Morphometrical analyses revealed high diversity of the eastern honey bee (Apis cerana) in mountains and islands in China

The eastern honey bee (Apis cerana) is of great importance for ecosystems and agriculture in Asia, whose diversity has yet to be explored. Previous studies have found a high diversity of A. cerana in mountainous areas or islands. To better understand the morphological diversity of A. cerana, we focused on the eastern Qinghai-Tibet Plateau (QTP), a region with high mountains, Weizhou Island, Yongxing Island and Hainan Island, much of which lacks systematic investigation of honey bee diversity. Five sampling sites in the plain were also selected as references. A total of 140 colonies of A. cerana were collected from 9 localities in QTP, 3 localities in islands, and 5 localities in plain. We used standard morphometry and geometric morphometrics to assess the level of diversity, in which principal component analysis and discriminant analysis were conducted. The results revealed the A. cerana populations from QTP and islands were differentiated from the plain populations. Moreover, two populations from QTP and one from Yongxing Island showed significant divergence. Our study provided insights into the A. cerana diversity and provides information for the effective conservation of A. cerana genetic resources in China.