Foraging behaviour of Apis mellifera adansonii (Hymenoptera: Apidae) on Combretum nigricans , Erythrina sigmoidea , Lannea kerstingii and Vernonia amygdalina flowers at Dang (Ngaoundéré, Cameroon)

In Cameroon, the demand for hive products is growing. Honey and pollen yields are low in this country, partly because of the poor knowledge of the apicultural value of the flora. To determine the apicultural value of Combretum nigricans Lepr. ex Guill. & Perr., Erythrina sigmoidea Hua, Lannea kerstingii Engl. & K. Krause and Vernonia amygdalina Delile, Apis mellifera adansonii Latreille activity was observed on the flowers of these plants in Ngaoundere from December 2001 to May 2002 and from December 2002 to May 2003. The flowers of each plant species were prospected for at least 4 days per month, between 07.00 and 18.00 h, for recording the nectar and/or pollen foraging behaviour of A. m. adansonii workers. Results show that A. m. adansonii harvested the nectar of each plant species. In addition, L. kerstingii and V. amygdalina were visited for pollen. The greatest number of workers foraging simultaneously on a plant varied from 26 (E. sigmoidea) to 4200 (V. amygdalina). Apis mellifera adansonii workers that visited flowers of a given plant species once generally remained with these nectar and/or pollen sources throughout the observation period. Thus C. nigricans, E. sigmoidea, L. kerstingii and V. amygdalina could be cultivated and protected to increase honey production; L. kerstingii and V. amygdalina could enable beekeepers to increase their pollen production as a hive product. During foraging, A. m. adansonii workers increased the pollination possibilities of each plant species.