Bee Diversity Associated with Canavalia rosea (Sw.) DC. (Fabaceae, Papilionoideae) in an Peri-Urban Patch of “Restinga”

Abstract

The Restinga is one of the physiognomies of the Atlantic Forest biome with the highest degree of anthropic impact, mainly due to disordered urbanization. The impacts generate habitat loss and threaten the animals and plants that inhabit this ecosystem. In the Restinga, the psammophilous vegetation have an important role in stabilizing the sandy substrate and maintaining the pollinator community. In this study, we analyzed the floral resources offered by Canavalia rosea to floral visitors between October 2019 and September 2020, in the Municipal Natural Park of Barreto’s Restinga, in Macaé, Rio de Janeiro, Brazil. Sampling was carried out from 8:00 am to 4:00 pm, covering a 250-meter transect in the sandy cord, counting the total number of open flowers and collecting visiting bees. The morphology of C. rosea flowers was described to relate to the functional traits of visitors, related to pollen and nectar collection. The pollen load of visitors was analyzed to estimate the degree of specialization in relation to C. rosea. A total of 192 individuals of 14 bee species were captured. There was a significant relationship between the availability of floral resources, measured by the number of open flowers and the richness and abundance of bees. The greatest richness of bees was observed between January and March and the greatest abundance in January. The most frequent visiting genera in C. rosea were Eufriesea, Centris and Xylocopa. The greatest richness of pollen types was observed in Eufriesea species. Most Xylocopa individuals showed C. rosea pollen. In this study, the importance of C. rosea as a source of floral resources for fourteen species of solitary bees was demonstrated. The data generated increases the knowledge about the ecological patterns of C. rosea and its floral visitors and may contribute to the maintenance and expansion of Restinga areas in urban environments.