Investigations on the bacterial flora as a potential biocontrol agent of chestnut weevil, Curculio elephas (Coleoptera : Curculionidae) in Turkey

Chestnut weevil, Curculio elephas L. (Coleoptera: Curculionidae) is the mos t effective pest of chestnut and oak all over the world. It causes approxim ately 25-30% economical damage to chestnut production per year in Turkey In this study, we investigated the bacterial flora of chestnut weevil collect ed in Black Sea Region (Turkey) during 1997 and tested it for the insectici dal activities. Based on colony colour and morphology, three isolates were determined. According to morphological, physiological and biochemical tests , they were identified as Bacillus lentimorbus, Pseudomonas fluorescens, an d Esherichia coli. The insecticidal activities of these bacterial isolates on third-instar larvae of C. elephas were investigated. As a result, the hi ghest insecticidal effect determined on C. elephas is 32% with B. lentimorb us. The effects of the rest of the isolates are 20% with P. fluorescens and 0% with E. coli.