Efficacy of the parasitoid wasp, Habrobracon hebetor in integrating with Matrine and Bacillus thuringiensis in the control of Anagasta kuehniella

In this research, the efficiency of the parasitoid wasp, Habrobracon hebetor (Say) in integrated with Matrine and Bacillus thuringiensis (Berliner) subsp. Kurstaki (Btk) against Anagasta kuehniella (Zeller), was investigated. Lethal and sublethal concentrations (LC30) of Matrine and Btk were determined by bioassay method on host larvae. To evaluate the preference of the host larval instars by the parasitoid, different larval instars were provided for parasitoid and the rate of parasitism was determined. The fourth and the fifth instar larvae of the host were treated with sublethal concentrations of Matrine and Btk then were provided for parasitoid in choice and non- choice conditions. The rate of paralysis, parasitism, egg-laying, emergence percentage and sex ratio of release wasps were determined. The results showed that female parasitoid preferred the fourth and fifth instar larvae of the host for parasitism. In the choice test, Matrine-treated larvae were more preferred by female parasitoid while in non-choice test, the highest amount of parasitism and egg-laying was related to the control treatment. The emergence percentage of adult wasps and their sex ratio (Female/Total), obtained from Matrine-treated fourth and fifth instar larvae, were 61 and 54% in the choice and 61 and 54% in the non-choice tests. The results showed that Matrine and Btk have significant potential in controlling of A. kuehniella. However, due to the sublethal adverse effects of these control agents on the efficiency of the parasitoid, simultaneous use of them with the parasitoid wasp, H. hebetor is not recommended.