Entomopathogenic fungal activity against pupae and adult Haematobia irritans (Diptera: Muscidae)

Abstract

The horn fly Haematobia irritans is one of the most important ectoparasites associated with grazing bovines This study investigated the pathogenic activity of Metarhizium anisciphae (E9, IBCB425 and IBCB159), Beativeria bassiana (JAB06, JAB07 and AM09), Isaria fumoscrosea (=Paecilomyces fumosoroseus) (IBCB133 and CB75) and Isaria farinosa (=Paecilomyces fannosus) (CG189 and CG195) fungi isolates on pupae and adult 11 irritans Groups of 20 pupae and 30 adult flies were respectively battled and sprayed with fungal isolate Suspensions containing to10(6), 1(0)7 and 10(8) conidia ml(-1) in bioassays conducted in laboratories In both assays the adult flies were fed bovine blood for 15 days, and death rates were assessed daily The E9 and IBCB425 M anisophae isolates caused pupae death at concentiations of 10(7) and 10(8) conidia ml(-1), and the JAB07 and AM09 B bassiana isolates Caused higher Pupae mortality at a concentration of 10(8) conidia ml(-1) 1 farmosa isolates were the most effective considering Pupae mortality, with the CG195 inducing more deaths (56 6%)in the 10(8) conidia ml(-1) concentration Suspension. Adult flies were more Susceptible to the fungi's pathogenic action, since the E9 isolate of M anisophae and all of the B bassiana induced death in 100% of the flies at the 10(8) conidia ml(-1) concentration Suspension The I fumosorosea and I farmosa isolates, oil the other hand, were less effective in controlling adult flies. In both stages. but mostly the adult phase, pathogenicity was great at higher conidial concentrations; (C) 2009 Elsevier B V All rights reserved.