Morphometric and mitochondrial variation of Apis mellifera L. and its relationship with geographical variables in parts of West and Central Africa

Abstract

In order to investigate the geographical distribution of morphological and mitochondrial variation of the Western honey bee in West and Central Africa, 175 colonies, sampled from 44 localities (or a subset therefrom), were subjected to geometric morphometric (GM), traditional morphometric (TM) and mitochondrial DNA analyses. The shape of the forewing differed significantly between the three ecological zones (rainforest, savanna and Sahel) and significantly correlated with latitude, longitude and altitude. A one-way ANOVA revealed a highly significant difference between the ecological zones in respect of the size of the forewing. Based on TM, no clear geographic clustering was observed, and the samples could not be unambiguously assigned to reference data of A. m. adansonii or A. m. jemenitica. However, a conspicuous geographic pattern was observed, with bees increasing in size northward in the west of the area, but southward in the east. Four mitochondrial haplotypes, previously reported from Africa, were found: A1 (n = 60), A4 (n = 58), A4′ (n = 14) and A14 (n = 1). The overall haplotype diversity was low (h = 0.485 ± S. E. 0.062) and small bees were found to bear the A1 haplotype while large bees had either A4 or A4′ haplotype.

Keywords:

• Honey bee
• mtDNA
• haplotype
• diversity; Apis mellifera adansonii
• Apis mellifera jemenitica

Acknowledgements

We wish to express our sincere gratitude to Beate Springer of Institut für Bienenkunde, Oberursel, for her assistance in dissections and measurements and to the Institute for providing the facilities and reference data. We are also grateful to the LLH Bieneninstitut Kirchhain and its parent organisation, Landesbetrieb Landwirtschaft Hessen, for providing the facilities for carrying out the mitochondrial DNA analysis. In this regard, we wish to particularly thank the head of the institute, Ralph Büchler and his entire staff, most especially the technicians –Sandra Backhaus, Anja von Gall, Gerda Waldschmidt and Elke Leider. Our special thanks go to the numerous beekeepers, honey hunters, public servants, traditional rulers (in particular, His Royal Highness, The Emir of Okuta in Kwara State, Nigeria, Alhaji Idris Abubakar, Shero Betete III), former students, friends and other well-wishers for their support during the first author’s field trips in Nigeria, Niger, Cameroon and Chad. The study was partially funded by the government of Nigeria through the Tertiary Education Trust Fund and Abubakar Tafawa Balewa University.

Disclosure statement

No potential conflict of interest was reported by the authors.