Oviposition preference and development of azuki bean weevil, Callosobruchus chinensis, on five different leguminous seeds

This study was conducted to determine the oviposition preference and development of azuki bean weevil, Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) on five different leguminous seeds a) cowpea cultivar Yeonbundongbu, b) white kidney bean cultivar Hwanghyubilho, c) soybean cultivar Daepung, d) mung bean cultivar Seonhwanogdu, and e) azuki bean cultivar Hongeon. A multiple-choice test and a no-choice test were conducted to record the number of eggs laid, total developmental time, number of adults emerged, and adult longevity of C. chinensis on the five different leguminous seeds. Both choice and no-choice tests revealed cowpea seed as the most preferred oviposition substrate. Total developmental time from egg to adult stage ranged from 28 to 31 days; developmental time was shortest on the cowpea. Successful development of C. chinensis was not observed on soybean or on kidney bean. Rate of adult emergence was higher on azuki and mung bean seeds with longer adult longevity of those emerged from azuki bean and cowpea. Higher egg laying preference and shorter developmental time with longer adult longevity of the beetle on cowpea probably signifies importance of physical as well as chemical attributes of the seed as an oviposition substrate other than evolutionary history of the insect.