Larvicidal Activities of Soapberry (Phytolacca Dodecandra) and Chinaberry (Melia Azedarach) Powders, Separate and Combined Application against Anopheles Species (Diptera: Culicidae) in Ethiopia

Abstract

Malaria mosquito larvicides of plant origin have comparative advantages. They are easily available, accessible to end users, and environmentally friendly as compared to synthetic insecticides for controlling malaria vectors. This study was undertaken to assess larvicidal activities of Soapberry (Phytolacca dodecandra) and Chinaberry (Melia azedarach) seed powders, separately and in joint application, against wild Anopheles species in Western Ethiopia. Aqueous and methanol solvents were used for botanical extractions. The
standard mosquito larvicidal bioassay procedures were employed using 1140 wild-collected 3^rd instar larvae of Anopheles mosquitoes. Results revealed that methanol extracts outperformed aqueous extracts when used alone, and Chinaberry seed products displayed the highest mortality compared to Soapberry seed products. When paired with Soapberry, methanol extracts were the most poisonous crude extract with the lowest median fatal concentration values against the mosquito larvae (LC95, 3.368 mg/L; LC50, 1.009mg/L). On the other hand, aqueous extracts of Soapberry (LC95, 112.52 mg/L; LC50, 6.64 mg/L) had high fatal concentration values against the mosquito  larvae. Larval mortality rate increased with concentration and the combination of the botanicals. The study recommends that joining Soapberry and Chinaberry seed extracts with higher concentrations of methanol is a promising control option against malaria mosquito larvae.