Spatial dynamics of stingless bee nesting (Apidae: Meliponini) in an urban area within the Atlantic Forest, Brazil

Abstract

Stingless bees (Meliponini) are eusocial insects that form perennial colonies and play a vital role in plant pollination. Our understanding of their biology, ecology, and nesting dynamics remains limited, especially in urban ecosystems. Nest surveys in cities can provide insights for conservation and management strategies, particularly as urban areas experience a high vegetation loss. We evaluated the factors influencing the spatial distribution of Meliponini nests in a medium-sized city in Brazil. We assessed the effects of tree abundance, richness, and density, along with tree attributes, on the abundance of stingless bee nests in 20 sampling units. Additionally, we evaluated nest persistence over time. Over 100 nests from four stingless bee species were recorded: Nannotrigona testaceicornis, Plebeia droryana, Trigona spinipes, and Tetragonisca angustula. Our findings revealed a nest decline over time, with human-induced causes accounting for more than 50% of nest losses. Tree abundance positively affected the total nest abundance. The bee species exhibited variations in nesting substrate preferences, showing responses to tree attributes such as diameter at breast height (DBH) and height. Unregulated urban expansion threatens stingless bee populations, primarily due to the removal of large, old trees that provide nesting cavities. Therefore, conservation efforts should focus on enhancing floral resources and preserving trees in urban areas to support stingless bee populations.