Susceptibility of Ceratitis capitata Wiedemann (Diptera : Tephritidae) to entomopathogenic fungi and their extracts

The effectiveness of seven strains of entomopathogenic fungi against Cerati tis capitata adults was evaluated in the laboratory. Adults were susceptibl e to five of seven aqueous suspensions of conidia. Metarhizium anisopliae a nd strain CG-260 of Paecilomyces fumosoroseus were the most pathogenic fung i, with 10-day LD50 values of 5.1 and 6.1 x 10(3) conidia/fly, respectively , when applied topically. Sublethal effects on fecundity and fertility of t he fungal-exposed females were also studied. The most effective fungus in r educing fecundity was P. fumosoroseus CECT 2705, with reductions on the ord er of 65% at 1 x 10(6) conidia/fly. M. anisopliae and Aspergillus ochraceus also showed significant reductions of fecundity (40-50% for most of the as sayed concentrations). Fertility was moderately affected by the fungi. M. a nisopliae at 1 x 10(6) conidia/fly was the most effective fungus, showing e gg eclosion reduction of over 50% compared with the control. In addition, c ulture broth dichloromethane extracts from the entomopathogenic fungi were tested for insecticide activity against C. capitata, including effects on f ecundity and fertility. The extract from M. anisopliae was the most toxic, resulting in about 90% mortality at a concentration of 25 mg/g of diet; und er these conditions, fecundity and fertility of treated females were reduce d by 94 and 53%, respectively, compared with untreated controls. (C) 2000 A cademic Press.