Effects of the Neonicotinoid Imidacloprid on the Feeding Behavior of Melipona quadrifasciata anthidioides Lep.

Abstract

Even though meliponines are among the greatest pollinating agents in Neotropical ecosystems, the populations of these bees are in decline due to anthropic actions, such as the indiscriminate use of pesticides. Neonicotinoids, such as Imidacloprid, are used in many crops and have been shown to be one of the pesticides groups with the most damaging effects on the health of bee colonies. The goals of this work were (1) to evaluate the ability of Melipona quadrifasciata, a native Brazilian stingless bee species, to detect the presence of Imidacloprid in artificial diets, and (2) to evaluate how this insecticide may affect their behavior. For this purpose, behavioral experiments were carried out in observation arenas where artificial flowers containing different concentrations of Imidacloprid (0%, 1%, 5%, 10%, and 20%) were made available to forager bees and their choice and behavior were registered. Our results showed that bee choices were not affected by the different concentrations of Imidacloprid, even at extremely high doses in the flowers (20%). It was also found that the presence of this insecticide interfered with the communication between individuals as a result of reduced antennation events. Both findings, the apparent inability of bees to detect the presence of the insecticide and the change in behavior caused by the exposition to the volatilized product, may rapidly lead to colony losses in nature.