The decline in bee populations worldwide has been associated with the use of pesticides in crop systems where these insects forage. The use of biopesticides, like spinosad, is preferred as an alternative method to control pests, because it is considered safer to non-target insects. In this study, we evaluated the lethal and sublethal effects of the spinosad-based formulation Tracer® on foragers of the stingless bee Plebeia lucii Moure (Apidae: Meliponini). Groups of bees were fed a pure diet (negative control) or a diet at different concentrations of spinosad. Positive control groups consisted of bees orally exposed to a diet with the neonicotinoid imidacloprid. Next, flight behavior, body mass, and respiration rate were evaluated in surviving bees. The results showed that bees´ survival was reduced by all concentrations of spinosad, when compared with the negative control. Bee locomotion-walking and flight-was reduced in accordance with the increase in spinosad concentrations; however, body mass and respiration rate were not altered. Our results show that the use of Tracer® in ecosystems visited by P. lucii can reduce forager bee survival and reduce their locomotion, generating a negative impact on pollination services provided by these bees.
Keywords: Ecotoxicology; Plebeia; organic farming; pollinator decline; spinosad.