Biology and overwintering potential of the pepper weevil, Anthonomus eugenii (Coleoptera: Curculionidae)

Abstract: Anthonomus eugenii Cano is one of the most challenging pest species associated with cultivated pepper plants (Capsicum spp.) in North America. The weevil causes significant damage to pepper fruits, which reduces production yield. Its egg, larval, and pupal stages all occur within the protected confines of the pepper fruit, sheltering it from insecticides and many natural enemies. Currently, the use of chemical insecticides, along with intensive crop scouting and cultural management are the main strategies used to control its populations. Information about its biology, ecology, and potential management is still limited and is mostly derived from specific locations such as Mexico and the southern United States. Recently, concerns about the development of resistance, and its potential to establish in temperate areas of North America have increased attention on the search for new tools and multidisciplinary approaches to control A. eugenii. In 2016, we studied the impact of pepper variety grown in greenhouse conditions on the incidence of pepper weevil in southern Ontario, Canada. Our survey showed that chili and jalapeno peppers had more weevils per fruit relative to habanero and shepherd peppers. Also, native host plants such as Solanum ptycanthum Dunal were found to support complete weevil development, albeit at a reduced developmental rate. In addition, we explored the cold tolerance of the pepper weevil through laboratory and field experiments. Cold tolerance studies showed that weevils were able to survive temperatures of -10 ºC but not -15 ºC, and that adult weevils could not survive long-term outdoor winter conditions. Together these findings can serve to inform the development of pest management strategies to mitigate future threats by this pest.