Stichillus japonicus
Creators: name: Lee, Jun-Ho
name: Kim, Sam-Kyu
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Phoridae
Stichillus
Stichillus japonicus

description: Stichillus japonicus (Matsumura, 1915)
(Figs. 1C, 1D, 2C, 2D, 4B, 4E, 5C, 5D, 7, 10)
Conicera japonica Matsumura, 1915: 17. Type locality: Hokkaido, Japan.
Conicera (Hypocerina? [Deuteroconicera, lapsus]) japonica: Schmitz, 1953: 292 (subgeneric assignment).
Stichillus japonicus: Takagi, 1962: 44 (generic assignment).
Stichillus matsumurai Schmitz, 1953: 276. Type locality: Sapporo, Japan (synonym).
Diagnosis. This species can be distinguished from other Stichillus species by the combination of the following characteristics: fore tarsomere 5 dark brown dorsally; male epandrial lobe not distinctly enlarged apically; inner projection on posterior margin of hypandrium long, conical, apically pointed; dorsal plate of aedeagus with pointed dorsal process and robust, pointed arm curved at middle forming obtuseangle on right side of ventrobasal portion; female tergite 9 with anterior margin bilobed.
Description. Male. Body length 3.71–4.7 mm (n=10). Head (Figs. 1C, 2C). Frons black, shiny, with three transverse rows of four long bristles and sparsely covered fine hairs; supra-antennal bristle absent; middle row of bristles slightly procurved. Ocellar region as in figure 2C. First flagellomere dark brown, pyriform, twice longer than wide; arista brown, located subapically. Palpus yellowish brown, with single long bristle on apex and some shorter bristles on near apex to ventral margin. Labrum and labella yellow, short. Thorax (Fig. 1C). Scutum and scutellum black. Posterior margin of scutum with 2–3 pairs of strong prescutellar bristles; innermost pair of bristles distantly spaced with each other. Scutellum with anterior pair of long narrow bristles and posterior pair of strong bristles distinctly longer than anterior bristles. Pleuron black; upper half of anepisternum covered with short setae. Legs (Figs. 1C, 4B, E). Black except fore tibia and fore tarsomeres 1–4 yellowish brown, dorsal face of fore tarsomere 5 dark brown (Fig. 4E). Fore tibia with one strong dorsal bristle on basal half and single longitudinal row of short dorsal setulae on entire length. Fore tarsomere 5 widened, with enlarged pulvilli. Midtibia with two dorsal longitudinal setal palisades on basal half, which fused together from middle to apical half, and with one pair of bristles on basal quarter (one dorsal and the other anterodorsal), one long anteroventral preapical bristle, two short dorsal preapical setae, and one long posteroventral apical spur. Hind tibia (Fig. 4B) with three dorsal longitudinal setal palisades along its whole length, one anterodorsal strong bristle on basal third, one anterodorsal preapical bristle, one dorsal and three ventral long apical spurs, and some posterior—posteroventral apical short setae. Wing (Fig. 5C). 3.5–4.35 mm long (n=10). Costal index 0.47–0.51. Mean costal ratio 1.07:1; range 0.95–1.14. Costal setae of costal section II 0.1–0.12 mm long. Vein Rs with single row of short, fine hairs on dorsal face except apical end. Vein R 2+3 absent. Vein M 1 slightly curved basally and nearly straight apically. Veins brown, membrane hyaline with yellow tinge. 7–10 alular setae present, 0.2–0.26 mm long. Halter black. Abdomen (Fig. 1C). Tergites black, shiny, extended posteromedially; tergite 2 elongated, approximately twice longer than tergite 1. Venter of abdomen blackish brown, with single pair of oval, weakly developed sternite 6. Hypopygium (Fig. 7A–C). Epandrium nearly symmetrical, dark brown; epandrial lobe elongated posteroventrally, covered with some short hairs, with rounded apex not distinctly enlarged apically. Hypandrium large, dark brown; lateral membranous lobe triangular, spinulose; inner projection on posterior margin of hypandrium large, sharply pointed, protruded ventrally (Fig. 7B); tip of inner projection situated far above bottom level of lateral membranous lobe. Cercus and hypoproct short, with some short hairs. Aedeagus (Fig. 7D, E). Dorsal plate dark brown, with pointed dorsal process; ventrobasal portion of dorsal plate with single robust, pointed arm curved at middle forming obtuse-angle on right side (Fig. 7E) and small rounded lobe on left side (Fig. 7D). Ventral membrane usually twisted at base and elongated ventrally, hyaline, approximately twice as long as maximum width of basal portion, tapering apically, spinulose basally.
Female. Body length 4.35–5.81 mm (n=10). Head (Figs. 1D, 2D). Similar to male, except first flagellomere smaller, globose, orange. Ocellar region as in figure 2D. Thorax (Fig. 1D). Similar to male. Legs (Fig. 1D). Similar to male, except fore apical tarsomere not widened, pulvilli not enlarged. Wing (Fig. 5D). Similar to male, 4.25–4.87 mm long (n=10). Costal index 0.49–0.52. Mean costal ratio 1.04:1; range 1–1.13:1. Costal setae of costal section II 0.11–0.16 mm long. 7–9 alular setae present, 0.2–0.32 mm long. Halter black. Abdomen (Figs. 1D, 7F, G). Tergites 1–6 well developed, black. Tergite 2 elongated as male. Tergite 7 absent (Fig. 7F, G). Tergite 8 (Fig. 7G) nearly rectangular, laterally rounded, dark brown, twice longer than wide. Tergite 9 (Fig. 7F, G) twice as long as wide, dark brown, with anterior margin bilobed, posterior margin rounded; posterior margin with two pairs of long hairs. Venter of abdomen blackish brown, with only sternite 9 discernable. Genital opening enlarged posteriorly (Fig. 7F). Cercus oval, apically with two long and some short hairs.
Specimens examined. Korea: 7♂ 2♀, Gangwon-do, Yangyang-gun, Seo-myeon, Osaek-ri, Mt. Seoraksan, 38°06′12.8″N, 128°27′22.5″E, 1004 m, 27.viii–7.ix.2017, pitfall trap, T. S. Kwon et al. leg. (KNU); 14♂ 6♀, ditto, 38°06′42.1″N, 128°27′39.7″E, 1401 m; 49♂ 10♀, ditto, 38°06′59.6″N, 128°27′50.4″E, 1596 m; 10♂ 1♀, ditto, 38°07′08.3″N, 128°27′55.7″E, 1706 m, 27.viii–9.ix.2017; 17♂ 3♀, Gyeongsangnam-do, Sancheong-gun, Sicheon-myeon, Jungsan-ri, Mt. Jirisan, 35°19′40.8″N, 127°44′29.7″E, 1223 m, 5–18.viii.2018, pitfall trap, T. S. Kwon et al. leg. (KNU); 23♂ 4♀, ditto, 35°19′53.8″N, 127°44′02.8″E, 1597 m; 28♂ 1♀, ditto, 35°20′04.9″N, 127°43′50.8″E, 1799 m; 28♂, ditto, 35°20′14″N, 127°43′51.3″E, 1907 m; 1♂, Gangwon-do, Pyeongchang-gun, Daegwallyeongmyeon, Hoenggye-ri, Mt. Sohwangbyeongsan, 37°45′42.5″N, 128°40′05.1″E, ca. 1300 m, 16.viii.2020, hand collecting, J. H. Lee leg. (NIBR); 1♀, ditto (KNU); 1♀, Gangwon-do, Pyeongchang-gun, Jinbu-myeon, Dongsan-ri, Mt. Odaesan, streamside near Jungdae Sajaam temple, 37°47′03.9″N, 128°33′45.2″E, ca. 934 m, 18.ix.2020, hand collecting, S. K. Kim leg. (KNU); 13♂ 2♀, Gangwon-do, Jeongseon-gun, Gohan-eup, Gohan-ri, Mt. Hambaeksan, near Changokbong Peak, 37°09′03″N, 128°54′37″E, 1330 m, 31.vii.2023, hand collecting, S. K. Kim leg. (KNU); 1♂ 2♀, Gangwon-do, Taebaek-si, Baeksan-dong, Mt. Yeonhwasan, 37°08′58.3″N, 129°00′37.8″E, ca. 814 m, 1.viii.2023, hand collecting, J. H. Lee leg. (KNU).
Ecology. This species was collected in mountainous area of relatively high altitude, about range of 700–1900 m above sea level in South Korea. Distribution pattern of the species is largely consistent with the collection records from Japan (Nakayama & Shima 2004). Adults can be found on leaves of wood fern (Dryopteris crassirhizoma), bamboo (Sasa borealis), and broadleaf shrubs in forests or rock surfaces in streamside showing wandering or feeding behavior (Fig. 10). Detailed ecological information including larval feeding habits is largely unknown.
Remarks. This species is somewhat similar to S. koreanus sp. nov. but can be readily distinguished from the latter by darkened fore apical tarsomere (not darkened in S. koreanus sp. nov.), not significantly enlarged apical portion of epandrium (greatly enlarged in S. koreanus sp. nov.), and conspicuous, robust arm of aedeagus curved forming obtuse angle (small, slightly curved arm in S. koreanus sp. nov.).
Distributions. Korea (Gangwon-do, Gyeongsangnam-do), China, Japan.
description: Published as part of Lee, Jun-Ho & Kim, Sam-Kyu, 2023, A taxonomic study on the genus Stichillus (Diptera: Phoridae) from South Korea, with a key to species from East Asia, pp. 381-398 in Zootaxa 5352 (3) on pages 386-388, DOI: 10.11646/zootaxa.5352.3.3, http://zenodo.org/record/8407390