Milisipepsis unicinctus O. Gorbunov, 2022

Gorbunov, O. G., 2022, A new species of the genus Milisipepsis O. Gorbunov et Arita, 1995 (Lepidoptera: Sesiidae) from Southeast Asia, with remarks on the genus, Russian Entomological Journal 31 (4), pp. 411-416 : 412-416

Milisipepsis unicinctus O. Gorbunov , sp.n.

Figs 1–12 .

MATERIAL. Holotype ♂ ( Figs 1–2 ) with labels: “S. Vietnam, Dong Nai, / Cat Tien National Park , / 11°26.439´N, 107°24.747´E, / 150 m, 25.IV.2018, / O. Gorbunov leg.”; “ SESIIDAE / Pictures Nos / 0377- 0378–2018 / Photo by O. Gorbunov ”; “ HOLOTYPUS ♂ / Milisipepsis unicinctus / O. Gorbunov, 2022 / O. Gorbunov des., 2022”.

Paratypes (38 ♂♂), 1 ♂, same locality as holotype, 10.IV.2018, O. Gorbunov leg. ; 1 ♂, same locality, 11.IV.2018, O. Gorbunov leg. ; 7 ♂♂, same locality, 19.IV.2018, O. Gorbunov leg. ( Sesiidae pictures Nos 0357-0366–2018) ; 6 ♂♂, same locality, 20.IV.2018, O. Gorbunov leg. ; 4 ♂♂, same locality, 21.IV.2018, O. Gorbunov leg. ( Sesiidae pictures Nos 0367-0372–2018) ; 3 ♂♂, same locality, 22.IV.2018, O. Gorbunov leg. ; 2 ♂♂, same locality, 23.IV.2018, O. Gorbunov leg. ( Sesiidae pictures Nos 0373-0376–2018) ; 3 ♂♂, same locality, 25.IV.2018, O. Gorbunov leg. ( Sesiidae pictures Nos 0379-0382–2018; a male with genitalia preparation No OG –011- 2022) ; 1 ♂, same locality, 30.IV.2018, O. Gorbunov leg. ; 8 ♂♂, same locality, 01. V.2018, O. Gorbunov leg. ( Sesiidae pictures Nos 0101-0116–2019) ; 1 ♂, Laos, Khammouang Prov. , Ban Khounkham (Na Hin), 18°13´N, 104°31´E, 200 m, 16.IV.2005, O. Gorbunov leg. ; 1 ♂, same locality, 23.IV.2005, O. Gorbunov leg. (genitalia preparation No OG–061-2018).

DESCRIPTION. Male (holotype) ( Figs 1, 2 ). Alar expanse 16.1 mm; body length 9.0 mm; forewing 7.5 mm; antenna 3.7 mm.

Head: antenna dorsally gradually changes from the base from brown with bronze sheen to dark brown to black with bright violet sheen, ventrally gradually changes from pale yellow to yellow with bright golden sheen to dark brown to black with bright violet sheen, distal ciliales part (12 joints) completely dark grey-brown with bronze sheen; scapus grey-brown with blue-purple sheen dorsally and silvery-white ventrally; two basal joints of labial palpus dark brown to black with bright greenish-blue sheen and a few white scales with purple tint both internally and ventrally, apical joint white with purple tint and admixture of individual dark brown to black scales; vertex dark brown to black with bright bronze sheen; pericephalic hairs dark brown to black with bright bronze sheen and a few white scales laterally; neck plate pale yellow-orange and a few grey-brown scales with greenish sheen.

Thorax: patagia orange with a few grey-brown scales with bronze-purple sheen anteriorly; tegula and mesothorax dark brown to black with dark blue-violet sheen; metathorax dark brown to black with greenish-bronze-violet sheen and small rounded orange spot laterally; posteriorly both metepimeron and metameron smoothly scaled, dark grey-brown with greenish-violet sheen and small orange spot on metepimeron laterally.

Legs: fore coxa dark brown to black with greenish sheen; fore femur externally brown with bronze-violet sheen, with slightly darker blue-violet sheen exterior-basally and narrow pale yellow stripe distally at exterior margin, internally entirely lemon yellow with golden sheen basally and dark brown to black with bronze-violet sheen distally; fore tibia dorsally dark brown to black with greenish sheen, ventrally dark grey-brown with bronze-violet sheen; fore tarsus dorsally dark grey-brown with blue-violet sheen and a few white scales with purple tint basally on three basal tarsomeres, ventrally brown grey-brown with bronze sheen and admixture of a few dark yellow scales on basal tarsomere; mid coxa dark brown to black with greenish sheen; mid femur externally dark brown to black with dark blue-violet sheen, narrowly dark grey-brown with bronze-violet sheen anteriorly and narrow yellow stripe distally at posterior margin, internally lemon yellow with golden tint; mid tibia dorsally dark brown to black with greenish sheen and a few pale yellow and white scales medially, ventrally dark grey-brown with bronze-violet sheen; spurs dark brown to black with bright blue-violet sheen, external spur silvery-white internally; first mid tarsomere dorsally dark brown to black with bright blue-violet sheen,ventrally dark grey-brown with bronze-violet sheen distally and yellow with golden tint basally; remaining tarsomeres dorsally dark brown with blue-violet sheen, ventrally grey-brown with silvery tint; hind coxa dark brown to black with greenish-violet sheen and a few white scales internally; hind femur externally dark brown to black with dark blue-violet sheen, anteriorly narrowly dark grey-brown with bronze-violet sheen and a few yellow scales distally and with narrow yellow stripe distally at posterior margin, internally lemon yellow with golden tint; hind tibia externally dark brown to black with blue-violet sheen and a few pointed white scales both medially and distally, internally lemon yellow with golden tint in basal half, in distal half dark brown to black with greenish-violet sheen and a few yellow scales basally; spurs dark brown to black with bronze-violet sheen and admixture of white scales internally on mid spurs; basal hind tarsomere completely dark brown to black with blue-violet sheen, remaining tarsomeres dark grey-brown with bronze-violet sheen, tarsomeres 2–4 each with large white spot with golden tint internally at base.

Forewing dorsally black with dark blue sheen basally; costal margin, CuA-stem and veins within external transparent area dark brown to black with dark violet sheen; anal margin and apical area dark brown with bronze sheen; discal spot brown with bronze sheen, extremely narrow with parallel margins; apical area extremely narrow, about 0.5 times as broad as cilia; transparent areas well-developed but covered with transparent scales with brownish tint; external transparent area extremely large, divided into four cells between veins R 5 –CuA 1; cilia dark brown with bronze sheen; ventrally costal margin from base to level of discal spot, CuA-stem, vein CuA 1, discal spot and anal margin yellow with golden sheen; costal margin distally of discal spot, veins M 1 –M 3 and apical area dark brown to black with dark violet sheen; cilia dark brown with bronze sheen.

Hindwing transparent but covered with sparse hyaline scales with brownish hue; veins narrowly dark brown to black with dark violet sheen; both discal spot and outer margin undeveloped; ventrally with small group of yellow-orange scales at base; cilia dark brown with bronze sheen.

Abdomen distinctly wasp-waisted: segment 1 narrowing sharply, segments 2–4 gradually broadened and segments 5– 7 gradually narrowed; dorsally dark brown to black with dark greenish-violet sheen, tergite 2 with narrow orange stripe distally; ventrally sternite 1+2 white with bluish tint and admixture of dark brown to black scales with dark greenish-violet sheen and narrow pale yellow-orange stripe distally, remaining sternites completely dark brown with dark greenish-violet sheen; anal tuft extremely small.

Male genitalia (paratype, genital preparation No OG– 011-2022) ( Figs 7–11 ). Tegumen-uncus complex well-developed, tegumen not separated from uncus; uncus bilobed and pointed apically, with a few long setae dorsally; tegumen with short pointed gnathos ( Fig. 7 ); valva ( Fig. 8 ) strongly turned up, slightly narrowed and rounded distally, mostly covered with long and short hair-like setae; saccus long, rounded basally; vinculum narrow, about twice as long as saccus ( Fig. 9 ); aedeagus long, ca. twice longer than valva ventrally ( Fig. 10 ), gradually narrowing distally, with two strong but small pointed spines subapically; vesica without cornuti ( Fig. 11 ).

Female. Unknown.

INDIVIDUAL VARIABILITY ( Figs 1–6 ). The specimens slightly varying in the number of orange scales on the patagia and white scales on the basal sternite of the abdomen. Wing expanse 15.6–17.6 mm; body length 7.6–9.1 mm; forewing length 6.9–7.9 mm; antenna length 2.8–3.7 mm.

DIFFERENTIAL DIAGNOSIS. By the structure of the forewing, M. unicinctus sp.n. is most similar to M. lasiocerus (type locality: NE. India, Meghalaya, Shillong) and S. helicellus (N. Vietnam, Ninh Binh Prov., Cuc Phuong). From the first species compared, this new species is distinguished by the colouration of the patagia (black with purple-blue sheen in M. lasiocerus , vs. orange with a few grey-brown scales with bronze-purple sheen anteriorly in M. unicinctus sp.n.), metathorax (black with purple-blue shine in M. lasiocerus , vs. dark brown to black with greenish-bronze-violet sheen and smal rounded orange spot laterally in the new species), and colouration of the abdomen (black with purple-blue sheen, tergite 2 with narrow white stripe distally in the species compared, vs. dark brown to black with dark greenish-violet sheen, tergite 2 with narrow orange stripe distally in M. unicinctus sp.n.; cf. Figs 1, 3 and 5 in this article with figs 40a and 40c in Arita et al., 2021). In addition, the new species is somewhat smaller (wing expanse 18 mm in M. lasiocerus ). From S. helicellus , M. unicinctus sp.n. differs in the colouration of the thorax (dorsally patagia dark brown to black with greenish-purple sheen anteriorly and yellow posteriorly; tegula dark brown with greenish-purple sheen and a small yellow spot at base of forewing; meso- and metathorax entirely dark brown with greenish-purple sheen in S. helicellus , vs. patagia orange with a few grey-brown scales with bronze-purple sheen anteriorly; tegula and mesothorax dark brown to black with dark blue-violet sheen; metathorax dark brown to black with greenish-bronze-violet sheen and small rounded orange spot laterally in M. unicinctus sp.n.; [cf. Figs 1, 3 and 5 in this article with figs 28 and 30 in Kallies, Arita, 2001] and abdomen dorsally (tergites 2 and 5 each with a narrow yellow to yellow-orange stripe distally; tergite 3 with a few yellow scales distally in the species compared, vs. only tergite 2 with narrow orange stripe distally in the new species). Apart from this, these two species are well distinguished from each other by the structure of the male genitalia [cf. Figs 7–11 in this article with figs 44a–d in Kallies, Arita, 2001]. From all other congeners, this new species is easily separable by the well-developed transparent areas of the forewing [cf. Figs 1, 3 and 5 in this article with fig. 8 in Špatenka, Arita, 1992, figs 27 and 28 in Špatenka et al., 1999, and figs 10 and 11 in Arita, Gorbunov, 2001] and colouration of the thorax and abdomen.

BIONOMICS. Specimens were collected in April among wasps and bees on moist soil near a drying puddle in Vietnam ( Fig. 12 ) and a drying Nam Sanam stream in the vicinity of a village of Ban Khounkham (Nahin) in Laos. They showed typical mud behavior [ Gorbunov, 2015; Skowron Volponi, Volponi, 2018] and usually appeared on wet soil early in the day.

HABITAT. In South Vietnam, this new species lives in a semi-evergreen lowland tropical rainforest dominated by tree species Lagerstroemia calyculata Kurz ( Lythraceae ), Tetrameles nudiflora R.Br. ( Tetramelaceae ), Anogeissus acuminata (Roxb. ex DC.) Wall. ex Guillem. et Perr. ( Combretaceae ), and Haldina cordifolia (Roxb.) Ridsdale ( Rubiaceae ). In Laos, it inhabits a primary monsoon semi-deciduous lowland tropical forest with Dipterocarpus alatus Roxb. ex G.Don , Hopea odorata Roxb. , H. ferrea Laness. ( Dipterocarpaceae ), Lagerstroemia cochinchinensis Pierre ex Laness. ( Lythraceae ), Afzelia xylocarpa (Kurz) Craib ( Fabaceae ) and Alstonia scholaris (L.) R.Br. ( Apocynaceae ) as the most dominant species.

DISTRIBUTION. Known from South Vietnam (Dong Nai Province) and Laos (Khammuang Province).

ETHYMOLOGY. The name of this new species, unicinctus , is derived from Latin “unus” for one or sole and “cingo” for girdle or surround, and corresponding to the colouration of the abdomen.

Acknowledgements. I want to express my heartfelt gratitude to Mr. Zamesov Aleksey Nikolaevich (Moscow, Russia) for the company and help during our successful trip to Laos in 2005, as well as to the staff of the Southern Branch of the Joint Russian-Vietnamese Tropic Center for all-round assistance during my expedition to Cat Tien National Park in 2018. I am indebted to Dr. Anatoliy V. Krupitsky (Moscow, Russia) for carefully checking the English of an advanced draft.

The study was conducted using the equipment of the Joint Usage Center “Instrumental methods in ecology” at the A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences (Moscow, Russia). The investigation was fulfilled within the State project № AAAA-A18- 118042490060 - 1 and 0089-2021-0007 .

Figures

Figs 1–6. Variability of Milisipepsis unicinctus sp.n.: 1–2 — holotype, alar expanse 16.1 mm, Sesiidae picture Nos 0377-0378–2018; 3–4 — paratype, alar expanse 15.5 mm, Sesiidae picture Nos 0367-0368–2021; 5–6 — paratype, alar expanse 15.9 mm, Sesiidae picture Nos 0379-0380–2021. Dorsal (1, 3, 5) and ventral (2, 4, 6) view. Рис. 1–6. ИЗменчивость Milisipepsis unicinctus sp.n.: 1–2 — голотип, раЗмах крыльев 16.1 мм, Sesiidae снимки №№ 0377-0378– 2018; 3–4 — паратип, раЗмах крыльев 15.5 мм, Sesiidae снимки №№ 0367-0368–2021; 5–6 — паратип, раЗмах крыльев 15.9 мм, Sesiidae снимки №№ 0379-0380–2021. Вид сверху (1, 3, 5) и сниЗу (2, 4, 6).

Figs 7–11. Male genitalia of Milisipepsis unicinctus sp.n. Genital preparation No OG–011-2022: 7 — tegumen-uncus complex; 8 — valva; 9 — saccus; 10 — aedeagus; 11 — apex of aedeagus. Scale bar 0.4 mm for 7–10, 0.1 for 11. Рис. 7–11. Гениталии самца Milisipepsis unicinctus sp.n. Препарат гениталий № OG–011-2022: 7 — тегумен-ункусный комплекс; 8 — вальва; 9 — саккус; 10 —Эдеагус; 11 — верШина Эдеагуса. МасШтаб 0,4 мм длЯ 7–10, 0,1 длЯ 11.

Fig. 12. Type locality of Milisipepsis unicinctus sp.n. near a drying puddle in Cat Tien National Park, 11°26.439´N, 107°24.747´E, 150 m, 25.IV.2018. Рис. 12. Типовое местонахождение Milisipepsis unicinctus sp.n. у пересыхаюЩей лужи в Национальном парке Кат Тьен, 11°26.439´с.Ш., 107°24.747´в.д., 150 м, 25.IV.2018.