Adaptive and foraging behavior of two stingless bee species (Apidae: Meliponini) in greenhouse mini watermelon pollination

Abstract

The growth of protected cultivation in world agriculture has driven crops traditionally cultivated in open field to greenhouse, which, in turn, prevent the access of pollinators to flowers. Therefore, it is necessary to identify suitable pollinators for closed environments. Stingless bees have been identified in Brazil as the ideal pollinators for crop pollination under greenhouse conditions. Colonies of two stingless bee species (Melipona subnitida Ducke) and Scaptotrigona sp. nov. were evaluated in a greenhouse during the flowering of seeded (diploid) and seedless (triploid) mini watermelon (Citrullus lanatus T.) varieties. The feasibility of using these bees in this production system was based on their adaptation and foraging behavior. M. subnitida did not show any interest to the crop under the experimental conditions; and this species stopped foraging trips and egg laying in a diapause-like stage. In comparison, Scaptotrigona sp. nov. foragers were active and collected floral resources soon after their introduction. Moreover, the foragers of Scaptotrigona sp. nov. showed an essential behavior for mini watermelon pollination, because they visited staminate and pistillate flowers from both seeded and seedless genotypes for nectar collection. Thus, we concluded that M. subnitida did not adapt to greenhouse mini watermelon cultivation under the experimental conditions and should not to be used for pollination purposes in this environment; however, Scaptotrigona sp. nov. adapted well as a pollinator in the greenhouse and can be used for mini watermelon pollination in protected culture.