Contribution of Apis mellifera (Hymenoptera: Apidae) to the Pollination and Yield on Citrullus lanatus (Cucurbitaceae) in Bockle and Pitoa, North Cameroon

Insect pollination is a key determinant of cucurbit productivity, yet little information is available on the role of Apis mellifera in watermelon production in northern Cameroon. This study was conducted in Bocklé (2023) and Pitoa (2025) to assess the contribution of A. mellifera to the pollination and yield of Citrullus lanatus . Investigations focused on the composition of the flower-visiting insect community, foraging behaviour, floral resources collected, bee abundance, and the effects of bee visits on crop reproductive performance. A total of 1195 floral visits belonging to eight insect species were recorded, of which 67.19% were performed by A. mellifera , the dominant floral visitor at both sites. Worker bees collected mainly nectar (61.08% of visits) and, to a lesser extent, pollen (38.91%), with peak foraging activity occurring between 08 : 00 and 10 : 00 h. Flowers visited by insects, particularly those exclusively visited by A. mellifera , exhibited significantly higher fruit set, seed number per fruit, and percentage of normal seeds than insect-excluded flowers. The contribution of A. mellifera to fruit set reached 83.33% across both experimental seasons, while its contribution to seed production and normal seed percentage was estimated at 23.96% and 86.43%, respectively. These findings demonstrate that A. mellifera is the principal pollinator of C. lanatus in Bockle and Pitoa. Establishing managed honeybee colonies near watermelon fields and adopting pollinator-friendly farming practices could represent effective agroecological strategies for sustainably improving watermelon production while conserving pollination ecosystem services.