Relações tróficas e resíduos de agrotóxicos em Bombus spp. (Hymenoptera: Apidae) no Rio Grande do Sul

Abstract

About 70% of cultivated plants, which are used directly for human consumption, have increased production as a result of pollination promoted by animals, especially bees. Of the 141 plant species grown in Brazil - for use in human consumption, animal production, biodiesel and fiber - approximately 60% (85 species) depend to some extent on animal pollination. Pollination services in agricultural areas depend on both domesticated species and wild bee populations. Among the pollinators, it is possible to highlight the bees of the genus Bombus, popular as ground manga, and which are the important pollinators in native and cultivated areas, depending on the poles and nectar of a wide variety of plants. Visit configurations and feeding behavior of field pollinators are important to define a relationship between Bombus species and plants they exploit. In Rio Grande do Sul, they have been described as Bombus morio Swederus, B. pauloensis Friese, B. bellicosus Smith and B. brasiliensis Lepeletier, but in recent years, B. brasiliensis has not been found the most. Pointed and proven research or population decline of these bees in various countries of the world, mainly as a result of the intensification of agriculture. The research was developed, addressing the aspects explained above (Bombus bee), and is divided into three articles. In article I, the objective was to update information on the geographic distribution of Bombus species present in Rio Grande do Sul and to provied information on their floral associations. During the field collection period, two Bombus species (B. morio and B. pauloensens) were identified in 32 municipalities sampled in the State, associated with 16 plant species belonging to 11 botanical families. In article II, the objective was to study the behavior of floral visits in B. morio and B. pauloensis by means of palinological analysis of corbicular pollen loads of individuals captured while foraging in areas of native and cultivated vegetation. The collections were carried in the spring and summer from 2017 to 2018. 54 pollen types of plants were identified associated with two of Bombus species, belonging to 98% native plants and herbs. In article III, the objective was to evaluate if there is pesticide residues in Bombus spp. collected near agricultural crops and urban areas, using the modified QuEChERS method and LC-MS/MS and GC-MS/MS. Of the 119 pesticides analyzed, only azoxystrobin, acetamiprid and metomil, showed detectable residues in the analyzed samples.