Comparative Studies on Larvicidal Efficacy of Ethanolic extracts of Carica Papaya Leaf and Leaf Stalk against Aedes sp

Abstract

Agents of mosquito vector control over the years have been more chemical insecticides. In order to ensure a safer environment, there is a need for a more environment-friendly substitute. Studies and reports on trials of Phyto extracts of plant parts as competent alternatives in reducing disease burden, being more target-specific, and causing less deleterious effects on the environment are rife. This study investigated the larvicidal efficacy of the ethanolic extracts of leaf and leaf stalk of Carica papaya on Aedes sp. larvae at different concentrations of 500 ppm, 750 ppm, and 1000 ppm, at 24, 48, and 72 h with mortalities recorded accordingly. Data were analyzed statistically using Analysis of Variance (ANOVA), probit analysis, and unpaired t-test. Results showed that mortality occurred across all concentrations. The highest concentration of 1000 ppm recorded 76.87% and 93.60% mortalities at 72 h for the extracts of C. papaya leaf and leaf stalk respectively. The calculated LC50 and LC90 values at 72 h exposure time were 543.46 ppm and 1643.84 ppm for C. papaya leaf and 442.01 ppm and 959.71 ppm for C. papaya leaf stalk. Variation in larval mortality between both extracts was significant (p<0.05) at the 24 and 48 h time and 750 and 1000 ppm concentration. Phytochemical screening of the plant materials revealed the presence of alkaloids, saponins, and terpenoids in equal strength in both extracts except flavonoids which were present as well in only the leaf and not the stalk extracts. Both extracts showed high larvicidal potency against the Aedes mosquito species.