Combination of Entomopathogenic Fungi with Essential Oil for Controlling Bean Fly, Ophiomyia phaseoli Tryon (Agromyzidae: Diptera)

Abstract

The objective of this study was to evaluate the compatibility of entomopathogenic fungi with repellants to control bean fly, Ophiomyia phaseoli Tryon (Agromyzidae: Diptera). Nine isolates of entomopathogenic fungi belonging to 3 genera and 5 species were screened for pathogenicity against bean fly. The results found that Beauveria bassiana isolate Bff and Metarhizium anisopliae isolate Mff caused 100% mortality to both its larval and adult stages. The repellency of 7 essential oil was also evaluated against adult bean fly in the laboratory. The results showed significant differences in repellency among essential oil and concentrations. Essential oil extract from pomelo peeling was the strongest repellant followed by eucalyptus and sweet basil. However, essential oil extract from camphor was the weakest repellant. On the other hand, these seven essential oils (pomelo, zingiber, citronella grass, eucalyptus, camphor, kaffir lime and sweet basil) at a concentration of 0.1% had no effect on the viability of conidia, but at higher concentrations it was found that citronella grass and zingiber reduced viability of B. bassiana. The results on the effect of essential oils on colony growth showed the same tendency as the one on the viability of conidia.