Pollination by insects is an essential ecosystem service. In tropical regions, many native plants naturally depend heavily on stingless bees as pollinators. But human generated actions are threatening their populations. A team of Mexican scientists have just reviewed the factors impacting stingless bees. The reviewed studies provided convincing evidence that the paramount dangers are habitat loss, agrochemicals, competition for resources, climate change, and the introduction of exotic species, including pathogens.
Pesticides are the most used in the conventional agricultural, and although the lower doses evaluated in some studies did not cause direct mortality of wild bees, they did have harmful sublethal effects on both adults and larvae, such as physiological, morphological, and behavioural impairments, which may ultimately decrease their fitness. The use of botanical and synthetic pesticides in crop fields alters the flower visitation rates of pollinator bees, which could significantly affect yield. However, there are currently few studies on the levels of pesticides to which stingless bees are exposed to in their habitats; further work in this area will help to better understand the risk caused by pesticides on stingless bee population
To prevent the extinction of native pollinators such as the stingless bees, governments need to develop initiatives to establish biological corridors. Such actions could be crucial to conserving ecosystems that provide services by buffering the joint effects of habitat loss and climate change. According to different studies, protecting conserved areas and restoring disturbed areas could improve habitat connectivity and safeguard ecosystem services, which could facilitate the dispersal and establishment of wild bees during distribution shifts.
Promoting urban gardens could be an option to offer food resources for species that inhabit urban areas. This technique has been shown to promote foraging by the Australian stingless bee Tetragonula carbonaria even more than natural habitats and plantings, increasing resource availability and potentially enhancing bee fitness.
The authors also provide perspectives for better under-standing these threats and options to address them. If we are to protect wild bee populations from extinction, it will be essential to develop policies and research related to the protection of the ecological areas of these important pollinators around the world.
Citation: TOLEDO-HERNÁNDEZ, E., PEÑA-CHORA, G., HERNÁNDEZ-VELÁZQUEZ, V.M. et al. The stingless bees (Hymenoptera: Apidae: Meliponini): a review of the cur-rent threats to their survival. Apidologie 53, 8 (2022). Full article is available for free download here: https://doi.org/10.1007/s13592-022-00913-w