Investigation on the parasitoids and pathogens of Asian corn borer overwintering larvae in the corn belt of China.

The parasitoids and pathogens of the Asian corn borer (Ostrinia furnacalis) overwintering larvae were investigated in 11 geographically distinct locations of 9 provinces of main corn growing area in China A tachinid fly, Lydella grisescens (Diptera, Tachinidae), a braconid wasp, Macrocentrus cingulum (Hymenoptera, Braconidae) and an ichneumon wasp, Eriborus terebrans (Ichneumonidae) were the major parasitic insects Beauvaria bassiana, Bacillus thuringiensis and two microsporidia, Nosema furnacalis and Nosema spp , were the major pathogens In general, O. furnacalis mortality caused by pathogens was higher than by parasitic insects Muscardine was the most prevalent disease, especially in the spring maize area The incidence was as high as 74 8%-80 4% in Dunhua and Gongzhuling of Jilin B bassiana was commonly used as microbial pesticide to control O. furnacalis in these area B thuringiensis was more prevalent in the summer maize area The incidence was 6 7%-13 7% N furnacalis prevailed in the spring maize area and Nosema spp distributed in the summer maize area Braconid wasp widely established in the summer maize area It attacked 0-17 9% of O. furnacalis larvae E. terebrans was most abundant in Chifeng of Intra Mongolia, Shuozhou of Shanxi, and Dunhua, attacked 1 5, 0 5 and 0 8 per cent of O. furnacalis larvae, respectively The tachinid fly was prevalent in all locations except Chifeng and Hengshui of Hebei, and most abundant in Shuozhou The parasitism was 0 7%-6 3%.