Effect of Metarhizium anisopliae inoculation on the mating behavior of three species of African Tephritid fruit flies, Ceratitis capitata, Ceratitis cosyra and Ceratitis fasciventris

Abstract

Bioassays were carried out in the laboratory to investigate the effect of inoculation by Metarhizium anisopliae on mating behavior of three species of fruit flies, Ceratitis cosyra, C. fasciventris and C. capitata. In all three species, inoculation by the fungus resulted in significant delay in the commencement of calling and mating of treated males as they spent substantial amount of time in grooming activity. In fungus-treated male flies, calling and mating started at 70.0–80.0 min after exposing them to untreated females. However, when females were treated, calling and mating started from 15.0 to 16.0 min. Fungus-treated males competed equally with untreated males for virgin female flies from day 0 to day 2 post-inoculation. There were, however, significant differences on day 3, with untreated males of the three fruit fly species having higher percentage of paring than fungus-treated males. There was no significant difference in the duration of pairing of fungus-treated males and untreated male of the three fruit fly species at day 0, 1 and 2 post-inoculation. However, on day 3 post-inoculation, there was a significant difference in the duration of mating with fungus-treated males having the lowest duration of mating. No significant differences in the percentage of mating between fungus-treated male and female flies; and the untreated flies at day 0, 1 and 2 days post-inoculation, except on day 3. The results are discussed with regard to application in autodissemination, baiting and the sterile insect techniques.