Dasymallomyia tachii Kato, sp. nov.
Creators: name: Kato, Daichi
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Limoniidae
Dasymallomyia
Dasymallomyia tachii

description: Dasymallomyia tachii Kato, sp. nov.
(Figs 4–5, 10B)
Diagnosis. Yellowish species with unpatterned wing (Fig. 4A). Presutural area of mesonotum and scutal lobe polished, with one black stripe and two pairs of black spots on prescutural area of mesonotum, and with two large dark spots on scutal lobe. Legs yellow with narrow brown ring at distal 1/6 of each femur. Halter pale yellow. Abdomen mainly brown. Clasper of gonostylus thin, blade-shaped, smooth at outer margin, rounded at tip. Lobe of gonostylus black, distinctly bifid; anterior branch about as long as posterior branch, rounded on distal part in lateral view; posterior branch strongly widened, bilobed at posteroventral corner.
Type material. HOLOTYPE male, JAPAN, Nansei Islands, Okinawa Is, Kunigami-son, Yona, N26.75, E128.22, 19.IV.1996, T. Tachi (LT / BLKU). PARATYPES: JAPAN: [Nansei Islands] 1 male 1 female, same data as holotype.
Description. Male.
Head. Grey, covered with long, yellow to black setae. Vertex often weakly yellowish on posterolateral part; narrowest part about twice as wide as scape. Antenna dusky yellow to brown, about twice as long as head. Scape cylindrical, 2.5 times as long as wide. Pedicel barrel-shaped, narrower on basal part, slightly longer than wide, half length of scape; widest part about as wide as scape. Flagellum 14-segmented, sometimes gradually darkened toward tip. Flagellomere oval on basal segments with short neck at each tip; distal segments narrower, bacilliform, with apical neck indistinct; each segment with black verticils, about 2–3 times as long as segment; basal 11 to 12 flagellomeres covered with whitish pubescence, shorter than each segment. Rostrum brown, slightly shorter than scape. Palpus brown to dark brown, 5-segmented, palpomeres 3 to 5 longest. Labellum brown to dark brown.
Thorax (Fig. 4B). Generally yellow, covered with long yellow setae, distinctly polished on presutural area of mesonotum and scutal lobe. Presutural area of mesonotum often largely brownish on middle part, with one polished black stripe and two pairs of polished black spots, sometimes pale brown along outlines; middle stripe almost same width in whole length, running from anterior end of mesonotum and ending slightly before transverse suture; middle stripe bearing narrow longitudinal line of pruinosity at middle in whole length; anterior lateral spot small, bacilliform, less polished than posterior one, situated at prescutal pit; posterior lateral spot much larger than anterior one, roughly roundish or triangular with rounded corners, as wide as or wider than middle stripe. Scutal lobe with two large, polished black markings, narrowly separated from or partly fused with each other; anterior marking triangular, situated at anterior corner; posterior one roundish, situated at middle, distinctly smaller than anterior one. Scutellum sometimes dark at base. Mediotergite dark brown, with small yellow area at anterolateral margin. Pleuron brown to dark brown on propleuron, anepisternum, dorsal and ventral end of katepisternum, ventral half of meron, and ventral part of laterotergite; dark areas on katepisternum more polished; dorsal half of anepimeron sometimes weakly dark. Dorsopleural membrane whitish yellow. Wing (Fig. 4C) hyaline, slightly tinged with yellowish brown, unpatterned. Veins mainly dark brown, yellowish on Sc and veins near wing base. R 3 about half length of R 4. R 4 weakly sinuous. Cell m 1+2 about twice as long as its petiole. Legs yellow, densely clothed with long yellow to dark brown setae; setae on coxae to basal parts of femora mainly yellow. Coxae with fore pair weakly dark at base. Femora each with narrow brown ring at distal 1/6, slightly shorter than wide. Tarsi indistinctly dark at each tip of tarsomeres; tarsomere 5 entirely dark. Claw slender and simple, about 2/3 length of tarsomere 5, strongly curved near middle. Halter pale yellow to yellow, about 1.8 times as long as mediotergite.
Abdomen. Brown, slightly yellowish on sternites, densely covered with long yellow setae; anterior part of tergite 1 yellowish; caudal margins of tergites weakly yellowish. Male terminalia (Figs 4D–E) with tergite 9 produced posteriorly at middle of caudal margin. Sternite 9 strongly produced ventrally at center. Gonocoxite longer than tergite 9, broad on basal part, rounded at tip. Clasper of gonostylus (Figs 4F–G) subhyaline, thin, about 1.5 times as long as lobe of gonostylus, wide on basal part, rounded at tip; outer margin smooth. Lobe of gonostylus black, distinctly bifid; anterior branch about as long as posterior branch, rounded on distal part in lateral view, curled outward at tip; posterior branch strongly widened and trilobed on distal 1/4, ventral corner with two points; small setose lobe present between anterior and posterior branches. Aedeagus (Figs 4H–I) conical flask-shaped; distal part stout rod-shaped, with claw-shaped lobe at tip; dorsal surface near tip with membranous region; tip directed posteroventrally.
Female.
Generally resembling male.
Female terminalia (Figs 5A–B). Tergite 9 narrow, slightly concaved at caudal margin. Tergite 10 1.2 times as long as wide; distal 1/6 separated from anterior part and interrupted medially by V-shaped notch. Cercus 1.5 times as long as tergite 10, weakly upcurved toward tip. Sternite 8 (Fig. 5C) roundly produced at caudal margin, about as long as wide. Hypogynial valve slightly longer than sternite 8, about twice wider than cercus in lateral view; tip ending at level of basal 1/3 of cercus. Sternite 9 (Fig. 5D) with central part roughly triangular, roundly convex near middle of lateral margin. Lateral part of sternite 9 slender and bilobed, extending beyond tip of central part; inner lobe straight, gradually narrow to tip; outer lobe strongly curved outward. Sternite 10 roundish and indistinct.
Measurements. Male (n = 2): body length 5.6–5.7 mm, wing length 6.4–6.5 mm. Female (n =1): body length 7.7 mm, wing length 7.8 mm.
Etymology. This species is named after the collector, Dr. Takuji Tachi. The specific name is a noun in genitive singular.
Distribution. Japan (Nansei Islands: Okinawa Is) (Fig. 10B).
Remarks. This species is similar to D. ditenostyla, but is differentiated from it by the following characters: mediotergite with small yellow area at anterolateral margin (anterior 1/3 yellow with tiny dark spot at middle of anterior end in D. ditenostyla); posterior spot on scutal lobe distinctly smaller than anterior one (Fig. 4B) (almost equal in size in D. ditenostyla (Fig. 3B)); pleuron with several distinctly dark areas (only on laterotergite in D. ditenostyla); posterior branch of clasper of gonostylus with three apical points (Fig. 4G) (two points in D. ditenostyla (Fig. 3G)); lobe of gonostylus without small tooth (Fig. 4F) (with small tooth at outer margin (Fig. 3F)).
description: Published as part of Kato, Daichi, 2022, Four genera of Limoniidae (Diptera) new to Japan with descriptions of new species, pp. 401-418 in Zootaxa 5168 (4) on pages 407-410, DOI: 10.11646/zootaxa.5168.4.1, http://zenodo.org/record/6902776