An investigation of Callosobruchus chinensis (Linnaeus) and its Hymenopterous parasitoid - Anisopteromalus calandrae (Howard).

Abstract

This study was focused on biology of Callosobruchus chinensis in rming seeds and its parasitoid, Anisopteromalus calandrae. First the life cycles were studied. The whole life cycle of C. chinensis is nearly 3 - 6 weeks at 28 - 30°C and 80.2 - 82% RH. C. chinensis has 4 larval instars. Mean reproductive capacity of C. chinensis is about 81.8 ± 3.91. Cannibalism docs not occur within the larval stages or pupal stages of C. chinensis. Life cycle of A. calandrae takes nearly 1 1 —23 days. Mean number of adult produced by a female is 46.3 ± 6.63. A. calandrae parasitizes post third larval instars, fourth larval instars and pre pupal stages of C. chinensis. Sex ratio of parasitoid, linearly related to the host age. Biological control of C. chinensis was also investigated. More than 50% of the pest (C. chinensis) population was suppressed by introducing 5 pairs of parasitoid (A. calandrae) to 100 mung seeds, with initial population of 5 pairs of pest.

This study was focused on biology of Callosobruchus chinensis in rming seeds and its parasitoid, Anisopteromalus calandrae. First the life cycles were studied. The whole life cycle of C. chinensis is nearly 3 - 6 weeks at 28 - 30°C and 80.2 - 82% RH. C. chinensis has 4 larval instars. Mean reproductive capacity of C. chinensis is about 81.8 ± 3.91. Cannibalism docs not occur within the larval stages or pupal stages of C. chinensis. Life cycle of A. calandrae takes nearly 1 1 —23 days. Mean number of adult produced by a female is 46.3 ± 6.63. A. calandrae parasitizes post third larval instars, fourth larval instars and pre pupal stages of C. chinensis. Sex ratio of parasitoid, linearly related to the host age. Biological control of C. chinensis was also investigated. More than 50% of the pest (C. chinensis) population was suppressed by introducing 5 pairs of parasitoid (A. calandrae) to 100 mung seeds, with initial population of 5 pairs of pest.