Investigation of the efficacy of some biopesticides by food exposure on Bombus terrestris L. (Hymenoptera: Apidae)

Abstract

Exposure effects of Beauveria bassiana strain Bb-1 (Nostalgist), Isaria fumosorosea (= Paecilomyces fumosoroseus) strain PFs-1 (Priority), Lecanicillium lecanii strain V1-1 (Nibortem), azadirachtin (Nimbecidine) and Bacillus thuringiensis var. kurstaki (Rebound) on Bombus terrestris workers were investigated under laboratory conditions. Bombus terrestris workers were exposed to the recommended doses of biopesticides orally via feeding treated sugar syrup and treated pollen, a total of 600 individuals were used during the study. The experiments were carried out between September and November 2019 in the Research and Application laboratory of apiculture in the Department of Animal Science in Isparta University of Applied Sciences, Turkey. It was found that observed side effects differ in terms of the application methods of the biopesticides. Although worker mortalities ranged between 6 and 16% (non-toxic) in treated pollen, mortality rates 100% (highly toxic) for B.t. var. kurstaki and azadirachtin, 44% (weakly toxic) for I. f. strain PFs-1 and 8–14% (non-toxic) for other biopesticides in treated sugar syrup. The results showed that the biopesticides other than Rebound and Nimbecidine were not toxic on workers of B. terrestris in laboratory conditions.

Keywords:

• Bumble bees
• pollinator
• entomopathogens
• botanical insecticides
• side effect

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

No funding was received for conducting this study.