Comparative Studies on the Larvicidal Action of Novaluron (Mosquiron® 100EC) and Moringa Oliefera (LAM) Seed Oil against Aedes Aegypti (Diptera: Culicidae) Larvae

Abstract

Inhibition of emergence (IE) by Novaluron (Mosquiron 100EC) and Moringa
oliefera Lam.(Moringaceae) seed oil (MOSO) was assayed with first and
fourth instar larvae of Aedes aegypti (Diptera: Culicidae) at ambient
laboratory conditions. graded concentration ranging from 3.125- 200ìg/ml
including a control were tested. Four replicates of each concentration in
RCBD were variously challenged with cohorts of 20 active larvae of a given
instar. Mortality resulting from eclosion inhibition was recorded at 3-hourly
intervals for 12 hours, and data analysed using log/probit transformation.
Results indicated dosage-related mortality differences. High concentration
of Novaluron gave 95% mortality of both 1st and 4th instars, while sublethal dosages resulted in 45 and 35% mortality of 1st and 4th instars, respectively. Exposure to Moringa oil resulted in 90 and 100% mortality of 1st and 4th instars, respectively, and sublethal dosages gave 30 and 25% mortality, respectively. Both toxicants showed significant (P<0.05) inhibition of emergence following post-treatment culturing. The IE50 values for 1st instar larvae were 4.546ìg/ml and 15.44ìg/ml of Novaluron and Moringa oil, respectively; and 8.028ìg/ml and 9.977ìg/ml, respectively, for 4th instar. Although the 1st instar larave were more susceptible, Novaluron was about twice more potent. Nevertheless, Moringa oil has shown promise as biopesticide for Ae. aegypti larvae control.

Key Words: Novaluron, Moringa oliefera, Aedes aegypti, Toxicity, Nigeria.