Evidence for potential of managing some African fruit fly species (Diptera: Tephritidae) using the mango fruit fly host-marking pheromone.

We investigated conspecific and heterospecific oviposition host discrimination among four economically important fruit fly pests of mango in Africa (Ceratitis capitata, Wiedemann; C. fasciventris, Bezzi; C. rosa, Karsch, and C. cosyra, Walker) with regard to host-marking behavior and fecal matter aqueous solutions. The objective of the study was to get insight into the potential of managing these pests using the host-marking technique. Observations were done on mango slices marked by the flies and treated with aqueous solutions of fecal matter of the flies, respectively. In both host-marking and fecal matter experiments, C. cosyra, which is the most destructive species of the four on mango, was exceptional. It only discriminated against hosts treated with its fecal matter but with lower sensitivity while C. capitata and C.fasciventris discriminated against hosts marked by it or treated with its fecal matter and with higher sensitivity. Our results provide evidence for potential of managing some of the major fruit fly species infesting mango in Africa using the host-marking pheromone of the mango fruit fly, C. cosyra.

A new mite IPM strategy: predator avoidance behaviour resulting from the synergetic effects of predator release and acaricide-treated nets.

BACKGROUND: Tetranychus evansi and T. urticae spider mites are known major pests of Solanaceae. Smallholders in Africa rely heavily on pesticide treatments. However, farmers claim that pesticides are generally ineffective despite high-frequency sprays. New management solutions are thus urgently needed. This study assessed the efficacy of using acaricide-treated nets combined with predatory mite release for controlling spider mites. RESULTS: The results showed the acaricide-treated net alone was more effective at reducing numbers of T. urticae than T. evansi. We observed the opposite for release of the predatory mite Phytoseiulus longipes. This difference could be explained by the specific dispersion strategies of the two spider mite pests; T. evansi is gregarious, whereas T. urticae dispersed rapidly. Joint application of both techniques resulted in a synergetic effect that reduced T. evansi and T. urticae spider mite numbers close to zero. The synergetic effect could be explained by predator avoidance behaviour of the prey spider mites, resulting in higher prey trapping and killing rates on acaricide-treated nets, while P. longipes fed on spider mite eggs. CONCLUSION: These techniques are profitable for smallholders as they are not expensive and avoid residues on the crop. © 2018 Society of Chemical Industry.