Insecticidal Activity of Bacillus thuringiensis on Larvae and Adults of Bactrocera oleae Gmelin (Diptera:Tephritidae)

The olive fruit fly Bactrocera oleae is a major olive pest in Algeriaand other Mediterranean countries. Its attacks, in some cases, seriously compromised production. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects. The objective of this study was to search for isolates toxic to larvae and adults of B. oleae. Four doses test were performed on neonate larvae, second instar larvae and third instar larvae. Seven Bt strains examined, showed highest toxicity levels against adults. 86% mortality was observed against neonate larvae after 7 days of application by Bt toxin isolate. The mortality of the second instar larvae was 65% mortality at dose of 108 UFC/mL. The third instar larvae was very susceptible to Bt strain with 70% of mortality. This study demonstrated that some local Algerian B. thuringiensis isolates exhibit toxic potential that could be used to control B. oleae.