United States 

Department of Effects of Fenvalerate and Azinphosmethyl 

Agricu tture on Scale Insects and Their Natural Enemies 

Forest Se mice in Loblolly Pine Seed Orchards @ m*e 

SoutheasEern Forest Stephen R. Clarke 

Experiment Station Gary L. DeBarr 

Research Paper C. Wayne Berisford 

SE-279 
Effects of Fenvalerate and Azinphosmethyl 

on Scale Insects and Their Natural Enemies 

in Loblolly Pine Seed Orchards 

Stephen R. Clarke, Gary L. DeBarr, and C. Wayne Berisford 

ABSTRACT synthesis and reduce tree growth (Walstad and others 

1973). lnfestations of three scale insects and one 

Fenvalerate and azinphosmethyl were applied monthly by hydraulic rnea&bug have been observed in loblolly pine, Pinus 

sprayer during the 1984 and 1985 growing seasons to loblolly 

~ines in a ~olloch Countv, GA, seed orchard. The orchard was taeda L., seed orchards in Georgia: the woolly pine 

infested with the striped Sne scale, Tourneyella pini (King), a scale, Pseudophilippia quaintancii Cockerell; the 

mealybug, Oracella acuta (Lobdell), and the woolly pine scale, 

Pseudophilippia quaintancii Cockerell. Azinphosmethyl caused striped pine scale; ~ou&e~e//a pini (King); the pine 

significant female scale and mealybug mortality, but fenvalerate tortoise scale, T. pan/i'cornis (Cockerell); and a 

generally did not. Alternating applications of the two insecticides mealybug, Orace//a am& (Lobdell). 

~roduced infestations intermediate between those treated onlv with 

kinphosmethyl or fenvalerate. More male scale insects emerged 

from shoots collected at this orchard from untreated trees than Pyrethroids are more toxic to some parasitoids than 

from shoots receiving insecticide applications. Parasitism of T. pini to their hosts (Coats and others 1979), and pvrethroids , . . - 

females was significantly higher on unsprayed trees only after the are less toxic'than organophosphorous insecticides third insecticide applications in 1984. Predation of female T. pini 

was generally lowest on trees receiving azinphosmethyl applica- to crawlers of T. pini (Clarke and others 1988). 

tions; Populations of T. pini and 0. acuta crashed in 1984, but this Pyrethroid applications therefore may disrupt the 

collapse was not related to insecticide applications. host-natural enemy complex that maintains the scale 

Azinphosmethyl caused heavy mortality of both sexes of T. pini insects at endemic levels, leading to scale insect 

and 0. acuta when individual branches were hand sprayed-in a outbreaks. Such insecticide-related outbreaks of 

Toombs County, GA, seed orchard, while fenvalerate did not. 

Parasitism rates on untreated branches were significantly higher scale insects are well documented. McClure (1 97710) 

than rates on treated branches only at the end of the ovewintering related resurgences in populations of the elongate 

period. More males emerged from fenvalerate-treated shoots, and hemlock scale, Fiorinia e~terna Ferris, to reductions more parasitoids emerged from untreated shoots. in its parasitoids and predators following insecticide 

Ground applications of azinphosmethyl caused significant mortality application. Luck and Dahlsten (1 975) associated 

of scale insects and mealybugs, whereas operational aerial the use of malathion for mosquito control with 

applications did not. These results suggest that aerial application 

of insecticides, even those highly toxic to scale insects, are outbreaks of the pine needle scale, Chionaspis 

ineffective in controlling established scale insect infestations. pinifoliae (Fitch). Bartlett and Ortega (1 952) discovered 

Repeated use of fenvalerate in seed orchards increases the that the effects of DDT residues on a parasite led to 

possibility of scale insect outbreaks. increases in frosted scale, Lecanium pruinosum 

Keywords: Pyrethroids, Toumeyella pini, Oracella acuta, Pseu- Coquillett, On walnut. 

dophilippia quaintancii, secondary pests. 

The objective of our study was to compare the effects 

In recent years, pyrethroid insecticides have frequently of field applications of fenvalerate and kinphosmeth~l 

replaced organophosphates for seed and cone insect on existing scale hsect and mealybug po~ulations 

control in southern pine seed orchards. Fenvalerate and their natural 6?nemiese 

(a pyrethroid) and azinphosmethyl (an organophosphorous insecticide) have been registered by the 

U.S. Environmental Protection Agency for use in 

these control programs. Fenvalerate has a lower Materials and Methods 

mammalian toxicity than azinphosmethyl; it therefore Whole-Tree Treatments is safer to apply (Berisford and others 1 985a, 1 985b). 

However, some outbreaks of scale insects in southern A 2-year study of the effects of fenvalerate and 

pine seed orchards have been related to ground azinphosmethyl on scale insect infestations was 

(Cameron 1989; Texas Forest Service 1980) and undertaken at a loblolly pine seed orchard in Bulioch 

aerial (Nord and others 1985) application of pyrethroid County, GA. Insecticides were applied monthly on 

insecticides. Severe scale insect infestations and the an operational basis from April to August in 1982 

consequential sooty mold growth may hinder photo- and 1 983 for seed and cone insect control, Infestations 
of T, pini, 0, acuta, and P. quaintancii became apparent 

in 1982 after the first application of fenvalerate. Three 

adjacent 1.2-ha blocks established in 1978, 1979, 

and 1980, respectively, were heavily infested. Aerial 

applications on the six rows at the end of the oldest 

block were discontinued in June 1984. These rows 

comprised about one-third of the block. Nine clones 

with at least four ramets in this area were identified, 

and one ramet from each clone was randomly 

assigned to each of the four treatments: fenvalerate 

(Pydrine 2.4 EC, Shell, Modesto, CA), azinphosmethyl 

(Guthione 2L, Mobay Chemical, Kansas City, MO), 

alternating applications of fenvalerate and azinphosmethyl, and no insecticide (control). Insecticides 

were applied monthly from the ground with a 

high-volume hydraulic sprayer several days after the 

operational aerial insecticide application in the rest 

of the orchard. Fenvalerate was applied at a concentration of 0.025 percent (wtlwt) and azinphosmethyl at 

0.1 8 percent (Wwt). There were three applications 

in 1984 at monthly intervals beginning in June and 

five such applications in 1985 starting in April. 

The remainder of the orchard was sprayed monthly 

from the air with insecticides at the registered rates 

from April to August. Fenvalerate was applied in 

April and August of 1984 and August 1985. Azinphosmethyl was used for all remaining treatments. 

Sample shoots, which included the current growth 

cycle plus about 10 cm of the previous growth cycle 

(Greenwood 1980), were collected every 1 to 2 weeks 

from June 1984 to December 1985. Clones were 

randomly selected for each sampling date, four per 

date in 1984 and two per date in 1985. Sample shoots 

were taken from the middie to lower crown of one 

ramet of each clone per treatment. Trees were visually 

divided into directional quadrants, and one or two 

shoots were clipped from each quadrant with a pole 

pruner. One ramet of each of the selected clones in 

the aerially sprayed portion of the orchard was also 

sampled in 1985. 

Shoots were examined under a dissecting microscope, 

and the female scale insects and mealybugs were 

counted and classified as 'live," "dead," 'parasitized," 

or "eaten by predators." Numbers of live females with 

eggs or crawlers, as well as the numbers and species 

of any predators, also were recorded. Empty mealybug 

resin cells were also counted. 

Additional shoots were collected biweekly from three 

trees per treatment for rearing purposes. Infested 

shoots were placed in 19.5- by 8-cm mailing tubes 

with a 6- by 1 '5-cm glass vial inserted in a hole drilled 

in the side. Two shoots were placed in each tube, 

with six tubes per treatment. Numbers and species 

of emerging natural enemies and male scale insects 

were recorded. 

Individual-Branch Treatments 

The short-term effects of fenvalerate and azinphosmethyl on established scale insect populations were 

examined at a loblolly pine seed orchard established 

in 1978 in Toombs County, GA. An outbreak of T. 

pini had begun in 1982 after initial aerial applications 

of fenvalerate and azinphosmethyl. Azinphosmethyl 

was applied aerially in May 1983 and in June and 

August 1984, It was applied four times from April to 

August in 1985 and five times from March to September in 1986. Azinphosmethyl was applied at 0.84 kg 

(Al)/ha in 1984 and 1985. At the other times, the 

recommended rate of 3.36 kg (Al)/ha was applied. 

The population collapsed in late 1984, but a resurgence occurred in mid-1 985. 

In November 1985, third-generation females were 

settling and males were present on the needles. 

One to three infested lower crown branches were 

then selected on 15 trees, and up to 8 infested shoots 

per branch were tagged. The branches were then 

randomly assigned one of three treatments: fenvalerate, azinphosmethyl, or no insecticide (control). The 

branches were selected so that there would be no 

spray drift between treatments. A total of 300 shoots 

was selected and about 100 shoots were assigned 

to each treatment. On November 8, insecticides 

were applied with a hand sprayer until needles and 

shoots were thoroughly wetted. Fenvalerate was 

applied at a concentration of 0.025 percent (vvtlvvt) 

and azinphosmethyl at 0.1 8 percent (Mwt). Ten 

sample shoots per treatment were randomly selected 

and collected in early December, and 30 per treatment 

were collected in late March. Female T. pini were 

categorized as "live,"dead," "parasitized,' or "eaten.' 

Numbers and species of major predators were 

recorded, and female 0. acuta were also counted 

when present. 
Ten shoots per treatment with visible male populations 

were also collected on the first sample date, and 10 

randomly selected needles per shoot were examined. 

Males were classified as 'live," 'dead,' 'parasitized,' 

or 'emerged.' 

In 1986, four to nine infested trees were treated on 

each of seven dates (table 1). Trees were selected 

in clusters to reduce environmental variation. As a 

result, numbers of trees treated varied somewhat by 

date. One lower crown branch per tree was sprayed 

with fenvalerate and one with azinphosmethyl. A 

third branch was designated as a ~ontrol.~nsecticide 

dosages were the same as those in 1985, Insecticides 

were applied 1 to 2 weeks after operational aerial 

sprays, and shoot collections on those trees were 

stopped prior to the next aerial spray. This irregular 

schedule (table 1) was undertaken in an attempt to 

minimize the effects of the aerial applications on the 

results of our study, because unsprayed sections 

were not available as at the B~allclch County orchard. 

Female scales and predators were counted and 

classified as described above. When male populations 

were present, 10 needles per shoot were randomly 

selected and the number and condition of the males 

were recorded. Additional infested shoots were 

collected from each treatment group and placed in 

mailing tubes for rearing. The numbers of males and 

parasitoids emerging were recorded. 

Data Analysis 

Analysis of variance for these experiments were run 

using PROC GLM (SAS 1982), and treatment means 

were separated with the Duncan option. Data from 

the first experiment were grouped by month (collections between treatments) and by year, while data 

from the second experiment were grouped by spray 

date or by collection date. Live scale insects per 

shoot in the first experiment were calculated as the 

average of the individual counts per shoot obtained 

on each tree, while percentages of mortality and 

parasitism were calculated as the ratio of total dead 

or parasitized on all shoots to the total living and 

dead. Similarly, branch averages or sums were used 

in the second experiment. Percentage data were 

subjected to an arc-sine square root transformation 

prior to anatysis. 

Results 

Whole-Tree Treatments 

Scale insect populations decreased substantiafly in 

both treated and untreated areas at the Bulloch 

County orchard during 1 984. Although populations 

of the three species declined in all treatments, trees 

treated monthly with azinphosmethyl had consistently 

fewer females per shoot than trees receiving the 

other treatments (table 2). Significantly higher numbers of live females were found on fenvalerate-treated 

shoots than on control at two times: higher numbers 

of 7: pini were found after the first spray and higher 

numbers of mealybugs after the third spray. Trees 

receiving the alternating treatments generally had 

infestations intermediate between the azinphosmethyl 

and fenvalerate treatments. 

In 1984, parasitism increased to over 50 percent for 

0, acuta but was under 8 percent for T. pini (table 

2). Parasitism of P, quaintancii was less than 2 percent. 

Significant differences were found only for T. pini 

after the third spray; unsprayed trees had a higher 

percentage of parasitism than sprayed trees. Predation on T. pini females was generally lowest on 

azinphosmethyl-treated trees, but significant differences between treatments were not found between 

the second and third sprays (table 2). 

Woolly pine scale populations resurged in 1985, but 

there were no significant treatment differences in the 

numbers of females per shoot in the pre-spray 

collections or after the first spray (table 3). Significant 

differences in numbers of live females per shoot 

were found only in the collections after the second 

and the final insecticide applications. Significant 

differences in mortality of settled females appeared 

after the second spray, at the time when secondgeneration crawlers were settling, and those differences continued through the year. Numbers of females 

per shoot and female mortality generally were not 

significantly affected by fenvalerate treatments. 

Ground applications of azinphosmethyl significantly 

reduced female populations, while trees that received 

the aerial azinphosmethyl applications had infestation 

levels similar to those in fenvalerate and control 

treatments. 

Toumeyella pini and 0. acuta populations were too 

low to determine treatment effects in 1985. 
P. qusintsncii 7. pin1 0. scuts Coccopnsgus Allotrops Acerophagus 

atalrsls males ~slers SPP SP SP 

CONTROL 

FENVALERATE 

Figure 1 -Numbers of male scale insects and parasitoids emerging 

in rearing tubes from infested foliage collected at the Bulloch County, 

GA, seed orchard in 1984. 

More males of all three scale species were reared 

from unsprayed than from sprayed shoots (fig. 1). 

Collections of Coccophagus spp. (Hymenoptera: 

Aphelinidae), parasitoids of T. pini, were also higher 

from control shoots. Numbers of a platygastrid, 

Allotropa sp., and an eneyrtid, Acerophagets sp. - both 

hymenopterous parasitoids of 0. acuta - were apparently not affected by any treatment. 

Individual-Branch Treatments 

ALTERNATING 

AZINPHOSMETHYL 

Numbers of live males on needles did not differ 

significantly between fenvalerate and control treatments, but the variability was high (table 5). Male 

mortality was highest in the azinphosmethyl treatments, while parasitism was significantly higher on 

control shoots than on sprayed shoots in the late 

summer. More T. pini males were collected from 

fenvalerate-treated shoots than from the other shoots, 

while more parasites emerged from males on unsprayed shoots (table 6). 

In the Toombs County orchard, numbers of live T. 

pini females were lowest and mortality was highest Female 0. acuta numbers again did not differ 

on the azinphosmethyl-treated shoots. Female significantly between control and fenvalerate-treated 

abundance usually did not differ significantly between while was highest On branches 

the fenvalerate and control treatments (table 4). sprayed with azinphosmethyl (table 7). Mortal0 

Parasitism of mature females was again generally increased in the control and azinphosmethyl treatlow, rising to 55.1 percent only at the end of the ments in the second half of July, but not in fenvalerate 

overwintering period (table 4). Parasitism was lower treatments. Parasitism was near zero in all treatments. 

on treated branches than on unsprayed branches at 

this time, but thereafter the parasitism rates differed 

significantly only once. 
Discussion 

Our results indicate that ground applications of 

atinphosmethyl cause significant increases in female 

scale insect mortality in southern pine seed orchards, 

while fenvalerate does not. These results reaffirm the 

importance of the relatively low toxicities of pyrethroids 

to loblolly pine scale insects in the onset and 

continuation of outbreaks. Azinphosmethyl and other 

organophosphorous insecticides have been shown 

to be more toxic than pyrethroids to T, pini crawlers 

(Clarke and others 1988). Bartlett and Ewart (1 951) 

determined that parathion-induced outbreaks of the 

brown soft scale, Coccus hesperidum L., were related 

to the low susceptibility of the scales to the insecticide 

as well as to the suppression of natural enemies. 

Though azinphosmethyl caused heavy mortality of 

both sexes, fenvalerate appeared more effective 

against T. pini males than females. Fewer males 

were collected from fenvalerate-treated trees than 

from untreated trees at the Bulloch County orchard 

(fig. 1). Although more males were generally collected 

from fenvalerate-treated infested needles at the 

Toombs County orchard (table 6), the higher total 

numbers of males and parasitoids collected from 

unsprayed needles suggest that fenvalerate caused 

male mortality as well as suppressed parasitism. 

Initial male populations (parasitized included) appeared similar in both treatments. Males may have 

been more sensitive to the insecticides than were 

the females, which were larger. Differences in mortality 

from insecticides between the sexes could also have 

been related to penetration. Females were immobile 

and usually covered with wax and honeydew, 

restricting insecticide penetration. Mates were also 

covered by a waxy secretion called a test. However, 

cracks sometimes occurred, and the top and bottom 

covers separated at the end prior to emergence to 

allow the male to exit. These cracks and separations 

could increase the susceptibility of males to insecticides. The higher numbers of males collected from 

untreated foliage at the Bulloch County orchard (fig. 

1) could also be attributed in part to insecticide-caused 

mortality. Insecticide-caused reductions in male 

populations may also affect female parasitism. Large 

populations of males can support and produce large 

numbers of parasites, many of which will also 

parasitize females (Clarke and others 1 989). 

The method of insecticide application appeared to 

be an important factor. Aerial applications may not 

provide as complete coverage of the foliage as ground 

applications. Barry and others (1984) found up to a 

95-percent reduction in spray deposition in the lower 

crown as compared with the upper tip of the canopy 

with aerial spraying. In our studies, the ground 

application of fenvalerate probably contributed to 

increased male mortality by providing better coverage 

and canopy penetration. Azinphosmethyl, when 

applied as a drenching spray, caused significant 

female scale insect and mealybug mortality. However, 

operational aerial applications of azinphosmethyl did 

not appear to increase mature P. quaintancii female 

mortality in 1985, and the T. pini infestation at the 

Bulloch County orchard resurged in 1986 and 

remained high through 1987 despite monthly aerial 

applications. These results are consistent with earlier 

findings. Orr (1931) and Asquith (1949) found 

high-pressure drenching sprays of insecticides more 

effective than fogs or mists in controlling settled 

scale insects. 

Differences in parasitism rates between treatments 

were generally nonsignificant. Rates were significantly 

higher for T, pini females on unsprayed shoots only 

during periods when aerial applications had ceased: 

the end of 1984 at the Bulloch County orchard and 

early 1986 after the overwintering period at the Toombs 

County orchard. Significantly higher parasitism for T. 

pini males occurred on unsprayed shoots at Toombs 

County in the late summer in 1986 after 1 112 months 

without aerial applications (table 5). These data 

indicate that ground applications of azinphosmethyl 

and fenvalerate reduce parasitoid activity. Croft and 

Brown (1 975) found azinphosmethyl to be moderately 

toxic to parasitoids, while the literature review by 

Berisford and others (1 985b) indicated that fenvalerate 

was highly toxic to many parasitoids. Fenvalerate did 

not reduce predation as did azinphosmethyl (table 

2). Fenvalerate has been reported as less harmful to 

certain predator populations than to hosts or parasites 

(Croft and Whalon 1982; Shour and Crowder 1980). 
Our observations and results indicate that aerial 

insecticide applications in seed orchards will normally 

have little effect on settled female scale insects, but 

they can resuft in lower resident natural enemy 

populations. Incomplete insecticide coverage may 

have significant impact on parasitoids. McClure 

(1 977 b) found that Aspidiotiphagus citrinus (Crawford), a parasitoid of F. externa, was almost eliminated, 

even when only half of an infested tree was sprayed 

with dimethoate 2E. Although our insecticide treatments suppressed natural enemies, they did not 

eliminate them. This result suggests that insecticide 

residues did not prevent migration from unsprayed 

shoots or trees to those nearby receiving insecticide 

applications. However, entire orchards or large blocks 

are generally sprayed in normal seed orchard 

operations. Such aerial applications can influence 

scale insect population dynamics (Clarke and others 

1990), and may leave little opportunity for reestablishOur data reconfirm that fenvalerate should be used 

with caution for the control of seed and cone insects. 

If populations of scale insects are evident, fenvaferate 

use should be avoided. Even alternating applications 

of fenvalerate with other insecticides such as azinphosmethyl may prolong established infestations. Ideally, 

other integrated management systems for seed and 

cone insects should be sought. Chemicals, including 

other pyrethroids, included in these programs should 

be effective against the target insects but lovv in 

mammalian toxicity. The insecticide selected should 

also be more toxic to scale insects and less detrimental 

to their natural enemies than is fenvalerate. 

The use of trade or firm names in this publication is 

for reader information and does not imply endorsement by the U.S. Department of Agriculture of any 

product or service. 

ment of natural enemies from untreated areas. Future 

management strategies ernpioying fenvalerate might The pesticides reported on and recommended here 

include returning to ground applications in susceptible were registered for the use described at the time 

areas, increasing the interval between sprays, or this manuscript was prepared. Since the registration 

leaving several rows or pockets of trees untreated to of pesticides is under constant review of State and 

maintain enough parasites to keep scale insect Federal authorities, a responsible State agency should 

populations at acceptable levels. be consulted as to the current status of these 

pesticides. 

The population collapses of T. pini and 0. acuta at 

the Bulloch County orchard and the lack of a 

resurgence in 1985 following fenvalerate applications 

indicate that environmental factors strongly influence 

the severity and duration of outbreaks of these pests. 

Insecticide applications alone probably cannot cause 

or maintain such outbreaks if other conditions are 

unfavorable. McClure (1 977a) reported the detrimental 

effects of adverse edaphic conditions on F. externa, 

while Flanders (1 970) described host "phenoimmunity," whereby environmental conditions rendered normally susceptible hosts temporarily immune 

to scale insect attacks. 

The T. pini population reduction at the Toombs County 

orchard during the ovenrvintering period indicates 

that different factors can interact to regulate populations. Numbers of females per shoot were higher in 

the fenvalerate treatment than in the control treatment 

in late 1985, but equal numbers were found in early 

1986. Parasitism was greater in the control treatment, 

suggesting that other mortality factors compensated 

for the reduced parasitism in the fenvalerate 

treatments. 

Acknowledgment 

We authors thank Tom Coffey, Mike Cody, and Angie 

Hylton for their help with the data collection. A special 

thanks to Jo Hughey for her work in the preparation 

of the tables. We are grateful to Weyerhaeuser Co. 

and Continental Forest Investments for the use of 

their seed orchards, and to Shell Chemical Co. and 

Mobay Chemical Corp. for providing the insecticides. 

This work was supported by grants from the Georgia 

Forestry Commission, Shell Development Co., and 

Weyerhaeuser Co. 
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Table 1 -Dates of fenvalerate and azlnphosmethyl tndiviidual-branch treatments and shoot 

colle~tlon schedule for the Toombs County, GA, seed orchard in 1986* 

Branch spray 

date 

Post-treatment Number Shoots collected per 

collection date of trees treatment per tree 

May 5 

May 16 

June 23 

July 3 

July 14 

July 28 

August 7 

June 2 

June 2 

June 9 

July 3 

July 14 

July 28 

July 14 

July 28 

July 28 

August 19 

August 19 

'Aerial azinphosmethyl spray dates: March 26, May 1, June 10, August 21, and September 8. 
Tabie 2- Mean numbers of Ilve Oracella acuta, Pseudophitippia quaintancii, and Tourneyella pini females per shoot 

and percent paras'rtfsm and predation in 1984 on trees sprayed with fenvalerate or a;rinphosmethyl at the Bultoch 

County, GA, seed orchard* 

0. acuta P, quaintancii T: pini 

Live females Percent Live females Live females Percent Percent 

Treatment per shoot parasitism per shoot per shoot parasitism predation 

Fenvalerate 

Control 

Akernating2 

Azinphosrnet hyl 

Fenvalerate 

Control 

Alternating* 

Azinphosmethyl 

Fenvalerate 

Gontroi 

Alternating* 

Azinphosmethyl 

FIRST TO SECOND SPRAY (JUNE 13 - JULY 15) 

26.7a 17.la 30.4a 3.9a 

37.9a 1 1.8ab 13.9b 2.5a 

26.0a 13.5ab 19.5ab 2.1a 

36.2a 6.0b 8.8b 4.4a 

SECOND TO THIRD SPRAY (JULY 16 - AUGUST 14) 

47.2a 6.0a 16.1a 5.9a 

56.2a 7.5a 15.0a 5.7a 

46.7a 4.9a 10.8a 6.3a 

63.0a 2.1 b 3.4b 4.4a 

AFTER THIRD SPRAY (AUGUST 15) 

53.2a 1.6a 3.7a 4.5b 

44.7a 1.6a 3.7a 7.la 

54,523 1.5~3 2.7ab 4.7b 

46.4a 0.5b 1.1 b 4.4b 

Within periods and columns, means followed by the same letter do not differ significantly (P = 0.05; Duncan's [I 9551 

multiple range test). 

'Sample shoots were collected weekly or biweekly between spray dates. 

2Fenvalerate sprayed in June and August; azinphosmethyl applied in July. 
Table 3--- Mean numbers of PseudopkiIippia quainfancii females per shoot and female mortality on trees sprayed with 

fenvaferats or =inphasmethyl at the Bulloch County, GA, seed orchard In 1985 

Collections made weekly or biweekly between - 

P re- April 8- May 6- June 6- July 15- Post- 1985 

Treatment spray May 5 June 5 Juty 14 Aug. 14 spray total 

Control 

Fenvalerate 

Alternating' 

Azinphosmethyl 

AeriaP 

Control 

Fenvalerate 

ARernat ingl 

kinphosmethyi 

AeriaP 

LIVE FEMALES PER SHOOT 

4.9b 6.9a 5.S 

14.9a 7.0a 3.8a 

6.0b 4.1 a 0.6a 

4,Ob 2.4a 1.3a 

8.0 4.7 4.0 

PERCENT FEMALE MORTALITY 

43.7ab 66.7ab 46.0a 

27.9b 48.8b 34. I a 

43.5ab 54.4ab 71.3a 

74.2a 74.7a 70.1 a 

53.6 54.9 39.3 

Within columns, means followed by the same letter do not differ significantly (P = 0.05; Duncan's [I 9553 multiple 

range test). 

TF envalerate and azinphosmethyl sprayed on alternate months. 

ZIncluded for the purpose of comparison. 
Table 4 -Mean number of Ilve fernafe fbumeyet1a pini per shoot md female mortality and parasitism on branches 

sprayed wfth fenvalerate or a;rlnphosmethyl at the Toornbs County, GA, seed orchard In Iate 1985 and 19861 

Spray date 

Treatment 

Nov. Nov. May May June July July July Aug, 

82 83 5 16 23 3 14 28 7 

Control 

Fenvalerate 

Azinphosmethyl 

Control 

Fenvalerate 

Azinphosmethyl 

Control 

Fenvaferate 

kinphosmethyl 

LIVE FEMALES PER SHOOT 

17.7a 10.5a 7.8a 14.1a 

6.6b 10.0a 6.8ab 14.8a 

4.9b 3.0b 3.8b 4.5b 

PERCENT FEMALE MORTALITY 

15.7b 27.0b 21.4b 26.4b 

23.8b 28.413 22.7b 27.9b 

44.5a 71.6a 52.la 72.5a 

PERCENT PARASITIZED FEMALES 

3.7a 4.7a 1.6a 0.6b 

l.1a 1.9a 2.2a 1.6ab 

1,7a 0,5a 6.4a 3,8a 

Within columns, means followed by the same letter do not differ significantly (P = 0.05; Duncan's [I 9551 multiple range 

test). 

'One to three collections of shoots were made at approximateb 10-day intervals after each spray. See table 1 for collection 

dates. 

2Data from shoots collected November 28, 1985. 

Qata from shoots collected March 24, 1986. 
Table 5 - Mean numbers of live and parasRCzed Tourneyella pin/ males and percent male mottaltty 

on branches sprayed wlth fenvalerate or arlnphosmethyl at the Toombs County, GA, seed orchard In 

November 1985 and the summer of 1986 

Spray date 

November June Job Jury Jub' August 

Treatment 81 232 32 1 42 283 73 

Control 

Fenvalerate 

Azinphosmethyl 

Control 

Fenvalerate 

Azinphosmethyl 

Control 

Fenvalerate 

Azinphosmethyl 

LIVE MALES 

13.la 19.la 32.8a 

9.7ab 18.7a 1 1.2a 

2.3b 0.5b 2.9a 

PERCENT MALE MORTAUTY 

54.9ab 44.2b 50.9b 

45.6b 46.1 b 59.5b 

77.4a 96.3a 92.4a 

PERCENT MALES PAMSITIZED 

1.2a 0.6a 0.3a 

O.Oa 0.3a 2.9a 

0. Oa 0.3a O.la 

Within columns, means followed by the same letter do not differ significantly (P = 0.05; Duncan's [I 9551 multiple 

range test). 

'Mean per 5 needles; needles collected November 28, 1985, 

*Mean per 10 needles; needles collected Jufy 28, 1986. 

3Mean per 1 0 needles; needles collected August 19, 1986. 
Tabie 6 -Numbers of Tourneyella pin! males and thelr Coccophagus spp. parasltolds reared from shoots treated 

with fenvalerate and arlnphosmethyi at the Toombs County, GA, seed orchard in November 1985 and July and 

August 11986 

Spray 

date 

Number of 

Collection tubes per T. phi Coccophagus 

date treatment Treatment males SPP. 

Fenvalerate 

November 8 November 29 10 Control 

Azinphosmethyl 

July 14 

July 28 

August 7 

August 7 

July 28 August 19 

Fenvalerate 

9 Control 

Azinphosmethy l 

Fenvalerate 

Control 

Azinphosmethyl 

Fenvalerate 

Control 

August 7 August 19 3 Fenvalerate 

Control 
Table 7-Mean numbers of Oracella acufa fernafes per shoot and percent mottality on branches 

sprayed with fenvalerate or arinphosmethyl at the Toombs County, GA, seed orchard in 1986 

Spray date' 

Treatment 

June Jury Jury JufV August 

23 3 14 28 7 

Control 

Fenvalerate 

Azinphosmethyl 

Control 

Fenvalerate 

Azinphosmethyl 

LIVE FEMALES PER SHOOT 

1.6ab 1.9a 3.0a 6.7ab 5.0a 

3.0a 2.4a 2.4a 9.6a 8.0a 

0.8b 0.4b 1 .Oa 1.6b 6.4a 

PERCENT FEMALE MORTALITY 

11 .l b1.7b 3.5a 11.1ab 15.4a 

8.5b 5.3b 5.5a 4.1 b 5.7a 

35.6a 42.5a 1 7.5a 37.Oa 32.4a 

Within columns, means followed by the same letter do not differ significantly (P = 0.05; Duncan's [I 9551 

mu ttiple range test). 

'See table 1 for collection dates, 
Clarke, Stephen R.; DeBarr, Gary L.; Berisfotd, C. Wayne. 1990. 

Effects of fenvalerate and azinphosmethyl on scale insects and 

their natural enemies in loblolly pine seed orchards. Res. Pap. 

SE-279. Asheville, NC: U.S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 14 pp. 

Ground applications of azinphosmethyl caused significant mortality of 

the scale insects Toumeyella pini (King), Pseudophilippia quaintancii 

Cockerell, and Oracella acuta (Lobdell), whereas aerial applications did 

not. Fenvalerate applications generally did not cause significant mortalrty, 

and alternating applications of the two insecticides produced infestations 

intermediate between those treated only with azinphosmethyl or 

fenvalerate. Parasitism and predation rates were sometimes significantly 

lowered by insecticide applications. 

Keywords: Pyrethroids, Toumeyella pini, oracella acuta, Pseudophilippia 

quantancii, secondary pests. 

Clarke, Stephen R.; DeBarr, Gary L.; Berisford, 6. Wayne. 1990. 

Effects of fenvalerate and azinphosmethyl on scale insects and 

their natural enemies in loblolly pine seed orchards. Res. Pap. 

SE-279. Asheville, NC: U.S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 14 pp. 

Ground applications of azinphosmethyl caused significant mortality of 

the scale insects Toumeyella pini (King), Pseudophiiippia quaintancii 

Cockerell, and Oracella acuta (Lobdell), whereas aerial applications did 

not. Fenvalerate applications generally did not cause significant mortality, 

and alternating applications of the two insecticides produced infestations 

intermediate between those treated only with azinphosmethyl or 

fenvalerate. Parasitism and predation rates were sometimes significantly 

lowered by insecticide applications. 

Keywords: Pyrethroids, Toumeyella pini, oracella acuta, Pseudophilippia 

quantancii, secondary pests.