Host location and acceptance by parasitoid, Habrobracon hebetor and effect of varying Bacillus thuringiensis treatment against rice moth, Corcyra cephalonica

Abstract

The combined effect of microbial pesticide, Bacillus thuringiensis Berliner (Bt), and insect parasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae) was evaluated for the management of rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae). This parasitoid is very useful in testing host-parasitoid interaction due to its high fecundity and short generation time. The host location and acceptance by parasitoid female, investigated by choice and no choice tests, showed marked preference towards later host instar larvae of C. cephalonica. Parasitoid induced mortality of Bt-intoxicated and Bt-reared host larvae was also investigated. C. cephalonica mortality was highest (72.00 ± 3.26%) and synergistic when host larvae were exposed to acute Bt treatment in conjunction with the parasitoid. A combined treatment of Bt with H. hebetor is an effective strategy in integrated pest control programmes of C. cephalonica and other stored grain pests.