Summary To investigate the impact of a novel biopesticide formulation (neem plus garlic oil emulsion - NGOE) in watermelon production, field trials were laid in the early- and late- cropping season of 2020. Watermelon seeds (var. Sweet Sangria F1) were sown in 36 plots which were grouped into 4 replicates of 9 treatments. Data collected include densities of leaf beetles, spiders and Apis mellifera L. (bees) using a modified Grizzly 2500/8 leaf blowervac. All data were subjected to variance analysis after appropriate transformation. Results showed that the most efficient treatment with respect to leaf beetles was 0.125% Magicforce® - Lambda-cyhalothrin 15g/L + Dimethoate 300 g/L (MF) + 5% NGOE in the early-crop, and 0.25% MF in the late-crop. Assessment of change in population densities revealed that 0.25% MF, followed by 0.125% MF + 5% NGOE was most suppressive of A. mellifera in the earlycrop. Corresponding ordering in the late-crop was: 0.25% MF followed by 0.125% MF + 3% NGOE. While treatment with NGOE suppressed ants by 27.99 – 56.21%, 0.25% MF did it by 45.49 – 63.51%. Similar trend was observed with respect to ant and spider densities. Though 0.125% MF + 5% NGOE treated plots consistently produced the highest number of fruits, followed by 0.25% MF, statistical analyses showed that except for 1% NGOE, other insecticide treatments were comparable in the late-, but not in the early-crop. While the effectiveness of Magicforce® in suppressing pest and improving yield of watermelon was highlighted, the potential of neem plus garlic oils formulation in managing pests of watermelon while relatively favouring the activities of beneficial arthropods, and improving yield was clearly noticeable.