Predatory capacity of a shorefly, Ochthera chalybescens, on malaria vectors

BACKGROUND: Since Ochthera chalybescens had been reported to prey on African malaria vectors, the predatory capacity of adults of this species on Anopheles gambiae sensu stricto was explored. METHOD: Predatory capacity of this fly on A. gambiae s.s. was tested at all developmental stages, including the adult stage in the laboratory setting. Effects of water depth on its predatory capacity were also examined. RESULTS: This study revealed that O. chalybescens preyed on mosquitoes at all life stages except eggs. It was able to prey on an average of 9.8 to 18.8 mosquito larvae in 24 hrs. Mosquito larva size and water depth did not affect predatory capacity. However, the predacious fly preyed on significantly more 2(nd)-instar larvae than on pupae when larvae and pupae were both available. CONCLUSION: Ochthera chalybescens is, by all indications, an important predator of African malaria vectors.