Impact of geographical origin and rearing medium on mating success and lateralization in the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

Changes in reproductive behavior of mass-reared insects have been investigated in a wide range of species. The geographical origin, as well as different mass rearing practices, may affect the existence and magnitude of lateralization. However, little is known regarding the biotic and abiotic factors affecting lateralization in laboratory-reared insect strains, in terms of rearing media and origin from which the strain had been collected from. Sitophilus oryzae is a destructive beetle species that attacks stored products worldwide. We investigated the impact of geographical origin and rearing media on male mating success and lateralization in three strains of S. oryzae [i.e., a Greek strain reared on wheat (GW), a Greek strain reared on maize (GM) and a Peruvian strain reared on maize (PM)], in order to assess factors that affect mating behavioral trends and the concomitant progeny production. Precopula, copula and whole mating duration were slightly higher in GW males over GM and PM males. Male weevils showed right-biased head-wagging behavior and left-biased copulation attempts, regardless of the tested strains. Male mating success was higher in males performing left-biased copulation attempts followed by right-biased head wagging behavior, without significant differences among the tested strains. Overall, this study adds knowledge to the mating behavior of S. oryzae, highlighting the impact of the geographical origin and the rearing commodity on male mating success and laterality. The quantification of male mating traits may allow comparisons with different strains and/or host cereals, offering reliable evaluations of the impact of different mass rearing procedures.