Host and ovipositional preference of rice weevil (sitophilus oryzae) depending on feeding experience

Abstract

Rice weevil, Sitophilus oryzae is one of the most devastating primary pests of stored grains. Adults feed mainly on endosperm, while larvae feed on germ, resulting in reduced germination and nutritional value of kernels. The influence of a commodity condition on the food preferences of S. oryzae has been well documented, but the influence of previous feeding experience ("natal habitat preference induction" - NHPI theory) has not yet been confirmed. This research aims to test the NHPI theory, to study the behavioural responses of S. oryzae virgin males and females to different grains (maize, wheat and barley) depending on rearing substrate and feeding history and to test host, feeding and oviposition preference. In a "Choice test", the host preference was determined based on the adult distribution on specific grains, feeding preferences based on grain damage (%) and grain loss (%), and ovipositional preference based on the progeny production. The results indicate that host, feeding and ovipositional preference of S. oryzae was not dependent on the previous feeding experience. Maize was the most preferential grain, regardless on the rearing substrate, for both male and female weevils. Grain damage, weight loss and progeny production were higher on maize, regardless on the rearing history.