Melastrongygaster orbitalis Shima

Shima, Hiroshi, 2015, Melastrongygaster, a new genus of the tribe Strongygastrini (Diptera: Tachinidae), with five new species from Asia, Zootaxa 3904 (3), pp. 427-445 : 439-440

Melastrongygaster orbitalis Shima , sp. nov.

Figs. 25–26 , 31–34

Male. Differing from D. atrata as follows: Head broadly black, shining black stripe on inner margin of frontoorbital plate continuous downward to gena, dark grayish pruinosity on outer 1/3 of lower 1/3 of fronto-orbital plate to outer 2/3 of parafacial, face and lower occiput; frons in profile slightly more rounded; parafacial nearly parallelsided, about 2/3 as wide as (about 1/ 2 in profile) 1st flagellomere at middle height; lower margin of face weakly warped forward, nearly level with vibrissal base; gena about 2/7 (about 1/ 5 in profile) as high as eye height; inner vertical seta fine, about 1/4 as long as eye height; ocellar seta nearly as long as inner vertical seta; 10–12 fine frontal setae; 2–3 subvibrissal setae; postocular setae short on upper 1/2; base of antenna nearly level with lower 1/4 of eye height in profile; antenna about 3/4 as long as face, 1st flagellomere about 1.5 times as long as wide and 2 times as long as pedicel. Thorax shining black in ground color, with very thin grayish pruinosity on postpronotal lobe and proepimeron and thin dark brownish pruinosity along transverse suture of scutum; 3 presutural dorsocentral setae; 2 katepisternal setae; subapical scutellar setae slightly longer than apical seta (4:3.5) and about 1.5 times as long as scutellum; discal scutellar setae indistinct among fine and long hairs on disc. Wing slightly more brownish tinged, especially on basal area; lower calypter more brownish; base of vein R4+5 without setula; relative lengths of costal sectors 2nd, 3rd and 4th approximately as 2:5:2.5; last section of vein CuA1 about 1/2 as long as dm-cu crossvein. Mid tibia with 1 anterodorsal, 2 posterodorsal, 2 posteroventral and 1 ventral setae; hind tibia with 3–4 anterodorsal, 3–4 posterodorsal and 1 ventral setae. Abdomen with very thin grayish pruinosity on anterior 1/2–2/3 of 3rd and 4th tergites and on almost entire 5th; syntergite 1+2 without median discal setae and with 1–2 pairs of long and strong median marginal setae; 3rd and 4th tergites each with 2–3 pairs of long discal and a row of strong marginal setae.

Male terminalia: Epandrium with 3 pairs of strong setae; surstylus nearly straight in lateral view, very weakly curved dorsally near apex, without distinct hair or pile; bacilliform sclerite very short and widely fused posteriorly with inner wall of surstylus; cerci in dorsal view excavated on basal 1/4 and separated on apical 5/8.

Body length: 5.5–6.4 mm.

Holotype male, Danburi, 800 m, 15 km NW Bao Lok, Vietnam, 29.v–1.vi.2002, S. Shinonaga ( NSMT).

Paratypes: 2 males, same data as holotype ( KUM).

Etymology. The specific named is taken from the rounded frons of this species, based on the Latin orbitus, meaning circular.

Distribution. Vietnam.

Figures

FIGURES 23 – 26. Habitus of adults. 23 – 24. Melastrongygaster kambaitiana sp. nov., male. 23. Lateral view. 24. Head in lateral view. 25 – 26. Melastrongygaster orbitalis sp. nov., male. 25. Lateral view. 26. Head in lateral view.

FIGURES 31 – 34. Male terminalia of Melastrongygaster orbitalis sp. nov. 31. Epandrium, surstylus and cerci in dorsal view (hairs omitted). 32. Same in lateral view. 33. Hypandrium, postgonite and phallus in lateral view. 34. 5 th sternite in ventral view (hairs on left side omitted). Scale: 0.1 mm.