A comparative in vivo metabolic extracts of M.koenigii (seed), Citrus paradisi, (seed) and the leaves stem barks and roots of Alstonei boonei, Althemanthera repens, Ecliptra prostrata and Rothmannia longiflora and their combination were compared with Ivermectin against the third infectious microfilaria larva of Simulium yahense. The result showed remarkable larvacidal properties for ivermectin and the plant species under study as they could induce significant mortalities at low and varying concentrations in the larva of S. yahense. The LD50 and LD90 values estimated for M. koenigii, Citrus paradisi, Alstonei boonei, Althemanthera repens, Ecliptra prostrata, Rothmannia longiflora, their combination and Ivermectin are 7.24 and 15.49, 3.72 and 15.92, 2.92 and 7.32, 3.02 and 12.98, 3.02 and 14.87, 2.47 and 6.61 and 2.43 and 5.37 respectively. The study revealed that Ivermectin, Althemanthera repens and the combination of the plant extracts could induce 100% mortality of the larva at 6.0, 9.0, 12.0 and 15.0mg/Kg respectively.
