Gnathochorisis malaisei Humala, 2021

Humala, Andrei E., 2021, First records of the genus Gnathochorisis Foerster (Hymenoptera, Ichneumonidae, Orthocentrinae) in the Oriental region, Journal of Hymenoptera Research 84, pp. 103-113 : 103

Gnathochorisis malaisei Humala sp. nov.

Figures 9-13

Material examined.

Holotype: Myanmar • ♀; N.E. Burma, Kambaiti ; 7000 ft [2100 m]; 24 May 1934; R. Malaise leg.; NHRS.

Diagnosis.

Gnathochorisis malaisei sp. nov. differs from congeners in having an areolet in fore wing, elongate area superomedia of propodeum (1.6 times as long as wide) (Fig. 12 ), yellowish face and reddish brown frons, with lower frontal orbits widely yellow (Figs 10 , 11 ), comparatively long T1 (about 2.5 times as long as wide posteriorly), and T2 transversely impressed in the middle.

This species resembles the Neotropical G. dilleri Humala, 2017 in the elongate area superomedia of propodeum, but it can be easily distinguished by the presence of lateral sections of anterior transverse carina, stouter hind femur (4.0 times as long as broad), yellow face and dark mesoscutum and propodeum.

Description.

Female. Body length 4.2 mm; fore wing length 3.5 mm.

Head. Head width 1.7 times its height; face width at level of antennal sockets 1.35 times its height, 0.5 times head width, subpolished and closely punctate; frons, vertex and occiput polished; occiput somewhat depressed, occipital carina present; eyes large, convex, without setae, inner orbits subparallel (Fig. 10 ); clypeus width 1.5 times its height, weakly separated from face, posterior margin of clypeus very weakly convex; anterior tentorial pits distinct; malar space 1.2 times as long as basal width of mandible; subocular sulcus distinct, sharp and straight; mandible bidentate, strongly tapered, lower tooth small (Fig. 10 ). Antenna longer than body, with 23 slender flagellomeres, all flagellomeres longer than wide; scape about twice as long as wide; first flagellomere 5.3 times as long as wide apically, second flagellomere 4.4 times as long as wide apically. Ocelli of moderate size, ocular-ocellar line 1.25 times and postocellar line 0.6 times as long as maximum diameter of lateral ocellus (Fig. 11 ); temple moderately short, 0.35 times as long as compound eye width.

Mesosoma. Mesosoma 1.4 times as long as maximum height, polished; epomia well developed; mesoscutum subpolished with dense light setae, notauli short, developed in anterior 1/3 of mesoscutum; scutellum not particularly high, with lateral carinae anteriorly; epicnemial carina complete, ending at upper corner of mesopleuron; sternaulus short but distinct (Fig. 9 ); mesopleuron, metapleuron and propodeum polished, with sparse setae; propodeal carination complete, excluding reduction of anterior sections of lateromedian longitudinal carinae. Area superomedia elongate, parallel-sided, 1.6 times as long as wide; short sections of posterior transverse carina connecting with lateral longitudinal carinae form small rounded apophyses; propodeal spiracle large, round, joined by short carina with pleural carina (Fig. 12 ). Fore wing with small petiolate areolet; vein 2m-cu with two bullae; vein 1cu-a slightly distad of vein M&RS; hind wing with nervellus (CU + cu-a) intercepted in lower 0.4, second abscissa of CU present. Hind coxa punctate; hind femur 4.0 times as long as maximum width (Fig. 9 ); hind basitarsus 0.4 times as long as hind tibia, tibial spurs long and slender, claws long and thin, strongly bent.

Metasoma. First metasomal segment 2.5 times as long as maximum width posteriorly, T1 subpolished, with distinct dorsal carinae reaching posterior margin; sternite and tergite fused, glymma absent, spiracle situated at basal 0.4 length of T1, apex of first sternite at 0.55 of segment. T2 as long as maximum width posteriorly, coriaceous, with small thyridium and some irregular longitudinal striae in anterior 2/3, subpolished in posterior third (Fig. 13 ); in profile T2 transversely impressed in the middle behind spiracles; remaining tergites nearly impunctate. Ovipositor slightly upcurved with dorsal subapical notch, ovipositor sheath 1.2 times as long as first tergite and 0.7 times as long as hind tibia.

Colour. Dark brown. Antenna light brown. Frons, vertex, occiput and temple brown; palpi, tegula, subtegular ridge, base of wings, fore and mid legs, hind trochanters and hind coxa anteriorly pale; face, frontal orbits, clypeus, mandibles, excluding reddish-brown teeth, malar space, gena, propleuron, most of pronotum, lower mesopleuron, mesosternum and hind coxa yellowish. Hind femur light brown medially, darkened dorsally, subanteriorly and posteriorly, hind tibia light brown, infuscate anteriorly and posteriorly, hind tarsus dark brown. Wings hyaline, veins and pterostigma light brown. Second tergite dark brown with thyridium and posterior margin yellowish, T3 anteriorly with yellowish band widened medially, other tergites mostly brown with posterior margins yellowish.

Male. Unknown.

Etymology.

The new species is named in honor of its collector René Malaise, a Swedish hymenopterist, expert on sawflies ( Hymenoptera : Symphyta ), famous for his invention of the "Malaise trap".

Distribution.

Myanmar [Burma].

Figures

Figures 9 - 13. Gnathochorisis malaisei sp. nov., holotype female 9 habitus, lateral view 10 head, anterior view 11 head and mesoscutum, dorsal view 12 propodeum, dorsal view 13 metasoma, tergites 2 - 3, dorsal view 14 original label. Scale bar: 1.0 mm (9).