Parasitoid complex of overwintering cocoons of Neodiprion huizeensis (Hymenoptera: Diprionidae) in Guizhou, China

Abstract

The conifer sawfly, Neodiprion huizeensis (Hymenoptera: Diprionidae), is an injurious leaf feeder of Pinus spp. (Pinaceae) in China. Its parasitoid complex of overwintering cocoons was investigated in Weining, Guizhou during 2012. The average parasitism rate of overwintering cocoons of N. huizeensis by the parasitoid complex was 34.6%. The parasitoid complex included Drino auricapita (Diptera: Tachinidae), ichneumonids, and Trichomalus sp. (Hymenoptera: Pteromalidae). The average parasitism rate of N. huizeensis by D. auricapita was 13.1%. The puparial period of D. auricapita averaged 16.4 ± 0.1 d. The female to male ratio was 1.1: 1. The ichneumonid complex included Aptesis grandis, A. melana, A. nigricoxa, Delomerista indica, Lamachus rufiabdominalis, L. nigrus, Bathythrix sp., Caenocryptus sp., Exyston spp., Gelis sp., Goryphus sp., and Olesicampe sp. The parasitism rate of N. huizeensis by ichneumonids was 17.1%. The parasitism rate of N. huizeensis by Trichomalus sp. was 4.5%, and the female to male ratio was 3.7: 1. The dominant species of parasitoids was D. auricapita followed by A. melana. The emergence of overwintered adults of N. huizeensis had two peaks: the first from the 17th to the 23rd of February, 2012; the second from February 29th to March 15th, 2012. The emergence of the parasitoid complexes coincided with each other and occurred from February 23rd to March 6th, 2012.