Diolcogaster translucida Zeng & Chen

Zeng, Jie, He, Jun-hua & Chen, Xue-xin, 2011, The genus Diolcogaster Ashmead, 1900 (Hymenoptera, Braconidae, Microgastrinae) from China, ZooKeys 129, pp. 49-87 : 79-83

Diolcogaster translucida Zeng & Chen sp. n. Figs 73-80

Description.

Female. Body length 3.0 mm, fore wing length 3.4 mm.

Head. Rather large, oval in anterior view, with antennal sockets high above middle level of eyes; strongly transverse in dorsal view, 1.4 × as wide as long and 0.8 × as long as that of mesonotum, with short white setae including eyes. Ocelli in a low, very wide triangle, the transverse, posterior tangent to the anterior ocellus just cutting the posterior pair. POL:OD:OOL=7.1:3.8:8.0. Vertex densely rugose, strongly convex and sharply constricted to occiput, with very short dense fine setae; frons also densely rugose; face slightly convex, rugose and setose, upper half with very indistinct median longitudinal carina, width of face 0.8 × as high as eye and clypeus combined (15.0:27.2); eyes of moderate size, inner margins of eyes slightly narrowed downwards, 1.8 × as high as wide (27.2:15.0); temple and gena feebly rugose-punctate and shiny, densely setose. Clypeus also rugose and setose; tentorial pits small, distance between tentorial pits 2.8 × as long as distance from pit to eye margin (12.8:4.6); malar space short, 0.2 × as long as eye height. Antennae slightly longer than body, with the preapical segment about thrice as long as wide; flagellomeres with bristly setosity, with placodes arranged regularly in 2 ranks except the apical one; apical segment subequal to preapical one in length. Flagellomere proportion: 2 L/W=2.9, 8 L/W=2.5, 14 L/W=2.3; L 2/14=1.6; W 2/14=1.3.

Mesosoma. Pronotum with two weakly indicated but distinct foveate furrows laterally. Mesoscutum shiny, evenly and densely rugose-punctate, with short setae all over; notauli not impressed. Disc of scutellum as strongly sculptured as the mesoscutum, with normal setosity, its rugose tip at middle widely interrupting the posterior, polished band of scutellum. Lateral, polished field reduced to a thin, parallel-sided strip. Ant erior margin of the postscutellum closely applied to the posterior margin of the scutellum so that, laterally, the phragma of scutellum is completely hidden. Scutellar sulcus deep, with few longitudinal carinae, its width 0.9 × as long as scutellum (19.0:20.4). Propodeum shiny, with a complete median keel; surface on each side of the median propodeal keel almost smooth, with dense obsolescent punctures, only with very short transverse ridging on immediate vicinity of longitudinal carina. Mesopleuron polished posteriorly and above precoxal sulcus, depressed below and there densely setigerous-punctate; precoxal sulcus long, broad, shallow with shallow longitudinal carina.

Wings. Forewing with vein r-m reduced to a mere hyaline point and more or less interstitial with vein r so that the areolet is virtually 3-sided, very small, slit-like. Vein r arising from distal 1/2 of pterostigma, far behind the middle, very obliquely placed on the pterostigma, meeting vein 2-SR at a 100 degree angle. Vein 1-R1 (metacarp) with distal end almost reaching to apex of marginal cell, 2.4 × as long as pterostigma, pterostigma 2.1 × as long as wide; r:2-SR:length of pterostigma=14.0:9.5:21.0. Second discoidal cell setose almost everywhere. Width of 1st discal cell:height of 1st discal cell =23.0:24.5. 1-CU1:2-CU1:m-cu=12.0:10.2:10. Hind wing broad, with vannal lobe beyond its widest part straight and fringed with short setae throughout.

Legs. Long and thin. Hind coxa large, just reaching past posterior margin of T3, with evenly and closely punctate surface, the interspaces very shiny. Hind tibia swollen toward apex and about 0.9 × as long as hind tarsus (57.0:66.2), with rather sparse fine spines. Inner hind tibial spurs much longer than outer ones, about 0.8 × as long as hind basitarsus (24.0:30.0); fourth tarsal segment shorter than fifth tarsal segment(9.2:10.0); apical segment of the front tarsus without a spine. Tarsal claws rather long, simple.

Metasoma. Slightly shorter than mesosoma. Tergites with short fine setae all over. T1 almost parallel-sided, roundly constricted at apical 1/5, with complete longitudinal groove; smooth, except for rugosity at posterior corners, 1.4 × as long as its width, 1.6 × as long as T2. T2 strongly transverse, anterior margin oblique each side besides the middle, with a more or less distinct parallel-sided median field that elongated and smooth, the lateral fields are not transverse and more or less aciculate-rugose, 0.5 × as long as its width and 1.4 × as long as T3. T3 also transverse, membranous, polished, separated from T2 by a deep groove. Tergites posterior to T3 more membranous; setae of metasoma very sparse, almost absent on T3. Ovipositor sheath with 2-3 strong and blackened modified setae at apex. Hypopygium small, evenly sclerotised, smooth with sparse fine setae, not surpassing the last tergite.

Colour. Body black, more or less brownish, except that metasoma yellow to brown. Antennae light brown, slightly darkened toward apex. Mouthpart yellow, palpi paler. Tegula whitish yellow. Fore and mid legs uniformly bright yellow; hind coxa black but brownish marginally, trochanter yellow, femur brown with the extreme base yellow; hind tibia lighter than femur but on basal half bright yellow, hind spurs bright yellow. T1 bright yellow, somewhat transparent, T2 and T3 brown; other tergites light brown. Wings hyaline; veins and pterostigma light brown, transparent.

Variation. Some individuals with head and hind coxa yellow.

Male.

Unknown.

Host.

Unknown.

Material examined.

Holotype: ♀, Yiliping (117°40'E, 27°43'N ~ 117°42'E, 27°44'N), Fujian, 1981. V. 5, legs. Huang Juchang, No. 20004177. Paratype: 1♀, Tianbaoyan, Yongan (117°17'E, 25°54'N ~ 117°27'E, 26°02'N), Fujian, 2001. VII. 15-18, legs. Xu Zaifu, No. 20020245; 1♀, Mt. Longqi, Jiangle (117°11'E, 26°23'N ~ 117°21'E, 26°43'N), Fujian, 1991. VII. 16, legs. Liu Changming, No. 20007159; 1♀, Mt. Tongledashan (111°20'E, 23°07'N ~ 111°29'E, 23°14'N), Yunan, Guangdong, 2003. VIII. 12-13, legs. Xu Zaifu, No. 20054526; 1♀, Fengxi (116°15'E, 24°31'N ~ 116°17'E, 24°32'N), Meizhou, Guangdong, 2003. VII. 29, legs. Chen Jujian, No. 20048755; 1♀, Mt. Nanling (112°59'E, 24°53'N ~ 113°05'E, 24°56'N), Ruyuan, Guangdong, 2003. VII. 23, legs. Xu Zaifu, No. 20049030; 1♀, Mt. Gutian (118°07'E, 29°14'N ~ 118°10'E, 29°16'N), Zhengjiang, 2005. V. 2, legs. Wu Qiong, No. 200616757; 1♀, West Mt. Tianmu (119°23'E, 30°20'N ~ 119°24'E, 30°20'N), Linan, Zhejiang, 1998. V. 25, legs. Zhao Mingshui, No. 20003376; 3♀♀, Baotianman (111°55'E, 33°29'N ~ 111°58'E, 33°32'N), Neixiang, Henan, 1998. VII. 14, legs. Chen Xuexin, No. 988345, 988654, 988701; 1♀, Mt. Huping (110°45'E, 30°02'N ~ 110°55'E, 30°07'N), Shimen, Hunan, 2009. VII. 9, Zeng Jie, No. 200901332.

Etymology.

The specific name “translucida” derives from the Latin adjective “translucidus”, referring to the colour of the whole body more or less transparent.

Distribution.

China (Henan, Zhejiang, Fujian, Hunan, Guangdong).

Remarks.

This species is similar to Diolcogaster xanthaspis (Ashmead, 1900), but can be distinguished by the ovipositor sheath with a modified apical seta (the latter without); and propodeum with surface on each side of the median propodeal keel smooth-liking, its sculpture reduced to coarse, obsolescent punctuation (the latter with propodeum coarsely rugose).