Rare male mating phenomenon in mulberry silkworm Bombyx mori

Abstract

Intersexual selection (female choice) is a widely observed phenomenon between mating partners in animal kingdom. Further, minority male mating advantage is a phenomenon, whereby genetic variability can be maintained in a population without genetic load at equilibrium. Such type of matings, though observed in almost all species of Drosophila are not reported in lepidopteran insects. So, in order to detect the rare-male effect in silkworm Bombyx mori L. the present investigations were carried out to study the mating success of Kalimpong-A and NB18 races of silkworm B. mori. In all experiments, female choice was employed. The experiments were conducted at nine different ratios. The results show that though both types of males are eqully successful in mating when present in equal ratio, they are more successful when they are in minority. This advantage disappears when males become common. Thus, the present observations provide evidence for the existence of minority male mating advantage in B. mori.