Dolichogenidea polystinelliphagous Liu & Chen, 2018

Liu, Zhen, He, Jun-Hua & Chen, Xue-Xin, 2018, The laevigata - group of the genus Dolichogenidea Mason, 1981 from China, with descriptions of 26 new species, Zootaxa 4436 (1), pp. 1-74 : 50-51

Dolichogenidea polystinelliphagous Liu & Chen , sp. n.

Figures 25 , 38

Description. Female. Body length 2.1 mm, fore wing length 2.5 mm.

Head. Transverse in dorsal view, 2× as wide as long and nearly as wide as mesoscutum. Temple dull and coarsely punctate, less constricted. Face transverse, nearly 0.8× as high as wide, dull with small punctures, pubescent, inner margin of eyes subparallel. Ocelli on low triangle, the posterior tangent to the anterior ocellus slightly cutting the posterior pair, distance between fore and a hind ocellus not shorter than diameter of an ocellus, POL:OD:OOL=4.2:2.8:4.2. Antenna as long as body, penultimate antennomere cubic to subcubic.

Mesosoma. Length:breadth:height=49.0:30.5:32.5. Disc of mesonotum shiny with shallow punctures, interspaces equal with diameter of punctures. Scutellar sulcus nearly straight, relatively narrow with carinae in between. Scutellum polished, smooth with indistinct punctuation. Propodeum dull, with long setose punctures on brow, strongly strigose above orifice, polished medially, posterior-lateral field polished, hind corners distinctly raised, relatively short. Mesopleuron polished, with indistinct shallow punctures anteriorly.

Legs. Spines on outer side of hind tibia sparse. Inner spur of hind tibia 2/5 length of basitarsus, outer one slightly shorter. Basitarsus of hind leg a little longer than tarsomeres 2–4 combined.

Wings. Pterostigma 2.5× as long as its widest part. Vein 1-R1 (metacarp) as long as pterostigma, 4.3× as long as its distance from the apex of the marginal cell. Vein r arising from middle of pterostigma, shorter than width of pterostigma, vein r a little longer than vein 2-SR, distinctly angled at their meeting, vein 2-M half length of vein 2- SR. 1 st discal cell 1.2× wider than high. 1 st submarginal cell of hind wing 2× wider than high. Vein cu-a slightly curved, vannal lobe beyond its widest part evenly convex.

Metasoma. Almost as long as mesosoma (47.5:49.0). T1 parallel-sided, 1.3× longer than wide posteriorly, basal one third indistinctly concave, turned-over part punctate-rugulose, tubercle polished. T2 evenly curved into T3, 3× wider than long in the middle, slightly uneven medially, subrugulose anteriorly and laterally. T3 1.2× as long as T2, tergites posterior to T2 polished, shiny and less pubescent. Ovipositor sheath 3/4 length of hind tibia, thin.

Colour. Body black. Tegula yellow. Palpi and spurs pale yellow. Antenna from base to apex yellow to yellowish brown. Ovipositor sheath, labrum, mandible and legs bright reddish yellow except hind coxa and hind third of tibia yellowish brown. Wing membrane hyaline, vein 1-R1, C+SC+ R and pterostigma yellowish brown, r, 2-SR, 2-M and other light brown, pterostigma with pale basal spot.

Viaration. Body length 2.5–4.5mm.

Male. Similar to female, except: T1 not that rugose, with independent punctures; antenna distinctly longer than body, penultimate antennomere 1.9× longer than wide; and medial part of propodeum not rugose.

Host. According to the label: Yponomeuta polystinellus Felderv ( Lepidoptera : Yponomeutidae ).

Material examined. Holotype: ♀, Xi’an , Shaanxi, 1974. V.31, Zhang Yingjun, No. 740343 . Paratypes: 8♀♀ 4♂♂, Xi’an , Shaanxi, 1974. V.31, Zhang Yingjun, No. 740343 ; 1♀ ♂, Taiyuan, Shanxi, 1987.I, Zhao Ruiliang, No. 870076 ; 3♀♀, Changchun , Jilin, 1992. VII.25, Lou Juxian, Nos. 951269, 951263, 951078 ; 2♀♀, Dongling, Shenyang , Liaoning, 1992. VII.9, Lin Naiquan, Nos. 20004513, 20004568.

Distribution. China (Shaanxi, Shanxi, Jilin, Liaoning).

Etymology. The specific name “ polystinelliphagous ”, referring to that it is a parasitoid of larva of Yponomeuta polystinellus Felderv.

Remarks. This species is similar to D. stenosis Chen et Song but differs from the latter by the following: 1 st discal cell 1.2× wider than high (the latter distinctly higher than wide); ocelli on low triangle (the latter high triangle); and spines on outer side of hind tibia sparse (the latter dense and numerous).

Figures

FIGURE 25. Dolichogenidea polystinelliphagous Liu & Chen, sp. n. a habitus, dorsal view; b head, frontal view; c fore wing; d head, dorsal view; e hind wing; f propodeum; g mesosoma, dorsal view; h T1–3, dorsal view. Scale line = 0.5 mm.

FIGURE 38. Distribution map of laevigata-group of Dolichogenidea species in China. *: Dolichogenidea parametacarp Liu & Chen, sp. n.; ■: Dolichogenidea partergita Liu & Chen, sp. n.; Δ: Dolichogenidea poliobrevis Liu & Chen, sp. n.; •: Dolichogenidea polystinelliphagous Liu & Chen, sp. n.; ♥: Dolichogenidea purdus (Papp, 1977); •: Dolichogenidea sandwico Liu & Chen, sp. n.; Ŧ: Dolichogenidea sicarius (Marshall, 1885).