PHAGO-REPELLENCY OF CULICIDAE BY APPLICATION OF NEEM SEED KERNEL EXTRACT
The extract from the seed of the Neem tree (Azadirachta indica) is known for its use by traditional medicine practitioners and its local use as mosquito repellent but little is known about its chemical properties. This research studies the efficacy of the use of the Neem Seed Kernel Extract (NSKE) as a mosquito (culicidae) repellent. Mosquito repellent is necessary considering that mosquitoes are detrimental to human health and economy. Local production and use of this repellent could enhance the Nigerian content in Phyto- chemical production and also increase the Nigerian Gross Domestic Product. NSKE mosquito repellent is better than synthetic mosquito repellent for its low mammalian toxicity. Activity test revealed an active area of 0.7855 m2; active period of 3 hours of rubbing, 45 minutes for spraying and as long as the lantern keeps burning for burning. The repellent should be re -applied after the recommended active period. The repellent breaks away into harmless products within a reasonable time. By this, it cannot produce harmful effects on man nor pollute his environment. Chromatographic and spectrophotometric analysis revealed that NSKE contains four methyl esters with 11, 14 - Eicosadienoic acid being the most active. These were found to produce phago-repellent anti-feeding effect but majority of the mosquitoes still recovered after the active period when the repellent was completely metabolized. This was okay, as the real effect is to stop the mosquitoes from biting not necessarily killing the mosquitoes. Besides mosquitoes, the repellent can be used to repel other insect pests.