甘肃陇南地区银杏大蚕蛾卵寄生蜂种类调查

银杏大蚕蛾Caligula japonica（Moore）作为危害核桃、板栗、银杏等坚果类果树的重要害虫之一，已经引起国内外广泛关注。明确银杏大蚕蛾卵期寄生蜂的种类、分布和自然寄生状况，可为银杏大蚕蛾天敌的保护利用提供科学依据。本文于2018-2019年在甘肃省陇南市银杏大蚕蛾核桃危害区采集该害虫的越冬卵并带回实验室培养，收集羽化的寄生蜂并记录其种类和数量，最后通过计算寄生率确定优势天敌物种。本研究共采集银杏大蚕蛾卵块1 114个约8万粒卵，平均单株核桃树木卵块数与卵粒数分别最高可达7.5块和533.5粒；共收集到膜翅目3科5属9种银杏大蚕蛾卵期寄生蜂，其中6种为首次报道；具体为旋小蜂科7种，包括平腹小蜂属4种：麻纹蝽平腹小蜂Anastatus fulloi、甘肃平腹小蜂A. gansuensis、日本平腹小蜂A. japonicus和梅岭平腹小蜂A. meilingensis；短角平腹小蜂属2种：白跗短角平腹小蜂Mesocomys albitarsis和枯叶蛾短角平腹小蜂M. trabalae；旋小蜂属1种：Eupelmus sp.；赤眼蜂科赤眼蜂属1种：螟黄赤眼蜂Trichogramma chilonis；姬小蜂科长尾啮小蜂属1种：短梗长尾啮小蜂Aprostocetus brevipedicellus。结果表明，旋小蜂科两种短角平腹小蜂数量最多，分布最广，物种优势度指数达86以上，为陇南地区野外寄生银杏大蚕蛾卵的优势性天敌，且卵块寄生率和卵粒寄生率分别最高可达55.91%和6.77%。本研究拓宽了银杏大蚕蛾自然天敌种类并为今后开发利用寄生蜂防治该害虫提供了理论依据。

Investigation on parasitoid species of Caligula japonica Moore eggs in Longnan area of Gansu Province

Caligula japonica (Moore), one of the most important pest of walnut, chestnut, ginkgo and other nut fruit trees, has been attracted wide attention. The objective of this study was to screen out the parasitic natural enemies, clarify their distribution and natural parasitism rate on C. japonica eggs, and provide scientific basis for the protection and utilization of those natural enemies. The overwintering eggs of the pest were collected and brought back to the laboratory during 2018 to 2019 from the area most seriously damaged by C. japonica in Longnan, Gansu Province. The number of parasitoid females and males emerged from each egg were collected and recorded. The parasitism rate of eggs and egg masses was calculated and the dominant natural enemy species were identified. In this study, a total of 1 114 egg masses, and approximately 80 thousand eggs of C. japonica were collected. The average number of egg masses and eggs per walnut tree were 7.5 and 533.5, respectively. Total of nine egg parasitoid species of C. japonica, belonging to five genera and three families of Hymenoptera, were found. Among them, six species were firstly reported on C. japonica eggs, and seven species were belonged to Eupelmidae, in which there were four Anastatus species (A. fulloi, A. gansuensis, A. japonicus and A. meilingensis), two Mesocomys species (M. albitarsis and M. trabalae), one Eupelmus species (Eupelmus sp.). In addtion, Trichogramma chilonis and Aprostocetus brevipedicellus belonged to Trichogrammatidae and Eulophidae, respectively, were identified. The species dominance index of M. albitarsis and M. trabalae was more than 86, and their average parasitism rate of egg masses and eggs were 55.91% and 6.77%, respectively. These results indicated that M. albitarsis and M. trabalae were the dominant natural enemies of wild C. japonica in Longnan area. This study provided important information on naturally occurring parasitoids of C. japonica and also provided a theoretical basis for the development and utilization of parasitoids to control this pest in the future.