Stichillus cylindratus Nakayama & Shima, 2004

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, Zootaxa 5352 (3), pp. 381-398 : 383-386

publication ID	https://doi.org/ 10.11646/zootaxa.5352.3.3
publication LSID	lsid:zoobank.org:pub:858051C8-824F-4A01-A700-8AA7F58A59BD
DOI	https://doi.org/10.5281/zenodo.8407454
persistent identifier	https://treatment.plazi.org/id/03EB87EB-FF85-F81E-808A-FF50CFCAC1AB
treatment provided by	Plazi
scientific name	Stichillus cylindratus Nakayama & Shima, 2004
status

Treatment

Stichillus cylindratus Nakayama & Shima, 2004 View in CoL

( Figs. 1A, 1B View FIGURE 1 , 2A, 2B View FIGURE 2 , 4A View FIGURE 4 , 5A, 5B View FIGURE 5 , 6 View FIGURE 6 )

Stichillus cylindratus Nakayama & Shima, 2004: 90 View in CoL . Type locality: Fukuoka, Japan.

Diagnosis. This species can be distinguished from other Stichillus species by the combination of the following characteristics: male epandrial lobe distinctly extended posteroventrally; tip of inner projection on posterior margin of hypandrium situated below bottom level of lateral membranous lobe of hypandrium; dorsal plate of aedeagus elongated, curved nearly perpendicularly, without pointed dorsal process, hooked apically, with single narrow, slightly curved arm on right side of ventrobasal portion; female tergite 9 elongated, anteriorly cylindrical.

Description. Male. Body length 2.31–3.67 mm (n=10). Head ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 ). 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 2A. First flagellomere brown to orange, oval, 1.4× longer than wide, apically pointed; 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. 1A View FIGURE 1 ). Scutum and scutellum black. Posterior margin of scutum with two pairs of strong prescutellar bristles; inner 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 blackish brown; upper half of anepisternum covered with short setae. Legs ( Figs. 1A View FIGURE 1 , 4A View FIGURE 4 ). Black except fore tibia and tarsus yellowish brown. 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. 4A View FIGURE 4 ) 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. 5A View FIGURE 5 ). 2.44–3.27 mm long (n=10). Costal index 0.49–0.52. Mean costal ratio 0.94:1; range 0.85–1.03. Costal setae of costal section II 0.08–0.1 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. 6–12 alular setae present, 0.15–0.21 mm long. Halter black. Abdomen ( Fig. 1A View FIGURE 1 ). Tergites black, shiny, extended posteromedially; tergite 2 elongated, approximately twice longer than tergite 1. Venter of abdomen blackish brown, sternite 6 not developed. Hypopygium ( Fig. 6A–C View FIGURE 6 ). Epandrium nearly symmetrical, dark brown; epandrial lobe enlarged posteroventrally, forming acute-angled posteroventral apex, covered with some short hairs. Hypandrium large, dark brown; posteroventral margin rounded, expanded ventrally; lateral membranous lobe triangular, spinulose; inner projection on posterior margin of hypandrium short, protruded ventrally ( Fig. 6B View FIGURE 6 ); tip of inner projection pointed, situated slightly below bottom level of lateral membranous lobe. Cercus and hypoproct short, with some short hairs. Aedeagus ( Fig. 6D, E View FIGURE 6 ). Dorsal plate dark brown, narrow, curved nearly perpendicularly, without pointed dorsal process; left side of tip of dorsal plate with hooked process curved downward, while right side of tip with pointed process slightly curved upwardly ( Fig. 6D, E View FIGURE 6 ); basal portion with single narrow, gently curved arm on right side ( Fig. 6E View FIGURE 6 ). Ventral membrane hyaline, elongated, subequal to the length of dorsal plate, anteriorly twisted, serrated on single side.

Female. Body length 3.72–4.81 mm (n=10). Head ( Figs. 1B View FIGURE 1 , 2B View FIGURE 2 ). Similar to male, except first flagellomere smaller, globose, orange. Ocellar region as in figure 2B. Thorax ( Fig. 1B View FIGURE 1 ). Similar to male. Legs ( Fig. 1B View FIGURE 1 ). Similar to male, except fore apical tarsomere not widened, pulvilli not enlarged. Wing ( Fig. 5B View FIGURE 5 ). Similar to male, 3.2–3.71 mm long (n=10). Costal index 0.48–0.53. Mean costal ratio 0.91:1; range 0.8–0.98. Costal setae of costal section II 0.08–0.1 mm long. 5–8 alular setae present, 0.15–0.21 mm long. Halter black. Abdomen ( Figs. 1B View FIGURE 1 , 6F–H View FIGURE 6 ). Tergites 1–6 well developed, black. Tergite 2 elongated as male. Tergite 7 absent ( Fig. 6F, G View FIGURE 6 ). Tergite 8 ( Fig. 6G, H View FIGURE 6 ) rectangular, dark brown, twice as long as width. Tergite 9 ( Fig. 6F–G View FIGURE 6 ) elongated cylinder-shaped, approximately 7× as long as anterior width, posteriorly covering only dorsal face at apical third; posterior portion distinctly widened, spatula-shaped, with some long hairs. Anterior portion of abdominal segment 9 usually concealed by segment 8 ( Fig. 6H View FIGURE 6 ). Venter of abdomen blackish brown, with only sternite 9 discernable. Genital opening enlarged posteriorly ( Fig. 6F View FIGURE 6 ). Cercus oval, with two long hairs and some short hairs.

Specimens examined. Korea: 2♂ 1♀, Jeollanam-do, Wando-gun, Gunoe-myeon, daemun-ri, Wando Arboretum , 34°21′27.2″N, 126°40′13.6″E, 128 m, 2–26.vii.2012, Malaise trap, J. S. Park & J. Yoon leg. ( KNU) GoogleMaps ; 1♂, Gyeongsangnam-do, Jinju-si, Ibanseong-myeon, Daecheon-ri , Gyeongsangnamdo Arboretum , 35°09′39.7″N, 128°17′41.3″E, 43 m, 1–15.vii.2014, Malaise trap, J. H. Hwang leg. ( KNU) GoogleMaps ; 12♂ 8♀, Jeollabuk-do, Jinan-gun, Maryeong-myeon, Gangjeong-ri , Mt. Gwangdaebong , 35°44′41″N, 127°21′25″E, ca. 381 m, 10–31.vii.2015, Malaise trap, National Institute of Agricultural Sciences ( NAAS) leg. (KNU) GoogleMaps ; 1♂, Jeollanam-do, Muan-gun, Cheonggye-myeon, Dorim-ri , mixed forest near Mokpo National University , 34°54′38.5″N, 126°26′29.1″E, 57 m, 26.vi–7.vii.2019, pitfall trap, T. S. Kwon et al. leg. ( KNU) GoogleMaps ; 3♂ 1♀, Jeollanam-do, Yeongam-gun, Yeongameup, Gaesin-ri , Mt. Wolchulsan , near Saja reservoir, 34°46′09.1″N, 126°43′38.9″E, 85 m, 26.vi–6.vii.2019, pitfall trap, T. S. Kwon et al. leg. ( KNU) GoogleMaps ; 2♂, Jeollanam-do, Gwangyang-si, Ongnyong-myeon, Chusan-ri , Southern Experimental Forest of Seoul National University in Mt. Baegunsan , 35°01′52.9″N, 127°36′24.8″E, ca. 97 m, 3– 15.vii.2019, Malaise trap, Nam & Park leg. ( KNU) GoogleMaps ; 1♀, Gyeonggi-do, Namyangju-si, Joan-myeon, Jinjung-ri , Mt. Ungilsan , 37°34′05.8″N, 127°16′56.6″E, ca. 162 m, 4.vii.2020, hand collecting, J. H. Lee leg. ( NIBR) GoogleMaps ; 2♂ 1♀, Jeollabuk-do, Wanju-gun, Unju-myeon, Wanchang-ri , near Mt. Daedunsan , 36°05′59.4″N, 127°18′02.4″E, ca. 190 m, 13.vi–24.vii.2021, Malaise trap, O. C. Kwon leg. ( KNU) GoogleMaps ; 1♂, Jeollabuk-do, Gimje-si, Geumgu-myeon, Seonamri , near Mt. Moaksan , 35°45′16.8″N, 127°01′34.4″E, ca. 183 m, 10–24.vi.2021, Malaise trap, J. H. Sohn et al. leg. ( KNU) GoogleMaps ; 1♂, Chungcheongbuk-do, Danyang-gun, Danyang-eup, Dodam-ri , inside of Geumgul cave , 36°59′47″N, 128°21′26″E, ca. 154 m, 17.vii.2021, hand collecting, J. H. Lee leg. ( KNU) GoogleMaps ; 5♂, 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, sweeping, S. Kim leg. ( KNU) GoogleMaps .

Ecology. This species was collected widely in mountainous regions in South Korea. Adults can be found on leaves of shrubs, wandering or feeding on leaf surfaces. Although one female was collected inside of cave in Danyang, the troglophily of the species is uncertain. Detailed ecological information including larval feeding habits is largely unknown.

Remarks. The aedeagus of S. cylindratus from Korea is slightly different from that of Japanese specimens illustrated in Nakayama & Shima (2004): left lower apical margin of dorsal plate not extended ventrally (slightly extended ventrally in Japanese specimen); right apical curved process usually long, reaching apical margin of left hooked process (short, not reaching apical margin of left hooked process in Japanese specimen). The hypopygium is similar to the Chinese species S. acuminatus Liu & Chou , but can be readily distinguished from the latter by position of inner projection of hypandrium and morphology of aedeagus.

Distributions. Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Jeollanam-do, Gyeongsangnam-do), Japan.