Multivariate morphometric analysis of local and introduced populations of Apis cerana (Hymenoptera: Apidae) on Hainan Island, China

摘要

To better understand the morphological characteristics of Apis cerana after a long-time in isolation from the Chinese mainland, coupled with the impact of recent exotic gene flow, multivariate morphometric analyses of A. cerana in Hainan Island were undertaken. A total of 1,020 worker bees of A. cerana were collected from three localities in Guangdong Province, nine localities in Hainan province, and five apiaries that were introduced from the adjacent mainland over two years. In all, 33 morphometric characters were measured, and multiple analyses including analysis of significance of difference, principal component analysis, discriminant analysis and cluster analysis were conducted. The samples were divided into three groups: Guangdong group (M), the introduced honey bee group (I), and the Hainan group (H). The local population in Hainan Province was differentiated from the honey bees collected from Guangdong Province. The population in Hainan was adapted to island environments over a long time in isolation, and this resulted in unusual morphologies, such as the smallest body size, smallest leg, and smallest wing among the populations, as well as a large cubital index. The size of most morphometric characters of Group I were between those of the Group M and Group H. Therefore, we conclude that the honey bee in Hainan Island is still differentiated from the honey bee on the adjacent mainland, even though many exotic alleles have been introduced onto the island in recent decades.