Dasymallomyia ditenostyla Alexander 1964
Creators: name: Kato, Daichi
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Limoniidae
Dasymallomyia
Dasymallomyia ditenostyla

description: Dasymallomyia ditenostyla Alexander, 1964
(Figs 3, 10B)
Dasymallomyia ditenostyla Alexander 1964: 219. Type locality: India, Assam, Manipur, Chingsao.
Diagnosis. Yellowish species with unpatterned wing (Fig. 3A). Presutural area of mesonotum and scutal lobe polished, with one black stripe and two pairs of black spots on prescutum, 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, rounded at tip, outer margin with small point near middle. 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, single-pointed on posteroventral corner.
Material examined. HOLOTYPE male, INDIA, Assam, Manipur, Chingsao, 5400 feet, 14.VI.1960, Schmid (USNM). Non-type material: JAPAN: [Nansei Islands] Amami Is: 1 male, Amami-shi, Sumiyô-chô-Ôaza-Yakugachi, Yakugachi-gawa River, near Yakugachi tunnel, alt. 50 m, N28.2283, E129.3600, 3.IV.2019, D. Kato (BLKU); 1 male, Uken-son, Yuwan, near 4th northern tributary of Kawauchi-gawa River, alt. 80 m, N28.2645, E129.3501, 4.IV.2019, D. Kato (BLKU); 1 male, Yamato-son, Yuwangama, alt. 250 m, N28.3511, E129.4218, 31.III.2019, D. Kato (BLKU).
Description. Male.
Head. Grey, covered with long, yellow to black setae. Vertex weakly yellowish on posterolateral end; 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 and half length of scape; widest part about as wide as scape. Flagellum 14-segmented, sometimes slightly darker on distal segments. 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 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. 3B). 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; 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 triangular with rounded corners, 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, almost equal in size to anterior one. Scutellum sometimes dark at base. Mediotergite dark brown on posterior 2/3, with tiny dark spot at middle of anterior end. Pleuron barely brownish at middle of anepisternum, dorsal and ventral ends of katepisternum, and middle of propleuron; ventral part of laterotergite dark brown. Dorsopleural membrane whitish yellow. Wing (Fig. 3C) hyaline, slightly tinged with yellowish brown, unpatterned. Veins mainly dark brown, yellowish on Sc and veins near wing base. R 3 about 1/3 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. Tibiae sometimes weakly dark at tips. Tarsi slightly dark at each tip of tarsomeres; terminal segment entirely dark. Claw slender and simple, about 2/3 length of tarsomere 5, strongly curved near middle. Halter pale yellow, about 1.8 times as long as mediotergite.
Abdomen. Brown on tergites and yellow on sternites, densely covered with long yellow setae; anterior part of tergite 1 yellowish; caudal margins of tergites weakly yellowish. Male terminalia (Figs 3D–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 3F–G) subhyaline, thin, about 1.5 times as long as lobe of gonostylus, wide on basal part, rounded at tip; outer margin with small point at middle. 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 bilobed on distal 1/4, pointed at each tip; small setose lobe present between anterior and posterior branches. Aedeagus (Figs 3H–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.
Measurements. Male (n = 3): body length 5.3–6.2 mm, wing length 6.2–7.2 mm.
Distribution. Japan (Nansei Islands: Amami and Okinawa Is) (Fig. 10B) and India (Assam).
Remark. It is the first record of this species from Japan. See remarks in the next species for comparison to similar species.
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 405-407, DOI: 10.11646/zootaxa.5168.4.1, http://zenodo.org/record/6902776