Large trees and artificial substrates support Asian stingless bee communities across green space habitats in urban environments

Urbanization is widely recognized as a significant threat to biodiversity. Stingless bees are vital pollinators in the tropics, yet their nesting site preferences in human-modified habitats are still poorly understood. This study aimed to examine the nesting substrate use, nesting tree species and size, nest height, and entrance orientation of Asian stingless bees in urban areas and to investigate whether landscape metrics (built-up area, NDVI, and forest cover) influence stingless bee richness and nest abundance. Using field surveys across 28 sites within four location types—parks, temples, schools, and universities—we recorded 207 nests representing nine stingless bee species across four genera (Heterotrigona, Homotrigona, Lepidotrigona, Tetragonula). Over 50% of all recorded nests occurred in man-made substrates, highlighting the bees’ flexibility in utilizing urban infrastructure when natural substrates are limited. The most commonly nesting stingless bee species in urban areas were Tetragonula pagdeni, followed by T. collina and T. fuscobalteata. Stingless bee species richness and nest abundance were higher in larger urban green spaces, including parks and universities; however, smaller sites, such as schools and temples also provided important nesting habitats. Seven stingless bee species collectively utilized 19 tree species and exhibiting variation in preferred tree diameter. The three most frequently used tree families were Moraceae, Fabaceae, and Magnoliaceae. Lepidotrigona satun, Heterotrigona itama, and Homotrigona apicalis tended to nest at relatively high positions, with average nest heights exceeding 2 m. Nest entrance orientations varied among stingless bee species; however, Tetragonula collina and T. fuscobalteata predominantly oriented their nest entrances toward the northwest. Additionally, generalized linear mixed models revealed no significant associations between the landscape variables and bee richness or nest abundance. Our findings highlight the adaptability of stingless bees to heterogeneous urban environments and demonstrate that both green spaces and built structures contribute to supporting their communities.