Reduced female mating receptivity and activation of oviposition in two Callosobruchus species due to injection of biogenic amines

Analyses of proximate mechanisms that control mating and oviposition behaviours in insects are important because they link behavioural ecology and physiology. Recently, seed beetles have been used as models to study evolution of female multiple mating and cost of reproduction including mating. In the present study, we investigated the effects of biogenic amines into the abdomens of females of two Callosobruchus species, Callosobruchus chinensis and Callosobruchus maculatus, on mating receptivity and oviposition behaviour. In C. chinensis, injection of octopamine and tyramine reduced receptivity to mating and tyramine and serotonin increased the number of eggs laid. Similarly, injection of tyramine reduced the receptivity of females and increased the number of eggs laid by females of C. maculatus. These results show the possibility that biogenic amines control mating receptivity and oviposition behaviour in females of two Callosobruchus species.