-(J:

\

\

\ \w

.01 mm

-I I ] \

í,

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-•íí/.-. -

;--W

i

.1

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f

.03 mm

Figure 45.—Parasitorhabditis terebranus n.

tail; C. male, tail; D, gubernaculum.

sp.: A, Head and neck; B. female,

75
membranes throughout entire body length.

Head asymmetrical with enlarged projecting

lateral lips. Cheilo-, pro-, and mesostom forming an elongate cylinder. Esophagus rhabditoid.

Ovaries paired. Spicules slender, paired ventrally arcuate. Bursa leptoderan with a varying number of rays.

Bunonema newmexicana Massey, 1964 Figure 46

Female: 0.34-0.43 mm; a = 12;b = 4;c = 14;

V=:56%.

Male: 0.35-0.45 mm; a = 15; b = 5; c = 9.

Cuticle with fine transverse striae between

rows of wartlike protuberances. Head asymmetrical with 6 cephalic setae, typically bunonematitoid. Prorhabdions prominent, rhabditoid, slightly expanded at base. Meso, meta, and

telorhabdions not apparent. Corpus and median

bulb of esophagus somewhat shorter than

isthmus and terminal bulb combined; terminal

bulb valvate. Nerve ring approximately at

middle of isthmus. Excretory pore not observed.

Amphidelphic, ovaries short, reflexed, occupying only one-third of body length. Vagina transverse, lips slightly protuberant. Cuticle overhanging the anal opening. Tail conoid, terminus

acute.

Male : Testis single, reflexed. Spicules paired,

elongate, slender, ventrally arcuate, over twice

length of gubernaculum. Gubernaculum troughlike, distal end almost encircling spicules, appears knobbed in lateral view. Bursa leptoderan, supported by 5 pairs of bursal rays.

Four pairs of visible ventrosubmedian caudal

papillae ; 1 preanal, 2, 3, 4 at base of tail. Tail

conoid, terminus acute.

Diagnosis,—B. newmexicana differs from

described species of the genus in the location

and number of bursal rays and position and

number of caudal papillae. Sachs (1949) lists

6 subgenera in the genus. In the writer's opinion, these are superfluous.

Type habitat—Associated with Scolytus ventralis in white fir.

Type locality,—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens,—Collection No. 31-B.

Numerous nematodes belonging to this genus

have been recovered from trees infested with

bark beetles; because of the dearth of described

material and the unavailability of type specimens, no attempt has been made to describe

them.

Genus Cylindrocorpus Goodey, 1939

Synonym: Cylindrogaster Goodey, 1927 (nee

Stal, 1855).

Type species: C, longistoma (Stefañski,

1922) Goodey, 1939.

Head with 6 forward-pointing conical lips.

Stoma exceedingly long. Procorpus and corpus

of esophagus fused into a cylindrical esophageal

bulb; isthmus and terminal bulb distinct, terminal bulb non-valvate. Ovaries paired, reflexed. Testis single. Spicules paired ventrally

arcuate, capitate. Tail with several pairs of

papillae.

Cylindrocorpus erectas Massey, 1960 Figure 47

Female: 0.95 mm; a = 16; b = 5.5; c = 8.8;

V = 47%.

Male : 0.77 mm ; a = 17 ; b = 7.7 ; c:= 19.8.

Cuticle thin, with fine longitudinal and transverse striations, the striations more apparent at

midbody. Body of female widest at middle,

sharply narrowing anteriorly from region of

esophagus and posteriorly to a long, finely

pointed tail. Body shape of the male more uniform in width throughout its entire length.

Head with 6 forward-pointing conical lips as

figured. Stoma elongate, one-third the length of

esophageal bulb, isthmus and terminal bulb

combined and composed of a short cheilostom,

cheilorhabdions buttonlike, a long protostom

and a short telostom. Esophagus typical of the

genus. Nerve ring slightly anterior to terminal

bulb. Excretory pore not discernible in specimens examined. Lips of vulva slightly protuberant. Vagina a short transverse slit, located

approximately at middle of the body. Ovaries

paired, opposed and reflexed, each uterus usually containing one egg at a time.

Male : Testis single, reflexed, spicules as illustrated. Cuticle of the tail expanded to form a

narrow bursa supported by 9 pairs of papillae

as figured. Tail moderately short, finely spicate.

Diagnosis,—Cylindrocorpus, closely related

to ctirzii Goodey, 1935. Differs from that species

in its stouter body form : C, erectus, both sexes,

a=16-17; C. curzii, female = 19-30, male = 23-

28; shorter tail in the female, stouter tail of

76
Figure 46.—Bunonema netvmexicana Massey, 1964: A. Head and neck;

B. head and neck, lateral view; C. female, tail; D, male, tail.

77
B

lffi:-rii:::iií| till tí«pill

¡ îM-:. im

.05 mm

D

Figure 47.—Cylindrocorpus erectus Massey, 1960: A. Head; B, maie, tail,

ventral view; C. maie, tail, lateral view; D. midsection female; E. female,

tail; F, face view.

78
the male. Inflated cuticle of the tail in the male

is supported by only 9 pair of papillae.

Type habitat,—Associated with Scolytus

multistriatus (Marsh) in American elm, Ulmus

americana L.

Type locality.—Albuquerque, New Mexico.

Type specimens,—Collection Nos. 8-V, 25-G.

Genus Acrostichus Rahm, 1928; Massey, 1962

Synonyms : Diplogasteritus Paramonov, 1952

Filipevella Lazarevskaya, 1965

Type species: Acrostichus toledoi Rahm,

1928

Cuticle with very prominent longitudinal and

moderately fine transverse striation. Head

usually narrowed forward from anterior end

of neck in lateral view. Stoma much deeper

than wide, 10-15 fx in depth, 2.5-4 ¡x in width,

consisting of a cheilostom with distinct prorhabdions. Meso, meta, and telorhabdions at

times fused forming a glottoid apparatus

armed with 2-4 dorsal and subventral teeth.

Esophagus typically diplogasteroid. Females

amphidelphic, ovaries usually strongly reflexed

with either meeting or crossing in region of

vulva. Females with a large reniform spermatheca. Spicules paired, ventrally arcuate cephalated. Gubernaculum massive, variable in shape.

Preanai and caudal papillae variable in number. Tail in both sexes filiform.

Acrostichus concolor Massey, 1962, Emended, 1970

Figure 48

Female: 0.53 mm; a = 14; b = 5; c = 3.7;

V = 475i>.

Male: 0.50 mm; a = 16; b = 4; c = 5.7.

Cuticle with prominent longitudinal striae.

Body widest near middle, tapering only gradually toward extremities. Neck strongly narrowed from anterior fourth of esophagus

forward. Amphid apertures minute, porelike, located near apices of lateral lips. Stoma 12 fx

deep, 3.5 /x wide. Mesorhabdion armed with a

dorsal tooth; the ventral metarhabdion with a

subventral tooth, the anterior dorsal tooth the

largest, the ventral metarhabdion with a small

denticle. Isthmus and terminal bulb of esophagus two-thirds length of procorpus and median

bulb. Nerve ring near middle of isthmus. Excretory pore adjacent to terminal bulb. Ovaries

paired, reflexed, nearly meeting at midbody.

Vagina a tranverse slit, opening into a reniform

spermatheca. Tail filiform.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate, cephalated. Gubernaculum

massive, almost as long as spicules. Eight pair

of caudal papillae : 1 and 2 preanai subventral ;

3 immediately postanal, 4, 5, 6, and 7 postanal

subventral, located at base of body as it narrows into the tail proper; 8 subdorsal and adjacent to number 7. Phasmids prominent in

some specimens. Tail filiform.

The species of Acrostichus, for the most

part, can be distinguished by variations in size

and shape of the massive gubernaculum. Gubernaculum of A. concolor distinguishes it from

other species in the genus.

Type habitat.—Associated with Scolytus

ventralis in white fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 34-A.

Acrostichus gubernatus n. sp. Figure 49

Female: 0.69-0.77 mm; a = 18.7-21.4; b:=

6.0-6.2; c = 2.5-3.0; V = 39-43%.

Male: 0.57-0.59 mm; a = 18.3-24.2; b=4.6-

5.3;c = 3.9-4.3.

Cylindroid. Cuticle with fine longitudinal and

transverse striations, ornamentation consisting

of 6 equally spaced striated lines in lateral view.

Lips rounded, each with a very fine papilla.

Cheilorhabdions and prorhabdions distinct.

Dorsal mesorhabdion modified into a large

heavily sclerotized tooth. Ventral metarhabdion

with a subventral tooth. Corpus of esophagus

widened at its base into a median bulb. Corpus

and median bulb approximately one-third

longer than isthmus and basal bulb, basal bulb

nonvalvate. Cardia conspicuous. Nerve ring at

midisthmus. Excretory pore opposite terminal

bulb. Hemizonid immediately anterior to excretory pore. Vulva with 2 flaplike processes.

Vagina transverse to oblique. Ovaries paired,

opposed and reflexed, the terminal ends crossed.

Uterus reniform, possibly acting as a spermatheca. Anus and rectum moderately conspicuous. Tail conoid to a very long filiform terminus.

Male: Testis single, reflexed 1 to 2 body

widths. Spicules ventrally arcuate, paired,

cephalated, 25 ¡x in length. Gubernaculum massive, shaped as figured, longer than spicules.

79
Figure 48.-

tail.

-Acrostichus concolor Massey, 1962, emended, 1970:/á. Female; B, head; C. male.

80
K ^Ä

ft }$>M

mmW- ^

1. \.''i:m

Figure 49.—Arcostichus gubernatus n. sp.: A, Head and

neck; B, head; C, midbody, female; D, male, tail; E,

female, tail.

27 fjL long. There are 8 pairs of caudal papillae,

2 pairs preanal ventrosubmedian, 5 pairs postanal ventrosubmedian, 1 pair immediately posterior to anal opening, and 4 pairs at the anterior end of the elongate terminus, 1 pair subdorsal, as illustrated. Tail ventrally arcuate to

a long filiform terminus. Bursa rudimentary.

Diagnosis.—Differs from all other species in

the genus in the massiveness of the gubernaculum and in the unique vulval flaps.

Type habitat,—Associated with Dendroctonus rufipennis in Engelmann spruce.

Type locality,—Mt. Taylor, New Mexico.

Type specimens,—Collection No. 34-C.

Acrostichus ponderosus Massey, 1962 Figure 50

Female: 0.6 mm; a = 16; b = 7; c = 3; V =

48%.

Male: 0.4 mm; a = 15; b = 5; c = 5.

Cuticle with prominent longitudinal and

transverse striations. Head narrowly rounded.

Stoma 10 iL in depth, 3 /x in width. Cheilo and

prorhabdions distinct. Dorsal mesorhabdion

modified into large clawlike tooth. Dorsal metarhabdion with a small denticle. Ventral metarhabdion with a small subventral tooth. Esophagus with a muscular corpus and median bulb,

basal bulb nonvalvate. Nerve ring at midisthmus. Excretory pore at base of basal bulb.

Ovaries paired, opposed and reflexed, terminal

ends crossed. Vagina a transverse slit. Lips of

vulva at times protuberant.

Male: Testis single, reflexed for a short distance. Spicules paired, ventrally arcuate, cephalated. Gubernaculum massive, nearly as long

as spicules. Nine pairs of caudal papillae located

as figured. Tail conoid to a filiform terminus.

Bursa rudimentary.

Diagnosis.—Differs from other species in the

genus in the shape of the gubernaculum.

Type habitat.—Associated with Ips ponderosae Sw. in ponderosa pine.

Type locality.—Bandelier National Monument, New Mexico.

Type specimens.—Collection No. 5-C.

Acrostichus taedus Massey, 1962 Figure 51

Female: 0.63 mm; a = 15; b = 5.4; c=3.6;

V = 43%.

Male: 0.55mm; a=:18; b = 4.4; c = 5.5.

Cuticle with prominent longitudinal and fine

transverse striations. Stoma 3 times deeper

than wide. Cheilo, pro, and mesorhabdions

81
Figure 50.—Acrostichus ponderosas Massey, 1962: A. Head and neck; B. head, ventral view; C. head, lateral view;

D, midbody, female; E, female, tail; F. male, tail; G. cuticle pattern.

distinct. Dorsal mesorhabdion modified into a

very large tooth. Ventral metarhabdion armed

with a comparatively large subventral tooth.

Corpus of esophagus distinctly widened at

base forming a median bulb, corpus and median

bulb one-third longer than isthmus and nonvalvate basal bulb. Nerve ring at midisthmus.

Excretory pore adjacent to nerve ring. Vagina

transverse. Lips of vulva only slightly protuberant. Ovaries paired, opposed and reflexed.

the terminal ends crossing. Tail conoid to a

filiform terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate, cephalated. Gubernaculum

nearly as long as spicules and shaped as illustrated. Nine pairs of caudal papillae located as

figured. Tail ventrally arcuate, conoid to a filiform terminus. Bursa rudimentary.

Diagnosis.—Differs from A. ponderosus in

82
.02 mm

.Olnrim

\

n "im

/I

Figure 51.—Acrostichus taedus Massey, 1962: A, Head and neck; B, midbody, female; C, female, tail; D, head; E. cuticular patlern; F. male,

tail.

83
shape of gubernaculum, in esophageal characters, and in number of teeth in pharynx.

Type habitat.—Associated with Dendroctomts terebrans in loblolly pine.

Type locality.—Lake City, Florida.

Type specimens.—Collection No. 10-H.

Genus Gerthornus Massey, 1966

Type species: Gerthornus balaenus Massey,

1966.

Cuticle with fine transverse and longitudinal

striations. Head broadly rounded, with 6 lips,

each lip bearing a prominent titlike papilla.

Amphids open on outer contour of lips. Stoma

very deep and broad, 30 /x by 14 ^. Cheilorhabdions and prorhabdions distinct, the prorhabdions sigmoid. Meso, meta, and telorhabdions

fused. Stoma armed with several large teeth,

both subdorsal and subventral. Ovaries paired ;

testis single. Male with several pairs of preanal

and postanal caudal papillae. Tail of both sexes

elongate.

Diagnosis.—Differs from other members of

the subfamily in the character and shape of the

stoma and its armature. The genus has affinities with Odontopharynx deMan, 1912, but

differs in the character of the esophagus.

Gerthornus balaenus Massey, 1966 Figure 52

Females: 0.81-1.06 mm; a = 22; b = 4.2-4.8;

c = 6.5-9.5;V = 54%.

Males: 0.73-0.81 mm; a = 20-22; b = 4.2-4.8;

c = 8.8-9.7.

Cuticle with fine longitudinal and transverse

striations. Head broadly rounded, more or less

flattened at the apex. Head composed of 6 lips,

each carrying a prominent, titlike papilla at

apices. Amphids well defined, opening on outer

contour of lips. Stoma 30 fi deep, 14 /x wide.

Cheilorhabdions distinct, forming apical arch

of stoma and overlapping prorhabdions. Prorhabdions almost twice length of cheilorhabdions, sigmoid, proximal portions with knotlike

swellings. Meso, meta, and telorhabdions fused,

bearing 6 large teeth, 2 subdorsal, 4 subventral.

The ventral mesorhabdions bear a rasplike

plate as figured. Esophagus consists of a broad

and very muscular procorpus, widening slightly

into a median bulb. Nerve ring one-third body

diameter posterior to median bulb. Excretory

pore slightly less than 1 body width behind

nerve ring. Hemizonid not seen. Ovaries paired,

reflexed at times beyond vulval opening ; proximal portion of each ovary containing spermatozoa. Vulva protuberant. Tail elongate, ending

in a minutely rounded terminus.

Male: Testis single, at times reflexed 1-2

body diameters. Spicules paired, 75 fx long,

slender, cephalated, ventrally arcuate. Gubernaculum keel shaped, one-third length of spicules with a sclerotized, forklike guiding process.

There are 7 pairs of ventrosubmedian papillae,

3 preanal and 4 postanal, situated as figured.

One pair of subdorsal papillae present. Tail

and terminus as in female.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 42 (Holotype),42-A (Allotype).

Genus Mikoletzkya (Weingärlner, 1955) Rühm, 1960

Synonyms : Diplogaster (Mikoletzkya) Weingärtner, 1955

Diplogaster (Fuchsia) of Micoletzky, 1922 (nee Fuchsia

Spuler, 1910)

Fuchsia (Micoletzky, 1922) of

Paramonov, 1952 and Rühm,

1956

Diplogaster (Mikoletzkyella)

Weingärtner, in Meyl, 1956

Mikoletzkyella (Weingärtner in

Meyl, 1956) Andrassy, 1958

Head broadly rounded. Cephalic papillae

weak to prominent. Stoma is usually deeper

than wide with prominent cheilo and prorhabdions. Dorsal metarhabdion bears a large clawlike tooth that extends well into the pharynx.

Subventral metarhabdion also bears a large

tooth which in some species extends into the

protostom and appears to bisect the dorsal

tooth in lateral view. Cuticle usually bears a

series of longitudinal ridges. Esophagus typically diplogasteroid. Ovaries paired, usually

reflexed. Testis single, sometimes reflexed.

Spicules paired. Gubernaculum unique in appearance, thick proximally with a thin troughlike distal extension. There are usually 8 pairs

of caudal papillae, although these may vary in

number, 3 pairs and 5 pairs postanal with a

group of 3 appearing immediately anterior to

84
Figure 52.—Gerthornus balaenus Massey, 1966: A, Female; B. male, tail; C. head.

85
^1 tií^^-

.OImm

the terminus or its extension. Tail may be quite

elongate or short and blunt.

Mikoletzkya bandelieri (Massey, 1960) Massey, 1966

Figure 53

Female: 0.77-1.2 mm;a= 21-26;b= 4.4-5.4;

c= 13-17 ;V= 53-56%.

Male: 0.64-1.0 mm;a= 20-24;b= 4.4-5.9;

c= 16-20.

Cuticle with prominent longitudinal striations. Head broadly rounded with moderately

prominent apical papillae. Pharynx 13 /x wide,

10 fx deep. Cheilo and prorhabdions very distinct. Amphids at base of lateral lips. Dorsal

metarhabdion developed intoa large claw-like

tooth, the ventral metarhabdion developed into a large subventral tooth extending past the subdorsal tooth at the middle of pharynx. There is a small buttonlike tooth at the base of the

pharynx that appears to be developed at the

junction of the telorhabdion, which is fused

with the metarhabdion. Corpus of esophagus

very muscular. Corpus and median bulb shorter

than length of isthmus and terminal bulb combined. Nerve ring at middle of isthmus. Excretory pore midway between nerve ring and terminal bulb. Hemizonid not apparent. Vagina

transverse. Lips of vulva protuberant. Amphidelphic, the ovaries reflexed. Spermatozoa present immediately preceding reflex of the ovary.

Tail narrows toa conical terminus.

Male : Testis single, reflexed. Spicules paired,

42-47 fjL in length, gubernaculum as illustrated,

16-18 fjL in length. There are8 pairs of preanal and caudal papillae arranged as figured.

Terminus bluntly conoid.

Diagnosis.—Differs from other species of the

genus in shape and length of tail and in length

of corpus and median bulb of the esophagus.

Habitat.—M. bandelieri has been found associated with Ips confusus in pinyon, with Dendroctonus frontalis and Ips avulsus in loblolly

pine, and with Ips ponderosae in ponderosa

pine.

Distribution.—Collected from Talladega National Forest in Alabama and from Bandelier

Figure 53.—Mikoletzkya bandelieri (Massey, 1960)

Massey, 1966: A. Head and neck; B, male, tail; C. female, tail.

86
National Monument and Santa Fe National

Forest in New Mexico.

Type specimens,—Collection No. 2-B-l (Holotype),2-Z (Allotype).

Mikoletzkya calligraphi n. sp. Figure 54

Female: 0.94 mm; a = 26.4; b = 5.3; c = 13.2;

V = 56%.

Male: 0.85 mm; a = 30;b = 5.4;c = 20.

Cylindroid. Cuticle with fine longitudinal and

transverse striae. Lips rounded with small elevated titlike papillae. Cheilo, pro, and mesorhabdions distinct. Dorsal and ventral metarhabdions armed with 2 large teeth which cross

at midpharynx. Meta and telorhabdions fused

forming a heavily sclerotized opening to

esophagus. Corpus of esophagus expanded at

anterior end to approximate width of median

bulb, muscular. Corpus and median bulb about

equal in length to isthmus and basal bulb.

Nerve ring at midisthmus. Both excretory pore

and hemizonid obscure. Lips of vulva protuberant. Vagina transverse. Uterus developed

into sausage shaped sac serving as a spermatheca. Ovaries paired, opposed and reflexed at

times beyond vagina. Anus and rectum conspicuous. Tail conoid to a sharply rounded

terminus.

Male : Testis single, reñexed. Spicules paired,

ventral arcuation extreme, cephalated. Distal

portion of shaft at right angles to manubrium,

60 fx in length. Gubernaculum shaped as figured.

There are 6 pairs of caudal papillae, 2 preanal

ventrosubmedian, 3 pairs ventral at base of tail,

1 pair dorsal at base of tail. Tail ventrally

arcuate, conoid to a short spicate terminus.

Diagnosis.—Closely related to M. bandelieri,

differs in length of spicules, number of caudal

papillae, and shape of male tail.

Type habitat.—Associated with Ips calligraphits in slash pine.

Ty%)e locality.—Patrick, South Carolina.

Tyi^e specimens.—Collection No. 24-R.

Mikoletzkya cervicula Massey, 1966 Figure 55

Female : Unknown.

Male: 0.79-0.90 mm; a = 22; b = 4.7-5.6;

c = 15.

Cuticle with fine longitudinal and transverse

striâtions. Head broadly rounded, grooves in lip

ring not apparent. Six lips, each with a moderately prominent apical papilla. Amphids open

on outer contour of lateral lips at contour of

head. Cheilorhabdions and prorhabdions distinct, about equal in length, cheilorhabdions

overlapping approximately one-third of prorhabdions. Meso, meta, and telorhabdions fused,

a large, subdorsal, clawlike tooth situated on

what appears to be the dorsal mesorhabdion ; a

large subventral tooth located on the same

structure. Two large denticles at base of

pharynx. Esophagus typically diplogasteroid.

Nerve ring midway of isthmus. Excretory pore

a little less than 1 body width behind nerve

ring. Hemizonid not observed. Testis single,

reflexed approximately 1 body width. Spicules

paired, 50 ¡JL long, ventrally arcuate, cephalated.

Gubernaculum 17 /x long, with a thin, troughlike, distal extension. Seven pairs of caudal

papillae: 3 preanal ventrosubmedian papillae,

3 postanal ventrosubmedian, and 1 subdorsal.

Phasmids plainly visible. Terminus finely

rounded.

Diagnosis.—Closely related to M. thalenhorsti (Rühm, 1956) Baker, 1962 and M. pinicola (Thorne, 1935) Baker, 1962. It differs

from the former in dentation of the stoma and

the length and shape of tail, and from the latter

in dentation of stoma, shape, and in size of

gubernaculum, and in the shorter tail and its

shape.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 42.

Mikoletzkya diluta Massey, 1966 Figure 56

Female: 0.80 mm; a = 20; b = 6; c = 10; V =

52%.

Male: 0.67-0.83 mm; a = 20-23.6; b = 6-6.5;

c = 11.8-12.4.

Body tapers rapidly from midbody to head.

Cuticle with fine longitudinal ridges from head

to tail. Head narrowly rounded. Cephalic papillae not observed. Cheilo and prorhabdions distinct; meso, meta, and telorhabdions fused, all

weakly sclerotized. The meso and metarhabdions bear a dorsal and subventral tooth.

Dorsal tooth typical of genus, subventral

variable in size and shape. A small tooth present at bottom of stoma, which is deeper than

wide. Esophagus typically diplogasteroid, with

isthmus and terminal bulb longer than corpus

87
III Wù

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D

,03 mm

I

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.04mm

^

Figure 54.—Mikoletzkya calligraphi n. sp.: ^. Head and neck; B, maie, tail; C. female, midbody; D. female, tail.

88
.01 mm

Figure 55.—Mikoletzkya cervicula Massey, 1966: A, Male; B, head.

89
îs\

\m

I :• -1;

mm

:iír..i!¡l-:í^"

:]\^'M

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D

Figure 56.—Mikoletzkya diluía Massey, 1966: A. Head and neck; B. head; C. male, tail; D. female, tail.

90
and median bulb combined. Nerve ring IV2 body

widths behind median bulb. Hemizonid opposite

nerve ring, excretory pore posterior to hemizonid. Ovaries paired, reflexed approximately

their entire length. Vagina a transverse slit

vulva v^ith protuberant lips. Tail conoid to a

sharp terminus.

Male: Testis single, reflexed at midbody filling entire body cavity. Spicules paired, ventrally arcuate, cephalated, relatively short and

stout, 23-31 /x in length. Gubernaculum 8-11 /x

in length. There are 8 pairs of preanal and

caudal papillae. Tail conoid to a spicate terminus.

Diagnosis.—Closely allied to M. pinícola;

differs in the sclerotization of the pharynx,

length of tail, and absence of discernible cephalic papillae.

Habitat.—Associated with Scolytus ventralis

in white fir and Dendroctomis pseudotsugae in

Douglas-fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 2-W.

Mikoletzkya inedia Massey, 1966 Figure 57

Female: 0.76-0.94 mm; a = 23-30; b=5-6.2;

c=12-14;V= 55%.

Male: 0.66-0.75 mm; a = 17-23; b = 4.5-5.3;

c=12.5-14.

Cuticle with fine longitudinal ridges extending the entire body length. Head with six small

papillae. Cheilorhabdions and prorhabdions

distinct, meso, meta, and telorhabdions fused.

Metarhabdions bearing a large dorsal clawlike

tooth and a subventral tooth as illustrated.

Stoma much deeper than wide. Amphids porelike, opening at base of lateral papillae.

Esophagus typically diplogasteroid. Isthmus

and terminal bulb longer than corpus and

median bulb combined. Nerve ring near middle

of isthmus. Excretory pore immediately anterior to initial swelling of terminal bulb, hemizonid immediately anterior to excretory pore.

Ovaries paired, at times reflexed to within a

body width of vulva. Vagina a transverse slit,

equidistant between terminal bulb and anal

opening. Lips of vulva protuberant. Tail conical, ending in a narrowly rounded terminus.

Male : Testis single, sometimes reflexed ; spicules paired, 38-45 /x in length, ventrally arcuate,

cephalated ; gubernaculum 15-18 /x long as figured. Eight pairs of preanal and caudal papillae. Tail conoid to a spicate terminus.

Diagnosis.—Closely related to M. pinícola

from which it differs in size, shape, and structure of gubernaculum.

Type habitat.—Associated with Ips sp. and

Dendroctonus ponderosae in ponderosa pine.

•. :;. r>^ Il II ,^ \- ••

'i^^JV^\

:• 1 ii

H'A -il

•• ■■;.!•-1<

:•. • /'-Il

n

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:r. II

Figure 57.—Mikoletzkya inedia Massey, 1966: A. Head

and neck; B, female, tail; C, male, tail.

91
Type locality,—Larimer County, Colorado.

Type specimens,—Collection No. 2-A (Holotype),2-K (Allotype).

Mikoletzkya laugcauda n. sp. Figure 58

Female: 0.77-0.81 mm; a = 15.5-18.5; b =

4.3-4.7; c=r5.7-6.1; ¥ = 51-52%.

Male: 0.63 mm; a = 27; b = 4.6; c = 8.3.

Body straight. Cylindroid. Cuticle with moderately fine transverse and longitudinal striations. Head broadly rounded with titlike papillae. Cheilo and prorhabdions distinct. Dorsal

meso, metarhabdion armed with a large tooth,

a pair of subventral teeth on the ventral metarhabdion. Corpus of esophagus strongly

muscled, slightly widened at base into a median

bulb. Basal bulb and isthmus somewhat shorter

than corpus and median bulb. Nerve ring at

midisthmus. Excretory pore immediately posterior to nerve ring. Cardia distinct. Lips of

vulva protuberant or continuous with body wall.

Vagina transverse. Ovaries paired, reflexed

past the vulval opening in some specimens.

Anus and rectum distinct. Phasmid obscure.

Tail conoid to an elongate acute terminus.

Male : Testis single, reñexed. Spicules paired,

37 IX in length, ventral arcuation extreme,

proximal end at ca right angles to distal end.

Gubernaculum as figured, the margins heavily

sclerotized. There are 7 pairs of caudal papillae,

2 pairs preanal ventrosubmedian, 1 pair immediately postanal ventrosubmedian, a group of

three at the point of terminal extension, 1 pair

dorsal and opposite the three terminal papillae.

Phasmid distinct. Tail conoid to an elongate

acute terminus.

Diagnosis,—Related to M, tornea. Differs in

structure of pharyngeal armature and in

coarseness of tail. M, langcauda is a generally

smaller species.

Type habitat,—Associated with Dryocoetes

confusus Sw. in corkbark fir, Abies lasiocarpa

var. arizonica (Merriam) Lemm.

Type locality.—Carson National Forest, New

Mexico.

Type speciniiens,—Collection No. 24-E (Holotype),28-U (Allotype).

Mikoletzkya pinicola (Thorne, 1935) Baker, 1962

Figure 59

Female: 1.3 mm; a = 25; b = 7.1; c = 15.1;

V = 51%.

Male: 1.1 mm; a = 31; b = 6.2; c = 15.1.

The following is Thome's original description: ''Body moderately slender, tapering anteriorly until width near lip region is about

one-half that at base of neck. Female tail convex-conoid to acute terminus, its length about

21/^ times anal body diameter. Male tail ventrally arcuate, convex-conoid with spicate terminus. Cuticle marked by fine transverse and

longitudinal striae. Longitudinal striae low,

obscure, about 44 at midbody, decreasing in

number toward the extremities. Viewed laterally, these longitudinal striae present double

rows of refractive, dotlike markings where they

cross the transverse striae. Lip region rounded,

with six forward-pointing, conical papillae.

Amphids appear as minute oval markings close

to the lateral papillae. Pharynx obscurely hexagonal from a face view; viewed laterally it

presents two distinct chambers bearing a central, massive, arcuate, dorsal tooth. Anterior

portion of esophagus four-fifths as long as

posterior but broader and more muscular.

Excretory pore a short distance posterior to

nerve ring. Intestine densely granular, its

lumen sinuous. Ovaries reflexed past vulva.

Vulva a transverse slit with protuberant labia.

''Male : Testis single, reflexed. Spicula yellow,

arcuate, slightly cephalated. Gubernaculum

thick proximally, with a thin troughlike distal

extension in which the spicula glide. Eight pair

of male caudal papillae.

''Diagnosis,—Diplogaster with the above

measurements. Longitudinal striae 44 at midbody, low, obscure, their presence indicated by

double rows of refractive dots. Tails of both

sexes less than 7% of body length. Six labial

papillae, forward-pointing, conical. Pharynx

divided into two chambers, armed with single,

massive, arcuate dorsal onchium. Female

amphidelphic, ovaries reflexed past vulva. Spicula arcuate, cephalated. Gubernaculum thick

proximally with thin troughlike distal extension. Eight pair of male caudal papillae."

Habitat,—Associated with Dendroctonus

ponderosae in lodgepole pine, Pinus contorta

Dougl.

92
.02 mm

03 mm

Figure 58.—Mikoletzkya langcauda n. sp.: A. Head and neck; B. head; C. female, tail; D. male, tail.

93
a

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o o

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Figure 59.—Mikoletzkya pinícola (Thorne, 1935) Baker, 1962: A. Head and neck; B, body cross section; C. cuticular pattern; D. head; E, male, tail; F. female, tail. (After Thorne, 1935).

Mikoletzkya pugnea Massey, 1971 Figure 60

Female: 0.68 mm; a = 25-26; b = 5.4-6.8; e =

11;V = 55%.

Male: 0.59-0.66 mm; a = 22-27; b = 4.7-5.6;

c = 9-ll.

Cuticle with moderately fine transverse and

longitudinal striations. Head rather broadly

rounded, with very small apical papillae.

Pharyngeal depth and width about equal.

Cheilo and prorhabdions distinct. Meso, meta,

and telorhabdions fused. Meso, metarhabdions

armed with a large subdorsal clawlike tooth;

a subventral tooth on the same structure nearly

meeting the subdorsal tooth at the middle of the

pharynx; ventral telorhabdion with a small

denticle. Esophagus typically diplogasteroid ;

corpus and median bulb as long as isthmus and

terminal bulb; lumen of isthmus and terminal

bulb very sinuous. Nerve ring located at anterior end of terminal bulb. Hemizonid not discernible. Excretory pore adjacent to posterior

94
-1 /

) I

\ I .03 mm

B

Figure 60.—Mikoletzkya pugnea Massey, 1971: A. Head and neck; B. female, tail; C. male, tail.

95
portion of terminal bulb. Cardia well developed.

Lumen of gut wide. Vulva with protuberant

lips. Vagina a transverse slit. Anus and rectum

conspicuous. Tail elongate conoid to a sharp

terminus.

Male: Testis single, with slight reflex. Spicules paired, cephalated, exceedingly arcuate,

distal end almost at right angles to proximal

end. Gubernaculum one-third as long as spicules, shaped as figured. Seven pairs of caudal

papillae, 2 pairs preanal ventrosubmedian, 4

pairs postanal ventrosubmedian, 1 pair subdorsal. Tail conoid to an acute terminus.

Diagnosis.—Closely related to M. ruminis

Massey, 1966; differs in the shape of the spicules and gubernaculum.

Type habitat.—Associated with Hylurgops

pinifex in red pine.

Type locality.—Hamden, Connecticut.

Type specimens.—Collection Nos. 24-P and

24-0.

Mikoletzkya ruminis Massey, 1966 Figure 61

Female: 1.13-1.18 mm; a = 22; b = 5.4-6;

c:=ll;V= 55%.

Male: 0.88-0.97 mm; a ==20-22; b = 5.0;

c = 12-14.

Cuticle with coarse longitudinal ridges extending from head to tail. In lateral view there

are 11 striations at midbody, each striation

appearing as a row of dots. Head broadly

rounded with six prominent apical papillae.

Amphids porelike, opening at the base of the

lateral papillae. Cheilo and prorhabdions distinct, coarse, the meso, meta, and telorhabdions

fused. There is a large dorsal clawlike tooth

developed by the meso and metarhabdions and

a large subventral tooth produced by the same

structure. Stoma 17 /x deep, 10 /x wide. Corpus

and median bulb of esophagus very muscular,

somewhat longer than isthmus and terminal

bulb. Nerve ring more than one body width

behind median bulb. Excretory pore not discernible. Amphidelphic, the ovaries reflexed

more than one-half their length. Vagina transverse. Vulva with slightly protuberant lips.

Tail conoid to a pointed terminus.

Male: Testis single, outstretched. Spicules

paired, ventrally arcuate, cephalated, 47-58 /x

in length. Gubernaculum expanded both distally and proximally as figured, the distal end

Figure 61.—Mikoletzkya ruminis Massey, 1966: A.

Head and neck; B. female, tail; C male, tail.

96
1/ 1/ ~-q ~-i^ I';=r':—- 'S:':—i

/:MÍÍ.i\

.^<

7^-^i

\ •••• \ .:• -r ^ ....

.01mm

V.'il

serving asa guide for spicules, 18-22 /x in

length.

Diagnosis,—Differs from other species of the

genus in shape and size of gubernaculum.

Type habitat,—Associated with Dendroctonus mfipennis in Engelmann spruce.

Type locality,—Type specimens collected on

Rabbit Ears Pass in Routt County, Colorado.

Other specimens have been taken from the

galleries of D, rufipennis in Engelmann spruce

near Libby, Montana.

Type specimens,—Collection No. 2-L.

Mikoletzkya tontea Massey, 1966 Figure 62

Female: 0.85-1.51 mm;a= 18-24;b= 4.3-5;

c= 4.3-6 ;V=: 48-50%.

Male : Unknov^n.

Cuticle v^ith fine longitudinal striations extending from the head to the tail. Head broadly

rounded v^ith six cephalic papillae, cheilo and

prorhabdions distinct, arranged as figured, v^ith

the prorhabdions overlapping the cheilorhabdions. Meso, meta, and telorhabdions fused, the

meso, metarhabdions armed v^itha large dorsal

clav^like tooth and v^itha large subventral clawlike tooth, the teeth crossing near the center of

the pharynx. Amphids porelike, minute openings at base of lateral lips. Stoma 10 /x in width,

12 /x in depth. Corpus and median bulb of

esophagus very muscular, their length exceeding that of the isthmus and terminal bulb.

Nerve ringa third ofa body width posterior to

the median bulb. Excretory pore two-thirds of a body width posterior to nerve ring. Amphidelphic, the ovaries reñexed nearly to vulva.

Lips of vulva slightly protuberant. Terminus

long, filiform.

Diagnosis,—Differs from other species of the

genus in the shape and length of tail, and in

the massive pharyngeal armature.

Type habitat,—Associated with Dendroctonus terebrans in loblolly pine.

Type locality,—Lake City, Florida.

Type specimens.—Collection No. 24.

Genus Mononchoides Rahm, 1928

Synonym : Eudiplogaster Paramonov, 1952.

Type species : Mononchoides longicaudus

Rahm, 1928.

Cuticle with prominent longitudinal striaFigure 62.—Mikoletzkya tornea Massey, 1966. A. Head

and neck; B, female, tail.

97
tions. Head rounded, papillated. Pharynx much

deeper than wide, separated by a large dorsal

clawlike tooth produced in the metastom and

protruding into the protostom, anterior portion

formed by cheilorhabdions and prorhabdions,

much wider than the posterior portion formed

by meso, meta, and telorhabdions which are

fused. At times a rasplike plate appears in

metastom. Amphids slightly posterior to lateral

cephalic papillae. Esophagus typically diplogasteroid. Amphidelphic. Vulva at midbody.

Testis single, sometimes reflexed. Spicules ventrally arcuate, cephalated. Gubernaculum variable in shape. Male with several pair of preanal

and caudal papillae. Bursa vestigial or absent.

There is considerable confusion as to the

systematic status of the genus Mononchoides.

The genus was established by Rahm (1928).

Subsequently it has been considered a synonym

of Diplogaster and of Eudiplogaster, In the

writer's opinion, Mononchoides is a valid genus,

and several species placed in the genus Eudiplogaster are rightfully members of the genus

Mononchoides.

Mononchoides adjunctus Massey, 1966 Figure 63

Female: 0.78-0.87 mm; a = 22-26; b = 5.9-

6.6; c = 2.9-3.9 ;V= 40-43%.

Male: 0.70 mm; a = 28; b = 5.5; c = 3.2.

Cuticle with moderately prominent transverse and longitudinal striations. Head broadly

rounded. Six lips, each with an apical papilla.

Lip ring with 16 longitudinal ridges, the

grooves broadened proximally. Stoma much

deeper than wide, with distinct cheilorhabdions

and prorhabdions. Cheilorhabdions overlap prorhabdions. Meso, meta, and telorhabdions

fused. Stoma divided into a wide anterior portion and a long posterior portion by a large,

subdorsal, clawlike tooth rising from the mesorhabdion. Procorpus of esophagus very muscular, widening into a distinct valvular median

bulb. Isthmus and terminal bulb two-thirds

length of procorpus and median bulb. Nerve

ring at middle of isthmus. Excretory pore onethird body width behind nerve ring. Hemizonid

immediately anterior to excretory pore. Ovaries

paired, each reflexed to vicinity of vulva. Lips

of vulva only slightly protuberant. Tail very

long, thread-like.

Male: Testis single, reflexed nearly 2 body

diameters. Spicules paired arcuate, cephalated.

Gubernaculum as illustrated. Viewed laterally,

with a broad, shallow hook at proximal end.

Seven pairs of caudal papillae, 6 ventrosubmedian, of which 2 are preanal, 4 postanal, and

1 pair subdorsal, situated at base of tail thread.

Phasmid plainly visible. Tail similar to that of

female.

Diagnosis.—Mononchoides adjunctus is

closely related to M. a7nericanus (Steiner,

1930), Chitwood and Chitwood, 1950, from

which it differs in location of caudal papillae,

nerve ring, and excretory pore, and in length

and proportions of tail.

Tijpe habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 43-A.

Genus Neodiplogaster Cobb, 1924

Synonym : Tylenchodon Fuchs, 1930.

Type species: Neodiplogaster trópica Cobb,

1924.

Head rounded, with prominent lip ring consisting of sclerotized ridges. Cheilo and prorhabdions obscure, dorsal meso-metarhabdions

bearing a clawlike tooth. Telorhabdions forming a long, narrow pharyngeal tube, with

knobbed to winglike sclerotized bases. Esophagus diplogasteroid. Amphidelphic. Vulva at or

near midbody. Female tail conoid to acute or

subacute terminus. Spicules paired, ventrally

arcuate, several pair of caudal papillae. Bursa

when present narrow and rudimentary. Tail

ventrally arcuate to a subacute terminus.

Neodiplogaster magulum n. sp. Figure 64

Female: 0.63-0.71 mm; a = 21.6-23.3; b =

4.90-5.82; c = 10.28-12.26; V = 52-56%.

Male: 0.76-0.80 mm; a = 26.0-30.2; b = 5.77-

6.04; c = 16.43-18.57.

Cylindroid. Cuticle with moderately coarse

transverse striae and very prominent longitudinal striae arranged in a series of 11 evenly

spaced lines at midbody. Lips rounded with

very small apical papillae obscure in many

specimens. Lip ring with 18 ridges. Cheilo and

prorhabdions obscure. Dorsal meso, metarhabdions bearing a large claw-like tooth. Subventral meso, metarhabdions appearing as a forward-pointing tooth. Telorhabdions forming a

long pharyngeal tube, with knoblike sclerotiza98
Figure 63.—Mononchoides adjunctus Massey, 1966. A, Female; B. male, tail; C, head.

99
Figure 64.—Neodiplogaster maguluni n. sp. ^. Head and neck; B. head; C. female, midbody; D. female, tail; E. male,

tail; F. spicule and gubernaculum.

tion at their bases. Esophagus diplogasteroid.

Nerve ring at midisthmus. Excretory pore

opposite terminal bulb. Lips of vulva protuberant. Vagina transverse with 2 heavily sclerotized processes at entrance to uterus. Ovaries

paired, reflexed at times 2-3 body widths past

vulva. Anus and rectum prominent. Tail conoid

to a subacute terminus.

Male: Testis single, reflexed, massive, filling

much of body cavity. Spicules paired, ventrally

arcuate, 44-46 /x long. Gubernaculum shaped as

figured, 17 fx in length. There are 9 pairs of

caudal papillae, 2 pairs preanal ventrosubmedian, 2 pairs postanal ventrosubmedian, a

series of 4 immediately anterior to terminus,

1 pair dorsal, immediately anterior to terminus.

Diagnosis.—Immediately distinguished from

N, pinicola by its distinctive cuticular pattern.

Type habitat—Associated with Dendroctonus terebrans in loblolly pine. It is probable

100
that this nematode is a true associate of Pissodes nemorensis Germ, which was extensively

associated with D. terebrans in the collection

area.

Type locality.—Nacogdoches, Texas.

Type specimens.—Collection Nos. 70-H, 70-1.

Genus Diplogasteroides deMan, 1912

Synonyms : Rhabditolaimus Fuchs, 1915

Rhabditidoides Rahm, 1928

Type species : Diplogasteroides spengelii

deMan, 1912.

Head with 6 lips. Stoma cylindrical consisting of a short cheilostom with distinct cheilorhabdions followed by a tubular protostom

formed by distinct prorhabdions. Meso, meta,

and telorhabdions fused forming a heavily sclerotized entrance to the esophagus. Dorsal meso,

metarhabdions usually bearing slender teeth,

ventral segments at times with small denticles

or teeth. Esophagus diplogasteroid. Ovary

single, prodelphic with or without a postuterine

sac. Tail usually elongate to filiform. Spicules

paired, ventrally arcuate, cephalated. Gubernaculum variable in form but usually keel

shaped. Several pair of caudal papillae. Bursa

rudimentary or absent.

Diplogasteroides bibrochus n. sp. Figure 65

Female: 0.71-0.80 mm; a = 18.8-21.1; b =

5.7-6.0; c = 7.1-7.8; V = 74-76%.

Male : 0.78 mm ; a = 22.2 ; b = 5.9 ; c=:9.2.

Body slightly ventrally arcuate. Cuticle with

fine transverse and longitudinal striations. Lips

rounded with inconspicuous papillae. Stoma

narrow, much longer than wide. Cheilorhabdions one-third length of prorhabdions. Dorsal

meso, metarhabdion with two slender teeth,

ventral segment with one ventral tooth immediately anterior to entrance of esophagus. Procorpus muscular, widening slightly into a

median bulb. Isthmus and basal bulb equal in

length to procorpus and median bulb. Nerve

ring immediately anterior to basal bulb. Hemizonid obscure. Excretory pore opposite basal

bulb. Cardia inconspicuous. Ovary single, reflexed at times approximately its entire length.

Oocytes in a portion of ovary arranged in 3

rows. Lips of vulva protuberant. Vagina transverse. Posterior uterine branch rudimentary.

Tail conoid to a filiform terminus.

Male: Testis single, reflexed. Spicules ventrally arcuate. Manubrium at right angles to

distal end, cephalated. Gubernaculum keel

shaped as figured. Eight pairs of caudal papillae, 2 pairs preanal ventrosubmedian, 5 pairs

postanal ventrosubmedian, 1 pair subdorsal,

all located as illustrated. Tail conoid, long,

slender, to a sharply rounded terminus.

Diagnosis.—Related to D. marshalli. Differs

in the number of teeth in the buccal cavity and

in conformation of tail in both sexes.

Type habitat.—Associated with Dendroctonus rufipennis in Engelmann spruce.

Type locality.—Mt. Taylor, New Mexico.

Type specimens.—Collection No. 30-J.

Diplogasteroides dimidius n. sp. Figure 66

Female: 0.55 mm; a = 22.7; b = 5.10; c = 5.5;

V = 71%.

Male: 0.52 mm; a = 26.2; b=:5.0; c = 7.15.

Cylindroid. Cuticle with very fine transverse

and longitudinal striations. Lips angular to

rounded without visible papillae. Cheilorhabdions short, one-fourth length of prorhabdions.

Meso, metarhabdions with 3 teeth, 1 dorsal, 1

subdorsal at junction of telorhabdion, 1 fine

tooth on ventral segment. Procorpus widening

only slightly to median bulb, muscular. Isthmus

widening to a narrow basal bulb. Nerve ring at

midisthmus. Excretory pore opposite posterior

end of basal bulb. Cardia conspicuous. Ovary

single, anterior reflexed. Lips of vulva slightly

protuberant. Vagina transverse. Posterior

uterine branch rudimentary. Anus and rectum

conspicuous. Tail conoid to filiform terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate, manubrium at approximate

right angles to distal end. Gubernaculum keelshaped, over one-third length of spicules. Seven

pairs of caudal papillae, 2 pairs preanal, 5 pairs

postanal, 1 pair of which are subdorsal. Tail

conoid to filiform terminus.

Diagnosis.—Related to Diplogasteroides picicola Rühm, 1956. Differs in number and placement of pharyngeal teeth, shape of spicules,

and much smaller size. D. dimidius has no

visible labial papillae and does not possess a

bursa.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 30-E.

101
mm

ta

mm

mi ?fr«l^ m'-\ vr-i^;;

-Mmkéf

ti

I:

Figure 65.—Diplogasteroides bibrochus n.

ing vulva; D, maie, tail.

Diplogasteroides ipini n. sp.

sp. ^. Head and neck; B. female, tail; C, portion of female body illustrâtFigure 67

Female: 0.70 mm; a = 21.2; b = 7.05; c = 6.35;

V = 72%.

Male: 0.69 mm; a = 23.2; b = 7.3; c = 7.7.

Body cylindroid. Cuticle with very fine transverse and longitudinal striations. Lips rounded

without visible papillae. Cheilorhabdions very

short, one-fifth length of prorhabdions. Meso,

metarhabdions bearing 3 teeth, 2 dorsal, 1 of

which is situated immediately anterior to entrance of esophagus. Procorpus and median

bulb longer than isthmus and basal bulb. Nerve

ring at midisthmus. Excretory pore not observed. Hemizonid opposite basal bulb. Cardia

prominent. Ovary single, reflexed at times to

vulva. Lips of vulva slightly protuberant. Vagina transverse. Posterior uterine branch

rudimentary. Anus and rectum conspicuous.

Tail conoid to filiform terminus.

Male : Testis single, reflexed. Spicules paired,

cephalated, ventral arcuation extreme as illustrated. Gubernaculum keel shaped, the proximal end with an acute sclerotized process.

There are 8 pairs of caudal papillae, 3 preanal

ventrosubmedian, 5 postanal, 4 ventrosubmedian, 1 pair subdorsal. Phasmid prominent.

102
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I

Figure 66.—Diplogasteroides dimidius n. sp. ^. Head and neck; B. portion of female body illustrating vulva; C.

male, tail; D. female tail.

103
Figure 67.—Diplogasteroides ipini n. sp. A. Head and neck; B, female, tail; C.

male, tail.

104
Tail conoid to filiform terminus. Bursa rudimentary.

Diagnosis.—Related to D, dimidius, varies in

shape of gubernaculum and in presence of a

rudimentary bursa.

Type habitat.—Associated with Ips pini in

red pine.

Type locality.—Caroline County, New York.

Type specimens.—Collection No. 30-O.

Diplogasteroides marshalli Massey, 1962 Emended

Figure 68

Female: 0.58-0.75 mm; a:=16; b = 5.8; c =

5.4;V = 67%.

Male: 0.58-0.85 mm; a = 16; b=:=5.2; c^7.4.

Body cylindroid. Cuticle with fine transverse

and longitudinal striae. Head rounded with

setose papillae. Stoma much deeper than wide.

Cheilorhabdions and prorhabdions distinct,

prorhabdions approximately 3 times the length

of cheilorhabdions. Dorsal meso, metarhabdions with denticle, a small tooth on ventral

segment near entrance to esophagus. Procorpus

widening slightly into median bulb, which is

indistinct in some specimens. Isthmus and basal

bulb longer than procorpus and median bulb.

Nerve ring slightly anterior to basal bulb.

Excretory pore opposite basal bulb. Cardia

distinct. Prodelphic, ovary reflexed threefourths its length. Oocytes in portions of ovary

arranged in 3 rows. Lips of vulva protuberant.

Vagina slightly oblique. Posterior uterine

branch rudimentary. Anus and rectum conspicuous. Tail conoid, elongate to a minutely

rounded terminus.

Male : Testis single, reflexed. Spicules paired,

cephalated, ventral arcuation extreme, manubrium at right angles to distal end. Gubernaculum keel shaped as illustrated, the distal end

curved, proximal end with sclerotized process.

Eight pairs of caudal papillae, 2 pairs preanal

ventrosubmedian, 5 pairs postanal ventrosubmedian, and 1 pair subdorsal. Tail ventrally

arcuate to spicate terminus.

Diagnosis.—D. marshalli is distinguished by

its nonfiliform tail, distinctive spicules and gubernaculum, and setose labial papillae.

Habitat.—Associated with Ips calligraphus

in ponderosa pine.

Type locality.—Bandelier National Monument, New Mexico.

Type specimens.—Collection No. 29-A.

Genus Dirhabdilainius Paramonov and Turlygina,

1955

Synonyms : Neodiplogasteroides (Rühm,

1956) Meyl, 1961

Diplogasteroides (Neodiplogasteroides) Rühm, 1956

Type species: Dirhabdilaimus pini (Fuchs,

1931) Paramonov and Turlygina, 1955.

Head with six lips, each with a fine or setose

papillae. Cheilorhabdions distinct, very short,

almost buttonlike. Pro and mesorhabdions

forming a very long cylindrical stoma. Metarhabdions forming entrance to esophagus, usually bearing teeth. Corpus of esophagus muscular, posterior portion usually expanded into

median bulb, isthmus muscular throughout

much of its length, terminal bulb nonvalvate.

Ovaries paired, reflexed. Female tail conical to

acute or subacute terminus. Spicules paired,

ventrally arcuate, cephalated. Several pair of

caudal papillae with or without a peloderan

bursa. Tail ventrally arcuate, short, usually

terminating in a short digitate tip.

Dirhabdilaimus nacogdochensis n. sp. Figure 69

Female: 1.12-1.17 mm; a =: 19-19.7; b = 5.9-

6.1;c = 12.9-13.9;V = 53%.

Male: 1.03-1.05 mm; a = 18.4-18.8; b = 5.9-

6.2;c = 22.1-24.1.

Body cylindroid. Cuticle with moderately fine

lateral and longitudinal striations. Amphids

porelike, opening laterally on lips. Lips rounded

with setose papillae. Cheilorhabdions short,

buttonlike. Pro and mesorhabdions fused,

forming an elongate stoma 34 ^ deep. Dorsal

and ventral metarhabdions with two prominent

teeth. Pharynx finely striated as figured.

Corpus of esophagus widened slightly into a

median bulb, corpus and median bulb nearly

one-third longer than isthmus and basal bulb.

Nerve ring at midisthmus. Excretory pore onethird body width posterior to basal bulb. Hemizonid only slightly posterior to basal bulb.

Cardia prominent. Lips of vulva protuberant.

Vagina short, transverse. Ovaries paired,

opposed and reflexed, each ovary may be reflexed several times in some specimens. Each

uterus containing 3-4 eggs in mature specimens. Anus and rectum conspicuous. Tail

conoid to a rather elongate, acute terminus.

Male : Testis single, reflexed. Spicules paired.

105
fe^^-^^-

Figure 68.—Diplogasteroides marshalli Massey, 1962 emended. A, Head and neck; B, male, tail; C. female, tail.

106
a'f:

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:. I

• i-..

/1.-

!:;/

r

Í/ il-, 11

II

m

Vt.U-

.03mm

A

M

.•:•=. y-ov- V • • ..-::•/.•.7;il

Figure 69.—Dirhabdilaimus nacogdochensis ii. sp. ^. Head and neck; B. maie, tail; C. female, tail; D, female,

mid body.

107
ventrally arcuate. Gubernaculum with proximal

end notched in lateral view, distal end heavily

sclerotized. Phasmid distinct. There are six

pair of caudal papillae, located as illustrated.

Tail ventrally arcuate to a very short subacute

terminus. Bursa not apparent in lateral view.

Diagnosis.—Differs from Dirhabdilaimiis

carolinensis Massey, 1967 by presence of striated pharynx.

Type habitat.—Associated with Dendroctonus terehrans in loblolly pine.

Type locality.—Nacogdoches, Texas.

Type specimens.—Collection No. 45-B.

Genus Rhabdontolainius (Fuchs, 1931) Filipjev and

Schuurmans Stekhoven, 1941

Synonyms : Rhabditolaimus (Rhabdontolaimus) Fuchs, 1931

Anchidiplogasteroides Paramonov and Turlygina, 1955

Type species: Rhabdontolaimus carinthiacus

(Fuchs, 1931) Filipjev and Schuurmans Stekhoven, 1941

Stoma about three times longer than wide.

Rhabdions heavily sclerotized. Dorsal metarhabdion with denticular ridges bearing varying number of teeth. Corpus of esophagus

muscular with a median bulb, basal bulb plus

isthmus usually shorter than corpus plus

median bulb. Vulva median, ovaries paired and

opposed. Female tail conoid to sharply rounded

or filiform terminus. Spicules paired, ventrally

arcuate.

Male: Tail ventrally arcuate to a spicate or

filiform terminus with 5 to 10 pairs of caudal

papillae with or without rudimentary leptoderan bursa.

Rhabdontolaimus adephagus n. sp. Figure 70

Female: 0.77-0.90 mm; a = 29.3-30.8; b =

5.5-6.4; c = 10.1-14;V = 51%.

Male: 0.70-0.79 mm; a = 29.8; b = 5.1-6.0;

c = 14.0-14.2.

Body cylindroid. Cuticle with fine transverse

striations, prominent longitudinal striations.

Lips distinct, rounded, with minute papillae.

Cheilorhabdions buttonlike, distinct. Prorhabdions slender. Metarhabdions bearing 5 slender

teeth, 3 dorsal, 2 subventral, only two visible in

lateral view. Corpus of esophagus slender,

median bulb conspicuous. Basal bulb slightly

wider than isthmus, corpus and median bulb

longer than isthmus and basal bulb. Nerve ring

at midisthmus. Hemizonid opposite nerve ring,

excretory pore immediately posterior to hemizonid. Cardia well developed. Lips of vulva at

times quite protuberant. Vagina very muscular,

transverse. Uteri serving as spermathecas.

Didelphic, oocytes in a double row for approximately one-half ovary length, then in single

row. Anus and rectum prominent. Tail conoid

to a sharply rounded, elongate terminus.

Male: Testis single, at times reflexed. Spicules paired, ventrally arcuate, manubrium

short. Gubernaculum as illustrated, the distal

end slightly hooked. There are 4 pairs of ventrosubmedian caudal papillae, 2 pairs preanal,

2 pairs postanal, 1 pair subdorsal, located as in

illustration. Tail ventrally arcuate, conoid to a

spicate terminus.

Diagnosis.—Related to Rhabdontolaimus

frontali n. sp. Differs in the coarseness of

pharyngeal teeth and rhabdions, and in shape

of gubernaculum.

Type habitat.—Associated with Dendroctonus frontalis in Virginia pine, Pinus virginiana

Mill.

Type locality.—Keysville, Virginia.

Type specimens.—Collection No. 60-B.

Rhabdontolaimus frontali n. sp. Figure 71

Female: 0.86 mm; a = 24.5; b = 5.8; c = 10.8;

V = 51%.

Male: 0.80 mm; a = 27.5; b = 6.25; c = 14.47.

Body cylindroid. Cuticle with faint transverse and longitudinal striae. Lips rounded,

flaplike with minute papillae. Cheilostom short,

cheilorhabdions buttonlike in lateral view. Protostom occupying fully half of buccal cavity,

ventral prorhabdion almost twice length of

dorsal prorhabdion. Meso, metarhabdions bearing teeth, 3 dorsal teeth rather long and

slender, 2 subventral teeth rather short and

stout. Corpus of esophagus muscular, procorpus

widening only slightly as it forms a median

bulb. Corpus and median bulb longer than

isthmus and basal bulb, basal bulb nonvalvate.

Nerve ring opposite anterior end of basal bulb.

Excretory pore passing through hemizonid and

located opposite basal bulb. Intestine thick

walled, cells with a single nucleus. Lips of vulva

protuberant. Vagina transverse. Ovaries at

times reflexed their entire length. Oocytes

108
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Figure 70.—Rhahdontolaitnus adephagus n. sp. A. Head and neck; B. female, midbody; C, female, tail; D,

male, tail.

109
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i»

li w. y

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B

.03mm

•••.•.•: : •!

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Figure 71.—Rhabdontolaimus frontali n. sp. ^4. Head and neck; B, female, midbody; C male, tail; D.

female, tail.

lio
arranged in double rows at their distal ends.

Uterus with valvelike processes at entrance to

vagina. Anus and rectum conspicuous. Tail

conoid to an elongate, acute terminus.

Male: Testis single, outstretched. Spicules

paired, ventrally arcuate, manubrium short,

rounded, anterior end open. Gubernaculum as

figured. There are 6 pairs of caudal papillae, 2

pairs preanal, 4 pairs postanal, all located as

illustrated. Tail ventrally arcuate, conoid to a

spicate terminus.

Diagnosis.—Related to Rhabdontolaimus

haslacheri (Fuchs, 1931) Paramonov and

Turlygina, 1955. Differs in pharyngeal conformation and in number and arrangement of

caudal papillae.

Type habitat.—Associated with Dendroctonus frontalis in loblolly pine.

Type locality.—Beaumont, Texas.

Type specimens.—Collection No. 60-A.

Rhabdontolaimus janae (Massey, 1962) n. comb.

Figure 72

Synonyms : Diplogasteroides janae Massey,

1962

Masseyus janae Paramonov, 1964

Female: 0.9-1.1 mm; a=20; b = 4; c = 8; V =

46%.

Male: 0.73mm; a=:21; b = 5; c = ll.

Body cylindroid. Cuticle with fine transverse

striations. Head broadly rounded with 6 papillate lips each with setose papillae. Stoma much

deeper than wide. Dorsal metarhabdion bearing

3 slender teeth, subventral segment with 2

small teeth near the entrance to esophagus.

Esophagus consisting of a muscular procorpus

widening into an ovoid median bulb. Isthmus

moderately slender, its length combined with

terminal bulb, shorter than procorpus and

median bulb. Nerve ring near middle of isthmus. Excretory pore adjacent to terminal bulb

and immediately posterior to hemizonid. Cardia

conspicuous. Lips of vulva protuberant, vagina

transverse. Didelphic, ovaries opposed and reñexed at times their entire length. Anus and

rectum prominent. Tail conoid to filiform terminus.

Male : Testis single, reflexed, at times nearly

reaching terminal bulb before reflexion. Spicules paired, ventrally arcuate, cephalated. Gubernaculum as figured. Seven pairs of caudal

papillae located as in illustration. Tail ventrally

arcuate, conoid to a spicate terminus.

Type habitat.—Associated with Ips calligraphus in longleaf pine, Pinus palustris Mill.

Type locality.—Olustee, Florida.

Type specimens.—Collection No. 30.

Massey, 1962 placed the species in the genus

Diplogasteroides. Paramonov, 1964, using only

Massey's illustrations and description, erected

a new genus, Masseyus. It is the author's opinion that the species rightfully belongs in the

genus Rhabdontolaimus.

Genus Panagrolaimus, Fuchs, 1930

Synonyms : Pseudorhabditis of Kreis, 1929

(nee Perroncito, 1880)

Asymmetricus Kreis, 1930

Type species: Panagrolaimus detritophagus

Fuchs, 1930.

Lips usually duplex, rarely amalgamated,

submedian usually asymmetrical. Cheilorhabdions and prorhabdions distinct. Meso, meta,

and telorhabdions fused and combined forming

entrance to esophagus, and at times bearing

teeth. Corpus of esophagus elongate, cylindrical, or spindle shaped, longer than isthmus and

valvate terminal bulb. Ovary single, reflexed to

vicinity of rectum. Tail variable in shape.

Testis single, spicules paired, ventrally arcuate.

Several pair of caudal papillae. Bursa absent.

Male terminus usually acute.

Panagrolaimus concolor Massey, 1964 Figure 73

Female : 0.86-0.90 mm ; a = 21 ; b = 4.3 ; c = 17 ;

V = 62%.

Male: 0.80 mm; a = 27; b = 4.7; c = 16.

Cuticle marked by fine transverse striae.

Lateral field marked by 2 parallel incisures

occupying one-eighth of body width. Lips distinct, roundly conical, each with a small forward-pointing papillae. Cheilostom short, prorhabdions over twice length of cheilorhabdions ;

meso, meta, and telorhabdions fused, joined

directly to lumen of esophagus. Corpus of

esophagus nearly one-third longer than isthmus

and terminal bulb combined; terminal bulb

ovate, valvate. Nerve ring located three-fourths

of a body width posterior to corpus. Excretory

pore one-half body width posterior to nerve

ring and at times passing through hemizonid.

Ovary typically panagrolaimoid, reflexed to

111
11.

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Figure 72.—Rhabdontolaimus janae (Massey, 1962) n. comb.: A. Head and neck; B. head, lateral view; C. head,

ventral view; D, female, tail; E, male, tail.

112
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MM

mm

Figure 73.—Panagrolaimus concolor Massey, 1964;

tail; E, male, tail.

A, Head and neck; B, head; C, female, midbody; D, female,

113
approximately 2 body widths anterior to anal

opening, postuterine branch short, approximately 1 body width in length. Lips of vulva

protuberant. Vagina transverse. Spermatozoa

located throughout the entire length of uterus.

Anal glands prominent. Terminus spicate,

acute.

Male: Testis reflexed approximately one

body width. Spicules paired, gubernaculum

characterized by the strongly sclerotized distal

end. Four pairs of ventrosubmedian caudal

papillae, 1 preanal, located three-fourths of a

body width anterior to the proximal end of the

spicules, 2 and 3 postanal, 1 pair postanal, subdorsal. Terminus acute.

Diagnosis.—Panagrolaimus concolor differs

from other species in the genus in the presence

of 2 lateral incisures, in location of excretory

pore, and in the strongly sclerotized distal portion of gubernaculum.

Type habitat.—Associated with Scolytus

ventralis in white fir, also with Dendroctonus

rufipennis in Engelmann spruce.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 10-T.

Panagrolaimus conophthori n. sp. Figure 74

Female: 0.96 mm; a = 27.3; b = 5.06; c = 16.4;

V = 57%.

Male: 0.95 mm; a = 29.4; b = 5.4; c = 18.0.

Body cylindroid. Cuticle with moderately fine

transverse and longitudinal striations, 4 lateral

incisures. Lips rounded, distinct, without papillae. Amphids conspicuous. Cheilorhabdions distinct, less than one-half length of prorhabdions.

Meso, meta, and telorhabdions fused. Dorsal

metarhabdion with a distinct tooth. Dorsal view

reveals two distinct denticles immediately posterior to prorhabdions, attachment indistinct

but probably occurring subdorsally on either

meso or metarhabdion. Esophagus panagrolaimoid, corpus with distinct valvelike apparatus

at midpoint of its length. Nerve ring at midisthmus. Excretory pore opposite nerve ring.

Cardia distinct. Lips of vulva protuberant,

vagina oblique. Ovary single, panagrolaimoid.

Posterior uterine branch slightly less than a

body width in length. Anus and rectum conspicuous. Anal glands well developed. Phasmid

prominent, located slightly anterior to terminus. Tail conoid to an acute terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate, velum well developed. Gubernaculum shaped as illustrated. There are 4

pairs of caudal papillae, 1 pair preanal ventrosubmedian, 2 pairs postanal ventrosubmedian,

1 pair dorsal, all located as figured. Tail conoid

to an acute terminus.

Diagnosis.—Related to Panagrolaimus concolor, but differs in the absence of visible

cephalic papillae, in number of lateral incisures, and in shape of spicules.

Type habitat.—Associated with Conophthorus coniperda Schwarz in the cones of

eastern white pine, Pinus strobus L.

Type locality.—Hamden, Connecticut.

Type specimens.—Collection No. 41-F.

Panagrolaimus leperisini n. sp. Figure 75

Female: 1.05 mm; a=:35.7; b = 5.17; c = 18.8;

V = 57%.

Male: 0.70 mm; a = 27; b = 4.4; c = 16.2.

Cylindroid. Cuticle with moderately coarse

transverse striae, fine, longitudinal striae, and

marked by 3 lateral incisures. Lips rounded,

papillate. Stoma 9-11 fx in depth. Cheilorhabdions distinct and somewhat shorter than the

conspicuous prorhabdions. Meso, meta, and

telorhabdions fused, meso, metarhabdions with

a prominent dorsal tooth. Anterior end of the

panagrolaimoid esophagus forming a collar

around the base of the prorhabdions. Corpus

longer than isthmus and basal bulb. Cardia

distinct. Nerve ring at midisthmus. Excretory

pore slightly posterior to nerve ring passing

through hemizonid. Lips of vulva protuberant.

Vagina short and slightly oblique. Ovary single,

reflexed, in some specimens reflexed twice.

Posterior uterine branch less than one-half

body width in length. Anus and rectum conspicuous. Anal glands prominent. Phasmid

distinct. Tail conoid to acute terminus.

Male: Testis single, reflexed one-third its

length. Spicules paired, ventrally arcuate,

cephalated, approximately 28 ^ in length. Gubernaculum as figured, less than one-half the

length of spicules. Five pairs of caudal papillae,

2 pairs preanal ventrosubmedian, 2 pairs postanal ventrosubmedian, 1 pair subdorsal, all

located as illustrated. Tail conoid to acute terminus.

Diagnosis.—Related to Panagrolaimus subelongatus (Cobb, 1914) Thorne, 1937, but dif114
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Figure 74.—Panagrolaimus conophthori n. sp.: A. Head and neck; B, head, lateral view; C. head, dorsal view; D,

female, midbody; E, female, tail; F. male, tail.

115
'.'••-ir?. !•.

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Figure 75. Panagrolaimus leperisini n. sp.: ^. Head and neck; B, head; C. female, midbody; D. female, tail;

male, tail.

116
fers in the more distinctive cheilo and prorhabdions and the presence of large tooth on

dorsal meso, metarhabdions. Also differs in

number of male caudal papillae.

Type habitat.—Associated with Leperisinus

aculeatîis in green ash, Fraxinus pennsylvanica

Marsh.

Type locality,—Chillicothe, Ohio.

Type specimens.—Collection No. 82-P.

Genus Neocephalobus (Steiner, 1929) Steiner, 1934

Synonym: Cephalobus (Neocephalobus)

Steiner, 1929

Type species : Neocephalobus aberrans

(Steiner, 1929) Steiner, 1934.

Lips broadly rounded with papillae. Stoma

divided into cheilostom with prominent cheilorhabdions and protostom with distinct prorhabdions, the dorsal prorhabdions forming a

platelike tooth which extends slightly into the

cheilostom. Esophagus consisting of a muscular

corpus widened at its base, a slender isthmus,

and a large valvate terminal bulb. Ovary single,

reflexed to vicinity of anal opening. Tail conoid

to an elongate, acute terminus. Testis single,

spicules paired, cephaloboid in structure. Gubernaculum usually linéate. Several pair of

caudal papillae with a single preanal ventrosubmedian papilla. Tail conoid to an elongate,

acute terminus as in female.

Neocephalobus judithae (Massey, 1964) n. comb.

Figure 76

Female: 0.75-0.78 mm; a = 17; b = 5; c = 8;

V = 58%.

Male: 0.64-0.70 mm; a=::20; b = 4.4; c = 13.

Cuticle with fine transverse striations. Lips

distinct, each with a minute apical papillae.

Depth of pharynx and width of head about

equaL Cheilostom about one-half the depth of

prostom, the cheilorhabdions distinct, convex

in lateral view ; meso, meta, and telostom fused,

joined directly to lumen of esophagus. Corpus

of esophagus equal in length to isthmus and

terminal bulb combined ; terminal bulb valvate.

Nerve ring at middle of isthmus. Excretory

pore adjacent to anterior end of terminal bulb,

passing through hemizonid. Ovary single, reñexed, its terminus extending beyond anal opening. Lips of vulva protuberant. Vagina oblique.

Uterus with stored sperm at anterior flexure.

Tail elongate, conoid; terminus subacute to

acute.

Male : Testis single, reflexed one to two body

widths. Spicules paired, cephalated, ventrally

arcuate. Gubernaculum one-third length of

spicules, linéate. Four pairs of caudal papillae,

1 preanal ventrosubmedian, 2 postanal ventrosubmedian, 1 pair subdorsal. Tail elongate,

terminus spicate, subacute to acute.

Diagnosis.—Related to N. aberrans (Steiner,

1929) Steiner, 1934. Differs in structure of

pharynx.

Habitat.—Associated with numerous bark

beetle species throughout the United States.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 10-R.

Genus Panagrodontus Thorne, 1935

Type species : Panagrodontus dentatus

Thorne, 1935.

Body cylindroid. Lip region rounded, continuous with neck contour. Lips three, duplex,

subventral being somewhat asymmetrical.

Amphids minute, cheilostom obscure, hexagonal in face view. Protostom triquestrious.

Dorsal mesorhabdion bearing a flat, plate-like

tooth. Corpus of esophagus cylindrical. Basal

bulb valvate. Ovary single, panagrolaimoid,

extending to vicinity of anal opening. Postuterine sac rudimentary. Tail conoid to spicate

terminus. Testis single, spicules paired, cephaloboid. Gubernaculum linéate. Several pair of

caudal papillae. Tail conoid to spicate terminus.

Panagrodontus dentatus Thorne, 1935 Figure 77

Thorne originally described the species as

follows :

Female: 0.6 mm; a==20; b = 5; c=:10; V =

59%.

Male : 0.6 mm ; a = 25 ; b = 5.5 ; c = 10.

''Body tapering both ways from near middle.

Tails of both sexes at first dorsally convexconoid, then convex, ending in a somewhat

spicate terminus which occupies one-third to

one-half of the total tail length. Transverse

striae moderately fine. Lateral field with three

obscure incisures, the area about one-eighth as

wide as body near the middle. Lip region

rounded, continuous with neck contour. Lips

three, duplex, the two subventral being some117
Figure 76.—Neocephalobus judithae (Massey, 1964) n. comb,

tail; C. face views; D, male, tail.

: A, Head and neck; B. female,

118
//Z7Öi^. %

Figure 77.—Panagrodontus dentatus Thorne, 1935: A. Male, tail; B. head; C face view; D. female, tail. (After

Thorne, 1935).

what asymmetrical. Amphids minute. Pharynx :

eheilostom obscure, hexagonal when seen in face

view; protostom triquestrious; dorsal mesorhabdion bearing a flat tooth-like plate about 2 /x

long opposed by a niche formed by the submedian mesorhabdions and metarhabdions. Esophagus: corpus cylindrical, at first almost filling

body cavity; isthmus about equal in length to

corpas ; bulb half as wide as neck with conspicuous ^^alvular apparatus. Intestinal walls at first

thin then gradually becoming much thicker

with a corresponding narrowing of the lumen.

Vulva a transverse slit with elevated labia.

Posterior uterine branch rudimentary, its

length equal to 1 or 2 body widths. Ovary extending forward, then reflexed and outstretched, the terminus reaching the rectum or,

frequently, extending into the tail. Average

size of eggs 20 />t x 50 fx, Testis single, the terminal portion reflexed. Spicula, gubernaculum,

and male caudal papillae as figured.

''Diagnosis.—Panagrodontus with above

measurements. Pharynx armed with a single

tootli located on the dorsal mesorhabdion. Tails

of sexes similar, at first dorsally convex-conoid,

then convex, ending in a somewhat spicate

terminus. Spicula, gubernaculum, and male

caudal papillae as figured.''

Habitat.—Associated with Dendroctonus

ponderosas in lodgepole pine.

Genus Plectonchus Fuchs, 1930 Emended

Type species : Plectonchus cunicularii Fuchs,

1930

Body cylindroid. Cuticle relatively thick, hyaline. Head rounded, lips with or without papillae. Pharynx very shallow. Cheilorhabdions

obscure. Prorhabdions most conspicuous, part

of stoma. Meso, meta, and telorhabdions flat,

horizontal, forming anterior entrance to esophagus. Corpus of esophagus cylindrical. Basal

bulb valvate. Vulva at approximately 70%.

Ovary single, reflexed, distal end anterior to

vulva. Postuterine sac absent. Tail conoid to a

thick narrowly rounded terminus. Testis single.

Spicules with slight ventral arcuation, bent

sharply at manubrium, short, thick, cephalated.

Gubernaculum grooved, more or less keelshaped with processes at proximal and distal

ends. Several pair of caudal papillae. Tail as in

female.

119
Plectonchus luolgos n. sp. Figure 78

Female: 0.57-0.60 mm; a = 20.4-24.4; b =

5.1-5.6; c = 9.7-11.3;V = 75%.

Male: 0.51-0.57 mm; a = 25.1-28.1; b = 4.2-

4.9;c = 9.8-12.3.

Cylindroid. Cuticle exceedingly thick, hyaline, without longitudinal or transverse striae.

Lips rounded with short hairlike papillae. Rhabdions fused, not distinguishable, forming a very

shallow stoma without visible teeth. Esophagus

panagrolaimoid with a cylindrical corpus,

width at base and anterior end essentially the

same, corpus longer than isthmus and basal

bulb combined. Nerve ring slightly posterior to

base of corpus. Excretory pore anterior to base

of corpus. Hemizonid not observed. Ovary

single, anterior to vulva, reflexed much of its

length. Lips of vulva protuberant. Vagina

slightly oblique. Postuterine branch absent.

Lips of anus usually protuberant. Rectum only

moderately conspicuous. Tail conoid to narrowly rounded terminus, constricted as figured.

Male : Testis single, reñexed. Spicules paired,

short, approximately 19 ¡m in length, cephalated,

ventrally arcuate, Gubernaculum as figured.

Tail conoid, ventrally arcuate. Terminus as in

female. There are 6 pairs of caudal papillae,

2 pairs preanal ventrosubmedian, 2 pairs postanal ventralsubmedian, 2 pairs dorsal submedian.

Diagnosis.—Differs from P. wyganti in the

presence of prominent cephalic papillae and in

the thickness of the cuticle. P. molgos is generally a smaller, stouter species.

Type habitat.—Associated with Hylurgops

subcostidatus (Mann.) in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 40-A.

Plectonchus wyganti Massey, 1964 Figure 79

Female: 0.7 mm; a = 30; b = 4.5; c = 11.5;

V = 77%.

Male : 0.6 mm ; a = 32 ; b = 4.6 ; c = 10.8.

Cuticle with very fine transverse striations.

Head consisting of 6 flattened lips each with an

apical papillae, obscure. Stoma very shallow.

Cheilorhabdions and prorhabdions forming the

stomatal chamber, evidently fused and not distinguishable ; meso, meta, and telorhabdions

fused, very lightly sclerotized. Esophagus

panagrolaimoid, the corpus equal in length to

isthmus and terminal bulb combined, slender,

tapering as it joins the isthmus; terminal bulb

ovate, valvate. Nerve ring encircling isthmus

well anterior to middle. Excretory pore one

body width anterior to the base of the corpus.

Ovary single, reflexed, laterally. Uterus containing sperms. Lips of vulva protuberant.

Distance between vulva and anus only slightly

greater than length of tail. Tail elongate, subacute.

Male: Testis reflexed, extending at times

nearly to esophageal bulb. Spicules paired,

cephalated, stout, ventrally arcuate. Gubernaculum two-thirds the length of the spicules,

7 pairs of ventrosubmedian caudal papillae (2

preanal, 5 postanal) and 2 pair subdorsal. Tail

elongate, conoid, terminus acute. Phasmids

prominent in both sexes.

Diagnosis.—Closely allied to P. cunicularii

Fuchs, 1930, but differs in pharyngeal and tail

characteristics and in the position of the excretory pore.

Type habitat.—Associated with Scolytus

ventralis in white fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 40.

Genus Panagroniacra Massey, 1964

Type species.—Panagromacra margaretae

Massey, 1964.

Head with 6 sclerotized forward-pointing

labial processes. Cheilorhabdions well developed, coarse. Meso, meta, and telorhabdions

distinct. Esophagus typically panagrolaimoid.

Ovary single, reflexed. Testis single, reflexed.

Spicules paired, cephalated. Gubernaculum distally bent, pronged, the prongs extending alongside the spicules. Several pairs of male caudal

papillae.

Diagnosis.—Immediately distinguished from

Panagrolaimus by the labial processes, the welldeveloped cheilorhabdions, and the distinctive

gubernaculum. The genus has affinities with

Macrolaimus in its pharyngeal characteristics.

Panagromacra margaretae Massey, 1964 Figure 80

Female: 1.55-1.77 mm; a = 32; b = 4.8-5.1;

c = 20-22 ;V= 58-60%.

Male: 1.26-1.64 mm; a=27-37; b=:4.4-5.3;

c = 20-24.

Cuticle with fine longitudinal and transverse

120
I

míiv^-:-l: m-

:im-^^^^

m mmmim

m

;#.••.

ff0M

.01mm

i;;::Sv.- \ \

,03 mm

^m' pi

iail

fcllll\

'pfeift] :j\^'; Mi .Ja.

mB. ryf^mif

I :.- ;••;; V-:-t ' -■■■";l ■■■,••.'

ifíl

Figure 78.—Plectonchus molgos n. sp.

tail; E, female, tail.

A. Head and neck; ß. head; C female, midbody; D. male,

121
"to mi!

Kill

maß pill mm

ijiSS

'mi ;-|:

:i:.!

':it!^>

//••fe.-••71 • -^.-rl--- I

.•;íI;-::.---Í-.~."^1\

ll:i;)rf-r:-.l.':-—g;-.!'

.01 m m

îlfil

^^^^li

m^

llfUî;

mmm

mi Wm

\\v. •;• i-.-,- I I • í

Figure 79.—Plectonchus wyganti Massey, 1964: A, Head and neck; B, head; C, female, midbody; D, maie, tail;

E. female, tail.

122
03 mm

; a' \i. 1.

Figure 80.—Panagromacra margaretae Massey, 1964:

body; D, female, tail; E, male, tail.

A, Head and neck; B. head; C, female, mid123
striations. Lateral area marked by 3 incisures

appearing as parallel bright lines along the

entire body length. Head slightly constricted

with 6 forward-pointing sclerotized labial processes appearing titlike in lateral view. Amphids

posterior to papillae. Cheilorhabdions and prohabdions strongly sclerotized, cheilorhabdions

nearly as long as prorhabdions, meso, meta, and

telorhabdions distinct, enveloped by anterior

end of esophagus. Esophagus panagrolaimoid,

the isthmus about one-half the length of the

corpus, terminal bulb valvate, cardia distinctive, as illustrated. Nerve ring near middle of

isthmus. Excretory pore slightly posterior to

nerve ring, at times passing through hemizonid

or immediately posterior to it. Ovary single,

reflexed, at times reaching vicinity of rectum.

Uterus as illustrated, with a spermatheca near

its anterior flexure. Vulva with protuberant

lips. Vagina oblique. Anal glands prominent.

Terminus acute.

Male: Testis reflexed. Spicules paired, ventrally arcuate. Gubernaculum distally pronged,

the prongs extending along either side of the

spicules as illustrated. Six pair of caudal papillie: 2 pair preanal ventrosubmedian, 2 postanal, 2 subdorsal, located as figured. Phasmid

conspicuous. Tail bluntly conoid to an acute

terminus.

Type habitat.—Associated with Scolytus ventralis in white fir. In addition, it is associated

with Dryocoetes confusus in subalpine fir. Dendroctonus adjunctus in ponderosa pine, and

Dendroctonus riifipennis in Engelmann spruce.

Type locality,—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specime7is.—Collection No. 39-B.

Genus Panagrobelus Thorne, 1939

Type species: Panagrobelus incisus Thorne,

1939.

Lips six, flaplike, inward-pointing with

strongly sclerotized borders. Cheilorhabdions

absent. Prorhabdions prominent. Meso, meta,

and telorhabdions fused with or without denticles. Esophagus panagrolaimoid. Ovary

single, reflexed to vicinity of anal opening.

Posterior uterine branch short or rudimentary.

Spicules ventrally arcuate, paired, cephalated.

Several pair of caudal papillae.

Panagrobelus phloeosini n. sp. Figure 81

Female: 0.65-0.76 mm; a = 18.6-23.7; b =

4.5-4.6 ; c = 23.7-24.8 ; V = 57-60 %.

Male: 0.52-0.65 mm; a = 25.4-27.7; b = 3.6-

4.2; c= 16.2-18.5.

Cylindroid. Cuticle with fine transverse striations, 3 lateral incisures visible from terminus

to anterior one-half of corpus of esophagus.

Lips flaplike and pointed inwards. Prorhabdions stout, forming distinctive part of stoma.

Meso, meta, and telorhabdions fused, meta,

telorhabdions with a subventral tooth. Esophagus panagrolaimoid. Corpus cylindrical, longer

than isthmus and basal bulb. Cardia conspicuous. Nerve ring at midisthmus. Excretory pore

opposite nerve ring and opening through hemizonid. Lips of vulva protuberant. Vagina

oblique. Ovary single, reflexed to within body

width of terminus. Oocytes arranged in double

row from distal end to within one and one-half

to two body widths of vulva, then in single row.

Nuclei of oocytes with large conspicuous nucleoli. Postuterine sac short, at times rudimentary.

Anus and rectum only moderately conspicuous. Tail bluntly conoid to an acute terminus.

Male: Testis single, reflexed one-third its

length. Spicules paired, ventrally arcuate,

cephalated, head distinctive and very heavily

sclerotized. Gubernaculum linéate, proximal

and distal end each with a pointed protrusion.

Tail slightly ventrally arcuate, conoid to an

acute terminus. There are 5 pairs of caudal

papillae, 2 pairs preanal ventrosubmedian, 2

pairs postanal ventrosubmedian, and 1 pair of

dorsosubmedian.

Diagnosis.—Related to P. scolyti Massey,

1964. Differs in number of lateral incisures, in

shape of spicules and gubernaculum, and in

presence of subventral tooth on meta-telorhabdion.

Type habitat.—Associated with Phloeosinus

dentatus (Say) in eastern redcedar, Juniperus

virginiana L.

Type locality.—Keysville, Virginia.

Type specimens.—Collection No. 41-D.

Panagrobelus scolyti Massey, 1964 Figure 82

Female: 0.7-0.8 mm; a = 23; b=:4.7; c=22;

V = 62%.

Male: 0.75 mm; a=:20; b=:4.2; c = 17.

Cuticle with fine transverse and longitudinal

striations. Lateral area marked by 2 incisures.

124
•:-|--;,í--.-.!:.v-./íitíir;

.02 mm

Il .•'"•. .'•.•••X- — I / ï:r- . <:«>>M •. I

03mm

t-' ••••;"!':":'^o|?57- •• ' ' • /

//:.• •••. •• /-•.. I 1-1 ••:.//

Figure 81.—Panagrobelus phloeosini n. sp.

£. maie, tail.

^. Head neck; female female, tail;

125
Head with 6 flaplike lips pointing inward.

Cheilorhabdions not distinct from prorhabdions, meso, meta, and telorhabdions fused,

joined directly to lumen of esophagus. Esophagus panagrolaimoid, isthmus and terminal bulb

somewhat shorter than corpus. Nerve ring at

middle of isthmus. Excretory pore adjacent to

anterior end of terminal bulb. Hemizonid immediately anterior to or surrounding excretory

pore. Ovary single, reflexed nearly to rectum.

Lips of vulva protuberant. Vagina oblique.

Postuterine sac rudimentary. Anal glands

prominent. Tail convex-conoid to acute terminus.

Male : Testis reflexed. Spicules paired, cephalated. Gubernaculum one-third the length of

spicules, shaped as figured. Three to five pairs

of ventrosubmedian caudal papillae and 1 pair

subdorsal. Tail conoid to an acute terminus.

Diagnosis,—Closely related to Panagrobelus

incisus Thorne, 1939, differs from that species

in size and in the number and arrangement of

the caudal papillae. Rühm (1956) made P.

incisus a synonym of P. coronatus (Fuchs,

1930). In the writer's opinion, P. incisvs is a

valid species, because of its size and arrangement of the male caudal papillae. P. scolyti

Massey, 1964 is distinct from P. coronatus

(Fuchs, 1930) Thorne, 1939, in size and number and arrangement of male caudal papillae.

Type habitat.—Associated with Scolytus

ventralis in white fir. In addition, it was found

associated with Dendroctonus adjunctus in

ponderosa pine, Scolytus multistriatus in

American elm, and with Leperisinus aculeatus

in green ash. It is one of the few nematode

species associated with bark beetles in both

coniferous and hardwood trees.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 41.

Genus Panagrellus Thorne, 1938

Synonym : Turbator Goodey, 1943.

Type species: Panagrellus pycnus Thorne,

1938.

Lip region narrow, low, rounded. Amphid

apertures minute, porelike. Pharynx panagrolaimoid. Cheilostom broad, symmetrical followed by shallow triquestrious protostom with

much heavier refractive walls. Meso, meta,

telostom fused and connecting directly with

lumen of esophagus. Esophagus panagrolaimoid. Corpus broadly cylindrical. Terminal

bulb with conspicuous valvular apparatus.

Ovary single, reflexed to vicinity of anal opening with or without postuterine sac.

Male : Testis single. Spicules elongate, linear,

ventrally arcuate usually with striking cephalation and furcate terminus. Gubernaculum

variable in shape, usually linéate. Several pairs

of caudal papillae. Tails in both sexes elongate,

acute.

Panagrellus leperisini n, sp. Figure 83

Female: 0.82-0.97 mm; a = 22.3-24.8; b =

5.6-5.8; c = 6.9-8.2; ¥ = 66-69%.

Male: 0.74-0.92 mm; a = 22-25; b = 6.0-6.3;

c = 8.2-8.4.

Cylindroid. Cuticle with very fine longitudinal and transverse striae, 4 lateral incisures,

the outside incisures more heavily sclerotized

than the inside. Lips rounded, each with a fine

setose apical papillae. Stoma shallow, rhabdions

only moderately sclerotized, cheilorhabdions

composing two-thirds of stoma, one-third composed of prorhabdions, meso, meta, and telorhabdions all more or less fused. Dorsal prorhabdion produced into short, blunt tooth,

dorsal meso, metarhabdion forming a flat toothlike projection. Esophagus panagrolaimoid.

Isthmus relatively short in some specimens, the

transition zone between corpus and isthmus indistinct. Nerve ring surrounding isthmus. Excretory pore opposite nerve ring. Hemizonid

opposite basal bulb. Cardia short but distinct.

Lips of vulva protuberant. Vagina oblique.

Ovary single, reflexed at times past the anal

opening. Mature specimens with larvae in

uterus. Posterior uterine branch up to 3 body

widths in length. Anus and rectum conspicuous. Tail conoid to an elongate, acute terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate with a hammer-shaped head

and a furcate terminus, velum distinct, extending from head to terminus. Tail ventrally arcuate, conoid to a long slender, acute terminus.

Phasmid conspicuous. There are 6 pairs of

caudal papillae, 2 preanal, 2 postanal, 2 subdorsal, all located as illustrated.

Diagnosis.—Related to P. pycnus, differs in

structure of stoma.

Type habitat.—Associated with Leperisinus

californicus Sw. in green ash.

126
pli!

líífslll:.-:;:!:!;

hmmâ

rÊâ te;-

:...Lr.:;'. -I

^•/^••;:'y^ V^i^- l/f^-ilv^.;^.\/i

|:*'^.^:¿¿J'>r^.:r."^V .

.02 mm

Figure 82.—Panagrobelus scolyti Massey, 1964: A,

tail; E. maie, tail.

Head and neck; B, head; C, female, midbody; D, female,

127
" ' 5)>H -^ V'--

.iMh: val

/

1^

.\iv.

mm -^

Figure 83.-

tail.

-Panagrellus leperisini n. sp.: A, Head and neck; ß. female, midbody; C. male, tail; D, head; E, female.

Type locality.—Rugby, North Dakota.

Type specimens.—Collection No. 87-A.

Genus Teratocephalus deMan, 1876

Synonym : Mitrephorus Linstrow, 1877.

Type species : Teratocephalus terrestris

(Bütschli, 1873) deMan, 1876.

Cuticle strongly annulated from head to

terminus. Lips flaplike, their perimeters

heavily sclerotized. Amphids porelike and located laterally at base of pharynx. Pharynx

with distinct cheilostom and protostom, rhabdions distinct. Meso, meta, and telorhabdions

forming entrance to esophagus. Anterior part

of esophagus cylindrical, hardly narrowing at

isthmus. Ovaries single, prodelphic. Tail very

elongate to an acute terminus. Spicules paired,

cephalated with or without gubernaculum.

Several pairs of caudal papillae.

Teratocephalus angustus n. sp. Figure 84

Female: 0.41 mm; a ==27.6-28.8; b = 3.8; c =

4.8-5.6; V = 50-52%.

Male : Unknown.

Slender, cylindroid. Cuticle coarsely annulated. Annules interrupted by 2 lateral inci128
:;-l

.02mm

:•.V:^:ííW:I^V■■•V.>]^•v•:l^' ..

Figure 84.—Teratocephalus angustus n.

cuticular pattern.

sp. A. Head and neck; B. head; C. female, midbody; D. female, tail; E.

129
sures. Lips flaplike, their perimeters heavily

sclerotized especially when viewed under phase

contrast illumination. Amphids porelike, their

openings heavily sclerotized and occurring

laterally at level of base of pharynx. Cheilostom and protostom distinct and of equal size.

Rhabdions distinct. Meso, meta, and telorhabdions fused and forming entrance to esophagus.

Esophagus cylindroid, transition between corpus and isthmus obscure, terminal bulb oblong,

valvate. Nerve ring 2 body widths anterior to

terminal bulb. Lips of vulva continuous with

body wall, obscure. Vagina obscure. Ovary

single, short, anterior. Postvulval sac absent.

Anus and rectum obscure. Tail conoid, very

long to an acute terminus.

Diagnosis,—Related to T, terrestris varies in

its distinctive amphid apertures and its

pharyngeal characters.

Type habitat.—Associated with Leperisinus

aculeatus in green ash.

Type locality.—Chillicothe, Ohio.

Type specimens.—Collection No. 88.

Genus Geraldius Sanwal, 1971

Synonym : Chambersiella bakeri Sanwal,

1957.

Type species: Geraldius bakeri Sanwal, 1971.

Cuticle finely striated, with lateral incisures ;

lip region with 6 cephalic cirri and 6 large

papillae ; anterior-most rhabdions of stoma distinct from the rest and modified to form hooklike structures; posterior part of stoma forming a long, narrow, vaselike channel surrounded

by esophageal tissue; amphids opening behind

anterior broad chamber of stoma; esophagus

without median bulb but with a valvulated

terminal bulb ; ovaries 2, opposed and reflexed ;

vulva median; testis single; male tail with

several pair of caudal papillae ; spicules paired

and not joined; gubernaculum present; tail of

each sex with a dorsally-hooked terminus.

Diagnosis.—The genus Geraldius is closely

related to Chambersiella, Santafea, and Diastolaimus. It differs from Chambersiella in

having 2 ovaries and from Santafea and Diastolaimus in having well-developed cephalic

cirri.

Geraldius bakeri (Sanwal, 1957) Sanwal, 1971

Figure 85

Female: 0.8-1.3 mm; a = 20-26; b=:3.5-5.6;

c = 7.8-10 ;V=: 49.6-53%.

Male: 1.04-1.37 mm; a=21-35; b = 4.3-5.9;

c = 10.4-ll.

Body gradually attenuated toward both ends.

Cuticle very finely striated and bearing two

lateral incisures. Head not marked off from

rest of body and without distinct lips. Cuticle

of lip region with six branched cirri. Six large

labial papillae on the head, one at base of each

cephalic cirri. Amphids opening through elliptical aperture behind main chamber of stoma.

Stoma broad, the walls heavily sclerotized and

divided into 3 regions, anterior, middle, and

posterior. Esophagus with cylindrical corpus

and without median bulb. Narrow isthmus

swelling into a terminal valvate bulb. Cardia

well developed. Nerve ring at midisthmus. Excretory pore at level of nerve ring. Ovaries

paired and reflexed, tips at times crossing each

other. Oocytes arranged in single file. Two uteri

running parallel to reflexed ovaries. Lips of

vulva protuberant. Vagina transverse, short.

Tail conoid to a dorsally hooked terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate, cephalated, 45 to 52 fx in

length. Gubernaculum roughly keel shaped.

Caudal papillae vary from 12-15 pairs, both

dorsal and ventral. Tail and terminus as in

female.

Habitat.—This species has been recovered in

association with Leperisinus aculeatus and

Phloeosinus dentatus in green ash and eastern

redcedar. Collections were made in the vicinity

of Chillicothe, Ohio, and Keysville, Virginia.

It was also found associated with Chramesus

hicoriae Lee. in pignut hickory, Carya glabra

(Mill.) Sweet, at the Ohio location.

Genus Santafea Massey, 1963

Type species: Santafea croca Massey, 1963.

Cuticle finely striate. Six prominent cephalic

papillae. Stoma similar to Chambersiella;

cheilorhabdions and protorhabdions distinct,

the meso, meta, and telorhabdions fused into a

glottoid apparatus which extends well back into

the procorpus of the esophagus. Amphids opposite telostom. Corpus of the esophagus without

130
Figure 85—Geraldius hakeri (Sanwal, 1957) Sanwal, 1971: A, Head and neck; B, head; C, female, midbody; D.

female, tail; E. male, tail.

131
a bulb but set oflf by a slight swelling at its

base; the isthmus expanding to a valvate terminal bulb. Ovaries paired; vulva at midbody.

Testis single, spicules paired, gubernaculum

present. Male tail with several pairs of caudal

papillae. Tails of both sexes with a hooked

terminus.

Diagyiosis.—Santafea is immediately distinguished from Chambersiella by the absence

of the cephalic cirri or hairlike setae and by the

presence of 2 ovaries.

Santafea damalis Massey, 1966 Figure 87

Santafea croca Massey, 1963 Figure 86

Female: 1.4-1.6 mm; a = 32; b = 6; c = ll;

V = 54%.

Male: 1.2-1.5 mm; a = 35; b = 7; c = ll.

Cuticle with very fine transverse striae and

2 lateral incisures. Body widest at the middle,

tapering to a moderately broadly rounded head

and a slender hooked terminus. Head with a

circlet of 6 prominent papillae. Stoma much

deeper than wide, consisting of a well defined

cheilostom and protostom, the cheilorhabdions

forming part of the cephalic arch. Meso, meta,

and telorhabdions fused to form the telostom

which extends well back into procorpus of

esophagus. Amphids opening opposite anterior

third of telostom. Esophagus with a cylindrical

procorpus and corpus, without a median bulb,

the isthmus expanding into a valvate terminal

bulb. Nerve ring at middle of isthmus. Excretory pore slightly anterior to terminal bulb.

Amphidelphic ovaries at times with reflexed

termini, oocytes arranged in tandem. Vulva at

midbody, lips protuberant, vagina transverse.

Anal opening very prominent; rectal glands

present. Terminus dorsally hooked as figured.

Male: Testis single, reflexed. Rectal glands

present. Spicules paired, gubernaculum present. Terminus hooked. There are 13 pairs of

caudal papillae, 4 pairs subventral and preanal,

1 pair lateral preanal, 1 pair postanal and

lateral, 4 pairs postanal subventral, 3 pairs

postanal and subdorsal.

Type habitat.—Associated with Scolytus

ventralis in white fir. Also collected in association with Phloeosinus neomexicanus Blkm.

in Utah juniper, Juniperus osteosperma

(Torr.) Little, in central New Mexico.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 38-B.

Female: 1.09-1.15 mm; a = 36-41; b = 4.8-

5.2;c = ll-14;V= 51%.

Male: 1.23-1.40 mm; a = 44-50; b = 5.0-5.8;

c = 13-14.5.

Cuticle with moderately fine transverse striations, marked by 2 lateral incisures. Head without distinct lips, but bearing 6 prominent, hornlike setae. Stoma 2 times deeper than wide.

Cheilostom 11/4 times depth of protostom;

cheilorhabdions and prorhabdions distinct.

Meso, meta, and telorhabdions fused into a

glottoid apparatus which extends well back

into procorpus of esophagus. Amphids opposite

base of telostom, I14 body widths from anterior

end. Esophagus with a cylindrical corpus and

procorpus without a median bulb, the isthmus

joining a valvate terminal bulb. Nerve ring at

middle of isthmus. Excretory pore slightly

anterior to nerve ring. Ovaries paired, at times

reflexed well beyond vulval opening, in some

specimens reflexed more than once. Lips of

vulva protuberant. Vagina transverse. Terminus dorsally hooked.

Male: Testis single, reflexed in some specimens. Spicules paired arcuate, cephalated. Gubernaculum slightly less than one-half length of

spicules. Ten pairs of caudal papillae: 4 pairs

preanal subventral, 6 pairs postanal, of which

4 pairs are subventral and 2 subdorsal, all situated as illustrated. Terminus dorsally hooked.

Diagnosis.—S. damalis differs from S. croca

Massey, 1963 in the larger size of the cephalic

papillae, the location of the amphidial openings,

and shape of gubernaculum.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine. Also found

with other bark beetle species, see list.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 38-M.

Genus Macrolaiinus Maupas, 1900

Type species: Macrolaimus crucis Maupas,

1900.

Head broadly rounded, continuous with body

contour, bearing 6 hornlike papillae. Lips arching over buccal cavity. Pharynx divided into a

broad cheilostom and protostom. Cheilorhabdions and prorhabdions prominent. Meso, meta,

and telorhabdions fused, obscure. Corpus of

esophagus cylindroid, isthmus narrow to the

132
.05mm

/ V'^ 1

v-\ \

II // Ki'i /; : ~ !

// i'--l' II ; 1.

A ,-'\ i «• •" 1

// \

• 1 1,1

^/" ^,!.. M ^^ V \t , ;•

.V y 1

Figure 86.—Santafea croca Massey, 1963: A, Head and neck; B. head; C. face views; D, maie, tail; E. female,

midbody; F, female, tail; G. amphid structure.

133
Figure 87.—Santafea damalis Massey, 1966: À, Female; B. male, tail; C, head.

134
valvate terminal bulb. Ovary single, reflexed,

panagrolaimoid with or without postvulval sac.

Tail conoid to a small acute terminus which

may or may not be hooked. Male tail usually as

in female. Testis single. Spicules paired, ventrally arcuate, cephalated. Gubernaculum variable in shape. Several pairs of caudal papillae.

Macrolaitnus taurus Thorne, 1937 Figure 89

Macrolaitnus canadensis Sanwal, 1960 Figure 88

Female: 0.99-1.2 mm; a = 34-36.6; b = 4.5-

4.9 ; C-: 13.5-14.8 ;V== 55-57%.

Male: 0.95-1.07 mm; a = 38.8-43; b = 4.2-

4.7; c = 16.7-19.8.

Body narrowing abruptly behind vulva. Cuticle with fine transverse striations, two lateral

incisuies. Head continuous with body contour.

Lips ¿irched over mouth cavity. Six hornlike

cephalic papillae. Buccal cavity spacious, divided into cheilostom and protostom. Cheilorhabdions and prorhabdions heavily sclerotized.

Meso, meta, and telostom fused, obscure.

Esophagus enveloping bases of prorhabions.

Procorpus and corpus blended, almost cylindrical ; no median esophageal bulb, isthmus narrow

and broadening into a valvate terminal bulb.

Cardia well developed. Nerve ring immediately

posterior to corpus. Excretory pore a body

width posterior to nerve ring, hemizonid immediately posterior to excretory pore. Lips of

vulva protuberant, anterior lip most prominent.

Vaginii oblique. Ovary single, reflexed extending to within a few body widths of anal opening. L terus distended to serve as a spermatheca. Postvulval uterine sac three-fourths body

width in length. Anus and rectum conspicuous.

Tail conoid to a small curved, acute terminus.

Male : Testis single, reflexed. Spicules paired,

ventrally arcuate with a small thornlike ventral spine. Gubernaculum large, pyramidshaped with a sclerotized process at each end.

Caudal papillae variable in number. Sanwal

lists 8 pairs, the author's specimens had only

6, as ligured. Tail ventrally arcuate, conoid to

a curved acute terminus.

Habitat,—Widespread throughout the western United States. The bark beetles with which

this s])ecies was associated are indexed in the

list of species.

Female: 1.3 mm; a==30; b = 5.9; c = 18;

V = 60%.

Male : 1.1 mm; a = 30 ; b = 5.8; c = 21.

Cuticle with moderately coarse transverse

striations, marked by 2 lateral incisures. Head

broadly rounded with 6 hornlike papillae. Lips

arched over buccal cavity. Cheilorhabdions and

prorhabdions heavily sclerotized. Cheilorhabdions hooklike in lateral view. Meso, meta, and

telorhabdions funneling into esophagus, lightly

sclerotized but distinct. Corpus of esophagus

cylindroid, isthmus narrow, widening into an

oval, valvate, muscular terminal bulb. Cardia

prominent. Nerve ring at midisthmus. Excretory pore slightly posterior to nerve ring. Lips

of vulva protuberant. Vagina slightly oblique.

Ovary single, panagrolaimoid. Postuterine

vulval sac approximately a body width in

length. Anus and rectum conspicuous. Phasmid

prominent. Tail conoid to a straight subacute

terminus.

Male: Testis single. Spicules paired, ventrally arcuate, cephalated. Gubernaculum

roughly keel shaped with a heavily sclerotized

distal end. There are 5 pairs of caudal papillae,

2 preanal, 3 postanal, 2 of which are subventral, 1 subdorsal. Male tail ventrally arcuate,

conoid to a subacute terminus.

Habitat.—Collected by Thorne in association

with Ips confusus Lee. in pinyon near Tabiona,

Utah. Specimens were also taken from green

ash at Rugby, North Dakota, where they were

associated with Leperisinus californicus.

Tylenchoidea (Örley, 1880) Chitwood and

Chitwood, 1937

Tylenchidae Örley, 1880

Tylenchinae (Örley, 1880) Marcinowski,

1909

Aglenchus (Andrassy, 1954) Meyl,

1961

A. exiguus Massey, 1969

Sychnotylenchinae ( Paramonov, 1967 )

Golden, 1971

Neoditylenchus Meyl, 1961

N. cornicidatits n. sp.

N, dendroctoni n. sp.

N. glandarius n. sp.

N. ovaritis n. sp.

135
Figure 88.—Macrolaimus canadensis Sanwal, 1960: A. Female; B. head; C. male, tail.

136
Figure 89—Macrolaimus taurus Thorne, 1937: A, Head and neck; B. head;

C. female, mîdbody; D. female tails show phasmids; E, male, tail; F. female,

tail.

137
A^. pinophilus (Thorne, 1935) J. anterior to terminus. Head slightly offset. Lips

B. Goodey, 1963 only faintly discernible in lateral view. Stylet

N. puniwopus Massey, 1969 slender with prominent basal knobs. Esophagus

A^. yasinskii Massey, 1969 with valvate metacorpus, the procorpus and

Sychnotylenchus Rühm, 1956 metacorpus equal in length to isthmus and

S, mutici n. sp. terminal bulb. Excretory pore prominent, adS. phloeosini Massey, 1969 jacent to center of terminal bulb of esophagus.

S. scolyti Massey, 1969 Nerve ring at middle of isthmus. Ovary single,

Ditylenchinae Golden, 1971 outstretched, very short in mature specimens ;

Pseudhalenchus Tarjan, 1958 postuterine branch short, one-half body width

P. damnatus Massey, 1966 in length. Vagina transverse. Lips covered by

vulval flap. Anal opening not discernible. Tail

Genus Aglenchus (Andrassy, 1954) Meyl, 1961 elongate, terminUS aCUte.

Synonym: Tylenchus (Aglenchus) Andrassy, Male: With general body characters of fe1954 male. Testis single, outstretched. Spicules

Type species: Aglenchus agrícola (deMan, typically tylenchoid. Gubernaculum and bursa

1884) Mevl 1961 ^^ figured. Tail elongate, terminus acute.

In general a small nematode (0.3-0.9 mm). , ^'Ti^'^'^V.^^^^^^^ to Aglenchus

Head well offset. Cuticle very markedly annu- bryaphüus (Sterner, 1914) Meyl, 1961; varies

lated. Stylet strong, with well developed knobs. I? ^^^, ^^^P^f ""{^^^ ^P^^.^f« ^^? gubernaculum.

Median bulb well rounded. Vagina muscular. ^^^^^^ ^^^J^^^î discernible anal opening.

Postuterine vulval sac present. Tail in both ^^^^ habitat-Taken from base of Engelsexes long and slender. Spicules paired, tylen- ^^^^. 7 ^^ ^^í^^«.*^^ ^^^^ Dendroctonus rufichoid. Gubernaculum small, linéate. Bursa ^^ \ T^^^ ^i!?!^;^ i xi ^/r •

leptoderan ^^^^ locality.—Wi. Taylor, New Mexico.

Type specimens.—Collection No. 49-A.

Aglenchus exiguus Massey, 1969 Figure 90 ^^^^^ Neoditylenchus Meyl, 1961

9 ^^-alV ^'^^ "^""^ a = 19.7; b = 4.6-4.9; c= ^y^^ ^p^^j^^. neoditylenchus dendrophilus

• ^ v^-^47o. (Marcinowski, 1909) Meyl, 1961

Male: 0.31-0.34 mm; a = 24.3-25; b = 4.6; c= Cephalic framework sclerotized. Stylet with

^-' • or without knobs or basal swellings. Esophagus

Body slender, ending in an elongate tail. with muscular valvate metacorpus and distinct

Cuticle coarsely annulated, the annules widest basal bulb. Ovary single; oocytes arranged in

at midbody and interrupted by very prominent from one to several rows. Well developed postlateral fields formed by two bright lines. Lat- uterine sac. Vulva at approximately 90%.

eral fields extending from two body widths Spicules and gubernaculum tylenchoid. Bursa

posterior to anterior end to eight body widths enveloping tail.

Key to species of Neoditylenchus in United States

1. Metacorpus of esophagus with valve plates

in anterior one-half 2

Metacorpus of esophagus with valve

plates at center 3

2. Metacorpus spindle shaped 4

Metacorpus ovoid ovarius n. sp.

3. Tail of female cylindroid, terminus broadly

rounded puniwopus

Tail of female conical, terminus narrowly

rounded 5

4. Stylet with well developed basal knobs ... 6

Stylet with base smooth, at best basal

swellings dendroctoni n. sp.

138
Figure 90.—Aglenchus exiguus Massey, 1969: A, Female; B. head; C. male, tail; D. female, tail;

E, anterior portion of body showing lateral field.

139
5.

6.

Anal opening obscure yasinskii

Anal opening not obscure pinophilus

Female tail tapering only slightly from ca

anal opening to terminus corniculatus n. sp.

Female tail tapering sharply from ca anal

opening to terminus glaiidarius n. sp.

ISeodityleuchus corniculatus n. sp. Figure 91 ISeodityleuchus dendroctoni n. sp. Figure 92

Female: 1.0-1.12 mm; a = 32.3-34.9; b = 7.2;

c = 29.6-32;V = 91%.

Male: 0.83 mm;a = 36;b = 6.1;c = 25.

Body ventrally arcuate, cylindroid. Cuticle

with moderately fine transverse striae at head

and neck. Lateral incisures not observed. Lip

region continuous with body contour. Cephalic

framework sclerotized. Stylet 8 /x in length,

with basal knobs; retractor muscles indistinct.

Dorsal esophageal gland outlet distinct. Corpus

of esophagus broad at distal end and narrowing

immediately anterior to metacorpus. Metacorpus pear shaped, valve plates located in its

anterior one-third. Anterior portion of dorsal

side of basal bulb glandular, a distinct valvular

apparatus present between basal bulb and intestine. Nerve ring a body width posterior to

metacorpus. Excretory pore opposite nerve

ring. Hemizonid a body width posterior to

excretory pore. Vagina a transverse slit, lips

protuberant. Ovary single, outstretched ;

oocytes arranged in a double row. Quadricolumella II/2 body widths in length. Posterior

uterine branch 1-2 body widths in length. Anus

indistinct. Rectum indistinct. Tail broadly

conoid to a sharply rounded terminus.

Male: Testis single, outstretched. Spicules

paired. Gubernaculum saucer shaped. Tail

conoid to a mucronate terminus. Bursa enveloping tail and joining body wall immediately

anterior to proximal end of spicules.

Diagnosis,—Related to Neoditylenchus

pityokteinophilus (Rühm, 1956) Meyl, 1961;

differs in esophageal characters and in the more

slender stylet.

Type habitat.—Associated with Scolytus

ventralis in white fir.

Type locality,—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Holotype and Allotype

Collection No. 6-T.

Female: 1.28 mm; a=:35; b = 9.1; c=?; V =

91%.

Male: 1.1 mm; a=:41; b = 7.5; c = 25.6.

Body ventrally arcuate, cylindroid. Cuticle

with moderately fine lateral striae, 2 widely

spaced lateral incisures spanning one-fourth

of body width, incisures especially prominent

on males. Lip region set off, rounded. Cephalic

framework sclerotized. Stylet with only small

basal thickenings, 11 /x in length; retractor

muscles obscure. Dorsal esophageal gland outlet discernible. Metacorpus pear shaped, small,

only slightly wider than base of corpus, valve

plates in anterior one-third. Basal bulb typical

of genus, anterior dorsal side glandular. Deirids

not observed. Nerve ring at anterior end of

basal bulb. Excretory pore 1-2 body widths

posterior to nerve ring. Hemizonid at posterior

end of basal bulb. Valvular apparatus between

basal bulb and intestine. Lips of vulva protuberant. Vagina transverse. Ovary single, at

times reflexed; oocytes arranged in a double

row. Quadricolumella short, at times less than

a body width in length. Posterior uterine

branch IY2 body widths in length. Anus and

rectum obscure. Tail conoid to a narrowly

rounded terminus.

Male: Testis single, outstretched. Spicules

paired tylenchoid. Gubernaculum distinctive, as

illustrated. Bursa enveloping tail and joining

body wall at proximal end of spicules. Tail ventrally arcuate, terminus mucronate.

Diagnosis.—Differs from other species in the

genus in the distinctive metacorpus and gubernaculum.

Type habitat.—Associated with Dendroctonus frontalis in loblolly pine.

Type locality.—Jonesville, Louisiana.

Type specimens.—Collections No. 83-C.

NetHÎitylenchus glandarius n. sp. Figure 93

Female: 1.12 mm; a = 35.5; b = 7.6; c=?;

V = 89%.

140
B

••.V %t:'^W.-

?K

r

\\- > '■■ "Yf \\

ti-^^^W I;:

.. A-./ Í ? ::

ft/

/if .03mm.

Í/ 1

?y i:

'.'•/ . /•.

3 /•;•

/:.'. /.•••'

Figure 91.—Neoditylenchus corniculatus n. sp.: ^. Head and neck; B. head; C. female, midbody; D. female, tail;

E, male, tail.

141
mí

lA

;|;;

:: Ä-.;ii§ ::^l

■■ >.'.;• •\;in>:- •il

;: ;••••.-Viiiv: "••I

• :^v. 111::-. ••>'

••••:.;;.|.II :l;:v

•:.*; . -ill iv;*.

••ten

•*- II

;i/

.01 mm.

03mm.

Figure 92.—JSeodUylenchus dendroctoni n. sp.: À. Head and neck; B. head; C. female, tail; D. male, tail.

142
Male : Unknown.

Body ventrally arcuate, eylindroid. Cuticle

with very fine transverse striations. Lateral

incisures not seen. Lip region rounded, continuous with body contour, over twice as wide as

high. Cephalic framework sclerotized. Stylet

slender, 10 ¡x in length, with small basal knobs ;

retractor muscles obscure. Dorsal esophageal

gland outlet distinct, the gland visible throughout entire length of corpus. Corpus widest at

the base. Metacorpus pear shaped, valve plates

slightly anterior to its center. Basal bulb broad,

its dorsal side glandular, muscular valvular

apparatus between basal bulb and intestine.

Deirids not seen. Nerve ring a body width

posterior to metacorpus. Excretory pore a body

width posterior to nerve ring. Hemizonid immediately anterior to excretory pore. Vagina

transverse, lips continuous with body wall.

Ovary with oocytes arranged in a single row.

Quadricolumella 3 body widths in length. Posterior uterine branch 1-2 body widths in

length. Anus and rectum obscure. Tail sharply

narrowing from anus to small rounded terminus.

Diagnosis.—Related to Neoditylenchus panurgus (Rühm, 1956) Meyl, 1961; differs in

dimensions of lip region, in apparent absence

of lateral incisures, and in esophageal characters.

Type habitat.—Associated with Dendroctontis brevicomis Lee. in ponderosa pine.

Type locality.—Pena Blanca, New Mexico.

Type specimens.—Collection No. 58-L

Neoditylenchus ovarius n. sp. Figure 94

Female: 2.0 mm; a = 43.7; b = 6.6; c=?;

V = 91^L

Male: 1.0 mm; a = 42; b = 7.5; c = 26.2.

Body ventrally arcuate, eylindroid. Cuticle

with fine lateral striae, without apparent lateral incisures. Lip region set off, rounded.

Cephalic framework sclerotized. Spear stout,

11 /x in length, with moderately coarse basal

knobs; retractor muscles obscure. Dorsal

esophageal gland outlet distinct. Metacorpus

almost round, the valve plates well anterior to

center. Basal bulb typical of genus. Deirids not

visible. Nerve ring three-fourths body width

posterior to metacorpus. Excretory pore over a

body width posterior to nerve ring. Hemizonid

immediately anterior to excretory pore. Vagina

a depressed transverse slit. Ovary outstretched,

massive; oocytes arranged in 2 rows. Quadricolumella approximately 4 body widths in

length. Posterior uterine branch 1-2 body

widths in length. Anus and rectum obscure.

Tail conoid to a narrowly rounded terminus.

Male: Testis single, outstretched, massive,

at times reaching beyond posterior end of basal

bulb. Spicules and gubernaculum typically

tylenchoid. Tail usually ventrally arcuate, some

specimens straight, conoid to mucronate terminus. Bursa enveloping tail and joining body

wall at proximal ends of spicules.

Diagnosis.—Related to Neoditylenchus pinophilus (Thorne, 1935) J. B. Goodey, 1963; differs in character of metacorpus and stylet.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Coconino National Forest,

Arizona.

Type specimens.—Collection No. 58 (Holotype) ; 58-A ( Allotype).

Neoditylenchus pinophilus (Thorne, 1935) J. B.

Goodey, 1963 Figure 95

Female: 1.5-2.5 mm; a = 36; b^ll.l; c = 33;

V = 91%.

Male: 1.0-1.5 mm; a = 34; b = 6.25; c = 36.

Size rather variable, females usually considerably larger than males. Cuticle finely striated. Lateral field a refractive band. Lip region

rather fiat, almost twice as wide as high, set off

by a slight constriction. Spear a little longer

than width of lip region, with small, though

distinct, basal swellings. Esophagus typical,

median bulb one-half to two-thirds as wide as

neck, valve plates at center. Vagina a deep

transverse slit. Ovary outstretched, variable in

length, sometimes reaching median bulb of

esophagus. Posterior uterine branch reaching

one-half to three-fourths the distance to anus.

Females approaching senility occasionally oviparous. Testis outstretched. Spicula threefourths as long as tail, most arcuate in distal

half. Gubernaculum thin, flat, arcuate, about

one-fourth as long as spicula. Female tail 2-3

times as long as anal body diameter, usually

rather uniformly conoid to small rounded

terminus. Phasmids a little posterior to middle

of tail. Distance between vulva and anus variable. Male tail ventrally arcuate, uniformly conoid

to pointed terminus. Bursa enveloping tail from

143
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.03 mm.

Figure 93.—Neoditylenchus glandarius n. sp.: /í. Head and neck; B. female, midbody; C

head; D. female, tail.

144
,01 mm.

mm.

Figure 94.—ISeoditylenchus ovarius n. sp.: A, Head and neck; B, head; C. female, tail; D. male, tail.

145
B

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Figure 95.—Neoditylenchus pinophilus (Thorne, 1935) J. B. Goodey, 1963: A, Head; B, ventral view, male, tail;

C. male, tail; D. female, tail. (After Thorne, 1935).

terminus to a point opposite proximal ends of

spicula.

Diagnosis,—Neoditylenchus from tunnels of

mountain pine beetle. Lip region truncated,

almost twice as wide as high, set off by a slight

constriction. Spear slightly longer than width

of lip region, with small basal swellings. Spicula three-fourths as long as tail. Bursa completely enveloping tail. Measurements as given

above.

Habitat.—Associated with Dendroctonus

ponderosae in lodgepole pine.

neoditylenchus puniwopus Massey, 1969 Figure 96

Female: 0.93-1.17 mm; a = 34.0-44.0; b = :6.2-

7.4;c = 31.1-35.2;V = 90%.

Male: 0.59-0.71 mm; a = 39.2-51.3; b = 4.5-

5.3;c = 23.5-30.8.

Body slender. Cuticle nearly smooth, transverse striae faintly visible in younger specimens. Head continuous with body contour. Lip

region twice as wide as deep. Stylet relatively

slender with prominent basal knobs over onethird longer than width of head. Esophagus

typical, metacorpus spindle shaped with large

central valvular plates. Terminal bulb well

developed. Nerve ring a body width posterior

to metacorpus. Excretory pore adjacent to

nerve ring. Hemizonid posterior to excretory

pore. Ovary outstretched, quadricolumella two

body widths in length. Postuterine branch a

body width in length. Lips of vulva slightly

protruding in some specimens. Vagina transverse. Anal opening barely discernible. Terminus broadly rounded.

Male: With anterior body characters of female. Testis single, outstretched. Spicules

paired tylenchoid, gubernaculum one-fourth

length of spicules. Bursa enveloping small

rounded terminus.

Diagnosis.—Closely related to Neoditylenchus abieticolus (Rühm, 1956) Meyl, 1961;

differs in body length and width, in its longer

and more slender stylet and in the nearly

smooth cuticle.

Type habitat.—Associated with Dendroctonus pseudotsugae in Douglas-fir.

146
Figure 96 Neoditylenchus puniwopus Masscy, 1969: A. Head; B. female; C. male, tail.

147
Tíjpe locality.—Santa Fe National Forest,

near Pecos, New Mexico.

Type specimens.—Collection No. 58-D.

Neodityleiichus yasinskii Massey, 1969 Figure 97

Female: 1.25-1.28 mm; a = 32.60-38.60; b =

8.54-8.62 ;c = 20.77-22.82 ;V = 89%.

Male: 0.94 mm; a = 37.16; b = 6.49; c = 18.8.

Body nearly straight when relaxed, narrow

at anterior end, widening rapidly near vulva.

Cuticle with moderately fine transverse striations. Lip region twice as wide as deep. Head

continuous with body contour. Stylet one-third

longer than the width of the head, with distinct

basal knobs. Esophagus typical of genus. Nerve

ring two body widths posterior to metacorpus.

Excretory pore three-fourths of a body width

posterior to nerve ring. Hemizonid immediately

posterior to excretory pore. Ovary single, outstretched on some specimens, reaching nearly

to basal bulb of esophagus. Postuterine branch

one body width in length. Vulvar lips protuberant. Vagina transverse. Anal opening obscure. Terminus subacute.

Male: Spicules tylenchoid. Gubernaculum as

figured. Bursa enveloping tail, terminus narrowly rounded.

Diagnosis.—Closely related to Neoditylenchm pinophilus (Thorne, 1935) Goodey, 1963;

differs from that species in shorter length,

shape of tail, and gubernaculum. Stylet knobs

considerably more prominent than pinophilus.

Also related to N. panurgus (Rühm, 1956)

Meyl, 1961; differing from that species in absence of a lateral field.

Type habitat.—Associated with Dendroctonus rufipennis in Engelmann spruce.

Type locality.—Mt. Taylor, New Mexico.

Type speciniiens.—Collection No. 58-F.

Genus Sychnotylenchus Rühm, 1956

Type species : Sychnotylenchus intricati

(Rühm, 1955) Rühm, 1956

Lip region distinctly set off, sclerotized. Lateral lips essentially narrower than subventral

or subdorsal. Stylet with strongly developed

subulate shaft; basal knobs, when present,

somewhat, elongate. Corpus of esophagus gradually widening from base of spear to metacorpus. Metacorpus spindle shaped, isthmus

narrow to elongate terminal bulb. Excretory

pore opening at level or anterior to metacorpus.

Vulva far posterior. Ovary single. Postuterine

sac well developed. Tail relatively short. Terminus broadly rounded. Testis single. Spicules

and gubernaculum typically tylenchoid. Bursa

peloderan. Terminus acute to subacute.

Sychnotylenchus inutici n. sp. Figure 98

Female: 0.94 mm; a = 35.5; b = 7.27; c =

45.71 ;V = 93%.

Male: 0.88 mm; a = 59.6; b=:6.47; c = 49.6.

Body ventrally arcuate, strongly narrowed

posterior to vulva. Cuticle marked with fine

transverse striae. Lateral incisures absent. Lip

region set off, rounded. Cephalic framework

sclerotized. Spear slender, 9.5 /x in length, with

elongate basal knobs or swellings, the dorsal

knob at times deformed by dorsal esophageal

gland outlet. Median bulb oblong ovate, basal

bulb broad, anterior one-third glandular with

muscular valvularlike organ between gut and

bulb. Nerve ring at midisthmus. Excretory

pore adjacent to metacorpus. Hemizonid at

posterior end of basal bulb. Lips of vulva elevated. Vagina oblique. Ovary single; oocytes

arranged in a single file and at times reaching

posterior end of basal bulb. Quadricolumella

over 2 body widths in length. Posterior uterine

branch IV2 body widths in length, at times

packed with sperm. Tail conoid to a broadly

rounded terminus, in some specimens flattened.

Male: Testis outstretched. Spicules and gubernaculum typically tylenchoid. Tail conoid to

mucronate terminus. Bursa arising at proximal

end of spicules and enveloping tail.

Diagnosis.—Related to Sychnotylenchus

scolyti. Differs in position of excretory pore

and in presence of basal stylet knobs.

Type habitat.—Associated with Scolytus

muticus Say in honey locust, Gleditsia triacanthos L.

Type locality.—Delaware, Ohio.

Type specimens.—Collection No. 29-B.

Sychnotylenchus phloeosini Massey, 1969 Figure 99

Female: 0.96-1.05 mm; a = 21-24; b = 9.3-

9.5; c=?;V = 92.6-93.6%.

Male: 0.66-0.89 mm; a = 29-38; b = 5.5-7.8;

c = 38-39.

Body stout, narrow at anterior end, becoming widest immediately preceding vulva. Cuti148
Figure 97.—Neoditylenchus yasinskii Massey, 1969: A. Female; B. male, tail.

149
Figure 98.—Sychnotylenchus mutici n. sp.: A, Head and neck; B, head; C. female, tail; D. female, midbody; E,

male, tail.

150
Figure 99.—Sychnotylenchus phloeosini Massey, 1969: A, Head and neck; B, head; C. face view; D. female, midbody; E. male, tail; F. female, tail.

151
ele with faint longitudinal and transverse

striations, most discernible in neck region, becoming very faint at midbody in mature specimens. Head slightly set off, flattened, lip region twice as wide as deep, the lateral lips

much narrower, protruding beyond body contour in face view. Stylet moderately slender

with obscure basal thickenings. Procorpus of

esophagus stout, narrowing into a prominent

ovate median bulb with distinct valvular apparatus. Terminal bulb as figured. Nerve ring at

middle of isthmus. Excretory pore slightly

posterior to median bulb. Hemizonid not discernible in specimens examined. Ovary reaching to the median bulb in mature specimens,

posterior uterine branch as figured. Vulva lips

protuberant. Vagina nearly transverse, anal

opening not discernible. Terminus broadly

rounded.

Male: Body relatively slender. Head and

lips as in female. Testis outstretched, reaching

nearly to basal bulb. Spicules paired, tylenchoid. Gubernaculum one-third to one-half

length of spicules. Bursa enveloping tail. Terminus subacute.

Diagnosis.—Closely related to Sychnotylenchus intricati (Rühm, 1955) Rühm, 1956.

Varies from that species in placement of excretory pore and nerve ring, absence of a lateral

field, and discernible anal opening.

Type habitat.—Associated with Phloeosinus

sp. in Rocky Mountain juniper, Juniperus

scopulorum Sarg.

Type locality. Bandelier National Monument, New Mexico.

Type specimens.—Collection Nos. 6-S (Allotype) ;6-U (Holotype).

Sychnotylenchus scolyti Massey, 1969 Figure 100

Female: 0.71-0.87 mm; a = 30.6-33.8; b =

5.5-6.2 ;c=?;V= 89-90%.

Male: 0.70-0.72 mm; a = 52-54; b = 5.2-5.4;

c = 31-35.

Body narrowest at anterior end, widest

immediately anterior to vulva. Cuticle almost

smooth, transverse striations very faint. Head

slightly set off. Lip region more than twice as

wide as deep, lateral lips narrower than other

four and protruding beyond body contour.

Stylet slightly longer than width of head, stout,

without basal knobs. Metacorpus spindle

shaped, muscular, with prominent valvular

apparatus. Isthmus slender, ending in a prominent elongate terminal bulb. Nerve ring onehalf body width posterior to median bulb. Excretory pore one body width anterior to median

bulb. Hemizonid about opposite anterior end of

basal bulb. Ovary outstretched, relatively short.

Quadricolumella prominent, approximately oneseventh ovary length. Posterior uterine branch

1% body widths long. Lips of vulva protuberant. Vagina transverse. Anal opening not discernible. Terminus broadly rounded.

Male: With head and esophageal characters

of female. Testis outstretched. Spicules paired,

tylenchoid. Gubernaculum one-third length of

spicules. Bursa enveloping tail. Terminus subacute.

Diagnosis.—Differs from Sychnotylenchus

ulmi (Rühm, 1955) Rühm, 1956 in stylet

length, absence of basal knobs on stylet, form

of metacorpus, and absence of a discernible

anal opening. S. scolyti is in general a smaller

species than S. ulmi.

Type habitat.—Associated with Scolytus

multistriatus in American elm.

Type locality.—Ft. Collins, Colorado.

Type specimens.—Collection No. 25-F.

Genus Pseudhalenchus Tarjan, 1958

Type species: Pseudhalenchus minutus Tarjan, 1958

Both sexes similar in appearance. Somatic

annulations light to moderately heavy. Lip

region annulation moderate to indistinct. Labial

framework sclerotized. Stomatostyle well deeloped, usually with distinct knobs. Deirids

(cervical papilla) observed on some specimens.

Metacorpus bulb of esophagus valvate with

distinct outline. Esophageal glands overlapping

intestine. Ovary monodelphic and prodelphic.

Vulva situated in posterior third of body. Rudimentary posterior uterus present. Male with

well defined spicules and gubernaculum, with

bursa (caudal alae) enveloping one-third to

two-thirds of tail. Lateral fields present, phasmids not observed in either lateral or dorsoventral view. Tail of both sexes elongate-conoid,

tapering, with minutely rounded to broadly

rounded terminus.

152
Figure 100.—Sychnotylenchus seolyti Massey, 1969: A. Female; B. face view; C. head; D. male, tail.

153
Pseudhalenchus damnatus Massey, 1966 Figure 101

Females: 0.93-1.1 mm; a = 37-43; b = 5.4-

6.2;c = 14-16;V = 75%.

Males : 0.61 mm ; a = 36 ; b = 6.1 ; c = 14-16.

Cuticle with fine annulations which become

quite coarse at tail. Lateral incisures absent.

Lip region continuous with neck contour. Stylet

short, stout, with well-developed basal knobs.

Median bulb of esophagus much longer than

wide, weakly muscular, slightly expanded in

comparison to procorpus. Deirids observed in

lateral field opposite nerve ring. Dorsal esophageal gland 6 body widths in length. Nerve ring

2 body widths posterior to median bulb. Hemizonid less than 1 body width behind nerve ring.

Excretory pore immediately posterior to hemizonid. Ovary single, outstretched; posterior

uterine branch less than 1 body width in length.

Lips of vulva slightly protuberant. Vagina

short, transverse. Tail tapering to a finely

rounded terminus.

Male: Testis outstretched. Spicules arcuate,

cephalated. Gubernaculum one-half length of

spicules. Bursa begins anterior to spicule cephalation and ends at two-thirds distance from

anus to terminus.

Diagnosis.—Differs from other species in the

genus in its larger size and absence of lateral

incisures; from Pseudhalenchus minutus Tarjan, 1958 in its shorter tail and placement of

bursa; and from P. anchilisposomus Tarjan,

1958 in location of vulva and length of posterior uterine branch.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection Nos. 44-A

(Holotype) ; 44-B (Allotype).

Neotylenchoidea (Thorne, 1941) Jairajpuri

and Siddiqi, 1969

Neotylenchidae (Thorne, 1941) Thorne, 1949

Neotylenchinae Thorne, 1941

Neotylenchus Steiner, 1931

N. nitidus Massey, 1969

Deladenus Thorne, 1941

D. ipini n. sp.

D. paradurus n. sp.

Hexatylinae Skarbilovich, 1952

Hexatylus Goodey, 1926

H. viviparus Goodey, 1926

Nothotylenchinae, 1941

Nothotylenchus Thorne, 1941

N. compactus n. sp.

N. parasimilis n. sp.

N. petilus n. sp.

Anguillonema Fuchs, 1938 -^

A. annamari n. sp.

A. leperisinin. sp.

Luella n. gen.

L. luculenta n. sp.

Paurodontidae (Thorne, 1941) Massey, 1967

Misticiinae Massey, 1967

Misticius Massey, 1967

M. mustus Massey, 1967

Family and subfamily of uncertain position

Dotylaphus Andrassy, 1958

D. lonchites n. sp.

Robleus n. gen.

R. cylindricus n. sp.

Genus Neotylenchus Steiner, 1931

Type species : Neotylenchus abulbosus

Steiner, 1931

Basal bulb of esophagus definitely set off

from intestine, dorsal esophageal gland sometimes enlarged until it forms a lobe extending a

short distance back over intestine. Lumen of

esophagus continuous, not interrupted by a

muscular valvular apparatus near base of

corpus. Spear generally with three definite

basal knobs. Ovary outstretched or reflexed;

with or without postuterine branch. Spicula,

gubernaculum, and bursa tylenchoid.

Diagnosis.—Neotylenchinae possessing a

definitely set off basal esophageal bulb and a

continuous lumen. Bursa, spicula, and gubernaculum tylenchoid.

Neotylenchus nitidus Massey, 1969 Figure 102

Female: 0.79-0.86 mm; a = 31.6-37.3; b =

5.7-6.8; c = ll.1-13.3; V = 83%.

Male : Unknown.

Body extended when relaxed. Cuticle with

moderately fine transverse striations. Lip region continuous with body contour, twice as

wide as deep. Stylet moderately coarse with

prominent basal knobs. Corpus of esophagus

cylindrical, somewhat widened at middle, then

"' This genus was placed in the subfamily Misticiinae

by Jairajpuri and Siddiqui, 1969. I do not agree with the

placement.

154
Figure 101.—Pseudhalenchus damnatus Massey, 1966: A, Female, B. male, tail; C. head.

155
Figure 102.—Neotylenchus nitidus Massey, 1969.

156
narrowing as it passes through nerve ring,

ending in a prominent basal bulb. Excretory

pore immediately posterior to hemizonid, both

approximately one-half body width anterior to

junction of esophagus and gut. Ovary single,

outstretched; quadricolumella occupying oneeighth of its total length. Posterior uterine

branch approximately one body width in length.

Vagina transverse. Anal opening only faintly

discernible in some specimens. Terminus acute.

Diagnosis.—Closely related to Neotylenchus

acutus Thorne, 1941; varies in prominence of

stylet knobs, character of junction of esophagus

and gut, and in presence of a posterior uterine

branch. It also varies in the absence of a lateral

field.

Type habitat,—Abandoned galleries of Dendroctonus rufipennis (Kby.) in Engelmann

spruce.

Type locality.—Red Feather Lakes, Roosevelt National Forest, Colorado.

Type specimens.—Collection No. 55.

Genus Deladenus Thorne, 1941

Type species: Deladenus durus (Cobb, 1922)

Thorne, 1941

Esophagus joining intestine immediately behind nerve ring, esophageal glands lying free

in body. A chamberlike valvular apparatus

sometimes present in corpus of esophagus.

Vulva located less than 10% from terminus.

Ovary prevulvar. Postuterine sac sometimes

present. Spicula and gubernaculum tylenchoid.

Bursa enveloping tail.

Deladenus ipini n. sp. Figure 103

Female: 0.89 mm; a = 30.3; b = 4.9; c = 43.3;

V = 93%.

Male: 0.66 mm;a = 37.8;b=:4.3;c = 25.2.

Body straight, cylindroid. Cuticle with moderately fine transverse striations. Lateral incisures obscure. Lip region set off, rounded, twice

as wide as high. Cephalic framework sclerotized. Spear 8 /x in length, stout ; basal knobs

very prominent, distinct. Protractor muscles

conspicuous, attached to body wall. Dorsal

esophageal gland outlet well defined in most

specimens. Corpus spindle shaped, with valvelike chamber slightly anterior to its midpoint.

Three distinct esophageal glands grouped

around anterior end of intestine. Deirids not

observed. Nerve ring 5 body widths posterior

to lip region. Excretory pore opposite nerve

ring. Hemizonid 2 body widths posterior to

nerve ring. Vagina short, transverse, lips of

vulva protuberant. Uterine pouch heavily sclerotized. Ovary single, outstretched; oocytes

arranged in single row for two-thirds of ovary

length, anterior one-third a double row. Quadricolumella 21/4 body widths in length. Postuterine pouch less than body width in length.

Anus and rectum obscure. Tail sharply narrowing from vulva to narrowly rounded terminus.

Male : Testis outstretched, reaching at times

beyond posterior end of esophageal glands.

Spicules and gubernaculum typically tylenchoid. Bursa enveloping terminus and joining

body opposite proximal end of spicules.

Diagnosis.—Differs from any other species

in the genus in presence of postuterine sac.

Type habitat.—Associated with Dendroctonus frontalis and Ips calligraphus in loblolly

pine.

Type locality.—Oakdale, Louisiana.

Type specimens.—Collection No. 82-L

Deladenus paradurus n. sp. Fis 104

Female: 0.85-0.92 mm; a = 30-36; b=:8.4-

ll;c= 21;V=:91%.

Male : Unknown.

Body straight, cylindroid. Cuticle with moderately fine transverse striations and 4 lateral

incisures arranged as figured. Lips continuous

with neck region. Cephalic framework sclerotized. Stylet 8 /x in length, basal knobs prominent; protractor muscles obscure. Dorsal

esophageal gland outlet distinct. Corpus of

esophagus spindle shaped, its valvular chamber

absent. Esophageal glands several body widths

in length, only one gland nucleus visible.

Deirids at level of excretory pore. Nerve ring

6-7 body widths posterior to head. Excretory

pore a body width posterior to nerve ring, walls

of tube heavily sclerotized and visible for several body widths as it extends posteriorly.

Hemizonid immediately anterior to excretory

pore. Hemizonion immediately posterior to excretory pore. Ovary outstretched, reaching at

times to nerve ring. Lips of vulva protuberant.

Vagina muscular, oblique, thick-walled. Muscular, pouchlike uterus. Quadricolumella ca 3 body

widths in length. Postuterine sac absent. Anus

157
.03mm

Figure 103.—Deladenus ipini n. sp.: A. Head and neck; B. head; C female, tail; D,

male, tail.

158
I V-;

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11'

and rectum conspicuous. Tail narrowing

sharply from vulva to an acute terminus.

Diagnosis.—Related to Deladenus durus

(Cobb, 1922) Thorne, 1941; differs in the

number and arrangement of lateral incisures,

and in the coarseness of the lateral striae. D.

paradtirus does not possess the ovoid valvular

chamber in the corpus of the esophagus.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 3-M.

Genus Hexatylus Goodey, 1926

Type species: Hexatylus viviparus Goodey,

1926

Esophagus base fused with intestine. Lumen

of esophagus witha distinct break near the

base of corpus where the lumen becomes much

wider, the walls heavier anda muscular valvular apparatus apparently is present. Pharynx

slightly sclerotized, forming several minute

guiding rings for the spear. Spear with three

well-developed basal knobs, each of which is

somewhat duplex. The outer surface of these

basal knobs is unusually refractive and conspicuous. En face the octagonal lip region is

observed to be divided into 12 approximately

equal sectors with four smaller triangular sectors at the submedial angles through which

the circlet of four papillae emerge. The basal

framework of the head retains the octagonal

pattern of the genus.

Hexatylus viviparus Goodey, 1926 Figure 105

Female: 1.0-1.5 mm;a= 15-35;b= 5-7;

c= 17-20;V= 89%.

With characters of the genus. Great variation

in width is found between females which have

reached their normal length but have not begun

egg production, and those approaching senility.

Senile specimens frequently somewhat shorter

than the younger forms associated with them.

Phasmids and deirids not observed. Lateral

field marked by four refractive lines, the two

outer ones being more prominent. Tissues of

the basal portion of the esophagus are somewhat less dense in texture than those of the

intestine to which they are fused. This basal

Figure 104.—Deladenus paradurus n. sp.: A. Head and

neck; B. head; C, lateral field; D, female, tail.

159
Figure 105.—Hexatylus vivíparas Goodey, 1926: A. Female; B, head.

160
portion encloses a number of nuclei, some of

which appear identical to those of the intestine

while others are probably the nuclei of the

esophageal glands. Nuclei of intestinal cells

less than one body width apart. Intestine probably four cells to a circumference but this point

was not definitely determined as cell walls were

not visible.

Ovary of adults reaching as far forward as

the nerve ring, the anterior portion made up of

several hundred massed oocytes which, as they

increase in size, are observed to be grouped

about a prominent rachis. Only the anterior

half of the ovary is occupied by the oocytes, the

remainder being a long tube in which the ova

develop. A short oviduct leads to a pouchlike

uterus. Vagina a broad transverse slit.

Habitat.—Associated with Dendroctonus

adjunctus in ponderosa pine, Dendroctonus

terebrans in loblolly pine, and Leperisinus

aculeatus in green ash.

Genus Nothotylenchus Thorne, 1941

Type species: Nothotylenchus acris Thorne,

1941

Cuticle thin, marked by fine transverse striae

which are interrupted by the lateral fields,

marked by 2 or more bright lines. Cephalic

framework in six sectors. Spear with rounded

basal knobs. Corpus of esophagus cylindroid,

with or without a fusiform valveless bulb.

Basal bulb of esophagus distinctly set off from

intestine, sometimes slightly lobed. Ovary outstretched, with oocytes arranged in single file.

Posterior uterine branch present. Spicules and

gubernaculum tylenchoid. Bursa peloderan.

nothotylenchus compactus n. sp. Figure 106

Female: 0.55 mm; a = 21.1; b = 4.9; c = 17.3;

V = 84%.

Male : Unknown.

Body ventrally arcuate. Cuticle with moderately fine transverse striae. Lips rounded,

continuous with body contour. Cephalic framework lightly sclerotized. Stylet 9 /x long,

strongly knobbed, retractor muscles indistinct.

Dorsal esophageal gland outlet obscure. Basal

bulb cylindroid, elongate. Deirids not observed.

Excretory pore one and one-half body widths

posterior to nerve ring. Hemizonid immediately

anterior to excretory pore. Vagina a transverse

slit. Lips of vulva continuous with body contour. Ovary outstretched, oocytes tandem.

Quadricolumella 1 body width long. Postuterine

branch a body width in length. Anus and

rectum obscure. Tail conoid to rounded knoblike terminus.

Diagnosis.—Differs from all other species in

the genus in the short, stout body conformation

and distinctly shaped tail.

Type habitat.—Associated with Phloeosinus

neomexicanus Blkm. in Rocky Mountain juniper.

Type locality.—Bandelier National Monument, New Mexico.

Type specimens.—Collection No. 36.

nothotylenchus parasimilis n. sp. Figure 107

Female: 0.61 mm; a = 29; b = 5.9; c = 16;

V=:81%.

Male : 0.54 mm ;a = 37;b = 7.4;c = 14.2.

Body slightly ventrally arcuate. Cuticle with

moderately coarse transverse striations, especially on neck and on tail. Lateral incisures

obscure, 4 noted on some specimens. Lips

rounded, continuous with neck contour. Cephalic framework sclerotized. Spear stout, 7.5 juin length, with large basal knobs. Retractor

muscles distinct. Dorsal esophageal gland outlet distinct. Basal bulb oblong, ellipsoid. Deirids

not observed. Excretory pore varies in position from posterior portion of nerve ring to

posterior portion of basal bulb. Hemizonid not

observed. Lips of vulva slightly protuberant.

Vagina oblique. Uterus serving as spermatheca.

Ovary single, outstretched; oocytes tandem.

Quadricolumella ca 2 body widths in length.

Posterior uterine branch over a body width

long. Anal opening inconspicuous, rectum obscure. Tail conoid to an acute terminus.

Male: Testis single, outstretched. Spicules

and gubernaculum tylenchoid. Tail conoid to an

acute terminus. Bursa extending from body at

midspicules posteriorly two-thirds of distance

from anus to terminus.

Diagnosis.—Related to Nothotylenchus similis Thorne and Malek, 1968. Varies in coarseness of transverse striae, number of lateral

incisures, and size of stylet. N. parasimilis is a

much smaller species.

Type habitat.—Associated with Ips grandicollis in loblolly pine.

Type locality.—Henderson, North Carolina.

Type specimens.—Collection No. 32-K.

161
miiil;i

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if ó /^— "

V- iv. • •■■■

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03 mm

yx:

Figure 106.—Nothotylenchus compactas n. sp.: A. Head and neck; B. head; C. female, tail.

162
m

àii..

m.

rate t\m:.^^- :::J.,

//^-.•.'•'•• :>'í#::.l

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IlB

.01mm.

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Figure 107.—]\othotylenchus parasimilis n, sp. :

female, midbody.

¡Ill;:

IS^RioÉ ill

03mm

Mm

mmi

isi

m

A, Head and neck; B, head; C maie, tail; D. female, tail; E,

163
Nothotylenchus petilus n. sp. Figure 108

Female: 0.57 mm; a = 40.5; b = 4.5; c = 18.0;

V = 76%.

Male : 0.57 mm ; a = 48.5 ; b = 5.0 ; c = 15.0.

Body slender, slightly ventrally arcuate. Cuticle with moderately coarse transverse striae,

especially prominent at neck and tail, 2 lateral

incisures. Lips continuous with neck, angular.

Cephalic framework sclerotized. Stylet relatively slender, strongly knobbed, 7.5 fx in

length; retractor muscles conspicuous and

attached to body wall. Dorsal esophageal gland

outlet discernible. Basal bulb oblong. Deirids

not observed. Excretory pore one-half body

width posterior to nerve ring, its tube heavily

sclerotized. Hemizonid immediately anterior to

excretory pore. Vulva lips protruding or continuous with body contour. Vagina transverse.

Ovary outstretched, oocytes tandem. QuadriW^i

III I

IirA'.-y

mm

:fiv;p::

: I

\:P.

.01 m m.

B

02 mm.

Figure 108.—Nothotylenchus petilus n. sp.

lateral field; F. female, midbody.

A. Head and neck; B. head; C. male, tail; D. female, tail; E. width of

164
columella ca 4 body widths long. Posterior

uterine branch over a body width in length.

Anus and rectum obscure. Tail conoid to an

acute terminus.

Male : Testis single, outstretched, short. Spicules and gubernaculum tylenchoid. Tail conoid

to an acute terminus. Bursa arising at body

wall opposite midpoint of spicules and extending posteriorly seven-eighths of distance between anus and terminus.

Diagnosis.—Related to Nothotylenchus medians Thorne and Malek, 1968 ; differs in number of incisures in lateral field, stylet muscles

attached to body wall instead of cephalic framework, and in length and point of attachment of

bursa.

Type habitat.—Associated with Dendroctomis terehrans in loblolly pine.

Type locality.—Henderson, North Carolina.

Type specimens.—Collection No. 82-D.

Genus Anguillonema Fuchs, 1938, Emended ^

Type species: Anguillonema xylebori (Roux,

1906) Rühm, 1955

Cuticle with transverse striae, with or without lateral incisures. Lips continuous with

neck region. Cephalic framework distinct.

Stylet relatively short, usually with distinct

basal knobs, dorsal knob at times deformed by

development of dorsal esophageal gland outlet.

Corpus spindle shaped, isthmus slightly constricted by nerve ring. Basal bulb distinct, at

times lobed on dorsal side. Ovary single, posterior uterine branch rudimentary. Anus and

rectum at times obscure. Testis outstretched.

Spicules and gubernaculum tylenchoid. Bursa

enveloping tail.

The genus has been unobserved since originally described by Fuchs. Original description

is herein amended to more adequately diagnose

the genus.

Anguillonema annaniari n. sp.^ Figure 109

Female: 0.76 mm; a = 32; b = 4.2; c=?;

V = 89%.

Male : 0.60 mm ; a = 35 ; b=: 5.0 ; c = 17.5.

Body straight, cylindroid except at extremities. Cuticle with moderately coarse transverse

striae, 2 lateral incisures. Lips continuous with

neck region, rounded, twice as wide as deep.

Cephalic framework sclerotized. Stylet 8 /x in

length, with small basal knobs, the dorsal knob

at times deformed by the prominent dorsal

esophageal gland outlet; retractor muscles obscure. Esophageal lumen can be traced to junction with intestine. Corpus spindle shaped, isthmus severely constricted by nerve ring, basal

bulb distinctive, usually lobed on dorsal side ; a

valvelike structure between basal bulb and intestine. Deirids not observed. Excretory pore

conspicuous, located over a body width posterior to nerve ring, wall of tube heavily sclerotized. Hemizonid immediately anterior to

excretory pore. Lips of vulva elevated, vagina

short and slanting anteriorly. Ovary outstretched or reflexed several times, sometimes

extending to nerve ring. Oocytes arranged in a

single row. Quadricolumella 1-2 body widths in

length. Posterior uterine branch rudimentary.

Anus and rectum obscure. Tail subcylindroid,

terminus broadly rounded, obtuse.

Male : Testis outstretched, at times reaching

posterior end of basal bulb. Sperm cells small,

highly refractive. Spicules and gubernaculum

highly refractive. Tail slightly ventrally arcuate. Terminus sharply rounded. Bursa enveloping tail and joining body wall one-half body

width anterior to proximal end of spicules.

Diagnosis.—Distinctive because of glandular

basal bulb and obtuse tail of female.

Type habitat.—Associated with Dendroctonus frontalis in loblolly pine.

Type locality.—Spurger, Texas.

Type specimens.—Collection No. 82-C, 82-E.

Anguillonema leperisini n. sp. Figure 110

^ Tills genus was placed in the subfamily Misticiinae

by Jairajpuri and Siddiqi, 1969. I do not agree with

the placement.

i Named in honor of my granddaughter, Anna Marie

Massey.

Female: 0.70-0.83 mm; a = 33-34; b = 4.2-

4.9;c = 29.7;V = 90%.

Male: 0.63mm; a = 36;b = 4.3;c = 21.6.

Body straight, cylindroid. Cuticle with moderately coarse transverse striations, lateral

incisures absent. Lips continuous with neck

region, rounded, twice as wide as high. Cephalic framework sclerotized. Spear 9-10 ¡x in

length, stout, with basal knobs, dorsal knob

usually deformed anteriorly by the prominent

dorsal esophageal gland outlet; protractor

muscles obscure. Corpus of esophagus spindle

shaped, isthmus severely constricted by nerve

ring, basal bulb massive, without dorsal lobe

165
Ili

mí

Iß mm

mai

mm.- mk :

P

•Wf -¿ill

i

à

ls>^-

m

01 mm

l-.: v;:t;^.^*;-«^3¡ii¿>i;: ::

;t

ir:

lili mmi

03 mm

Figure 109.—Anguillonenia aimaniari n. sp.: A, Head and neck; B. head; C. female, midbody; D.

female, tail; E, male, tail.

166
lili lim

:: •^[ ::ll;:-

Itijßä

ma

Wöy

W^:

'm

keñ

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ym

mi

.01mm

L03mm

r.. i ^ ^ I

í

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Figure 110.—Anguillonema leperisiiii ii. sp.

female, tail; D. male, tail.

/4. Head and neck; B. head; C.

167
and filling body cavity. Deirids not observed.

Excretory pore prominent, ca 1 body v^idth

posterior to nerve ring, tube heavily sclerotized.

Hemizonid immediately anterior to excretory

pore. Lips of vulva slightly elevated. Vagina

short, oblique. Ovary usually reñexed one to

several times : oocytes tandem. Quadricolumella

1-2 body widths in length. Posterior uterine

branch rudimentary. Anus and rectum obscure.

Tail narrov^ing but little from vulva to terminus. Terminus broadly rounded, obtuse.

Male: Testis outstretched. Spicules and gubernaculum tylenchoid. Bursa enveloping tail

and joining body wall at proximal end of spicules.

Diagnosis.—Related to Anguillonema annaynari; differs in the shape and character of

basal bulb, in the longer and stouter stylet, and

in the shorter, more obtusely rounded tail.

Type habitat.—Associated with Leperisinus

aculeatus in green ash.

Type locality.—Chillicothe, Ohio.

Type specimens.—Collection No. 82-P.

Luella n. gen.""'

Nothotylenchinae : Cuticle finely striated,

without lateral incisures. Stylet slender,

smooth, without basal knobs or thickenings.

Basal bulb of esophagus distinctly set off from

intestine, junction unique and slightly overlapping intestine. Ovary single, reñexed;

oocytes arranged in a single row. Posterior

uterine branch rudimentary. Female anus and

rectum obscure. Terminus filiform. Spicules and

gubernaculum tylenchoid. Bursa arising onehalf body width anterior to proximal end of

spicules and extending one-third of the distance

to terminus.

Diagnosis.—Immediately distinguished from

Nothotylenchiis by the smooth delicate stylet,

absence of lateral striae, and junction of

esophagus and intestine, and in the filiform tail

in both sexes.

Luella luculenta n. gen., n. sp. Figure 111

Female: 0.69 mm; a = 33.6; b=:5.1; c = 7.3;

V = 80%.

Male : 0.69 mm ;a = 33.6 ;b=r4.8 ;c = 8.1.

Body straight to slightly ventrally arcuate.

Cuticle with fine transverse striae. Without

lateral incisures. Lips continuous with neck

region. Cephalic framework sclerotized. Stylet

8 /x in length, slender, without basal knobs;

retractor muscles obscure. Dorsal esophageal

gland outlet obscure to prominent. Corpus of

esophagus cylindrical, basal bulb distinctly set

off from intestine, at times lobed ; lumen visible

throughout entire length. Nerve ring massive.

Excretory pore prominent, immediately posterior to nerve ring, its tube heavily sclerotized.

Hemizonid very conspicuous and immediately

anterior to excretory pore. Lips of vulva

slightly elevated. Vagina short, transverse.

Ovary reflexed; oocytes tandem. Quadricolumella 1-2 body widths in length. Posterior

uterine branch rudimentary. Anus and rectum

obscure. Tail constricted from vulva to a filiform terminus.

Male: Testis outstretched. Spicules and gubernaculum tylenchoid. Tail as in female. Bursa

arising one-half body width anterior to proximal end of spicules and extending one-third of

the distance to terminus.

Type habitat.—Associated with Ips pini in

red pine.

Type locality.—Caroline Co., New York.

Type specimens.—Collection No. 82-0.

Genus Misticius Massey, 1967

Type species : Misticius mustus Massey, 1967

Lip region only slightly offset; labial framework lightly sclerotized. Knobs of stylet flattened at base. Metacorpus weakly developed

without a valvular apparatus, but a thickening

of the lumen walls; terminal bulb overlapped

by intestine and emptying subventrally into

gut. Excretory pore located far forward, at

times nearly opposite base of spear. Hemizonid

located near nerve ring. Ovary single, prodelphic. Spicules cephalated. Gubernaculum

tylenchoid. Bursa rising at proximal end of

spicula and extending four-fifths length of tail.

Misticius mustus Massey, 1967 Figure 112

^' Named in honor of Mrs. Luella Kramer, Principal

Clerk, Albuquerque, New Mexico Unit, Rocky Mountain

Forest and Range Experiment Station.

Female: 2.7 mm (2.4-2.9) ; a==68 (66-79) ;

b = 11.5 (9.6-13.0); 0=^27 (23-32); V = 89%

(87-91).

Male: 1.83 mm (1.59-2.4); a = 64.7 (61.1-

68.7); b = 10.5 (10.4-10.7); c=:27.0 (21.8-

30.5).

Cuticle with moderately fine annulations consistent throughout body length. Lateral inci168
M

ïmm

• •••;...H •• ':ä •.

:: ••.U;^\\\-:

mm

.01mm.

mtSore

^t*^:^

:iiî-:if

m

M "J

Figure 111.-

mal)', tail.

.03 mm.

-huella luculenta n, gen., n. sp.: A, Head and neck; B. head; C. female, midbody; D, female, tail; E,

169
Figure 112.—Misticius mustus Massey, 1967: A, Head and neck; B, female, midbody; C, female, tail; D. male, tail;

E, male, tail, ventral view; F. quadricolumella; G, portion of ovary showing spermatheca.

170
sures absent. Lip region very slightly sclerotized. Stylet moderately stout, length 13 /x (13 /x14 fx), with prominent basal knobs appearing

flattened at the base in lateral view. Orifice of

the dorsal esophageal gland immediately behind

base of spear. Metacorpus weakly developed,

spindle shaped, without a valvular apparatus,

but a thickening of the walls forming the lumen

of the esophagus at the metacorpus. Terminal

bulb of esophagus elongated and extending into

intestine up to two body widths and emptying

subventrally into gut. Excretory pore far forward, at times within 2 fx of base of spear,

ranging from 2-15 /x from base of that organ.

Hemizonid located slightly more than one body

width posterior to nerve ring. Ovary prodelphic, in some specimens slightly reflexed.

Quadricolumella very elongated, several body

widths in length in mature specimens. Spermatheca as figured. Posterior uterine branch

elongate, up to four body widths in length. Tail

terminus minutely rounded.

Male: With cuticular, head, and neck characteristics of female. Testis outstretched ; spicules paired, stout, arcuate, and cephalated.

Gubernaculum troughlike in lateral view, approximately one-third length of spicules. Phasmids as figured. Bursa joining body slightly

anterior to proximal end of spicules and extending to within 16 /x of spicate terminus.

Type habitat,—Galleries of Dendroctonus

pseudotsugae in Douglas-fir.

Type locality,—Pecos, New Mexico.

Type specimens,—Collection No. 46.

Genus Dotylaphus Andrássy, 1958 Emended

Type species: Dotylaphus ruehmi Andrássy,

1958

Females: Cuticle thick, with several lateral

incisures. Head rounded. Lips indistinct. Stylet

dorsally arcuate, with or without basal knobs.

Dorsal and ventral shafts appearing to be separate. Esophagus unique, terminating in two

large glands lying free in body cavity, each

gland with a distinctive outlet, appearing

fingerlike, their walls heavily sclerotized, an

outlet in each gland. Esophageal-intestinal

juncture indefinite. Vulva posterior. Ovary development indistinct.

Males: Head rounded. Cuticle as in female.

Stylet straight, slender, with oblique basal

thickenings. Esophagus as in female, except

for glandular outlets which are not apparent.

Testis outstretched. Spicules and gubernaculum

tylenchoid. Bursa peloderan.

The genus is dimorphic in that males and

females bear distinctively different stylets ; the

male stylet is straight with a normal subulate

shaft and shaft ; however, the basal thickenings

are oblique. Female spear is coarse and long,

dorsally arcuate, the shafts appearing separate.

Dotylaphus lonchites n. sp. Figure 113

Females: 1.36-1.5 mm; a = 58.1-64.6; b=?;

c=?;V=?.

Males: 1.09-1.15 mm; a = 46.5-49.1; b=?;

c = 19.6-20.7.

Cylindroid. Cuticle thick, with fine transverse striae and 6 lateral incisures. Lip region

round, indistinct, continuous with body contour. Cephalic framework indistinct. Stylet 22 /x

in length, with prominent oblong basal knobs,

dorsally arcuate, dorsal and ventral shaft appearing separate, dorsal shaft more coarse than

ventral. Subulate portion of dorsal shaft spearlike, heavily sclerotized. Musculature unusual

and apparently attached from shafts of spear

to walls of vestibule. Esophagus distinctive,

terminating in two large glands, dorsal and

ventral, each with a distinctive finger-like outlet, the walls of the tubular outlet heavily sclerotized. Nerve ring 5 body widths from anterior

end. Excretory pore and hemizonid a body

width posterior to nerve ring. Ovary, vulva, and

anus indistinct. Tail cylindroid to an obtuse

terminus.

Male: Cuticle as in female. Head rounded,

lips indistinct. Stylet slender, straight, 12 /x in

length, with oblique basal thickenings. Esophagus as in female, but without the fingerlike

esophageal gland outlets. Testis outstretched.

Spicules and gubernaculum tylenchoid. Bursa

peloderan, joining body wall one-half body

width anterior to proximal end of spicules.

Tail conoid to a subacute terminus.

Diagnosis.—Differs from Dotylaphus ruehmi

Andrássy, 1958 in stylet characteristics, in the

number of lateral incisures, and in size.

Type habitat,—Associated with Dendroctonus terebrans in loblolly pine; also associated

with Dendroctonus adjunctus in ponderosa pine

at Oak Creek Canyon, Arizona.

171
03 mm

•..7 yo oo\-

::;/;o:Ooo*-

•:î!

Figure 113.—Dotylaphus lonchites n. sp.: A, Female, head and neck; B, female, head; C. female, tail; D, cuticle

illustrating lateral incisures; E. male, head; F. male, tail; G, male, head and neck.

ill

riiv.

:mw

172
Type locality.—Oakdale, Louisiana.

Type specimens.—Collection No. 82-F.

Robleus n. gen,*'

Cuticle with fine transverse striations. Head

broadly rounded, lips indistinct. Stylet with

heavily sclerotized subulate shaft, ventrally

bent at anterior end, prominently knobbed.

Basal lobe of esophagus elongate, cylindrical,

glandular throughout its entire length. Ovary

short, oocytes arranged in a single row. Oviduct long and serving as a spermatheca. Uterus

conspicuously muscular. Anus and rectum obscure. Tail cylindroid to obtuse terminus.

Diagnosis.—Distinctive because of its unique

stylet and esophagus, short ovary, and prominent uterus.

Robleus cylindricus n. gen., n. sp. Figure 114

Females: 0.62-0.68 mm; a = 28.1-31.8; b =

2.8-3.0; c=?;V= 87%.

Males : Unknown.

Cylindroid. Cuticle with fine transverse

striae, lateral incisures not discernible. Lip

region broadly rounded, indistinctly set off,

hardly discernible. Cephalic framework indistinct. Amphids not observed. Stylet 19 /x in

length, subulate shaft ventrally bent at anterior

end and exceedingly heavily sclerotized, twothirds total spear length, knobs very conspicuous, musculature prominent. Dorsal esophageal

gland outlet not discernible. Procorpus short,

basal bulb cylindrical, exceedingly long and

glandular. Lumen visible throughout its entire

length, anterior portion of basal bulb with

indistinct radial muscles and several fingerlike

ducts protruding from lumen. Cardia-like

organ at base of esophagus with 3 prominent

nuclei. Nerve ring severely constricting anterior portion of basal lobe imparting the appearance of a median bulb. Excretory pore onehalf body width posterior to nerve ring. Hemizonid immediately anterior to excretory pore.

Ovary single, oocytes arranged in a single row.

Oviduct packed with exceedingly minute sperm

cells. Quadricolumella 2 body widths in length.

Lips of vulva only slightly protuberant. Vagina

a very short, transverse slit. Uterus prominent,

muscular, shaped as illustrated. Anus and rec-

^' Named in honor of my grandson, Robert Lee

Verzino.

tum obscure. Phasmids obscure. Tail cylindroid

to an obtuse terminus.

Type habitat.—Associated with Dendroctoniis frontalis in loblolly pine.

Type locality.—Spurger, Texas.

Type specimens.—Collection No. 83-E.

Robleus cylindricus appears to be the freeliving stage of an insect parasite, in all probability a parasite of an insect associate of the

southern pine beetle.

Aphelenchoidea (Fuchs, 1937) Thome, 1949

Aphelenchoididae (Skarbilovich, 1947) Paramonov, 1953

Aphelenchoidinae Skarbilovich, 1947

Aphelenchoides Fischer, 1894

A. conophthori n. sp.

A. hylurgin. sp.

A. pityokteini n. sp.

A. polygraphi n. sp.

A. rhytium Massey, 1971

A. tennidens Thorne, 1935

Bursaphelenchtis Fuchs, 1937

B. bestiolus n. sp.

B. corneolus Massey, 1966

B. elytrus Massey, 1970

B. newmexicanus n. sp.

B. pityogeni n. sp.

B. scolyti n. sp.

B. talonus (Thorne, 1935) J. B.

Goodey, 1960

B. tritrunculus n. sp.

B. wilfordi Massey, 1964

Laimaphelenchus Fuchs, 1937

L. pannocaiidus Massey, 1966

L. penardi (Steiner, 1914) Filipjev and Schuurmans Stekhoven,

1941

L. pensobrinus Massey, 1966

L. phloeosini n. sp.

Ektaphelenchtis (Fuchs, 1937)

Skrjabin et al, 1954

E. josephi n. sp.

E. obtusiis Massey, 1956

E, prolobos Massey, 1964

E. sandiaensis Massey, 1964

E. smaelus n. sp.

E. terebranus n. sp.

Cryptaphelenchus (Fuchs, 1937)

Rühm, 1954

C. cirrus n. sp.

C. ipinius n. sp.

173
Figure 114.—Robleus cylindricus n. sp.: A. Female; ß. head; C. dorsal view, posterior end of esophagus.

174
C. latus (Thorne, 1935) Rühm,

1956

Omemeea Massey, 1971

0. Tïiaxbassiensis Massey, 1971

Teragramia n. gen.

T, Willi n. sp.

Berntsemts n. gen.

B, brachycephalus (Thorne,

1935) n. comb.

B. labiosus n. sp.

Seinurinae Husain and Khan, 1967

Seinura Fuchs, 1931

S. arizonensis n. sp.

AS. attenuata n. sp.

S. pini Massey, 1966

Genus Aphelenchoides Fischer, 1894

Body usually long and slender. Cuticle with

fine transverse striae, with or without lateral

incisures. Lip region offset, the six nonannulated lips supported by hexaradial internal

sclerotizations. Stylet with or without basal

knobs. Esophagus distinguished by a prominent metacorpus containing well developed crescentic valve plates. Dorsal esophageal glands

lobelike and lying free in the body cavity, its

orifice in metacorpus. Ovary prodelphic, oocytes

arranged in one or more rows. Postuterine

branch present or absent. Vulva posterior.

Spicules paired. Bursa and gubernaculum absent. Male tail usually ventrally arcuate, with

a variable number of papillae.

Aphelertchoides conophthori n. sp. Figure 115

Female: 0.48 mm; a = 23; b = 8.3; c = 13.1;

V = 70%.

Male: 0.55 mm; a=:26; b = 8.7; c = 15.

Body cylindroid. Cuticle marked by 2 lateral

incisures, indistinct in many specimens. Transverse striae very faint. Lip region set off,

rounded. Cephalic framework sclerotized. Lips

distinct. Stylet with prominent triangular basal

knobs, 12 /x in length, its retractor muscles indistinct. Metacorpus ovate, valve plates at

center, dorsal esophageal gland outlet indistinct. Dorsal esophageal gland long, slender, 5

body widths in length. Nerve ring slightly less

than 2 body width posterior to metacorpus.

Excretory pore opposite or slightly anterior to

nerve ring. Hemizonid not observed. Lips of

vulva slightly elevated. Vagina oblique. Ovary

short, oocytes tandem. Postuterine branch 4

body widths in length. Anal opening distinct.

Rectum obscure. Tail conoid to a bluntly

rounded mucronato terminus.

Male: Body straight. Head, neck and cuticular characteristics similar to female. Testis

single, outstretched. Sperm cells exceedingly

large. Spicules paired, the dorsal limbs bent

near distal end, ventral limb not closing with

dorsal limb. Apex high, ventral rostrum short.

Tail ventrally arcuate. Two pair of postanal

papillae. Terminus mucronato, sharply pointed.

Diagnosis.—Related to Aphelenchoides sinodendroni Rühm, 1957; differs in the presence

and shape of knobs of stylet and in the shape

and character of the male and female terminus.

Spicules distinctive.

Type habitat.—Associated with Conophthorus coniperda in the cones of eastern white

pine.

Type locality.—Hamden, Connecticut.

Type specimens.—Collection No. 78-P.

Aphelenchoides hylurgi n. sp. Figure 116

Female: 0.57 mm; a = 26.6; b=:10.2; c = 14.7;

V = 66%.

Male : Unknown.

Body ventrally arcuate, cylindroid. Without

lateral incisures. Transverse striae absent or

very faint, only discernible on neck region in

some specimens, otherwise cuticle smooth. Lip

region set off, rounded. Cephalic framework

sclerotized. Lips distinct. Stylet 13 /x in length.

Retractor muscles indistinct. Metacorpus almost round, anterior portion glandular, valve

plates located posteriorly. Esophageal gland

outlet indistinct. Dorsal esophageal gland 4

times body width in length. Nerve ring onehalf body width posterior to metacorpus. Excretory pore slightly posterior to nerve ring.

Hemizonid not observed. Lips of vulva protuberant, the posterior lip more than anterior.

Ovary at times reflexed and reaching to the

nerve ring, single, oocytes arranged in a single

row. Posterior uterine branch one and one-half

body widths in length. Anal opening distinct,

rectum obscure. Tail conoid. Terminus 3-

pronged, the prongs in various shapes as

figured.

Diagnosis.—Related to Aphelenchoides aligarhensis Siddiqui, Husain, and Khan, 1957;

differs from that species in size and conformation of lateral striae; similar to A. astero175
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11

Figure 115.—^plieieiîcfioirfes conophthori n. sp.: ^. Head and neck; B. female, midbody; C. head; D. maie, tail;

E. female, tail.

176
i,

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Figure 116.—Aphelenchoides hylurgi n. sp.: ^. Head and neck; B. head; C. female, midbody; D-E. female, tails.

177
catidatus Das, 1960; differs in absence of lateral incisures. Differs from both species in

placement of valve plates in metacorpus.

Type habitat.—Associated with Hyhtrgops

pinifex in eastern v^hite pine.

Type locality.—Gorham, Maine.

Type specimens.—Collection No. 78-G.

Aphelenchoides pityokteini n. sp. Figure 117

Female : 0.54-0.74 mm ; a = 28.5-29.6 ; b = 9.5-

11.3;c = 22.8-24.6;V = 72-75%.

Male: 0.54mm; a = 27.2;b=:9.1;c=r21.8.

Body ventrally arcuate, cylindroid. Lateral

incisures absent. Cuticle v^ith moderately fine

transverse striae. Lip region set off, rounded.

Cephalic framev^ork sclerotized. Lips distinct.

Stylet 12 fx in length, w^ith small basal knobs or

thickenings, retractor muscles distinct. Metacorpus oblong, ovate; dorsal esophageal gland

outlet obscure. Valve plates median. Dorsal

esophageal gland slender, 4 body widths in

length. Nerve ring one-half body width posterior to metacorpus. Excretory pore opposite

nerve ring. Hemizonid not observed. Lips of

vulva protuberant, posterior lip protruding

more than anterior. Vagina oblique. Ovary outstretched. Oocytes arranged in a double row.

Postuterine branch 6 body widths in length,

anterior end with a heavily sclerotized pluglike

body which may act as a valve for sperm cells

stored in postuterine branch. Anal opening and

rectum obscure. Tail conoid to a rather sharply

rounded terminus.

Male: With cuticular, head, and neck characteristics of female. Testis outstretched. Spicules paired, very heavily sclerotized. Apex low,

ventral rostrum short. Tail ventrally arcuate,

with a variably shaped terminus, from bluntly

rounded to mucronate to sharply pointed. There

are 2 pairs of postanal papillae.

Diagnosis.—Closely related to Aphelenchoides tenuidens Thorne, 1935. Differs in the

absence of lateral incisures and in character of

lateral striations.

Rühm, 1956 erred in placing A. tenuidens

in the genus Ektaphelenchus. The shape of the

spicules, the presence of a visible anal opening,

the fine stylet conformation, and lip shape all

preclude its placement in the genus Ektaphelenchus.

Type habitat.—Associated with Pityokteines

sp. infesting corkbark fir.

Type locality.—Sandia Mts., Cibola National

Forest, New Mexico.

Type specimens.—Collection No. 78-0 (Holotype) ;78-N (Allotype).

Aphelenchoides polygraphi n. sp. Figure 118

Female: 1.18-1.30 mm; a = 41.16-48.33; b =

12.6-14.0; c = 16.1-21.7;V=:69%.

Male: 1.04-1.26 mm; a = 39.4-48.2; b = 11.8-

12.6; c = 16.6-19.7.

Body cylindroid. Cuticle finely annulated with

2 lateral incisures. Lip region rounded, set off.

Cephalic framework sclerotized. Lips distinct.

Stylet 15-16 /x in length, with small basal

knobs. Retractor muscles distinct, but weak.

Metacorpus spheroid with anterior section

glandular. Dorsal esophageal gland distinct,

5-6 body widths in length. Nerve ring ca 1

body width posterior to metacorpus. Excretory

pore opposite nerve ring. Lower lip of vulva

protuberant. Ovary with oocytes in a single

row. Posterior uterine branch 4-5 body widths

in length. Sclerotized valvelike organ at juncture of ovary and postuterine branch. Anus

and rectum as illustrated. Tail conoid to an

acute terminus.

Male: Testis single, outstretched. Spicules

massive, with short ventral, obtuse rostrum.

One pair of preanal papillae, two pairs of postanal papillae. Tail ventrally arcuate, terminus

as in female.

Diagnosis.—Distinctive because of massive

spicules and their conformation.

Type habitat.—Associated with Polygraphiis

hoppingi in Engelmann spruce.

Type locality.—Flagstaff, Arizona.

Type specimens.—Collection No. 78-Q.

Aphelenchoides rhytium Massey, 1971 Figvire 119

Females: 0.78-0.94 mm; a = 43-48; b = 11.7-

13.4;c = 16-21;V = 67%.

Males: 0.70-0.78 mm; a = 47-54; b = 10.6-

13.0; c = 19-22.

Cuticle with fine transverse striations. Head

broadly rounded, set off by constriction. Stylet

11 /x long, with prominent basal thickenings,

muscles well defined under dark field illumination. Metacorpus ovate to oblong ovate. Dorsal

esophageal gland slender, ca 6 body widths long.

Nerve ring slightly over a body width behind

metacorpus. Excretory pore adjacent and

178
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Figure 117.—Aphelenchoides pityokteini n. sp.: A, Head and neck; B, female, midbody; C. head; D. female, tail;

E, male, tail.

179
i il

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Figure 118.—Aphelenchoides polygraphi n. sp.

tail.

A, Head and neck; B, female, midbody; C. female, tail; D, male,

slightly posterior to nerve ring. Hemizonid onehalf body width posterior to excretory pore.

Lips of vulva protuberant. Ovary single, outstretched. Walls of uterus strongly thickened

as it enters vagina. Posterior uterine branch

4-6 body v^idths long. Tail conoid to a unique

digitate terminus.

Male : Testis single, outstretched ; spicules as

figured. Tv^o pair of caudal papillae located as

figured. Tail conoid then digitate.

Diagnosis.—Related to Aphelenchoides

hamatus Thorne and Malek (1968). Diflfers in

general body proportions, absence of lateral

incisures, and in the outstretched ovary.

Habitat,—Associated v^ith Ips calligraphus

in loblolly pine, and v^ith Chramesus hicoriae

in pignut hickory.

Tijpe locality.—Baker Mills, New York.

Type specimens.—Collection No. 56-T.

180
mim0i

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31

111

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Figure 119.—Aphelenchoides rhytium Massey, 1971: A. Head and neck; B, fiead; C. female, midbody; D. maie,

tail; E. female, tail.

181
Aphelenchoides tenuidens Thorne, 1935 Figure 120

Female: 0.8 mm; a=:37; b = 7.7; c = 20;

V = 75%.

Male: 0.75 mm; a = 39; b = 7.1; c = 15.

Body tapering rapidly anteriorly, the widest

at esophageal bulb being 21/2 times that of lip

region. Female tail 3 times as long as anal body

diameter, slightly convex-conoid to the abruptly

conoid terminus, which does not bear a distinct

muero. Male tail slightly bent ventrally, terminus mucronato. Four pair of submedian papillae present, 2 pairs preanal and 2 caudal.

Spicula about two-fifths as wide as body, arcuate in distal half, proximally almost straight

on dorsal side; ventral side ñexible when spicula are extruded.

Distinct striations of the cuticle interrupted

by a wing area, which near middle of nema is

about one-eighth as wide as body. Lip region

amalgamated, caplike, set off by constriction.

Vestibule well cuticularized. Spear very slender, its length almost twice width of lip region,

with obscure basal swellings. In living specimens distinct joint observed near middle of

spear. Esophageal bulb ovate, with strong musculature, a little more than half as wide as

neck; nerve ring one bulb length behind bulb.

Excretory pore slightly back of nerve ring.

Intestines densely granular. Ovary outstretched, sometimes almost reaching esophagus. Posterior uterine branch reaching one-half

to three-fourths the distance to anus. Eggs half

as wide as body; 21/2 times as long as wide.

Testis usually outstretched, occasionally reflexed a short distance.

Diagnosis.—Aphelenchoides, Spear twice as

long as width of lip region, with obscure basal

swellings. Male terminus with muero, female

terminus without muero. Spicula two-fifths as

wide as body, proximally almost straight on

dorsal side, ventrally slender, flexible. Male

caudal papillae arranged as shown in figure.

Associate of Dendroctonus ponderosae.

Genus Bursaphelenchus Fuchs, 1937

Synonym : Aphelenchoides (Bursaphelenchus) (Fuchs, 1937) Rühm, 1956

Type species : Bursaphelenchus piniperdae

Fuchs, 1937

Male tail with thin sclerotized terminal extension forming a spadelike clasping organ, at

times multi-pronged. Spicules variable in

shape. Lip region well set off, with well sclerotized framework. Stylet plain or with moderately developed basal thickenings. Metacorpus ovate, with crescentic valve plates at or

near center, the anterior portion glandular.

Ovary outstretched or reflexed, with oocytes

arranged in one to several rows. Posterior

uterine branch usually elongate and acting as a

store for spermatozoa.

Bursaphelenchus bestiolus n, sp. Figure 121

Female: 0.83 mm; a = 31.8; b=:12.2; c = 17;

V = 74%.

Male: 0.67 mm;a = 32;b = 10.7;c = 18.3.

Body cylindroid, ventrally arcuate. Cuticle

with fine transverse striae, without lateral

incisures. Lip region set off, rounded. Cephalic

framework sclerotized. Stylet 13-14 /x, slender,

without basal knobs, retractor muscles distinct.

Metacorpus elongate, ovate, the anterior onethird glandular. Dorsal esophageal gland 3-5

body widths in length. Nerve ring two-thirds

body width posterior to metacorpus. Excretory

pore and hemizonid not observed. Ovary outstretched, the oocytes arranged in 3 rows. Anterior lip of vulva modified into protective flap.

Posterior uterine branch 8-9 body widths in

length. Anus and rectum visible, but indistinct.

Tail conoid to a sharply rounded terminus.

Male: Testis outstretched. Spicules paired,

shaped as figured, reaching almost to dorsal

body wall, ventral rostrum relatively short.

There are 3 pairs of ventrosubmedian papillae,

1 pair preanal, 2 pairs postanal. Tail ventrally

arcuate to a claw-shaped terminus.

Diagnosis.—Closely related to Bursaphelenchus talonus (Thorne, 1935) J. B. Goodey,

1960 ; varies in the shape of the spicules and in

the presence of the vulva flap.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Bandolier National Monument, New Mexico.

Type specimens.—Collection No. 28-R.

Bursaphelenchus corneolus Massey, 1966 Figure 122

Female: 0.65-0.70 mm; a = 29; b = 10.5; c =

18.5;V-73%.

Male : 0.57-0.70 mm ; a = 35 ; b = 10.5 ; c = 18.5.

Cuticle nearly smooth, transverse striations

very faint. Head caplike, lips distinct. Stylet

182
• :J

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Figure 120.—AphelenchoUles tenuidens Thorne, 1935:

tail; D. spiciile. (After Thorne, 1935).

A. Head and neck; B. female, tail; C. male,

183
any "V

• /.•."^''••. *. 1.11

M .I Hi'-I

Figure 121.—Bursaphelenchus bestiolus n. sp.: ^. Head and neck; B, head; C. female, tail; D. female, midbody;

E. male, tail.

without basal knobs or thickenings. Median

bulb of esophagus slightly longer than wide in

lateral view; esophageal gland length over 3

times body width. Nerve ring immediately

posterior to median bulb. Excretory pore 1

body width posterior to nerve ring. Hemizonid

immediately posterior to excretory pore. Ovary

outstretched, reaching beyond posterior end of

esophageal glands. Sperm duct packed with

spermatozoa ; posterior uterine branch reaching

to within 2 body widths of anal opening, packed

with spermatozoa. Vulva covered by a cuticular

flap. Tail hooked as figured.

Male: Testis single, reflexed at times as

much as 3 body widths. Spicula relatively short.

184
Figure 122.—Bursaphelenchus corneolus Massey, 1966: À. Male; B. female; C. head; D. spicula.

185
Three pairs of postanal ventrosubmedian papillae. Tail hooked ; with spadelike terminus.

Diagnosis,—Closely related to Bursaphelenchus eggersi (Rühm, 1956) Goodey, 1960. B.

corneolus differs in smaller size of female, presence of vulval flap, and size and shape of spicula.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens,—Collection No. 37-L.

Bursaphelenchus elytrus Massey, 1971 Figure 123

Female: 0.89-0.96 mm; a = 35-41; b=:9.6-

11.6;c = 17-21;V = 73%.

Male: 0.83-1.04 mm; a = 41-52; b = 10.4-

14.2;c = 21-26.

Cuticle with very faint transverse striations.

Lip region set off by constriction, lips distinct.

Stylet 15 /x long, with basal thickenings. Metacorpus oblong ovate. Dorsal esophageal gland

4-5 body widths long. Excretory pore opposite

metacorpus. Nerve ring slightly over one-half

body width posterior to metacorpus. Hemizonid opposite nerve ring. Lips of vulva only

slightly elevated. Ovary relatively short, outstretched. Posterior uterine branch 7-8 body

widths long. Tail conoid to a narrowly rounded

or acute terminus, sclerotized.

Male: Testis outstretched, spicules uniquely

shaped for genus, with sharply pointed ventral

rostrum, tip of dorsal limb obscure, with a

short rounded projection as it joins transverse

bar. Three pairs of caudal papillae located as

figured. Terminus acute.

Diagnosis.—Differs from other species in

genus in shape and conformation of spicules.

Habitat.—Associated with Hylurgops pinifex in red pine and in eastern white pine.

Type locality.—Hamden, Connecticut.

Type specimens.—Collection No. 56-W.

Bursaphelenchus newinexicanus n. sp. Figure 124

Female: 1.5 mm; a = 40.4; b = 14.2; c = 28.1;

V = 73%.

Male: 1.25 mm; a = 47.4;b = 13.2;c = 26.3.

Body cylindroid. Cuticle with very fine transverse striae, no lateral incisures. Lip region set

off, rounded. Cephalic framework sclerotized.

Stylet fine, without basal knobs, 15 /x in length;

retractor muscles distinct. Median bulb elongate-spheroid, anterior one-fifth glandular.

Dorsal esophageal gland outlet obscure. Dorsal

esophageal gland 4 body widths in length.

Nerve ring two-thirds body width posterior to

median bulb. Excretory pore immediately posterior to median bulb. Ovary outstretched.

Oocytes arranged in 3 rows. Anterior lip of

vulva modified into flap. Posterior uterine

branch massive, 6-7 body widths in length and

usually packed with sperm cells. Anal opening

distinct. Rectum appearing as a thin line in

lateral view. Tail conoid to a narrowly rounded

terminus.

Male: Testis outstretched, Spicules paired,

with short ventral rostrum, the apices modified into a knob. Tail ventrally arcuate with 2

pairs of papillae, 1 pair immediately preanal,

1 pair postanal. Terminus 3-pronged, the outer

prongs acute, the center prong somewhat

shorter and less acute.

Diagnosis.—Related to Bursaphelenchus

elytrus. Differs in the shape of spicules and in

the form and conformation of male terminus.

Type habitat.—Associated with Hylurgops

sp. in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 37-U.

Bursaphelenchus pityogeni n. sp. Figure 125

Female: 0.94 mm; a = 30; b = 13.8; c = 25.7;

V = 73%.

Male : 0.82 mm ; a = 31 ; b = 12.1 ; c = 22.4.

Body cylindroid. Cuticle with 2 lateral incisures, transverse striae fine. Lip region

rounded, lips distinct. Cephalic framework

sclerotized. Stylet 14-15 /x in length, with small

basal knobs or thickenings; retractor muscles

distinct. Dorsal esophageal gland outlet obscure. Median bulb oblong, anterior one-eighth

glandular. Dorsal esophageal gland approximately 3 body widths in length. Nerve ring twothirds body width posterior to metacorpus.

Excretory pore immediately posterior to metacorpus. Hemizonid not observed. Vulva with

distinct fiap, lips slightly elevated. Ovary outstretched with oocytes arranged in 3 rows.

Posterior uterine branch massive, filling body

cavity, 5-6 body widths in length. Anal opening distinct. Rectum appearing as a fine line.

Tail conoid to a small rounded terminus.

186
Figun 123.—Bursaphelenchus elytrus Massey, 1971: A. Head and neck; B, head; C. female, tail; D. female, midbod y ; E, male, tail.

187
(ííiií

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. V;

liaiI

111

i!

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.01mm.

'MEA

03 mm

Figure 124.—Bursaphelenchus newmexicanus n. sp.: A, Head and neck; B, head; C, female, midbody; D. male, tail

E, female, tail.

188
Figure 125.—Bursaphelenchus pityogeni n. sp.

E, male, tail.

A, Head and neck; B, head; C, female, tail; D, female, midbody;

189
Male: Testis outstretched. Sperm cells relatively large. Spicules paired, ventral rostrum

elongate, sharply pointed. Apex squared, hammerlike in lateral view^. Tv^o pairs of ventral

papillae, 1 pair preanal, 1 pair postanal. Terminus sharply pointed.

Diagnosis.—Differs from other species in

presence of lateral incisures.

Type habitat.—Associated with Pityogenes

carinulatus (Lee.) in ponderosa pine.

Type locality.—Mt. Taylor, Cibola National

Forest, Nev^ Mexico.

Type specimens.—Collection No. 56-J.

Bursaphelenchus scolyti n. sp. Figure 126

Female: 0.84 mm; a = 40; b = 12.3; c = 20;

Y = 72%.

Male: 0.80 mm; a = 38; b = 11.7; c = 25.3.

Body cylindroid. Cuticle relatively smooth,

v^ith faint transverse striae. No lateral incisures. Lip region set off, rounded. Lips and cephalic framev^ork distinct. Stylet slender, 11.5

fjL in length, v^ith small basal knobs or swellings,

retractor muscles indistinct. Metacorpus oblong

ovate, anterior one-eighth to one-fourth glandular. Dorsal esophageal gland outlet indistinct. Dorsal esophageal gland over 5 body

widths in length. Nerve ring three-fourths body

width posterior to metacorpus. Excretory pore

opposite nerve ring. Hemizonid not observed.

Lips of vulva protuberant. Ovary outstretched ;

oocytes arranged in a single row. Posterior

uterine branch large, up to 7 body widths in

length, filling entire body cavity and acting as

a storage compartment for relatively large

sperm. Anus and rectum indistinct. Tail conoid,

elongate, to a finely rounded terminus.

Male : With head and neck characteristics of

female. Testis single, outstretched, relatively

short. Spicules paired with thornlike apex extending toward dorsal body wall, ventral rostrum slender, elongate. Two pair of postanal

ventrosubmedian papillae. Tail extremely ventrally arcuate. Terminus 3-pronged, center

prong bluntly rounded, outer prongs to an acute

point, claw-like in lateral view.

Diagnosis.—Distinctive because of comparatively short stylet, long slender tail of female,

and shape and conformation of spicules.

Type habitat.—Associated with Scolytus

multistriatus in American elm.

Type locality.—Ft. Collins, Colorado.

Type specimens.—Collection No. 19-E.

Bursaphelenchus talonus (Thorne, 1935) J. B. Goodey,

I960 Figure 127

Female: 0.8 mm; a = 33; b=:8.3; c = 25;

V = 73%.

Male : 0.8 mm ; a = 47 ; b = 10 ; c = 25.

Anteriorly body is slightly convex-conoid to

the amalgamated, truncate, definitely set off lip

region, which is one-third as wide as the neck

at the bulb. Female tail convex-conoid to the

blunt, rounded terminus, which bears no muero.

Male tail ventrally arcuate, ending in cuticular,

talonlike terminus. Spear slender, without basal

knobs, its length equal to twice the width of the

lip region. Vulva with slightly elevated labia.

Ovary extending forward, then reñexed a short

distance. Posterior uterine branch reaching

three-fourths the way to the anus. Eggs 2 to

21/^ times as long as body width. Testis reflexed a short distance.

Diagnosis.—Bursaphelenchus with above

measurements. Male with "mitten-shaped''

spicula and cuticular talonlike terminus. Female tail conoid to the blunt rounded terminus,

which bears no muero. Lip region amalgamated, definitely set off. Spear without basal

knobs, its length equal to twice width of lip

region.

Associate of Dendroctonus ponderosae.

Bursaphelenchus tritrunculus n. sp. Figure 128

Female: 0.65 mm; a = 29.2; b = 9; c = 11.4;

V = 71%.

Male: 0.65 mm; a=:29; b = 9; c = 23.4.

Body cylindroid. Cuticle with moderately

prominent transverse striae, especially visible

at neck region and between anus and terminus.

No lateral incisures. Lip region barely set off,

rounded. Cephalic framework sclerotized. Stylet

fine, 13 ¡i in length, without basal knobs, retractor muscles distinct. Metacorpus ovate,

anterior one-third glandular. Dorsal esophageal

gland outlet obscure. Dorsal esophageal gland

3-4 body widths in length. Nerve ring immediately posterior to metacorpus. Excretory pore

opposite nerve ring. Hemizonid not observed.

Ovary at times reflexed, oocytes arranged in a

double row. Posterior uterine branch 3-4 body

widths in length and usually containing numer190
I

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pel

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mil llïSIff

03 mm

mm

:: '•••V.I-. .i:í/:,;.;/:

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Figur<í 126.—Bursaphelenchus scolyti n. sp.

E. male, tails.

kmm hmm

A. Head and neck; B. head; C. female, tail; D. female, midbody;

191
.-••:i

mill

m :m^:

'M:

Figure 127.—Bursaphelenchus talonus (Thorne, 1935) J. B. Goodey,

1960: A, Head and neck; B. male, tail; C. female, tail. (After Thorne,

1935).

192
.•l/il :!:ï

JíiivB

ii~i

si:; 11-VI ..II

í:l:>^ll^1:i

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Figure 128.—Bursaphelenchus tritrunculus n. sp.: ^. Head and neck; B. female, midbody; C. head; D. female, tail;

E. ventral view, male, tail; F. lateral view, male, tail.

193
ous sperm cells. Anus and rectum indistinct.

Tail attenuated to an acute terminus.

Male: Testis single, outstretched, relativelyshort. Spicules with apices broadly rounded,

and a prominent, obtuse ventral rostrum. There

are two pairs of caudal papillae, 1 pair preanal,

1 pair postanal. Tail ventrally arcuate. Terminus spadelike, the outer edges semiacute, the

inner core obtuse.

Diagnosis.—Especially distinctive as it bears

characteristics commonly found in the genus

Cryptaphelenchus as they relate to the head

and to the spicula.

Type habitat.—Associated with Dendroctonus terebrans in loblolly pine.

Type locality.—Nacogdoches, Texas.

Type specimens.—Collection No. 79-C.

Bursaphelenchus wilfordi Massey, 1964 Figure 129

Female: 0.9 mm; a = 60; b = 15; c==:27; V =

70%.

Male: 0.67-0.75 mm; a = 61; b = 10; c = 26.

Cuticle smooth. Lip region expanded, caplike.

Spear slender, without basal knobs, obscure in

many specimens. Median bulb of esophagus

symmetrically oval. Dorsal esophageal glands

prominent, approximately 4 body widths in

length. Nerve ring conspicuous, one-half body

width posterior to median bulb. Excretory pore

and hemizonid not observed. Ovary outstretched, at times nearly reaching to esophageal gland. Postuterine branch elongate, extending nearly to the anal opening, sperm cells

present in both uterus and postuterine branch.

Tail conoid to a subacute terminus as figured.

Male : Testis reñexed. Spicula mitten shaped,

the distal end almost square in lateral view.

Three pairs of ventrosubmedian caudal papillae: 1 preanal; 2 postanal, 3 postanal immediately posterior to number 2. Terminus spadelike, sclerotized.

Diagnosis.—Bursaphelenchus wilfordi is

closely related to B. cryphali (Fuchs, 1930) J.

B. Goodey, 1960, and B. crenati (Rühm, 1956)

J. B. Goodey, 1960. It differs in its smaller size,

shape of spicula, and length of the postuterine

branch.

Type habitat.—Associated with Scolytus

ventralis in white fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 37-F.

Genus Laimaphelenchus Fuchs, 1937 Emended

Type species : Laimaphelenchus moro Fuchs,

1937

Aphelenchoidinae : Terminus in both sexes

stalked, bearing suckerlike tubercles or irregular projections. Ovary single, with oocytes

arranged in a single row. Postuterine branch

rudimentary to several body widths in length.

Vulva with or without vulval flap. Stylet plain

or with well developed basal knobs. Metacorpus

ovate, the dorsal esophageal glands well developed.

Key to the Laimaphelenchus associated with bark beetles in

the United States

1. Terminus stalked, bearing suckerlike tubercles in both sexes 2

Terminus stalked, bearing irregular projections in both sexes pannocaudus

2. Vulva with flap 3

Vulva without flap phloeosini n. sp.

3. Spicules strongly ventrally arcuate, ventral

rostrum distinct, spicules less than 30 [x permrdi

Manubrium of spicules projected into indistinct ventral rostrum, spicules more

than 30 /x pensobrinus

194
:?i.#:

:;;^:-!¿:

.M.::':

Figure 129.—Bursaphelenchus wilfordi Massey, 1964.: A. Head and neck; B, head; C. female, tail; D. female, midbc>dy; E, maie, tail.

195
Lainiapheleuchus pannocaudus Massey, 1966 Figure 130

Female: 0.79-0.86 mm; a = 50; b = 13; c = 23;

V = 70%.

Male: 0.65-0.78 mm; a = 50; b = 13; c = 22.

Body slender. Cuticle with very faint transverse striations. Head rounded, set off, lips

approximately tv^ice as v^ide as deep. Stylet

with prominent basal knobs. Median bulb of

esophagus ovate, nearly spheroid. Nerve ring a

body width posterior to median bulb. Excretory

pore anterior to nerve ring. Hemizonid not observed. Dorsal esophageal gland 6 times body

width in length. Ovary outstretched, reaching

nearly to distal ends of esophageal glands, posterior uterine branch 3-6 body widths in length,

uterus filled with granular, circular spermatozoa. Vulva slightly elevated. Terminus ragged

in appearance with bristlelike protuberances.

Male: Testis outstretched, almost reaching

posterior end of esophageal glands. Spicula

arcuate with low rostrum. Tail semicircular,

with 1 pair of postanal caudal papillae. Terminus as in the female.

Diagnosis,—This species is closely related to

Laimaphelenchus lignophilus (Körner, 1954)

J. B. Goodey, 1960. It differs in its smaller size,

number of male caudal papillae, and absence of

a bursa.

Type habitat.—Associated with Dendroctoniis adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 37-K.

Laimaphelenchus penardi (Steiner, 1914) Filipjev and

Schuurmans Stekhoven, 1941 Figure 131

Synonyms : Aphelenchus penardi Steiner,

1914

Aphelenchoides penardi (Steiner,

1914) Filipjev, 1934

Specimens of Laimaphelenchus very similar

to L. penardi have been collected in association

with several species of bark beetles throughout

the United States. Steiner's original description

of the species is quite meager. Type specimens

are not available for study ; it may be that the

species being designated as penardi in collections throughout the country may be something

quite different. Only by a monographic study

of the genus can correct speciation be determined. The following description is based on a

translation of Steiner's original description.

Only the female is known.

Body small anteriorly. Cuticle finely annulated, without setae. Head and neck annulated ;

with 3 lips. Esophagus with a typical aphelenchoid bulb. Nerve ring not broader than wide ;

excretory pore ventral to the nerve ring.

Vulva two-thirds of the length from the

front end. Female ovary developed anteriorly.

Postuterine branch rudimentary. Tail proportionately short, gradually attentuated to a terminus with 4 papillaelike appendages resembling one another.

Measurements : Length 0.573 mm a = 30

Esophagus 0.054 mm b = 10.6

Tail 0.029 mm c =20

Width 0.019 mm

The following description is of specimens

taken in association with Scolytus ventralis

from white fir, and in the author's opinion is

Laimaphelenchus penardi.

Female: 0.70-0.80 mm; a = 30; b = 8.8-9.2;

c = 18.4-20 ;V = 68-70%.

Male: 0.70-0.80 mm; a = 39.2-41; b=:ll.l11.9; c = 15.2-17.

Body cylindroid, ventrally arcuate, at times

almost a spiral. Cuticle with 2 lateral incisures,

appearing as a broad band in lateral view,

annulations moderately coarse. Lip region set

off, rounded. Cephalic framework sclerotized,

lips distinct. Stylet 14-15 /x in length, with well

developed basal knobs; retractor muscles discernible but not well developed. Metacorpus

ovate, the dorsal esophageal gland outlet not

discernible, the gland approximately 5 body

widths in length. Nerve ring one-half body

width posterior to metacorpus. Excretory pore

one-half body width posterior to nerve ring.

Hemizonid not discernible. Vulva with a prominent vulval flap. Ovary single, reaching beyond

distal end of dorsal esophageal gland; oocytes

arranged in a single row. Postuterine branch

up to 4 body widths in length. Anus and

rectum as illustrated. Tail conoid to a stalked

terminus bearing four suckerlike tubercles.

Male : With head and neck characteristics of

female. Testis outstretched. Tail ventrally arcuate; there is one pair of postanal caudal pa196
Il

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í 11 vi .•.:!

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i

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m-im

i

f

p

fill

111

Figure 130.—Lainiaphelenchus pannocaudus Massey, 1966:

D. male, tail; E. female, tail.

I

t

.4. Head and neck; B. female, midbody; C head;

197
Figure 131.—Laimaphelenchus penardi (Steiner, 1914) Filipjev and Schuurmans Stekhoven, 1941: A, Head and

neck; B, female, midbody; C. male, tail; D. female, tail; E, lateral field.

198
pillae. Spicules strongly ventrally arcuate, with

a low distinct rostrum. Terminus as in female.

Laimaphelenchus pensobrinus Massey, 1966 Figure 132

Female: 0.46-0.53 mm; a = 30; b = 10; c = 21;

V=:70%.

Male : 0.51 mm ; a=:33 ; b = 10.5 ; c = 17.

Cuticle finely annulated. Lateral field interrupted by 2 incisures. Lip region set off, lips

distinct. Stylet with prominent basal knobs.

Median bulb of esophagus ovate ; dorsal esophageal gland over 4 body diameters in length.

Nerve ring 1 body width behind median bulb.

Excretory pore less than 1 body width posterior to nerve ring. Hemizonid not apparent.

Ovary outstretched, at times reaching well

beyond distal end of dorsal esophageal gland;

postuterine branch up to 21/^ body diameters

in length. Vulva with cuticular flap. Tail dorsally convex, conoid, terminating in 4 suckerlike tubercules.

Male : Testis single, outstretched, reaching to

within 4 body diameters of dorsal esophageal

gland. Spicula arcuate. Anal opening covered

by a cuticular flap. Two pairs of ventrosubmedian papillae. Tail semicircular. Terminus

as in the female.

Diagnosis.—Closely related to Laimaphelenchus penardi (Steiner, 1914) Filipjev and

Schuurmans Stekhoven, 1941. It differs in its

generally smaller size, number and location of

caudal papillae, and in size and shape of spicula

and presence of anal flap on male.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 37-J.

Laimaphelenchus phloeosini n. sp. Figure 133

Female: 0.51 mm; a = 23.3; b = 8.45; c =

15.50;V = 72%.

Male : 0.50 mm ; a = 30 ; b = 8.18 ; c = 12.8.

Cylindroid, ventrally arcuate. Cuticle with 2

lateral incisures and moderately fine annulations. Cephalic framework sclerotized, lips distinct. Stylet 12-13 ^ with well developed basal

knobs, retractor muscles obscure. Metacorpus

ca circular, anterior sector glandular; dorsal

esophageal glands 5 body widths in length.

Nerve ring slightly less than a body width

posterior to metacorpus. Excretory pore at

nerve ring. Vulva lips slightly elevated without

flap. Ovary single, outstretched, at times reaching beyond the distal end of esophageal glands.

Posterior uterine branch 3-4 body widths in

length. Anus and rectum as illustrated. Tail

conoid to 4 very small stalked tubercles.

Male : With head and neck characteristics of

female. Testis single, outstretched. Spicules

paired, ventral rostrum pointed, reduced in

size. One pair of postanal ventrosubmedian papillae. Tail ventrally arcuate to terminus as in

female.

Diagnosis.—Differs from Laimaphelenchus

pensobrinus and L. penardi in the smaller size

of the terminal tubercles, in size and shape of

spicules, and absence of a vulval flap.

Type habitat.—Associated with Phloeosinus

dentatus in eastern redcedar.

Type locality.—Keysville, Virginia.

Type specimens.—Collection No. 79-E.

Genus Ektaphelenchus (Fuchs, 1937) Skrjabin et al,

1954 Emended

Synonym : Parasitaphelenchus (Ektaphelenchus) Fuchs, 1937

Cryptaphelenchoides J. B. Goodey,

1960

The type species Ektaphelenchus hylastophilus (Fuchs, 1930) Skrjabin et al, 1954, was

originally described in the genus Parasitaphelenchus by Skrjabin and others in 1954, who

presented Parasitaphelenchus hylastophilus

forma ateri Fuchs, 1930 as the type species.

Body cylindroid. Head offset, angular in lateral view. Lips distinct and separate, the lateral

lips narrower than the other four. Lateral

fields obscure or absent. Stylet with a wide

lumen with or without basal knobs. Metacorpus

ovate, with the anterior one-third to one-half

glandular in composition. Prominent valve

plates at or posterior to middle of bulb. Dorsal

esophageal glands well developed and elongate,

usually 7-8 body widths in length. Vulva posterior, lips usually not elevated. Postuterine

branch occasionally several body widths in

length. Anus and rectum usually not visible,

the gut ending as blind diverticulum. Spicules

ventrally curved with a prominent ventral

rostrum. Caudal papillae usually present.

199
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fill

11 fi»'

¡I« 's!

à

m mi

Figure 132.—Laimaphelenchus pensobrinus Massey, 1966: A, Head and neck; B. female, midbody; C. head; D.

female, tail; E, male, tail.

200
m kmà

Figure 133.—Laimaphelenchus phloeosini n. sp.: A. Head and neck; B. head; C. female, tail; D.

male, tail.

201
Key to the female species of Ektaphelenchus associated with

bark beetles in the United States

1. Postuterine branch several body widths in

length sandiaensis

Postuterine branch rudimentary or not

over a body width long 2

2. Stylet 25 /x or less 3

Stylet over 30 /x terebranus n. sp.

3. Terminus obtuse obtusus

Terminus acute or subacute 4

4. Stylet with basal swelling 21 /x in length .. prolobos

Stylet with prominent basal knobs josephi n. sp.

Stylet without knobs 16 /x in length smaelus n. sp.

Ektaphelenchus josephi n. sp/ Figure 134

Female: 0.83-0.92 mm; a=29.5-33; b=8-9,

c=?;V= 75-77%.

Male: 0.71 mm; a=::32; b = 7; c = 12.

Body cylindroid, ventrally arcuate. Cuticle

without lateral incisures, with very fine transverse striae. Lip region fiat, set off. Lips distinct. Cephalic framework strongly sclerotized.

Stylet 22 /x in length with prominent basal

knobs which are angular in lateral view. Subulate shaft more strongly sclerotized than shaft.

Retractor muscles distinct. Dorsal esophageal

gland outlet conspicuous in anterior third of

metacorpus. Median bulb oblong, much longer

than wide, anterior third glandular. Dorsal

esophageal gland relatively slender, 5 body

widths in length. Nerve ring slightly less than

a body width posterior to metacorpus. Excretory pore a body width posterior to nerve ring.

Hemizonid immediately posterior to excretory

pore. Lips of vulva only slightly protuberant.

Vagina oblique. Ovary single, outstretched,

comparatively short. Oocytes arranged in a

double row, in some specimens three rows for

a very small portion of its length as figured.

Quadricolumella prominent, approximately a

body width in length. Postuterine branch short,

less than a body width in length. Anus and

rectum not visible. Tail conoid to a narrowly

rounded terminus.

Male: Testis single, outstretched, Spicules

mitten shaped, apex high, dorsal arm heavily

sclerotized. Ventral rostrum prominent and

sharply pointed. Three pairs of caudal papillae,

1 pair immediately preanal ventrosubmedian,

1 pair immediately postanal ventrosubmedian,

7 Named in honor of my son, Joseph.

and 1 pair postanal ventral, ca 2 body widths

anterior to terminus. Tail conoid, extremely

ventrally arcuate. Terminus a short rigid hairlike filament.

Diagnosis,—Allied to E. prolobos; differs

from that species in the prominent triangular

knobs of stylet and in the terminus of the male.

Type habitat.—Associated with Dendroctonus ponderosae in limber pine, Pinus flexilis

James.

Type locality.—Capillo Peak, Manzano

Mountains, Cibola National Forest, New

Mexico.

Type specimens,—Collection No. 37.

Ektaphelenchus obtusus Massey, 1956 Figure 135

Female: 0.8 mm; a = 30; b = 8; c=: ?; V = 78%.

Male: 0.7 mm; a = 23; b = 7; c = 14.4.

Body cylindroid, ventrally arcuate. Cuticle

with moderately fine annulations. Lip region set

off, angular. Cephalic framework sclerotized.

Lips distinct. Stylet 24 /x in length, without

basal knobs or thickenings; retractor muscles

distinct and prominent. Metacorpus oblong

ovate, the anterior one-third to one-half glandular. Dorsal esophageal gland outlet prominent. Dorsal esophageal gland 7-8 body widths

in length. Nerve ring ca 1 body width posterior

to metacorpus. Excretory pore ca two-thirds

body width posterior to nerve ring. Hemizonid

not observed. Lumen of intestine distinct for

entire length. Ovary single, outstretched. Postuterine branch rudimentary, less than a body

width in length. Rectum and anus absent. Tail

conoid to an obtuse terminus.

Male : With head and neck characteristics of

female. Testis outstretched. Spicules with a

202
Figure 134.—Ektaphelenchus josephi n. sp.: Â. Female; B. head; C. male, tail.

203
Figure 135.-

male, tail.

-Ektaphelenchus obtusus Massey, 1956: A. Head and neck; ß. head; C, female, tail; D.

204
distal strongly sclerotized footlike projection.

There are 3 pairs of caudal papillae, 1 pair preanal ventrosubmedian, 2 pairs postanal ventrosubmedian. Tail ventrally arcuate, conoid to an

obtuse terminus.

Diagnosis.—Differs from other members of

the genus in the obtuse terminus in both sexes

and in the footlike projection at the distal end

of the spicules.

Type habitat,—Found in galleries and beneath wing covers of Dendroctonus rufipennis.

Type locality.—Red Table Mountain, White

River National Forest, Colorado.

Type specimens.—Collection No. 22.

Ektaphelenchus prolobos Massey, 1964 Emended

Figure 136

Female: 0.70-0.81 mm; a = 0.35; b=:8.5;

C=z?;V=:79%.

Male : 0.61 mm ; a = 35 ; b = 7.0 ; c = 14.0.

Body cylindroid, ventrally arcuate. Cuticle

without lateral incisures, marked by fine lateral striae or annulations. Lip region angular,

set oif. Cephalic framework sclerotized. Lips

distinct. Stylet 12 fi in length, with small basal

swellings. Retractor muscles at best indistinct.

Metacorpus oblong ovate, anterior one-third

glandular, its duct indistinct. Dorsal esophageal

gland 7-8 body widths in length. Nerve ring

two-thirds of a body width posterior to metacorpus. Excretory pore one-third body width

posterior to nerve ring. Hemizonid immediately

posterior to excretory pore. Ovary single, outstretched. Posterior uterine branch ca 1 body

width in length, containing sperm cells. Anus

and rectum absent. Tail conoid to sharp terminus.

Male : With head and neck characteristics of

female. Testis outstretched. Spicules mitten

shaped as figured. Tail ventrally arcuate, with

three pairs of papillae, one pair immediately

preanal, two pair postanal and located as figured. Terminus acute.

Diagnosis.—Differs from Ektaphelenchus

sandiaensis Massey, 1964 in the presence of

basal knobs on the spear and in its shorter

posterior uterine branch.

Type habitat.—Associated with Dryocoetes

confusus in corkbark fir.

Type locality.—Rio Grande Grant, Carson

National Forest, New Mexico.

Type specimens.—Collection No. 28-T.

Ektaphelenchus sandiaensis Massey, 1964 Emended

Figure 137

Female: 0.63-0.64 mm; a = 28-31; b = 8.0-

8.5;c=?;V= 81%.

Male: 0.62-0.64 mm; a = 32; b = 8.0-8.5;

C=:16.

Body cylindroid, ventrally arcuate. Cuticle

with moderately coarse transverse striae, without lateral incisures. Lip region almost continuous with body contour. Cephalic framework

lightly sclerotized, lips distinct. Stylet 25 /x in

length, without knobs or basal thickenings,

retractor muscles distinct, appearing as twisted

bundles. Metacorpus ovate, the anterior onefourth glandular, but hardly set off from basal

portion, its duct indistinct. Dorsal esophageal

gland approximately 8 body widths in length.

Nerve ring two-thirds body width posterior to

metacorpus. Excretory pore a body width posterior to nerve ring and immediately posterior

to hemizonid. Ovary single, outstretched, at

times beyond the posterior tip of dorsal esophageal gland. Posterior uterine branch 4-5 body

widths in length and containing sperm cells.

Anus and rectum absent. Terminus obtuse.

Male : With head and neck characteristics of

female. Testis single, outstretched. There are

3 pairs of ventrosubmedian caudal papillae, 1

pair preanal, 2 pairs postanal, located as figured. Spicules mitten shaped. Tail ventrally

arcuate to a strongly sclerotized acute terminus.

Diagnosis.—Varies from other species in the

genus in the length of the posterior uterine

branch, in the shape of the lips, and sclerotized

terminus of male.

Type habitat.—Associated with Scolytus

ventralis in white fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 22-F.

Ektaphelenchus smaelus n. sp. Figure 138

Female: 0.63-0.65 mm; a = 38-39; b=::7.3-

7.6; c=:?; ¥= 76-77%.

Male : Unknown.

Body cylindroid, ventrally arcuate. Cuticle

with moderately fine lateral striae, without lateral incisures. Lip region slightly set off, angular. Cephalic framework sclerotized. Lips

distinct. Stylet with or without slight basal

205
'Ilílv .02mnn

pill

Eil ivii-:\ "

lv>^>>llV.'-V-J

Ü

Figure 136.—Ektaphelenchus prolobos Massey, 1964 Emended: A, Head and neck; B. maie, tail; C, female, tail.

swellings, 16 /x in length ; retractor muscles indistinct. Metacorpus oblong ovate, anterior

one-third glandular, the glandular duct indistinct. Dorsal esophageal gland 8 body widths

in length. Nerve ring a body width posterior to

metacorpus. Excretory pore immediately posterior to nerve ring. Hemizonid not observed.

Ovary outstretched. Posterior uterine branch

rudimentary. Rectum and anal opening absent.

Tail conoid to an acute terminus.

Diagnosis.—Differs from all other species in

genus in general tail conformation.

206
Mi

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c

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03 mm

//•.:••/. ••.»••• •./.'"•'".Il

// •;y/•-• ^- •••• :>;^v:7/

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W;•^

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a

Figure 137.—Ektaphelenchus sandiaensis Massey, 1964 Emended: A, Head and neck;

head; C, female, tail; D, male, tail.

B.

207
Ektaphelenchus terebranus n. sp. Figure 139

Figure 138.—Ektaphelenchus smaelus n. sp. : A, Head

and neck; B, head; C, female, tail.

Type habitat,—Associated with Dryocoetes

confusus in subalpine fir, Abies lasiocarpa

(Hook.) Nutt; also found associated with Ips

pini and Pityophthorus sp. in eastern white

pine at Neola, West Virginia.

Type locality.—Rabbit Ears Pass, Routt National Forest, Colorado.

Type specimens,—Collection No. 11-V-l.

Female: 0.84 mm; a = 30.4; b = 7.6; c=?;

V = 80%.

Male : Unknown.

Body cylindroid. Cuticle with very coarse

transverse striae and no visible lateral incisures. Lip region well set off. Cephalic framework strongly sclerotized. Stylet 35 fx in length,

without knobs, musculature very prominent,

appearing as twisted rope. Median bulb massive, the anterior one-third glandular, its duct

and tube strongly sclerotized. Dorsal esophageal gland 8-9 body widths in length. Nerve

ring slightly less than a body width posterior

to metacorpus. Excretory pore which opens

through hemizonid slightly less than a body

width posterior to nerve ring. Ovary single,

outstretched. Posterior uterine branch rudimentary. Rectum and anal opening absent. Tail

conoid to narrowly rounded terminus.

Diagnosis.—Closely related to Ektaphelenchus obtusiis Massey, 1956. Varies in its more

coarse transverse striations, its longer spear,

more prominent spear muscles, visible duct to

the glandular anterior portion of metacorpus,

and in its narrowly rounded terminus.

Type habitat.—Associated with Dendroctonus terebrans in loblolly pine stumps.

Type locality.—Nacogdoches, Texas.

Type specimens.—Collection No. 79-D.

Genus Cryptaphelenchus (Fuchs, 1937) Rühm, 1954

Synonyms : Parasitaphelenchus {Cryptaphelenchus) Fuchs, 1937

Parasitaphelenchus {Steineria)

Fuchs, 1937 (nee Steineria

Mikoletzky, 1922)

Type species: Crytaphelenchus macrogaster

(Fuchs, 1915) Rühm, 1956

Length usually less than one-half mm. Lips

rounded, usually continuous with body contour. Cephalic framework sclerotized. Cuticle

with or without lateral incisures. Stylet less

than 10 /x. Metacorpus ca spheroid, muscular.

Dorsal esophageal gland well developed. Ovary

single, short. Posterior uterine branch absent.

Anus and rectum absent. Spicules paired, mit208
Cryptaphelenchus cirrus n. sp. Figure 140

m

' > /

.a/

I i

w

V\ I

j03mm

/ .->

/ //

:/ \

'I /

'./ /

'/ <

/ V

-i

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\\

Female

V = 78%

0.30 mm; a = 25; b = 6.25; c=?;

Male : 0.27 mm ; a = 22.5 ; b = 5.92 ; c = 12.5.

Body ventrally arcuate, cylindroid. Cuticle

with moderately coarse transverse striae, lateral incisures not observed. Lip region continuous with body contour, wider than long. Cephalic framework sclerotized. Stylet 8 />i in

length, slender, without basal knobs or thickenings, retractor muscles indistinct. Metacorpus

ovate, filling body cavity, its width greater than

its length in many individuals, anterior portion

glandular, crescentic valve plates at or near

the center. Dorsal esophageal gland outlet indistinct. Dorsal esophageal gland extends ca 3

body widths posterior to metacorpus. Excretory pore opening through hemizonid and located opposite nerve ring. Lips of vulva indistinct in many specimens. Ovary short; oocytes

arranged in a double row. Posterior uterine

branch absent. Anal opening and rectum absent. Tail ventrally arcuate, conoid, elongate

to a subacute terminus.

Male : Testis outstretched. Spicules with ventral rostrum sharply pointed and turning downward in lateral view. Apex prominent, elongate.

Posterior anal lip heavily sclerotized. There are

two pair of ventrosubmedian papillae, 1 pair

immediately anterior to anal opening, the other

pair immediately anterior to terminus. Tail

ventrally arcuate, terminus acute.

Diagnosis.—Differs from other species in the

genus in tail characteristics of the female.

Type habitat.—Associated with Ips confusus

in pinyon.

Type locality.—Bandelier National Monument, New Mexico.

Type specimens.—Collection No. 8-Z.

Figure 139.—Ektaphelenchus terebranus n. sp.: A.

Head and neck; B, female, midbody and tail.

ten shaped, the apex high and at times distinctly developed. Ventral rostrum usually

elongate, acute. Posterior anal lip heavily sclerotized. There are 2 pairs of caudal papillae.

Cryptaphelenchus ipinius n. sp. Figure 141

Female: 0.43 mm; a==23.2; b = 6.3; c=?;

V=:79%.

Male : 0.26 mm ; a = 19.4 ; b==7.0 ; c = 11.1.

Body ventrally arcuate, cylindroid. Cuticle

with fine lateral striae. Lateral incisures not

observed. Lip region continuous with body contour, rounded. Cephalic framework sclerotized.

Stylet 8.5 /x in length, with distinct basal knobs,

retractor muscles indistinct. Median bulb al209
Figure 140.—Cryptaphelenchus cirrus n. sp.: A, Head and neck; B, head; C, male, tail; D, female, tail.

most round, anterior portion glandular. Dorsal

esophageal gland outlet indistinct. Dorsal

esophageal gland ca 3 body widths in length.

Nerve ring a body width posterior to median

bulb. Excretory pore opening through hemizonid and located opposite nerve ring. Lips of

vulva slightly protuberant. Ovary outstretched,

at times reaching almost to median bulb;

oocytes arranged in 3 rows. Posterior uterine

branch absent. Tail thickly conoid to an acute

terminus.

Male : Testis single, outstretched, short. Spicules with prominent ventral rostrum, apex

extremely high. There are 2 pairs of ventrosubmedian caudal papillae, 1 pair located immediately anterior to the anal opening, the other

immediately anterior to terminus. Tail ventrally arcuate, terminus acute.

Diagnosis,—Related to Cryptaphelenchus

latus (Thorne, 1935) Rühm, 1956; differs in

finer striations of cuticle and in shape of spicules.

Tijpe habitat.—Associated with Ips pini and

Pityophthorus sp. in eastern white pine.

210
Figure 141.—Cryptaphelenchus ipinius n. sp.: A. Head and neck; B. head; C. female, tail; D. male, tail.

211
Type locality.—Caroline County, New York.

Type specimens.—Collection Nos. 81-H

(Holotype) ; 81-K (Allotype).

Cryptaphelenchus latus (Thorne, 1935) Rühm, 1956

Figure 142

Female : 0.4 mm; a = 20; b = 5.2; c = 13.5;

V = 80%.

Male : 0.4 mm ; a = 20 ; b = 4.7 ; c = 13.

Body straight, unusually broad for a Cryptaphelenchus, tapering anteriorly until lip region

is about two-fifths as wide as the neck at the

bulb. Lateral field marked by four lines. Annulation broad, obscure. Body slightly narrowed

ventrally at vulva. Female tail slightly arcuate,

conoid to pointed terminus. Male tail ventrally

arcuate, conoid to pointed terminus. Lip region

set oif by slight depression, lips obscure. Spear

with well developed basal knobs. Esophageal

bulb very large. Hyaline esophagus extends

back from bulb unusually long distance before

merging with intestine. Excretory pore located

about opposite first granules of intestine.

Granules of intestine and body generally large.

Vulva a depressed transverse slit, anterior lip

overlapping. Vagina at first extending in and

forward, then bent to nearly right angles with

body axis. Ovary outstretched. Female rectum

and anus inconspicuous. Two pairs of conspicuous, conical male papillae, one slightly preanal

and other at beginning of distal third of tail.

Spicula elongate, mitten-shaped, cephalated.

Sex ratio about eight females to each male.

Diagnosis.—Cryptaphelenchus of small size,

and broad body with above measurements.

Spear with basal knobs. Esophageal bulb comparatively massive. Intestinal granules beginning almost 2 body widths behind bulb. Excretory pore about opposite anterior end of intestine. Body slightly contracted at vulva. Spicula

elongate, mitten-shaped. Tail of female slightly

/.0-- 6]^.-:

^^r;

'^/o:^:;:;#p;:.,

• IV.':- • -M »••7,

Figure 142.—Cryptaphelenchus latus (Thorne, 1935) Rühm, 1956. A, Head and neck; B. male, tail; C. uterine

tract; D. female, tail. (After Thorne, 1935).

212
arcuate, that of male conspicuously arcuate.

Terminus acute.

Beneath elytra and in tunnels of Dendroctonus pcmderosae.

Genus Omemeea Massey, 1971

Type species: Omemeea maxbassiensis Massey, 1971

Aphelenchoidinae : Lip region heavily sclerotized, umbrellalike in a lateral view. Cephalic

framework refractive, distinct. Stylet exceedingly long with very prominent basal knobs,

subulate shaft longer than the shaft. Metacorpus oblong, ovate, the anterior portion

glandular. Dorsal esophageal gland robust,

relatively short. Excretory pore obscure, anterior to metacorpus. Ovary outstretched, postuterine branch several body widths in length.

Female anal opening obscure. Male tail usually

arcuate with sclerotized terminal membrane.

Spicules paired with prominent ventral rostra.

Omemeea maxbassiensis Massey, 1971 Figure 143

Female: 0.64-0.77 mm; a = 31.4-34.6; b =

8.8-9.7; c = 22.6-23;V = 77-79%.

Male: 0.63-0.75 mm; a = 32.0-35.8; b = 8.6-

9.0; c = 19.5-19.7.

Body straight, cylindroid. Cuticle with faint

transverse striae and marked with 3 lateral

incisures. Lip region sclerotized, set off with

angular overhang in some specimens, appearing umbrellalike in lateral view. Cephalic

framework with six heavily sclerotized sectors.

Amphids not discerned. Spear exceedingly long,

23-26 /x, the subulate shaft longer than the

shaft, the knobs prominent and strongly sclerotized at point of muscle attachment. Vestibule and its extension very distinct and geometrically formed. Metacorpus oblong ovate,

the anterior portion glandular. Dorsal esophageal gland 2-3 body widths in length. Nerve

ring two-thirds of a body width posterior to

metacorpus. Excretory pore obscure, located

anterior to metacorpus, more readily visible on

immature specimens. Hemizonid two body

widths posterior to metacorpus. Ovary single,

outstretched. Posterior uterine branch 4-5 body

widths in length, usually containing sperm.

Prominent vulval flap present. Anal opening

obscure. Tail conoid to a sharp, heavily sclerotized terminus.

Male: With head and neck characteristics

similar to females. Testis outstretched or reflexed, spicules paired with a prominent sharply

pointed ventral rostrum. Tail arcuate with terminal flap. There are 3 pairs of caudal papillae,

1 pair preanal, obscure, 2 pairs slightly anterior

to the terminus.

Type habitat,—From galleries of Leperisinus

californicus infecting green ash.

Type locality.—Omemee, North Dakota.

Type specimens.—Collection No. 78-X.

Teragramia n. gen.^

Lip region set off, rounded. Cephalic framework sclerotized. Stylet slender, subulate shaft

only slightly wider than shaft. Vagina extending anteriorly from vulval opening. Posterior

uterine branch prominent, several body widths

in length. Female tail obtuse, clublike in lateral

view. Spicules massive, distinctive. Male tail

with membranous flap, distinctively reflexed on

preserved specimens.

Diagnosis.—Differs from other members of

the subfamily in shape and size of the spicules,

in the distinctive vulva and in the shape of the

tails of both sexes.

Teragramia willi n. gen,, n, sp.® Figure 144

Female: 0.57-0.63 mm; a:= 23.4-29.8; b =

7.9-8.6; c = 13-13.6;V = 75%.

Male: 0.52-0.60 mm; a = 28.4-28.8; b = 8.2-

8.6; c = 19.2-20.

Ventrally arcuate, cylindroid. Cuticle with

fine transverse striae, 2 lateral incisures. Lip

region set off, rounded. Cephalic framework

sclerotized. Spear fine, 11 /x in length, subulate

shaft only slightly wider than shaft, without

basal knobs; retractor muscles distinct. Metacorpus oblong ovate, crescent-shaped valves at

or near center, anterior one-third glandular.

Dorsal esophageal gland outlet indistinct. Dorsal esophageal gland stout, approximately 4

body widths in length. Nerve ring approximately 1 body width posterior to metacorpus.

Excretory pore at or slightly below base of

metacorpus. Hemizonid slightly posterior to

nerve ring. Lips of vulva slightly elevated.

Vagina extending anteriorly, ca one-half body

width. Ovary outstretched ; oocytes arranged in

s Named in honor of my wife, Margaret (reverse

spelling).

^ Named in honor of my grandson, Will Verzino.

213
.01 mm

wm

Jill:: ÍJ

iî>

I::;::/ /i\;-V-••• . ir

I i i

I i 1 i ; ;í

I

I

' . / /

I.:---

;i 1 ñ

ñ %

Figure 143,

dAtg

.03 mm

in

■■•\

Jniemeea maxbassiensis Massey, 1971: A, Head; B. face view;

C. lateral view, male, tail; D. head and neck; E, female, midbody; F, ventral

view, male, tail; G. female, tail.

214
ill

®

A^x

'. I

I !

/ I

.01mm

Figure 144.—Teragratnia willi n. gen., n. sp.: A. Head and neck; B. head; C. male, tail; D. female, tail.

215
3 rows. Posterior uterine branch stout, ca 3

body widths in length. Anal opening and rectum indistinct. Tail conoid to an obtuse terminus, club shaped in lateral view.

Cuticle of male with distinct annulations in

the region of the tail. Testis single, outstretched. Spicules massive, the apices high, the

ventral rostra short. Two pair of caudal papillae, 1 pair preanal, 1 pair near terminus. Terminus obtuse, with a membranous flap. Tail

extremely ventrally coiled on the majority of

preserved specimens as illustrated.

Type habitat.—^Associated with Dendroctomis Valens in ponderosa pine.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 21-B.

Berntsenus ii. geii/*^

Type species : Berntsenus brachycephalus

(Thorne, 1935) n. comb.

Cuticle with faint transverse striae, with or

without lateral incisures. Lips expanded, 3

times wider than deep, petiolate. Stylet, under

phase illumination, with heavily sclerotized

subulate shaft, lightly sclerotized ventral aperture visible. Esophagus short. Metacorpus massive, filling body cavity in some specimens,

round to oblong. Dorsal esophageal gland stout.

Lips of vulva continuous with body wall. Vagina short. Posterior uterine branch 2-3 body

widths in length. Ovary single. Anus and rectum conspicuous. Terminus subacute. Spicules

paired, dorsal shaft lightly sclerotized, ventral

segment less sclerotized than dorsal shaft. Apex

low. One pair of postanal and ventrosubmedian

papillae. Tail ventrally arcuate, conoid; subacute to acute terminus.

Diagnosis.—Related to Ektaphelenchus but

easily distinguished by its narrower lip region,

shape of metacorpus, its longer postuterine sac,

and the presence of a conspicuous anus and

rectum. Male spicules much less refractive with

a low apex and delicate rostrum.

Berntsenus brachycephalus (Thorne, 1935) n. comb.

Figure 145

Female: 0.95-0.96 mm; a = 25.6-27.3; b = ll;

c = 21.8-21.9;V = 75%.

Male: 0.82-0.84 mm; a = 37.3-41.1; b = 10.3~

10.5;c = 22.3-27.9.

Form cylindroid. Cuticle with fine transverse

striae, lateral incisures not discernible. Lip

region set off, broadly expanded, 3 times wider

than deep. Lips petiolate, distinct. Stylet

unique, subulate shaft heavily sclerotized, ventral aperture distinct, shaft lightly sclerotized

and faintly visible under phase contrast illumination, without basal knobs, 17-18 fx in

length. Musculature conspicuous, running from

base of spear to base of lips. Esophagus short.

Metacorpus round to ovate, anterior one-fifth

glandular. Crescentic valves at center. Dorsal

esophageal gland stout, approximately 4 body

widths in length. Excretory pore located midway between metacorpus and nerve ring. Lips

of vulva continuous with body wall. Vagina

short, slightly oblique. Ovary single, outstretched; oocytes arranged in double row.

Posterior uterine branch 2-3 body widths in

length. Anus and rectum conspicuous. Tail

conoid to a subacute terminus.

Male: Testis single, outstretched. Spicules

with apex low, with ventral segment forming a

slight ventral rostrum. Spicules unrefractive,

ventral rostrum difficulty visible under both

bright field and phase contrast illumination.

Only one pair of caudal papillae visible, they

are postanal ventrosubmedian. Tail ventrally

arcuate, conoid to a subacute to acute terminus.

Type habitat.—Associated with Dendroctonus ponderosae in lodgepole pine.

Type locality.—Provo Basin, Utah.

Type specimens.—Thorne Collection—USDA,

Beltsville, Maryland. Slides No. 10-C and 10-D.

Berntsenus lahiosus n. sp. Figure 146

10 Named in honor of Dr. Carl Berntsen, Assistant

Director, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

Female: 0.71-0.82 mm; a = 28-33; b = 8-12;

c = 23-24 ;V = 71-72%.

Male : Unknown.

Cylindroid. Cuticle with fine transverse

striae, lateral incisures not observed. Lip region set off, flat; lips rounded laterally. Cephalic framework sclerotized. Stylet uniquely

shaped for subfamily, with distinct basal thickenings, subulate shaft heavily sclerotized, retractor muscles distinct. Median bulb ovate.

Dorsal esophageal gland outlet obscure. Dorsal

esophageal gland relatively robust, 4-5 body

widths in length. Nerve ring one-half body

width posterior to metacorpus. Excretory pore

216
I-: s; i

iiíM

:•>.!;

c

.01 mm

.03 mm

Figure 143.—Bernlsenus brachycephalus (Thorne, 1935) n. comb.: A.

Head and neck; B. head; C. female, midbody; D. male, tail; E. female,

tail.

217
Figure 146.—Berntsenus labiosas n. sp.: A. Female; B, head.

218
slightly posterior to nerve ring. Hemizonid

immediately posterior to excretory pore. Lips

of vulva slightly protuberant. Vagina oblique.

Ovary outstretched. Oocytes arranged in a

double row. Posterior uterine branch 4-5 body

widths in length. Anus distinct, rectum obscure. Tail conoid to an acute mucronate-like

terminus.

Diagnosis.—Differs from B, brachycephalus

in its smaller size, in the presence of distinct

basal thickenings on stylet, and in the elongate

postuterine branch.

Type habitat,—Associated with Pityokteines

elegans in white fir.

Type locality.—Sandia Mountains, Cibola

National Forest, New Mexico.

Type specimens.—Collection No. 78-L.

Genus Seinura Fuchs, 1931

Type species : Seinura mali Fuchs, 1931

Labial framework lightly sclerotized, no

hexoradiate star surrounding oral aperture.

Stylet plain, with or without basal swellings or

small knobs. Hemizonid surrounding or behind

excretory pore. Metacorpus longer than wide,

crescentic valve plates usually located behind

middle. Ovary single, outstretched, with

oogonia in one to five rows, with or without

postvulvar sac. Female tails elongate, conoid to

filiform. Male tail ventrally arcuate, elongate

conoid to filiform or tapering to spicate terminus. Spicules paired with knoblike apex and

beaklike ventral rostrum. Caudal papillae vary

from one to four pairs.

Key to the species of Seinura associated with bark beetles in

the United States

1. Females with vulval flap 2

Females without vulval flap attentuata n. sp.

2. Lip region definitely set off arizonensis n. sp.

Lip region more or less continuous with

body contour pini

Seinura arizonensis n. sp. Figure 147

Female: 1.12 mm; a = 40.4; b = 13.5; c = 12.6;

V = 73%.

Male : Unknown.

Cylindroid. Cuticle with very fine annulations, lateral incisures not discernible. Lip

region set off, rounded. Cephalic framework

lightly sclerotized. Lips indistinct. Stylet 20 fx

in length, without basal knobs or thickenings.

Retractor muscles indistinct. Metacorpus ovate,

the anterior one-third glandular. Dorsal

esophageal gland outlet not visible. Dorsal

esophageal gland 4-5 body widths in length.

Nerve ring three-fourths body width posterior

to metacorpus. Excretory pore through hemizonid and ca 1 body width posterior to the

nerve ring. Lips of vulva continuous with body

contour, anterior lip forming a distinct flap.

Ovary outstretched, at times reaching beyond

the distal end of the dorsal esophageal gland,

the oogonia in 4 rows. Postuterine branch

broad, filling most of body cavity in some specimens, 3-4 body widths in length. Anus and

rectum as illustrated. Tail filiform to an acute

terminus.

Diagnosis.—Seinura with lip region set off

and with elongate tail, not filiform.

Type habitat.—Associated with Ips integer

(Eichh.) in ponderosa pine.

Type locality.—Prescott, Arizona.

Type specimens.—Collection No. 56-F.

Seinura attenuata n. sp. Figure 148

Female: 0.95 mm; a = 42.7; b = 13.1; c=?;

V = 60%.

Male: 0.70 mm; a = 31.7; b = 8.46; c = 9.

Body cylindroid. Cuticle with no discernible

lateral incisures, annulations very fine. Lip

region hardly set off. Cephalic framework sclerotized. Lips distinct. Stylet 20 /x in length,

without basal knobs or thickenings, the retractor muscles indistinct. Dorsal esophageal

gland outlet indistinct. Metacorpus oblong

ovate, approximately one-half the anterior portion glandular, valvular plates below the center.

Nerve ring a body width posterior to metacorpus. Dorsal esophageal gland 6-7 body

widths in length. Excretory pore opposite nerve

ring and running through hemizonid. Ovary

outstretched, reaching in some specimens be219
,03mm

Figure 147.—Seinura arizonensis n. sp.: A. Head and

neck; B, female, midbody; C, female, tail.

yond the distal end of the dorsal esophageal

gland. Lips of vulva continuous with body contour. Postuterine branch ca IV2 body v^idths in

length. Anal opening and rectum obscure. Tail

conoid to a filamentous terminus.

Male : With head and neck characteristics of

female. Testis short, outstretched. Spicules

with low rounded prominent ventral rostrum.

There is one pair of postanal ventral papillae.

Tail ventrally arcuate, conoid to a filamentous

terminus.

Diagnosis,—Related to Seinura pini Massey,

1966; differs in the spear length and in the

more attenuated tail of both sexes.

Type habitat.—Associated with Dendroctonus terebrans in loblolly pine.

Type locality,—Oakdale, Louisiana.

Type specimens.—Collection No. 67-A.

Seinura pini Massey, 1966 Figure 149

Female: 0.81-0.83 mm; a = 32-34; b = 7.2~

9.5;c=?;V = 71-75%.

Male: 0.78mm; a = 31;b = 8.9;c = 12.4.

Head continuous with body contour, lips

distinct. Spear 26 ¡JL long, without basal knobs

or thickenings. Median bulb of esophagus oblong ovate, anterior and posterior portions very

glandular. Excretory pore one and one-third

body widths posterior to median bulb. Hemizonid immediately posterior to excretory pore.

Dorsal esophageal glands prominent, 4-5 times

body width. Ovary outstretched, at times overlapping distal end of esophageal glands. Anterior lip of vulva forming a flap. Vagina transverse, posterior uterine branch 1 body width in

length. Anal opening not observed. Terminus

spicate.

Male: Testis single, outstretched, occupying

approximately two-thirds of body length. Spicules paired, with prominent ventral rostrum.

One pair postanal caudal papillae. Terminus

spicate.

Diagnosis.—Closely related to Seinura mali

Fuchs, 1931 but differs in the shorter length of

female tail and absence of a discernible anal

opening.

Type habitat.—Associated with Dendroctonus adjunctus in ponderosa pine.

Type locality.—Ruidoso, New Mexico.

Type specimens.—Collection No. 37-D.

220
Figure 148.-

tail.

-Seinura attenuata n. sp.: A, Head and neck; B, female, midbody; C. female, tail; D. male.

221
immm

Figure 149.—Seinura pini Massey, 1966: A. Head and neck; B, female, midbody; C, female, tail; D,

male, tail.

222
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228
APPENDIX

Nematode Parasites and Associates by

Bark Beetle Species

Chramesus hicoriae Leconte

Aphelenchoides rhytium Massey, 1970

Laimaphelenchus penardi (Steiner, 1914)

Filipjev and Schuurmans Stekhoven,

1941

Santafea damalis Massey, 1966

Conophtkorus coniperda Schwarz

Aphelenchoides conophthori n. sp.

Panagrolaimus conophthori n. sp.

Dendroctonus adjunctus Blandford

Acrostichus ponderosus Massey, 1962

Bunonema sp.

Bursaphelenchus bestiolus n. sp.

Bursaphelenchus corneolus Massey, 1966

Cephaloboides rotundus n. rank n. sp.

Deladenus paradums n. sp.

Diplogasteroides marshalli Massey, 1962

Dotylaphus lonchites n. sp.

Ektaphelenchus obtusus Massey, 1956

Gerthornus balaenus Massey, 1966

Hexatylus sp.

Laimaphelenchus pannocaudus Massey,

1966

Laimaphelenchus pensobrinus Massey,

1966

Macrolaimus canadensis Sanwal, 1960

Mikoletzkya cervicula Massey, 1966

Mononchoides adjunctus Massey, 1966

Neocephalobus judithae Massey, 1964 n.

comb.

Neoditylenchus ovarius n. sp.

Panagrobelus scolyti Massey, 1964

Parasitaphelenchus dendroctoni Massey,

1966

Parasitorhabditis sp.

Parasitylenchus stipatus Massey, 1966

Plectus acuminatus Bastian, 1865

Plectus annulatus Maggenti, 1961

Plectus parietinus Bastian, 1865

Pseudhalenchus damnatus Massey, 1966

Rhabdontolaimus sp.

Santafea damalis Massey, 1966

Seinura pini Massey, 1966

Teregramia willi n. gen. n. sp.

Dendroctonus brevicomis LeConte

Aphelenchoides sp.

Bursaphelenchus bestiolus n. sp.

Bursaphelenchus wilfordi Massey, 1966

Contortylenchus brevicomi (Massey, 1957)

Rühm 1960

Ektaphelenchus obtusus

Neoditylenchus glandarius n. sp.

Parasitorhadbitis sp.

Rhabdontolaimus sp.

Seinura sp.

Dendroctonus frontalis Zimmerman

Anguillonema annamari n. sp.

Aphelenchoides rhytium Massey, 1970

Aphelenchoides sp.

Bursaphelenchus sp.

Deladenus ipini n. sp.

Hexatylus viviparus Goodey, 1926

Luella luculenta n. gen. n. sp.

Mikoletzkya bandelieri (Massey, 1960)

Massey, 1966

Monohystera sp.

Neoditylenchus dendroctoni n. sp.

Neoditylenchus sp.

Nothotylenchus sp.

Parasitaphelenchus gallagheri (Massey,

1960) J. B. Goodey, 1960

Parasitorhabditis sp.

Rhabdontolaimus adephagus n. sp.

Rhabdontolaimus frontali n. sp.

Robleus cylindricus n. gen., n. sp.

Santafea damalis

Dendroctonus ponderosae Hopkins

Aphelenchoides tenuidens Thorne, 1935

Berntsenus brachycephalus (Thorne, 1935)

n. gen., n. comb.

Bursaphelenchus conurus (Steiner, 1932)

J. B. Goodey, 1960

Bursaphelenchus talonus (Thorne, 1935)

J. B. Goodey, 1960

Contortylenchus reversus (Thorne, 1935)

Rühm, 1956

229
Dendroctonus ponderosae Hopkins (Continued)

Cryptaphelenchus latus (Thorne, 1935)

Rühm, 1956

Ektaphelenchus josephi n. sp.

Ektaphelenchus obtusus Massey, 1956

Laimaphelenchus penardi (Steiner, 1914)

Filipjev and Schuurmans Stekhoven,

1941

Laimaphelenchus pensobrinus

Macrolaimus canadensis

Mikoletzkya inedia Massey, 1966

Mikoletzkya pinícola (Thorne, 1935)

Baker, 1962

Neocephalobus judithae

Neoditylenchus pinophilus (Thorne, 1935)

J. B. Goodey, 1963

Nothotylenchus sp.

Panagrodontus dentatus Thorne, 1935

Parasitaphelenchus acroposthion (Steiner,

1932) Rühm, 1956

Parasitorhabditis sp.

Dendroctonus pseudotsugae Hopkins

Aphelenchoides sp.

Bitrsaphelenchus sp.

Contortylenchus reversus

Ektaphelenchus obtusus

Mikoletzkya diluta Massey, 1966

Misticius mustus Massey, 1967

Neocephalobus judithae

Neoditylenchus puniwopus Massey, 1969

Neoditylenchus sp.

Parasitaphelenchus beccus n. sp.

Parasitorhabditis sp.

Santafea damalis

Seinura sp.

Sphaerularia dendroctoni Massey, 1956

Dendroctonus rufipennis Kirby

Acrostichus gubernatus n. sp.

Aglenchus exiguus Massey, 1969

Anaplectus granulosus (Bastian, 1865)

deConick and Schuurmans Stekhoven,

1933

Bunonema sp.

Bursaphelenchus talonus (Thorne, 1935)

J. B. Goodey, 1960

Contortylenchus reversus (Thorne, 1935)

Rühm, 1956

Diplogasteroides bibrochus n. sp.

Ektaphelenchus obtusus

Ereptonema fimbriatum Anderson, 1966

Mesorhabditis longistomis n. sp.

Mikoletzkya ruminis Massey, 1966

Monohystera sp.

Mononchoides adjunctus Massey, 1966

Neocephalobus judithae

Neoditylenchus pinophilus

Neoditylenchus yasinskii Massey, 1969

Neotylenchus nitidus Massey, 1969

Panagrolaimus concolor Massey, 1964

Panagromacra margaretae Massey, 1964

Parasitaphelenchus gallagheri ( Massey,

1960) J. B. Goodey, 1960

Parasitaphelenchus sp.

Parasitorhabditis sp.

Plectus assimilis Bütschli, 1873

Plectus parietinus Bastian, 1865

Prionchulus punctatus (Cobb, 1917) Clark,

1960

Santafea croca Massey, 1963

Sphaerularia dendroctoni

Dendroctonus simplex Leconte

Aphelenchoides sp.

Ektaphelenchus obtusus

Laimaphelenchus pensobrinus

Neocephalobus sp.

Neoditylenchus sp.

Dendroctonus terebrans (Oliver)

Acrostichus ponderosus

Acrostichus taedus Massey, 1962

Aphelenchoides rhytium

Bursaphelenchus tritrunculus n. sp.

Contortylenchus terebranus n. sp.

Dirhabdilaimus nacogdochensis n. sp.

Dotylaphus lonchites n. sp.

Ektaphelenchus smaelus n. sp.

Ektaphelenchus terebranus n. sp.

Hexatylus sp.

Laimaphelenchus penardi

Mikoletzkya tornea Massey, 1966

Neocephalobus judithae n. comb.

Neodiplogaster pinicola Steiner, 1930

Nothotylenchus petilus n. sp.

Parasitorhabditis terebranus n. sp.

Rhabdontolaimus janae (Massey, 1962) n.

comb.

Santafea damalis

Seinura attenuata n. sp.

Dendroctonus valens Leconte

Aphelenchoides sp.

Ektaphelenchus obtusus

Parasitorhabditis terebranus n. sp.

Plectus parietinus

Poikilolaimus sp.

Prionchulus sp. • Teragramia willi n. gen. n. sp.

Dryocoetes affaber (Mannerheim)

Ektaphelenchus smaelus n. sp.

230
Dryocoetes confusus Swaine

Acrostichus concolor Massey, 1962

Aphelenchoides sp.

Bursaphelenchus wilfordi Massey, 1964

Ektaphelenchus prolobos Massey, 1964

Laimaphelenchus penardi

Laimaphelenchus pensobrinus Massey,

1966

Macrolaimus canadensis

Mikoletzkya langcaudus n. sp.

Neocephalobus judithae

Neoditylenchus sp.

Panagromacra margaretae

Parasitorhabditis sp.

Plectonchus wyganti Massey, 1964

Plectus makrodemas Massey, 1964

Plectus parietinus

Dryocoetes sp.

Acrobeloides sp.

Aphelenchoides sp.

Eucephalobus sp.

Thada sp.

Tylenchus sp.

Hylurgops pinifex (Fitch)

Aphelenchoides hylurgi n. sp.

Aphelenchoides polygraphi n. sp.

Aphelenchoides sp.

Bursaphelenchus elytrus Massey, 1971

Bursaphelenchus sp.

Contortylenchus bullus n. sp.

Gerthornus sp.

Mikoletzkya pugnea Massey, 1971

Mikoletzkya^^,

Neocephalobus judithae

Panagrolaimus sp.

Parasitorhabditis hylurgi n. sp.

Parasitorhabditis ipini n. sp.

Parasitylenchus coronatus n. sp.

Hyluraops subcostulatus (Mannerheim)

Aphelenchoides sp.

B irsaphelenchus newmexicanus n. sp.

Gerthornus balaenus Massey, 1966

Mikoletzkya pugnea Massey, 1971

Neocephalobus judithae

Panagrolaimus concolor

Parasitaphelenchus sp.

Plectonchus molgos n. sp.

Ips avulsus (Eichhoff)

A nguillonema annanfiari n. sp.

Aphelenchoides rhytium

Aphelenchoides sp.

Hexatylus viviparus

Laimaphelenchus penardi

Mikoletzkya bandelieri

Mikoletzkya sp.

Nothotylenchus similis Thorne and Malek,

1968

Parasitorhabditis sp.

Parasitorhabditis sp.

Parasitylenchus avulsi Massey, 1958

Rhabdontolaimus frontali n. sp.

Santafea damalis

Tylenchus sp.

Ips calligraphus German

Aphelenchoides rhytium Massey, 1971

Bursaphelenchus tritrunculus

Contortylenchus grandicolli (Massey,

1957) Rühm, 1960

Deladenus ipini n. sp.

Diplogasteroides marshalli

Ektaphelenchus obtusus

Laimaphelenchus penardi

Luella luculenta n. sp.

Mikoletzkya calligraphi n. sp.

Monohystera sp.

Parasitaphelenchus procerus n. sp.

Parasitorhabditis sp.

Rhabdontolaimus janae

Seinura pini

Ips confusus Leconte

Acrostichus ponderosus

Aphelenchoides sp.

Contortylenchus elongatus (Massey, 1957)

Nickle, 1963

Cryptaphelenchus latus (Thorne, 1935)

Rühm, 1956

Laimaphelenchus penardi

Laimaphelenchus pensobrinus

Macrolaimus canadensis

Mikoletzkya bandelieri

Parasitaphelenchus gallagheri

Parasitorhabditis sp.

Parasitylenchus pilifronus Massey, 1958

Plectus sp.

Santafea croca

Ips cribicollis (Eichhoff)

Contortylenchus cribicolli n. sp.

Diplogasteroides marshalli

Mikoletzkya bandelieri

Parasitorhabditis sp.

Ips grandicollis (Eichhoff)

Anguillonema sp.

Aphelenchoides rhytium

Contortylenchus grandicolli ( Massey,

1957) Rühm, 1960

Laimaphelenchus penardi

Nothotylenchus similis

Parasitorhabditis hastidus n. sp.

231
Ips integer (Eichhoff)

Aphelenchoides polygraphi n. sp.

Diplogasteroides tnarshalli

Ektaphelenchus obtusus

Laimaphelenchus pannocaudus

Laimaphelenchus penardi

Mikoletzkya bandelieri

Neoditylenchiis sp.

Parasüaphelenchus gallagheri

Plectus sp.

Seinura arizonensis n. sp.

Ips knausi Swaine

Laimaphelenchus penardi

Macrolaimus canadensis

Mikoletzkya inedia Massey, 1966

Parasitaphelenchus sp.

Parasitorhabditis sp.

Ips lecontei Swaine

Acrostichus ponderosus

Aphelenchoides sp.

Contortylenchus elongatus

Cryptaphelenchus sp.

Diplogasteroides marshalli

Ektaphelenchus obtusus

Laimaphelenchus pensobrinus

Macrolaimus canadensis

Mikoletzkya inedia

Parasitaphelenchus gallagheri

Parasitorhabditis sp.

Parasitylenchus sp.

Seinura pini

Ips pilifrons Swaine

Parasitylenchus ovarius Massey, 1958

Parasitylenchus pilifrons Massey, 1958

Ips pini (Say)

Contortylenchus sp.

Contortylenchus spirus (Massey, 1957)

Rühm, 1960

Diplogasteroides ipini n. sp.

Ektaphelenchus obtusus

Ektaphelenchus smaelus

Luella luculenta n. gen. n. sp.

Macrolaimus canadensis

Neoditylenchus sp.

Parasitorhabditis ipini n. sp.

Parasitylenchus ipinius n. sp.

Parasitylenchus ovarius

Parasitylenchus sp.

Ips ponderosae Swaine = Ips calligraphus

(German)

Acrostichus ponderosus

Aphelenchoides sp.

Contortylenchus grandicolli

Diplogasteroides marshalli

Ektaphelenchus obtusus

Laimaphelenchus pensobrinus

Macrolaimus canadensis

Mikoletzkya bandelieri

Parasitaphelenchus gallagheri

Parasitorhabditis sp.

Ips sulcifrons Wood

Contortylenchus spirus

Parasitylenchus elongatus Massey, 1964

Ips yohoensis Swaine

Parasitylenchus ovarius

Leperisinus aculeatus (Say)

Anguillonema leperisini n. sp.

Geraldius bakeri

Hexatylus viviparus

Laimaphelenchus penardi

Omemeea maxbassiensis

Panagrobelus scolyti

Panagrolaimus leperisini n. sp.

Parasitylenchus sp.

Plectus sp.

Teratocephalus angustus n. sp.

Leperisinus californiens Swaine

Aphelenchoides sp.

Laimaphelenchus sp.

Macrolaimus taurus

Omemeea maxbassiensis Massey, 1971

Panagrellus leperisini n. sp.

Orthotomicus caelatus (Eichhoff)

Contortylenchus orthotomici n. sp.

Parasitylenchus oriundus n. sp.

Orthotomicus ornatus Swaine

Allantonema orthotomici n. sp.

Phloeosinus dentatus (Say)

Geraldius bakeri

Laimaphelenchus phloeosini n. sp.

Panagrobelus phloeosini n. sp.

Phloeosinus neomexicanus Blackman

Laimaphelenchus pensobrinus

Nothotylenchus compactus n. sp.

Parasitorhabditis sp.

Santafea croca

Sychnotylenchus phloeosini Massey, 1969

Pityogenes carinulatus (Leconte)

Bursaphelenchus pityogeni n. sp.

Parasitaphelenchus sp.

Pityokteines elegans Swaine

Aphelenchoides pityokteini n. sp.

Berntsenus labiosus n. sp.

Ektaphelenchus prolobos

Macrolaimus canadensis

Neoditylenchus sp.

Parasitorhabditis sp.

Rhabdontolainus adephagus n. sp.

Santafea croca

232
Pityophthoriis sp.

Bursaphelenchus sp.

Contortylenchus tomici (Bovien, 1937)

Rühm, 1956

Neoditylenchus sp.

Parasitaphelenchus sp.

Parasitorhabditis hastulus n. sp.

Parasitylenchus senicus n. sp.

Polygraphus hoppingi Swaine

Aphelenchoides polygraphi n. sp.

Macrolaimus canadensis

Neoditylenchus yasinskii Massey, 1969

Panagromacra margaretae

Parasitorhabditis cluniculus n. sp.

Parasitylenchus parasitus n. sp.

Pseudohylesinus grandis Swaine

Parasitorhabditis gracilis n. sp.

Pseudohylesinus nebulosus (Leconte)

Bursaphelenchus sp.

Neoditylenchus sp.

Pa7^asitylenchus undulatus n. sp.

Scolytus multistriatus Marsham

Aphelenchoides sp.

Bursaphelenchus scolyti n. sp.

Cylindrocorpus erectus Massey, 1960

Geraldius bakeri

Laimaphelenchus penardi

Panagrobelus scolyti

Panagrolaimus leperisini

Parasitaphelenchus oldhami Rühm, 1956

Santafea damalis

Sychnotylenchus scolyti Massey, 1969

Scolytus muticus (Say)

Sychnotylenchus mutici n. sp.

Scolytus ventralis Leconte

Acrostichus concolor

Aphelenchoides sp.

Bunonema newmexicana Massey, 1964

Bursaphelenchus wilfordi

Ektaphelenchus sandiaensis Massey, 1964

Laimaphelenchus penardi

Laimaphelenchus pensobrinus

Macrolaimus canadensis

Mesorhabditis longistomis n. sp.

Mikoletzkya diluta Massey, 1964

Neocephalobus judithae

Neoditylenchus sp.

Panagrolaimus concolor Massey, 1964

Panagromacra margaretae

Parasitaphelenchus sp.

Parasitorhabditis sp.

Parasitylenchus elongatus Massey, 1958

Parasitylenchus scrutillus Massey, 1964

Plectonchus wyganti

Plectus eurycerus Massey, 1964

Plectus parietinus

Santafea croca

Tylenchus sp.

Index to Genera of Nematode Parasites

and Associates of Bark Beetles

Page

Acrostichus 79

Aglenchus 138

Allantonema 19

Angiiillonema 165

Aphelenchoides 175

Berntsenus 216

Bunonema 73

Bursaphelenchus 182

Cephaloboides 64

Contortylenchus 37

Cryptaphelenchus 208

Cylindrocorpus 76

Deladenus 157

Diplogasteroides 101

Dirhabdilaimus 105

Dotylaphus 171

Ektaphelenchus 199

Geraldius 130

Gerthornus 84

Hexatylus 159

Laimaphelenchus 194

Luella 168

Macrolaimus 132

Mesorhabditis 64

Mikoletzkya 84

Misticius 168

Mononchoides 97

Neocephalobus 117

Neodiplogaster 98

Neoditylenchus 138

Neotylenchus 154

Nothotylenchus 161

Omemeea 213

Panagrellus 126

Panagrobelus 124

Panagrodontus 117

Panagrolaimus 111

Panagromacra 120

Parasitaphelenchus 55

Parasitorhabditis 67

Parasitylenchus 21

Plectonchus 119

Pseudhalenchus 152

Rhabdontolaimus 108

Robleus 173

Santafea 130

Seinura 219

Sphaerularia 52

Sychnotylenchus 148

Teragramia 213

Teratocephalus 128

1^ U.S. GOVERNMENT PRINTING OFFICE: 1973 0-500-574

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