Baiting and Male Annihilation Techniques for Fruit Fly Suppression in Africa

Abstract

The use of protein baits and the male annihilation technique (MAT) is gaining importance in Africa as one of the major components of fruit fly suppression strategies. A variety of commercial food baits including GF-120, Nulure, Mazoferm, Hymlure, Questlure, Biolure and Fruit fly Mania are available locally for use by growers although the need for identification and registration of more efficient baits cannot be overemphasized. Spray mixtures of these protein hydrolysates and killing agents applied as spot sprays commonly reduce fruit fly populations by 80–90 %. Based on bait spray costs, yield data and monetary gains, a cost-benefit ratio of 1:9.1 has been reported, which is generally acceptable for smallholder and large-scale fruit producers alike. Research has also seen formulation of liquid protein baits into solid bait stations and they are now availability as commercial products for management of fruit flies on the continent. A deployment strategy of M3 bait stations that decreases the number of units required from the perimeter to the centre of the orchard was found to effectively maintain low fruit fly populations below the threshold level before, during and after citrus harvest. The male annihilation technique (MAT) involves the deployment of high densities of trapping stations consisting of a male attractant combined with a killing agent. MAT is being promoted across Africa as a component of IPM strategies against different fruit fly species. Several male attractants such as methyl eugenol, cuelure, trimedlure, EGOlure, ceralure, terpinyl acetate can be used with an appropriate toxicant. In suppression trials using methyl eugenol or terpinyl acetate plus malathion for the suppression of Bactrocera dorsalis or Ceratitis cosyra, respectively, up to 60–96 % reduction in puparia/kg fruits was achieved. Due to the quarantine nature of the complex of fruit flies inhabiting Africa and zero tolerance of fruit flies in sensitive quarantine markets, the use of a combination of management techniques is being advocated and a combined application of protein baiting and MAT have been reported to further reduce fruit infestation to 1.1–3.1 %. To access sensitive quarantine markets, postharvest treatment of the fruits is encouraged to remove any remaining insects in the produce.