Abundance and distribution of West Indian sweet potato weevil, Euscepesbatatae (Waterhouse) (Coleoptera: Curculionidae), in Samoa

Abstract

Surveys were conducted in the two main islands of Upolu and Savaii to determine the distribution and document the abundance of West Indian sweet potato weevil at different topographic areas in Samoa. A total of 28 farm localities were surveyed in August and October, 2016. Farm types, agronomic practices and farmer knowledge of the weevil were determined. About eighty percent of farmers were not aware of the presence of E. batataebecause of the lack of interest in sweet potato cultivation. Those that were aware of E. batatae commonly observed this pest in vines and rarely in tubers. It was also discovered that E. batataewas present in all levels of topography but inland areas had a higher weevil population as compared to coastal and highland areas. This indicates the influence of altitude on weevil population; lower altitudes have warm temperatures which are suitable for weevil population growth. Furthermore, this survey was carried out during the dry season and most sweet potato populations thrived in such periods compared to the wet season. Information gathered from this study would enable agricultural extension officers and farmers to become aware of the presence of E. batatae and to initiate control measures for it, if necessary.