Insecutor Inscitiae Menstruus
Vol. XIIAPRIL-JUNE.

1924

Nos. *-6

UNDESCRIBED SPECIES OF NEMATOCERAFROM JAPAN(Diptera)
Bv CHARLES P. ALEXANDER
The new species of Diptera described in this paper wereincluded in material sent to me by my friends, Prof. Teiso
Esaki and Dr. Tokuichi Shiraki. With the exception of theFormosan Ptychoptera, the flies were taken in the mountainous
sections of central Honshiu by Professor Esaki. The twogenera, Bittacomorphellaand Di.omonus,are of especialinterestin that all of the species known hitherto are Nearctic. Thetypes are preserved in the writer's collection through the kindness of the collectors.
Family PTYCHOPTERIDAE
Ptychoptera formosensis, new species.
Male.-Length 8.4 mm.; wing 8.6 mm.
Frontal prolongation of head and the palpi pale brownish
yellow, the distal segments of the latter a little darker.
Antennae with the scape and base of the first flagellar segment
yellow, the remainder of the flagellum brownish black. Vertex
and occiput broad, shiny blue-black.
Mesonotum deep black, the praescutum with deep, longitudinal impressions; scutellum reddish yellow; postnotum blueblack. Pleura and pleurotergites of postnotum light yellow.
Halteres brown. Legs with the coxae light yellow; trochanterslight yellow; femora obscure yellow, the tips narrowly darkened; tibiae pale brown, the tips narrowly darker; tarsi brown.
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M ENSTR U U SlVings with a faint grayish tinge, the costal and subcostal cells
more yellowish; two very narrow,cross-bands, one along thecord extending from R to midlength of Cu", the second band
more obiique, slightly interrupted, extending from the stigma
at tlre tip of R, to the lork of. M. Wing-surface with themacrotrichiae extensive, in the basal cells extending almost tothe base. Venation: Rs shorter than r-vn, the latter subequal
to m-cu and in alignment; abortive anal vein conspicuous andwith macrotrichiae.
Abdomen orange-yellow; tergites two to six with the caudal
margins broadly black; segments seven and eight black;hypopygium orange; sternites uniformly dull orange. Male
hypopl'gium large, the ninth tergite profoundly incised, thelateral lobes being very long, digitiform, their tips directedventrad across the genital chamber.
H abitat.-Japan (Taiwan).
Holotype, J, Funkiko, April 25, 191? (T. Shiraki).
The present species is most closely related to P. annq,nd'alei
I am indebted to Dr. Annandale for theBrunetti (India).
privilege of studying one of the type males of the latter species.
The following supplementary notes on P. annandalei' may besupplied:
The coloration of the mesonotal praescutum is brilliant
metallic blue with decided opalescent reflections; the anterior
part of the postnotum with a large circular light yellow areawith opalescent reflections. Venation with the deflection ofRn*. short to subobsolete, r-m being correspondingly lengthened; cell Rn much shorter in proportion to the length of its
petiole (Rn,,) than in formosensis.
The ninth tergite is very short at its base, the lateral lobes
being greatly prolonged into slender, digitiform pale lobes thatare slightly enlarged at their distal ends and here provided withblack setae. Dististyle complex, consisting of a flattened blade
whose dorsal inner edge is provided with a broad margin ofshort, blackened teeth, the ventral distal angle produced lateradand caudad into a pale, fleshy clavate lobe that is provided withseveral coarse, erect bristles; mesal face of this blade, near

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51

the base, produced mesad into a subconical lobe that is provided with short setae, especially on the cephalic face and near
the apex. Ninth sternite appearing as two stout reddish brownlateral lobes, the truncate apex of each densely provided withlight yellow appressed silken setae, the caudal face with adense pencil or fascicle of black setae directed mesad andcaudad, not quite contiguous across the midline; notch between the lobes U-shaped; back of this notch a median lobe
that is slightly widened distally, the apex truncate. Aedeagus
conspicuous, subtended on either side by a small chitinizedapophyse, which terminates in a small point directed ventradand laterad.
In P. forrnosensi,s, the tergite is generally similar but thedististyle and ninth sternite are entirely different in structure,
the chitinized lobes being replaced by silken yellow setae.
Bittacomorphella

nipponensis, new species.

Feruale.-Length 10-L1 mm.; wing ?.5-9.4 mm.
Rostrum silvery; palpi pale yellow. Antennae setaceous,
Head black, the front, anterior part ofblack throughout.
vertex and the orbits silvery white.
Mesonotal praescutum and scutum black, the lateral margins
broadly silvery; scutellum brown; postnotum pale brownish
silvery. Pleura blackish, heavily silvery pruinose. Halteres long,
pale, the knobs infuscated. Legs with the fore coxae blackened,
the remaining coxae and the trochanters reddish yellow; femora
pale basally, passing into brownish black at the tips, the fore
and middle femora only narrowly pale basally, the posterior
femora with only the tips darkened; tibiae black, hairy; basitarsi black, the apical two-fifths (fore leg), one-third (middleleg) or one-fifth (posterior leg) snowy-white; tarsal segments
two and three snowy-white; terminal two segments abruptly
narrowed, brownish black. Wings gray, the small stigma pale
brown; extreme base of wing faintly yellowish; veins black.
Macrotrichie very sparse, confined to the extreme outer marginsof cells Sc' R, and Ro. Venation about as in B. sackeni.
Abdomen dark brown, the caudal margins of the segments

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narrowly paler; terminal abdominal segments with appressed
silvery pubescence.
II abitat.-Japan (Honshiu).
Holotype, !, Hinoiimata, Iwashiro-no-kuni, altitude 4,000
feet, July 24,1923 (T. Esaki); flying near surface of mountainstream.
Paratype, Q, Ozenuma, on boundary between Iwashiro-nokuni and Kotsuke-no-kuni, altitude 6,545 feet, July 26, t923
( T . E s ak i) .
Bittacomorphella ni,pponens'is is most closely related to B.
sackeni (R<ider) of western North America, from which it
differs notably in the great reduction in number of macrotrichirin the cells of the wing. In sackeni these include the entire
distal sixth of the wing.
Family BLEPHAROCERIDAE
Blepharocera esakii, new species.
Male.-Lensth about 8.5 mm.; wing 9.8 mm.
Labrum shiny black, the maxillary palpi and remaining
mouthparts pale brown. Antennae black throughout. Front
light gray pruinose; remainder of the head darker gray.
Pronotum light gray. Mesonotum gray with three darkbrown stripes, the median stripe broad and indistinctly bisecte<lby a capillary pale line; an incomplete transverse suture, extending mesad to the mesal edge of the lateral praescutal stripes;
scutal lobes dark brown, the median area light gray pruinose;
scutellum light gray, the caudal margin broadly black; postnotum very short, gray pruinose. Pleura light grav pruinose.
Halteres obscure orange-yellow throughout.
Legs with theouter faces of the coxae more or less darkened, the innerfaces of the mid-coxae and trochanters with dense black setae:
femora and tibiae obscure yellow, the tips broadly dark brown;
tarsi dark brown. Wings subhyaline, the extreme base conspicuously light yellow; costal margin narrowly tinged withpale brown; veins black; Cu and its branches paler on basal
half . Venation: Rs long, fully five to six times the basal
deflection of Rr*r.

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Abdominal segments grayish brown, the basal tergite clearer
gray, the extreme caudal margins of the segments pale.
H abitat.-lapan (Honshiu).
Holotype, J, Mt. Takao, Musashi-no-kuni, altitude about
500 feet, May 7,7922 (T. Esaki); beside a stream in denseforest.
This interesting Blephorocera is named in honor of thecollector, my friend, Prof. Teiso Esaki. B. shirakii Alexander
is readily told from the present species by its general blackcoloration and smaller size.
Family MYCETOPHILIDAE
Macrocera ephemeraformis, new species.
Male.-Length about 9.5 mm.; wing 8.4 mm.; antenna 27 mm.
Front and palpi brownish black. Antennae very long, asshown by the measurements; basal segment of scape glabrous,
obscure yellow basally, the apex blackened; second segment
very short; basal segment of flagellum brown on basal third,
the apex yellowish white; succeeding flagellar segments withthe basal third black, the apex yellowish, the amount of black
becoming further reduced on the intermediate and terminalsegments. Head black.
Mesonotum light brown, sparsely yellowish pollinose, withthree conspicuous shiny black stripes; scutellum and postnotum
chiefly dark brown. Pleura black, the region surrounding thewing-root light brown. Halteres testaceous, the knobs yellow.
Legs with the fore and middle coxae obscure yellow, the anterior face more infuscated; posterior coxae largely brown;
trochanters brownish yellow; fore femora brown, near theapex with a conspicuous subterminal spine; posterior femorayellow; remainder of legs passing into brown. Wings grayish
subhl'aline, the costal region variegated with bright yellow andbrown, the markings alternately arranged; the brown marks
include conspicuousseams at h; tip of. Scr; tip of Rr; arculus;
origin of Rs,' a large blotch at fusion of R and M, continued
caudad as a paler cloud along vein Cu, almost to the wingmargin; a spot on Ra*u opposite to and nearly confluent with5+

INSECUToRINSCITI,4 MENSTRUUS

the area at Rr; on R,,, and a conspicuousapical cloud continued
back along vein Rn*u; veins yellow, brown in the infuscatedareas; a very small paler brown cloud at tip of vein Cu, but
none at tips of the medial veins. Anal angle of wing square,more so than in any described speciesof the genus. Venation:
Petiole of cell M fully one-half Rr*, ; fusion ol M and Cu,"
relatively extensive, about two-thirds the section of M beyond it.
Abdomen with the basal five segments obscure yellow, thecaudal margins of the segments conspicuously blackened; terminal segments and hypopygium uniformly blackened.
H abitat.-Japan (Honshiu).
Holotype, /, Mountains near Kawamata, Shimotsuke-nokuni, July 24,1923 (T. Esaki).
This remarkable fungus-gnat is the largest species of thegenus known to the writer. In its general appearance it differs
so strikingly from the Nearctic species of. Macrocera that it
might appear that a new genus is necessary for its reception.
The Oriental M. alternafa Brunetti, however, appears to form
a connecting link between the groups. The anal angle of thepresent species is practically rectangular. The specific namewas suggestedby Professor Esaki, the fly presenting a curious
resemblance to certain may-flies, as Heptagenia and Ephemera.

INSECUTOR INSCITI,€

fiI
flDiomonus esakii, new species.
Male.-Length 11.5 mm.; wing 11.4 mm.
Female.-Length 11 mm.; wing 10.2 mm.
Rostrum and palpi black. Antennae black, the terminal six
segments abruptly yellowish white. Head shiny black, theyellowish ocelli placed in almost a transverse line, the median
one a little smaller than the laterals.
Thorax entirely coal-black, with short, delicate black pile.
Halteres black, the extreme base of the stem a little brighter.
Legs with the coxae black, very slightly pruinose; trochantersand extreme bases of femora yellow; remainder of legs black,the terminal tarsal segment a little paler; no spine on midfemur. Wings subhyaline, the costal margin more yellowish;
apical fourth of wing uniformly infuscated; an irregularlytIMDNSTRUUS

55

circular brown cloud in the bases of cells R, and Ru and aconspicuouswash at the end of vein Czr; veins brown, darker
in the clouded areas. Venation: Sc, ending some distancebeyond the origin of Rs, Sc, immediately before this origin
in the female, far before in the male; cell R, very tiny, subquadrate in the female, completely obliterated in the male; tipof anal vein atrophied.
Abdomen black.
In the female, the basal tarsal segments are paler than in
the male and the abdomen shows faint bluish reflections.
H abitat.-Japan ( Honshiu ).
Holotype, J, Yumoto, Shimotsuke-no-kuni, altitude 5,820
feet, July 23,7923 (T. Esaki).
Allotopotype, Q.
This beautiful and striking fungus-gnat is named in honorof the collector, Professor Esaki. The previously described
species of. Diomonus are all Nearctic. The obliteration ofcell R, in the type male is presumably an abnormality of thespecimen. Such individuals would run to the subfamily
Mycetophilina. The nearest ally of D. esakii is the genotype,D. nebulosus Walker.