The cuckoo bumble bee, Bombus chinensis, has a fragmented habitat, as revealed using the maximum entropy approach (Hymenoptera: Apidae)

As vital pollinators, bumble bees play an important role in ecology and agricultural economy, but the decline in diversity and abundance has received widespread attention. Bumble bees of the subgenus Psithyrus are obligate social parasites that invade the nests of other bumble bees as part of their life cycle. This dependency on other colonies may make Psithyrus bumble bees vulnerable to decline and extinction. Hence, conservation strategies and potentially suitable habitats should be identified for these vulnerable species. Here, the potential distribution of a cuckoo bumble bee endemic to China, Bombus ( Psithyrus ) chinensis (Morawitz 1890) (Hymenoptera, Apidae), was predicted based on species distribution data and ten bioclimatic or environmental variables. Four important variables, namely, the minimum temperature of the coldest month, growing degree days, isothermality, and mean temperature of the warmest quarter, contributed the most to the distribution model. The maximum entropy method (MaxEnt) revealed that the potential distribution of B. chinensis was fragmented under current climate conditions. The areas of potential habitat with low suitability, moderate suitability, and high suitability were 455,451 km 2 , 170,260 km 2 , and 116,111 km 2 , respectively. Eight provinces were evaluated as critical regions for B. chinensis conservation, especially Sichuan, Xizang, Yunnan, and Ningxia Provinces. In conclusion, the results reveal a cuckoo bumble bee’s fragmented distribution and provide a basis for its conservation strategies. The areas identified as highly suitable for B. chinensis should be considered primary conservation areas.