Bait location by ground foraging ants (Hymenoptera: Formicidae) in mopane woodland selectively sprayed to control tsetse fly (Diptera: Glossinidae) in Zimbabwe

Abstract

AbstractFood-baited dishes were used to monitor the impact of ground-sprayed DDT (4% WP @ approx. 200 g/ha) and deltamethrin (0.05% SC @ 2.6 g/ha) for tsetse fly (Glossinaspp.) control, on epigeal ants in mopane woodland in north-western Zimbabwe. Twenty species of ants were recorded at dishes baited with various types of food.Pheidolespp. andMonomorium opacumForel (Formicidae: Myrmicinae) were predominant, both in the number of baits attended and in the number of workers present at individual baits. Season apparently had a greater effect on the composition and activity of the ground foraging ant assemblage than did either pesticide. There was a decline in the rate at which baits were found and in species richness of the ant assemblage as the dry season progressed and several species also showed changes in their ability to locate baits. There was no major pesticide induced disruption of the species richness or food finding ability of the diurnal ground foraging ant assemblage sampled. However, foraging success byPlatythyrea cribrinodis(Gerstaecker) (Formicidae: Ponerinae) was reduced immediately after spraying with deltamethrin. Subtle effects of either insecticide on rarer species cannot be discounted from the results of this study.