Deuterixys bifossalis Zeng & Chen

Zeng, Jie, He, Jun-Hua & Chen, Xue-Xin, 2011, The genera Deuterixys Mason, 1981 and Wilkinsonellus Mason, 1981 (Hymenoptera, Braconidae, Microgastrinae) from China, with description of two new species, ZooKeys 120, pp. 27-40 : 30-31

Deuterixys bifossalis Zeng & Chen sp. n. Figs 1-7

Description.

Female.

Body length 3.68 mm, fore wing length 3.20 mm.

Head. In frontal view antennal sockets just above middle level of eyes, 1.6 times as wide as long and 1.1 times as that of mesoscutum. Ocelli large and in a equilateral triangle, POL: OD: OOL=3.6:4.0:2.7. Frons and vertex smooth and shiny, scattered with short fine setae; vertex sharply narrowed behind eyes, area behind ocellar area sharply oblique, smooth and shiny, without setae; temple and gena feebly punctate and shiny, with dense setae. Face and clypeus shiny but feebly rugulose-punctate, with dense short fine setae; width of face 0.5 times height of eye and clypeus combined (16.3:31.2); inner margins of eyes adjacent to face parallel-sided; eyes very large, 1.5 times as high as wide (31:21), temple behind eyes very short. Tentorial pits large, distance between tentorial pits 5 times distance from pit to eye margin; malar space very short, 0.1 times as long as eye height; apical segment of labial palp longer than the two preceding segments, respectively. Antenna longer than body; flagellomeres with placodes arranged regularly in 2 ranks; the third flagellum slightly longer than the fourth flagellum; apical segment as long as preapical one; preapical segment 2.3 times as long as wide. Flagellomere proportions: 2 L/W=2.92, 8 L/W=2.40, 14 L/W=2.50; L 2/14=1.40; W 2/14=1.20.

Mesosoma. Mesoscutum densely and evenly punctate and setose; notauli not impressed, but indicated by a band of shallow and dense duller sculpture. Disc of scutellum also densely punctate, its rugose tip interrupting the posterior, polished band of scutellum, with dense short setae all over; scutellar sulcus deep with a few strong carina and 1.2 times as long as scutellum (15.5:12.8). Propodeum highly polished, virtually without sculpture except for a strong medial longitudinal carina and weak transverse ridges in immediate vicinity of longitudinal carina and lateral margin, with strong rugae distal to spiracle. Epicnemial furrow distinct, area before it raised above rest of mesopleuron; precoxal sulcus short, shallow, only indicated by few punctures anteriorly. Mesosternum with dense setigerous punctures. Lateral metanotum mostly smooth and shiny, with longitudinal striae posteriorly and below spiracle.

Wings. Forewing without areolet, radial vein r arising from distal third of pterostigma; veins r and 2-SR meeting at a 165~170 degree angle; r:2-SR: length of pterostigma = 13:10:31; vein 1-R1 1.3 times as long as pterostigma, pterostigma 2.5 times as long as wide. 1-CU1:2-CU1:m-cu=11:11:8. Hind wing narrow.

Legs. Hind coxa shiny, feebly punctate, scattered with short setae. Hind tibia gradually swollen apically and about 0.9 times as long as hind tarsa (54.5:63.9); inner hind tibial spurs about 0.9 times as long as hind basitarus (22.0:25.8); forth tarsal segment slightly shorter than fifth tarsal segment (7.8:8.4). Hind tibia with few spines on outer side, rather fine and not dense enough to give the tibia a markedly prickly appearance.

Metasoma. TI dilated medially, the greatest medial width 1.5 times its apical width, with strong medial longitudinal groove almost reaching to posterior margin, 1.5 times as long as its greatest width and 2.1 times as long as TII, medial groove with a shallow transverse carina. TII+III slightly constricted at extreme apex of second suture. TII subtrapezoid, 0.6 times as long as its basal width and 0.9 times as long as TIII, with a pair of strong rugulose-marked longitudinal grooves delimiting a median field that slightly narrowed posteriorly. TIII rectangular, smooth and shiny, with anterior margin arched medially, median field not indicated. Tergites posterior to TIII more membranous, shiny. All tergites scattered with setae. Ovipositor sheath shorter, 0.7 times as long as hind basitarsus. Hypopygium strongly and evenly sclerotized, blunt but not truncated apically, sparsely clothed with short setae.

Colour. Body mostly yellow; head evenly yellow except for black ocellar area; mesosoma brown except for yellow mesoscutum and scutellar disc; mesopleuron yellow except epicnemium. Antenna evenly yellowish brown, scape brownish dorsally, pedicel yellow; palpi and tegula whitish yellow. Legs whitish yellow basally, slightly darkened toward apex, claws brown, extreme apex of hind femur and tibia and extreme base of hind tibia brownish. Sternites of metasoma whitish yellow; TI light yellow, the other tergites brown and gradually paler apically. Wings hyaline, very slightly infuscate; veins brown but veins 1-R1, A and M+Cu grey, pterostigma brown.

Male.

Unknown.

Host.

Unknown for this species, but all previous host records from Europe and North America indicate that Deuterixys spp. are parasites of Bucculatrix spp. ( Bucculatricidae ) ( Nixon 1965, Mason 1981, Whitfield 1985).

Materials examined.

Holotype: ♀, Mt. Qingliangfeng (118°52'E, 30°04'N; 119°12'E, 30°31'N), Linan, Zhejiang, 2005. VIII. 9, leg. Min Shi, No. 200607234. Paratype: 1♀, Mt. Yinggeling (109°31'E, N 19°04'N), Hain0061n, 2007. V. 24-25, leg. Jingxian Liu, No. 200702641.

Etymology.

The specific name “bifossalis” derives from the Latin prefixion “bi-” and adjective “fossalis”, referring to both distinct lateral grooves enclosing a median field of the second tergite.

Distribution.

China (Zhejiang, Hainan).

Remark.

This species is similar to the Palaearctic species Deuterixys rimulosa (Niezabitowski, 1910), but can be distinguished from the latter by having TI not transverse (more transverse in Deuterixys rimulosa ), and vein 1-R1 of fore wing longer than pterostigma (the latter subequal to or slightly shorter). It also differs from the other Oriental species Deuterixys patro (Nixon, 1965) by TII and TIII not forming a carapace and having exposed the following tergites (the latter TII and TIII enlarged to form a carapace and following tergites retracted).