Comparative Studies on the Larvicidal Activity of Lantana camara Linn. (Wide Sage) and Tithonia diversifolia (Hemsl) A.Gray (Mexican Sunflower) Leaf Extract on Anopheles Mosquito Larvae

Abstract

The larvicidal activity of Lantana camara and Tithonia diversfolia leaf extract against anopheles mosquito larvae was investigated in this study during October 2019 in the Centre for Disease Surveillance (Malaria Research Laboratory) University of Jos. Anopheles mosquito larvae was obtained from stagnant water pond behind Zoology Undergraduate Research Laboratory. Aqueous and methanolic extraction was carried out on the dried and pulverized leaves of both plants. Three different concentrations were used for the treatments which were 100mg/ml, 50mg/ml, and 25mg/ml. 48 containers(specimen bottles) were used with each containing 10 larvae. Each concentration had three replicates and a control also in triplicate. The treatments were observed for 24 hours after which it was observed that all the extracts were effective against the larvae and the difference being only in the lethal time. The mean mortality was highest for Tithonia diversifolia aqueous extract followed by Lantana camara aqueous extract, after which is Lantana camara methanolic extract and then Tithonia diversifolia aqueous extract. Mortality of Anopheles mosquito larvae exposed to the plant extracts increased with exposure and concentration of extracts. The higher the concentration, the higher the mortality rate of the larvae. Going by the above deductions, it can be rightly put that the effect of the extract is dose and time dependent as evidenced by increase in the percentage mortality with increase in concentration and time. The extracts from both plants contain bioactive compounds against larvae of anopheles mosquito and could be used in stagnant water bodies and drainages which are known to be breeding sites for mosquitoes and the leaves of both plants could be used in the production of mosquito repellants. The study also recommends that both plants be planted around residential areas to prevent breeding of anopheles mosquitoes.