Out of Africa: novel source of small hive beetles infesting Eastern and Western honey bee colonies in China

Abstract

Small hive beetles (SHB, Aethina tumida Murray, Coleoptera: Nitidulidae) are parasites of social bee colonies endemic to sub-Saharan Africa and have become an invasive species. Even though the global spread of SHB seems inevitable, the origin of novel introductions and their impact on new host populations need to be investigated to foster mitigation. Here, we report a case of SHBs from China and use COI gene sequencing to trace their origin. Since July 2018, beetle infestations of Eastern (Apis cerana) and Western (Apis mellifera) honey bee colonies with clinical symptoms were repeatedly reported from two Chinese provinces. These infestations apparently had a severe impact on A. cerana. Using morphometrics, genetics and clinical symptoms in the field, the beetles were confirmed to be A. tumida. The DNA sequences suggest an introduction from a yet unidentified African source similar to the Philippines, but very different to any other previously reported SHB haplotypes. The establishment of SHB in China underlines the need to limit novel introductions. Given that Eastern honey bees and possibly other Apis spp. are susceptible to SHB infestations, our findings highlight the need for adequate protection measures of endemic Asian honey bees.