Entomofauna de abelhas visitantes de Crambe abyssinica Hochst. (Brassicaceae) associado às variáveis ambientais

Abstract

Crambe abyssinica, or simply “crambe” as it is popularly known, is an oleaginous plant in the Brassicaceae family, important as an alternative winter crop and for biodiesel. Bees (Apidae) in general, and particularly social bees are important pollinators of crops; they depend almost exclusively on pollen and nectar from flowers. The aim of this study was to evaluate the fluctuation of bees during the flowering of C. abyssinica, correlating with abiotic factors. The study was conducted at the experimental farm of UFGD in Dourados, MS, Brazil. The insects were sampled weekly with a 30-cm wide entomologic sweep net every 2 hours from 8h00 to 16h00 during the blooming weeks, totalizing 5 daily samples. Data were analyzed with Pearson correlation for the variables temperature, relative humidity and wind speed. In Hymenoptera order, in the Apidae family, Apis mellifera Linnaeus, 1758, Geotrigona mombuca Smith, 1863, Exomalopsis (Exomalopsis) fulvofasciata Smith, 1879 e Plebeia sp. Schwarz, 1938,. In Halictidae family Dialictus sp. Robertson, 1902 was gathered. One of the factors that contributed to the presence of these insects in the culture was plenty of resources available, the pollen contained in large quantities because each plant has many flowers. Bees were observed throughout the flowering of the culture, and environmental variables affected differently the fluctuation of insects. The fourth week of bloom was the period when there was a greater number of bees in flowers, coinciding with the flowering peak, period in which there are more flowers in anthesis. The present study is the first report of bees occurring in Crambe abyssinica in Brazil. We observed that the potential pollinator is Apis mellifera and the environmental variables influence differently among the bees.