Efficacy of the insect growth regulator novaluron in the control of dengue vector mosquitoes Aedes aegypti and Ae. albopictus

Insect Growth Regulator (IGR) novaluron is an alternative to synthetic neuro-inhibitory insecticides. Present study was designed to assess appropriate dosages of novaluron for dengue vector control. Larvae of Aedes aegypti and Ae. albopictus were exposed to a concentration series of novaluron (Rimon EC10) for two fixed exposure periods of 7-days and 14-days to determined LC50 and LC99 values. Inhibition of adult emergence (IE50 and IE99) was determined by a 14-day exposure. Semi-field experiments were conducted by exposing cohorts of Ae. aegypti larvae to IE99, 2 × IE99 and 10 × IE99 novaluron concentrations in water storage buckets (10 L) and plastic barrels (200 L). For the 7-day exposure, LC50 values were 0.047–0.049 ppm and LC99 were 0.144–0.151 ppm. For 14-day exposure, these values were 0.002–0.005 ppm and 0.006–0.01 ppm respectively. For both species, IE99 was 0.001 ppb under semi-field conditions, and was effective for nearly 2 months. Novaluron concentration 0.01 ppb was effective up to 3 months, with an IE of 89–95%. Authorities should critically review a reduction of the presently recommended field dosage of 200 ppm novaluron by × 100 or more. This would provide the same efficacy but mitigate environmental pollution, development of vector resistance, and financial losses.