Hygiella proclinata

Hiroshi Shima & Takuji Tachi, 2016, New species of Hygiella Mesnil (Diptera: Tachinidae), parasitoids of leaf insects (Phasmatodea: Phylliidae), Journal of Natural History 50 (25), pp. 1648-1668 : 1661-1663

Hygiella proclinata sp. nov.

( Figures 3 A – D, 6A – E)

Description

Male. Head black in ground colour, brown on anterior triangular portion of gena, with dense grey/white pruinosity, slightly darker on upper fronto-orbital plate; frontal vitta velvety brown; antenna brown/black; palpus red/yellow, darkened on basal half. Vertex about one-quarter of head width; frontal vitta widened anteriorly, subequal in width to fronto-orbital plate at middle; parafacial weakly narrowed below, slightly wider than (nearly as wide as in profile) first flagellomere at middle height; gena 0.36 (about one-third in profile) of eye height. Inner vertical seta about two-thirds of eye height; outer vertical seta absent; ocellar seta about two-thirds of inner vertical seta; one reclinate orbital seta, subequal in length to ocellar seta; two subequally long proclinate orbital setae subequal in length to reclinate orbital seta; six frontal setae, lowest seta nearly level with middle of pedicel; fronto-orbital plate with two or three rows of fine short sparse hairs; facial ridge with several short setae on lower quarter; three or four subvibrissal setae; gena with many dense fine hairs on genal dilation mixed with two or three strong hairs on anterior portion; occiput with a row of black hairs on upper portion and two or three rows on lower portion. Antenna falling short of lower margin of face by about half length of pedicel; pedicel with many short hairs and a long strong seta which is about twice as long as pedicel; first flagellomere about three times as long as pedicel; arista thickened on basal one-fifth, short pubescent on basal half and almost bare apically. Palpus rather weakly clavate, slightly longer than pedicel and first flagellomere together.

Thorax including scutellum black in ground colour, with rather thin grey pruinosity; scutum with five rather broad longitudinal vittae, median three vittae merged on postsutural area; pleura with thin grey pruinosity. Three presutural and three postsutural acrostichal setae; three presutural and four postsutural dorsocentral setae; three katepisternal setae, lowest seta very fine or indistinct; anatergite with several minute hairs; scutellum with one strong basal, two short and fine lateral, one strong subapical and one short apical setae on each side and one pair of discal setae, basal seta about fourfifths as long as subapical seta and about 1.5 times as long as scutellum, lateral seta at most half as long as scutellum, apical seta slightly shorter than scutellum; distance between bases of subapical setae only slightly shorter than that between basal and subapical setae of corresponding side.

Wing hyaline, only weakly and evenly tinged with brown; tegula and basicosta black; lower calypter translucent pale brown. Costal spine about 1.5 times as long as costal setae; second costal sector bare below; basal node of vein R4+5 with three or four fine hairs dorsally and two or three ventrally. Relative lengths of costal sectors second, third and fourth approximately as 2: 5: 3; vein M from dm-cu crossvein to its bend about 1.5 times distance between the bend and wing margin.

Legs black; pulvilli pale brown. Fore tibia with one posterior seta; mid tibia with two anterodorsal setae; hind tibia with a regular row of rather closely set anterodorsal setae, several posterodorsal and two or three ventral setae. Fifth tarsomere rather elongate, about 1.5 times as long as fourth tarsomere on each leg; claws and pulvilli subequal in length to fifth tarsomere.

Abdomen black in ground colour, thinly covered with grey pruinosity on thirrd and fourth tergites, the pruinosity thinner on posterior portion of each tergite, mid dorsal longitudinal vitta distinct; fifth tergite with dense dark brown nap dorsally and ventrally, anterior and posterior margins and mid dorsal longitudinal portion narrowly polished. Hairs on dorsum dense, fine, short and recumbent, very short on fifth tergite on nap; syntergite 1 + 2 with a pair of median marginal setae; third tergite with a pair of strong median marginal and lateral marginal setae; fourth and fifth tergites with a row of marginal setae; discal setae absent; fifth sternite with V-shaped median cleft.

Male terminalia. Cerci with median lobe broad and apical portion curved, and beaklike in lateral view; surstylus in lateral view directed downward and apical quarter turned posteriorly; distiphallus in dorsal view widely separated in V-shape, without serration on dorsal margin; ejaculatory apodeme long and curved.

Female. Unknown. Body length: 9.2 mm.

Host.

Phasmatodea , Phylliidae : Phyllium siccifolium (Linnaeus) .

Etymology

The specific name is taken from the presence of male proclinate orbital setae on the head.

Holotype male, Mt. Hon Ba, Khan Hoa Prov., Vietnam, 1 – 4.v.2013 host collected, late v – early vi.2013 emerged, ex P. siccifolium nymph, T. Hasegawa ( BLKU).

Distribution

Vietnam.

Figures

Figure 3. Hygiella proclinata sp. nov. (A, B) Habitus and head in lateral view. (C, D) Puparium in lateral view and posterior view. Scales: 1 mm.