A Study on the Larvicidal Properties of Ethanolic Leaf Extracts of lupinus arboreus (Yellow Bush) On Mosquito

Abstract

This work investigated the larvicidal properties of the leaf extracts of yellow bush (Lupinus arboreus) on mosquito. The leaves of Lupinus arboreus and mosquito larvae were collected from Ihiagwa and Nekede, Owerri, Imo State respectively using sterile containers. The leaves were washed, air dried and ground into powdery form. Fifty grams (50 g) of the sample was soaked in 250 ml of ethanol and shaken at regular intervals. After 48 hours of soaking, the percolates were then filtered using whatman filter paper and the solvent (ethanol) evaporated using rotary evaporator to obtain ethanol extract of Lupinus arboreus. Phytochemical studies were also conducted qualitatively to identify the presence of bioactive chemical constituents. The results showed that all the mosquito larvae were weakened after 10-20 minutes of observations at different concentrations of 20 ml/15 ml, 40 ml/15 ml, 80 ml/15 ml and 160 ml/15 ml obtained from stock solutions made from 5 g of extract in 15 ml of distilled water. The mortality rate of the larvae after 24 hours at different concentrations ranged from 2-10. The highest mortality rate occurred at 160 ml/15 ml. The mortality rate of mosquito larvae after 48 hours ranged from 5-15. The concentration of 160 ml/15 ml again recorded the highest mortality rate of 15 mosquito larvae while 20 ml/15 ml concentration had the least mortality of 5. Phytochemical constituents such as glycosides, flavonoids and steroids were abundantly present, while phenol and alkaloids were also present but in trace amounts. The result obtained in this study has given hope in the race to find an effective, eco-friendly means of controlling or killing mosquito larvae. Therefore, Lupinus arboreus could be used at high concentration in controlling mosquito larvae.