Species diversity and activity of parasitoids of the sweetpotato butterfly, Acraea acerata, in Uganda.
AbstractThe species range, activity and relative abundance of parasitoids attacking the sweetpotato butterfly, Acraea acerata Hew. (Lepidoptera: Nymphalidae) in Uganda was investigated. Samples of eggs and larvae of the sweetpotato butterfly were collected from some of the major sweetpotato growing districts of Uganda to identify the range of parasitoids in the country. Monthly surveys to collect samples of caterpillars from selected sites were also carried out to evaluate percentage parasitism over time. The collected samples were reared in the laboratory for parasitoid emergence. Results showed that the sweetpotato butterfly is attacked by three larval parasitoid species in Uganda, namely, Meteorus sp. (AKW), Charops sp. (AKW) and Caricelia normula Wyatt. No parasitoids emerged from eggs, indicating an absence of egg parasitoids. Charops sp. was the most abundant parasitoid species at all sites, Meteorus sp. had moderate occurrence, while C. normula was the least abundant. Percentage parasitism was found to be rather low to afford significant control on its own. Nevertheless, long term impact of parasitoids is important in moderating pest population dynamics. It is, therefore, important to conserve the native natural enemies by avoiding over use of insecticides.
Key Words: Acraea acerata, biological control, Caricelia normula, Charops sp., Meteorus sp., natural enemies, percentage parasitism, parasitoids, Uganda
(African Crop Science Journal 2001 9(1): 157-164)