Stingless bees (Hymenoptera: Apidae, Meliponinae) abundance and diversity as affected by biotic and abiotic factor in fragmented neotropical habitats

Despite the concerns and controversy over a putative global pollination crisis there is little information on the response of stingless bees, the most important native pollinators in the Neotropics, to land-use change. Their abundance and species richness has been affected due to severe threats from human activities that have resulted in landscape fragmentation. We recorded stingless bee colony abundance, temperature variation in the nesting sites, effect of fragment size and the forest variables on stingless bee community in three sites with different level of anthropogenic activities in the Soconusco region, Chiapas, Mexico: 1) Agroforestry (cacao crop 7 ha); 2) Grassland (12 ha); 3) Urban area (3 ha). A total of 67 nests were found, representing five stingless bee species, Tetragonisca angustula (Lepeletier, 1811), Trigona fulviventris (Guérin, 1845), Scaptrotrigona mexicana (Guérin, 1845), Scaptotrigona pectoralis (Dalla Torre, 1896) and Oxytrigona mediorufa (Cockerell, 1913). Although there were no effect of forest variables on bee richness and abundance between Grassland and Agroforestry, we observed changes in bee community composition as well as tree diversity in urban site. In particular nesting tree site habits were associated to two tree species:  Ficus involuta (Moraceae, 29%) and Cordia alliodora (Boraginaceae, 22%). T. angustula and T. fulviventris had nests exposed to temperatures 5.7ºC above the average temperature recorded in the other species. The urban site presented the highest temperature variation. After a year of observations the grassland was the site with less loss of nests and with the largest number of new nests established.