Biopesticides Activity of the Extracts of Three Medicinal Plants in the Developmental Stages of Malaria Vector, Anopheles Gambiae Giles (Diptera: Culicidae)

Background and purpose: The insecticidal potential of Carica papaya (male and female species), and Spondias mombin were tested against the developmental stages of the malaria vector; Anopheles gambiae in the laboratory at an ambient condition. Materials and Methods: Methanolic leaves extracts of S. mombin and C. papaya (male and female species) were carried out using cold extraction method. The extracts were evaporated and concentrated using a rotary evaporator under low pressure to make solvent-free. The An. gambiae larvae and pupae were exposed to 0.1, 0.2, 0.3, 0.4, and 0.5% concentrations of the plant methanolic extracts for 24 hours and their mortality was recorded. Results: Results indicated that C. papaya (male species) caused significantly higher mortality of the An. gambiae larvae and pupae than the other plant extract tested (p< 0.05). It caused 100% larval mortality and 95% pupal mortality at 0.5% concentration. However, it was observed that the larvae were more susceptible to the extracts of all the plants tested. Data were analyzed using Analysis of Variance and log probit analysis. Conclusion: All the three medicinal plants screened in this work showed high potency to induce mortality of both the larval and pupal stages of the malaria vector and could consequently be used to reduce malaria prevalence in the endemic areas of Nigeria.