The genera Deuterixys Mason, 1981 and Wilkinsonellus Mason, 1981 (Hymenoptera, Braconidae, Microgastrinae) from China, with description of two new species

Abstract The genus Deuterixys Mason, 1981 of the tribe Cotesiini (Hymenopteran, Braconidae, Microgastrinae) is recorded from China for the first time. Two new species, Deuterixys bifossalis Zeng & Chen, sp. n. and Deuterixys curticalcar Zeng & Chen, sp. n., are described and illustrated, and a key to the Old World species of Deuterixys is given. In addition, Wilkinsonellus paramplus Long & van Achterberg, 2003 is recorded from China for the first time and illustrated.


Introduction
The tribe Cotesiini (Braconidae, Microgastrinae) was established by Mason (1981) with most members parasitizing on Macrolepidoptera. A few species of this tribe have been used in biological control of lepidopteran pests. The genera Deuterixys and Wilkinsonel-lus are two small genera of this tribe, and both characterized by a longitudinal median groove at least at basal half of the first tergite and without an areolet of fore wing.
The genus Deuterixys proposed by Mason (1981) includes four Old World species of Nixon's (1965Nixon's ( , 1976) carbonarius group of Apanteles Förster. This genus includes 14 described species widespread in the world except in the Afrotropical region, of which seven occur in the Old World and seven in the New World (Nixon 1965;Tobias 1971Tobias , 1976Papp 1983bPapp , 1990Whitfield 1985;Austin and Dangerfield 1992;Marczak and Buszko 1994;Yu et al. 2005). Most species of the known hosts of this genus are leaf miners, including the genera Bucculatrix and Leucoptera of the family Lyonetiidae and Stigmella of the family Nepticulidae (Lyle 1925;Wilkinson 1936Wilkinson , 1940Telenga 1955;Nixon 1965;Tobias 1976Tobias , 1986Papp 1983a;Whitfield 1985;Marczak and Buszko 1994;Gates et al. 2002), which may cause damage in forests. Therefore, species of Deuterixys may play an important role in controlling those forest pests. Recently two new species of this genus are found in China among specimens of Parasitic Hymenoptera Collection of Zhejiang University (ZJUH) and described in this paper. They represent the first record of the genus Deuterixys Mason for China.
The genus Wilkinsonellus was proposed by Mason (1981) to include four Old World species of Nixon's (1965) henicopus and daira group of Apanteles Förster, including five described species occurring in Oriental region, four in the Australasian region and one in the Afrotropical region (De Saeger 1944;Nixon 1965;Austin and Dangerfield 1992;Chou 1999;Long and van Achterberg 2003;Chen and Song 2004;Ahmad et al. 2005;Yu et al. 2005). One species, Wilkinsonellus iphitus (Nixon 1965) was previously recorded from Hainan and Taiwan of China (Chou 1999;Chen and Song 2004). Here we report another species of this genus, W. paramplus Long & van Achterberg, 2003, from China for the first time.

Material and methods
Specimens studied are deposited in the Parasitic Hymenoptera Collection of Zhejiang University, Hangzhou, China (ZJUH). Descriptions and measurements were made under a stereomicroscope (Zeiss Stemi 2000-C). All figures were made by a camera (Q-Imaging, Micropublisher, 3.3 RTV) attached to a stereomicroscope (Leica MZ APO, Germany) and Auto-Montage Pro version 5.0 software.
Terminology and measurement follows Nixon (1965) and Mason (1981), vein terminology follows the modified Comstock-Needham system (van Achterberg 1979). Abbreviations used in this paper are as follows: POL = postocellar line, OOL = ocularocellar line, OD = ccellar diameter; TI = the first tergite of metasoma, TII = the second tergite of metasoma, TIII = the third tergite of metasoma; L = length, W = width. Vein 1-R1 of fore wing as long as or slightly shorter than pterostigma. [TI posteriorly weakly to moderately converging, its basal width at most 1/3 greater than its apical width. Pterostigma less wide, 2.7-2.9 (-3.0) times longer than wide. 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 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.
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.
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 D. 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). Head. In frontal view antennal sockets distinctly above middle level of eyes, head 1.6 times as wide as long and 1.1 times as that of mesoscutum. Ocelli small and in a high triangle, POL: OD: OOL=4.0:2.4:6.2. Frons and vertex smooth and shiny, covered with dense short fine setae; vertex sharply narrowed behind eyes, area behind ocellar area sharply oblique, smooth and shiny, without setae; temple and gena feebly striate and shiny, with dense setae; face shiny and discretely but distinctly punctate, 0.9 times as wide as height of eye and clypeus combined, with dense setae; inner margins of eyes adjacent to face slightly converging ventrally; eye moderate size, 1.7 times as high as wide (15.6:9.0), temple behind eyes subequal in length to width of eye. Clypeus feebly rugulose, with dense short fine setae; tentorial pits small, distance between tentorial pits twice distance from pit to eye margin (5.7:2.8); malar space short, 0.2 times as long as eye height; apical segment of labial palp longer than the preceding segment but shorter than the next preceding segment. Antenna longer than body; flagellomeres with placodes arranged regularly in 2 ranks except the apical 6 segments; the third flagellomere subequal to the forth flagellomere in length; apical segment slightly longer than preapical one. Flagellomere proportions: 2 L/W=4.10, 8 L/W=4.05, 14 L/ W=1.88; L 2/14=2.00; W 2/14=0.92. Mesosoma. Mesoscutum densely and evenly punctate, with normal setae; notauli absent. Disc of scutellum as densely punctate as mesoscutum, with normal setae; the posterior, polished band of scutellum continuous, not interrupted medially; scutellar sulcus shallow with a few weak carinae and as long as scutellum. Propodeum highly polished, virtually without sculpture except for a strong medial longitudinal carina and very short transverse ridges in immediate vicinity of longitudinal carina and lateral margin, with strong rugae around spiracle. Epicnemial furrow indistinct, area before it slightly raised above rest of mesopleuron; precoxal suture indistinct, only indicated by a large shallow depression. Mesosternum with dense fine setigerous punctures. Laterally metanotum mostly smooth and shiny.
Metasoma. TI parallel-sided, with a very feebly rugose triangular area and a strong and smooth medial longitudinal groove on anterior 2/5, densely rugulose and turns over on posterior 3/5, 1.6 times as long as its greatest width and 1.5 times as long as tergite II. TII+III constricted at the level of the crenulate second suture. TII rectangular, densely and strongly rugose, with strong longitudinal striae posteriorly, without trace of median field, 0.6 times as long as its basal width and 1.7 times as long as tergite III. TIII transverse, broadened posteriorly, longitudinally aciculaterugulose and densely and strongly rugulose. Tergites posterior to TIII more membranous, shiny; all tergites with scattered short fine setae. Ovipositor sheath very short, only 0.4 times as long as hind basitarsus, curved downwards. Hypopygium short, strongly and evenly sclerotized, truncated apically, sparsely clothed with long setae.
Colour. Body mostly black; metasoma brownish to light brown except black TI to TIII. Antenna almost brown, basal third yellowish ventrally. Mouthparts yellow with brown margin, palpi white. Tegula brown. Legs yellow, somewhat whitish; fore and middle coxae brownish laterally, all claws brown; hind coxa and tarsus brown; hind tibia brownish and darkened apically, its apical third strongly darkened. Wings hyaline; veins grey except brown submarginal vein, pterostigma grey and laterally brown.
Variation. Vein 1-SR 1.1-1.4 times as long as pterostigma, pterostigma 2.6-3 times as long as wide. Veins and pterostigma light brown, more or less transparent. Antenna, mouthparts and tegula sometimes darkened.