Foraging and pollination activity of Xylocopa olivacea (Hymenoptera: Apidae) on Vitellaria paradoxa (Sapotaceae) flowers at Ouro-Gadji (Garoua, Cameroon)
To evaluate the impact of Xylocopa olivacea (Hymenoptera: Apidae) on Vitellaria paradoxa (Sapotaceae) yields, the foraging and pollination activities of this carpenter bee were studied in January 2011 and from January to February 2012 at Ouro-Gadji. Treatments included unlimited flowers access by all visitors, bagged flowers and limited visit by X. olivacea only. The seasonal rhythm of X. olivacea activity, its foraging behavior on flowers and its pollination efficiency were recorded. Results show that, carpenter bee intensively harvested nectar and pollen. The mean foraging speed was 9.84 flowers per min. The fruiting rate of unprotected flowers is significantly higher that of protected flowers. Through its pollination efficiency, X. olivacea provoked a significant increase of the fruiting rate by 13.40%. Hence, conservation and installation of X. olivacea nests close to V. paradoxa populations are recommended to improve fruit and seed yields of this plant in the region.