摘要
绕茧蜂属Ropalophorus Curtis,1837是茧蜂科中的一个小属,迄今世界上仅记载有2种。一种为R.clavicornis(Wesmael),1835,分布于欧州及日本,寄生于云杉八齿小蠹Ips typographus及I.amitinus成虫体内;另一种为R.wisconsinensis Shenefelt,1960,仅分布于美国,由于该种是用诱捕器捕到的,因此,其奇主不详,但有可能为I.pini(Shenefelt,1960)。
Ropalophorus polygraphus Yang, sp nov.Female. Body black and polished, 2.2-2.4mm in length. Head transverse, in dorsal view 2 times as broad as long with temple slightly expanded exterio-posteriorly (Fig. 1).Male. Like female. Body black with gaster dark purple-brown, 2.3-3.1mm in length, Antenna filiform, 17-segmented and as long as the whole body; pedicel drumlike, its length approximately the same as width; flagellum with each segment same length except the last one and gradually getting narrower from base to apex.Biology. All specimens were reared from the braconid cocoons collected in the gallaries of Polygraphus polygraphus Linnaeus on pine, Pinus armandii and spruce, Picea crassisfolia, with the adult mummies of the bark beetle, whose elytra were shed, just beside each cocoon without exception. With 3 couples of freshly emerged wasps from the cocoons put in 3 glass vials containing healthy beetles of the pest, it was observed that they could parasitize the beetles. The braconid female ran after the beetles rapidly and rode on them, piercing into their bodies many times with ovipositor through the suture between posterior margin of pronotum and basal margin of elytra. Obviously, the host of the new broconid is adult of P. poygraphus (Coleoptera: Scolytidae).Distribution. Shaanxi and Gansu Provinces, China.Type material. Holotype (?), Houzhenzi, Zhouzhi, Shaanxi, a cocoon was collected on 27.Ⅸ.1984, emerged on 10.Ⅴ.1984, the cocoon was beside the died adult of Polygra phus polygraphus in its gallery on Pinus armandii, Yang Zhong-qi. Paratypes: 16 (?) (?), 6 (?) (?), the data are the same as holotype; 6 (?) (?) 1(?), Miaoping, Mianxia, Shaaxi, cocoons were collected on 29.Ⅳ. 1984, emerged on 12.Ⅴ.1984, host and trees are the same as holotype, Yang Zhong-qi and Wang Bin-hai; 4 (?) (?), Liancheng, Lanzhou, Gansu, cocoons were collected on 12.Ⅴ.1985, emerged on 22, Ⅴ.1985, cocoons were beside died P. polygraphus adults in their galleries on Picea crassifolia, Yang Zhong-qi. Holotype was deposited in the Entomologica Museum of the Northwestern Agricultural University. Paratypes in the Insect Collections of the Northwestern College of Forestry and the Museum mentioned above respectively.The new species is similar to the other 2 species in the genus, but it may be distinguished by the key below.
