Efficacy of a Sudanese Strain of Entomopathogenic Fungus, Metarhizium anisopliae Met. Sorokin on Puparia of Bactrocera dorsalis Hendel, Under Laboratory Conditions

Abstract

Fruit flies (Diptera: Tephritidae) are among the main constraints that limit horticultural production in Sudan. The country has an enormous potential for horticultural production, over its wide range of climatic conditions and diverse ecosystems. However, it is threatened by an invasion of exotic fruit flies over its long borders with neighbouring countries, and by its weak interception and quarantine procedures. Although entomopathogenic fungi are known to attack fruit flies, very few efforts have been exerted to confirm their efficacy in integrated pest management (IPM) strategies against fruit flies. The fungus Metarhizium anisopliae Sorokin has been found on the dead body of a larva of white grub, Schizonycha sp. (Coleoptera: Melolonthidae), at Kenana Sugarcane Farm. A laboratory experiment was undertaken by applying four different concentrations (20 × 106, 10 × 106, 5 × 106 and 2.5 × 106) of the fungus on the pupae of Bactrocera dorsalis in order to inhibit adult emergence. The results showed that adult emergence from the pupae of B. dorsalis was inhibited by the tested concentrations of M. anisopliae. The inhibition increased with increasing concentrations. LC50 and LC90 values for the fungus were 10 × 106 and 18 × 106 conidia/ml, respectively. The mentioned fungus can be incorporated in fruit fly management strategy.