Diversity and Economic Significance of Insect Pollinators on Watermelon Farms in Ogun State, South West Nigeria

Watermelon production in Ogun State has expanded substantially in recent years, driven by growing consumer demand and commercial interest. Adequate pollination by insects is essential for fruit set and marketable yield quality. However, the diversity of pollinating insects and their contribution to watermelon productivity in South West Nigeria has not been quantified. This study documents the species diversity of insect pollinators visiting watermelon flowers on commercial farms in Ogun State and assesses their relative contribution to pollination. Timed observation transects will be conducted over two cropping cycles on 15 farms in Ijebu Ode, Sagamu, and Abeokuta South LGAs. Pollinators will be recorded through direct observation and sweep net collection, identified to order or species level where possible, and their floral visitation rates measured. Fruit set, seed number, and fruit weight will be compared between plots with free pollinator access and those with partial insect exclusion using mesh cages. This study tests the hypothesis that bee-mediated pollination significantly enhances watermelon yield outcomes under commercial farm conditions in Ogun State. Recommendations for pollinator conservation practices applicable to commercial vegetable farms will be produced. Keywords: insect pollinators, watermelon, pollination services, Ogun State, bee diversity