Effect of entomopathogenic fungus, Beauveria bassiana, on functional response and reproduction of parasitoid wasp, Aphidius matricariae Haliday (Hym.: Braconidae)

In this research, the effect of entomopathogenic fungus, Beauveria bassiana (Ascomycota, Hypocreales), on functional response (in laboratory) and reproduction (in microcosm) of parasitoid wasp, Aphidius matricariae Haliday (Hym.: Braconidae) on its host, Myzus persicae (Sulzer) (Hem.: Aphididae) was investigated. Illustrating number of mummified aphids versus initial density of green peach aphid showed type III functional response. The results declared the parasitoid wasp had maximum efficiency to parasite green peach aphid when both wasp and aphid were not exposed to the entomopathogenic fungus. In this case, values of b and Th were 0.1053 and 0.0179, respectively. The previous infection of green peach aphid significantly affected the number of produced mummies and fungus-sporulating cadavers after 16 days. The mean numbers of produced mummies for control, parasitized aphids in 24 and 72 h intervals after fungal infection were 14.33±2.86, 10.66±2.13 and 6.66±1.33, respectively and indicated that relative timing for parasitism and fungal infection was determinant in ultimate result of the competition.