The development of resistant seeds to manage this pest is a big challenge for breeders. We investigated the oviposition preference and development of C. chinensis on two susceptible mungbean cultivars (Seonwha and Gyeongseon) and one previously reported resistant cultivar Jangan, compared to the susceptible cowpea, Yeonbun, by offering a multiple choice test and a no-choice test. Additional, insect stage wise development of C. chinensis was also examined at four temperatures (20, 25, 30 and 35℃). The both choice tests results showed that the cowpea is the most suitable seed host for oviposition. Total developmental time from egg to adult stage ranged from 27.01 to 38.2 days, and developmental time was shortest on the cowpea and longest on Jangan mungbean. However, no successful development of C. chinensis on Jangan mungbean occurred at all constant temperatures. Higher rate of adult emergence and longer adult longevity were found on cowpea and mungbean except Jangan mungbean. Results suggest, higher performance of C. chinensis on cowpea and mungbean might be governed by physical as well as chemical attributes of the seeds. Thus, Jangan mungbean could be stand as a resistant one against bruchids and it could be a resistant sources for successful breeding.

Although expression of foreign genes in a crop species has been target techniques for powerful protection against insect pests, classical breeding programs using varietal resistance of a crop are still being processed. It is, however, frequently difficult to find key products expressed from resistance-related genes in the variety, and those action mechanism. Here, an unterminated story about seed of a mungbean (Vigna radiata) variety with high resistance against the adzuki bean weevil and the bean bug is introduced. The two insects cannot survive on seeds of the variety, although they well develop on susceptible ones. Molecular markers linked to the resistance were selected through BAC library screening and near isogenic lines, and finally a bruchid resistance gene was suggested after map-based cloning approaches. Starvation and chemicals were suggested for a resistant mechanism and a related factor through feeding and behavior experiments, respectively. The seed flour was extracted with organic solvents, and isolated into several fractions on chromatography. Several peaks on HPLC in a fraction were related with the high mortality of the bean bug. A partial structure in an isolated chemical was observed before full identification.

This study was conducted to determine the oviposition preference and development of adzuki bean weevil, Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) on five different leguminous seeds a) cowpea, b) white kidney bean c) soybean cultivar Daepung d) mung bean and e) azuki bean. A multiple choice test and a nochoice 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; shortest of that on the cowpea followed by adzuki and mung bean seeds. Successful development of C. chinensis was not witnessed on soybean or on kidney bean. Rate of adult emergence was higher on adzuki and mung bean seeds with longer adult longevity of those emerged from adzuki 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. Cowpea seeds can possibly be used as a pull stimulus either as a trap crop or as a stimulant in the mechanical traps against C. chinensis where other leguminous host crops are grown as main crops.