Evaluation of Novel Insecticides for Control of Dengue Vector Aedes aegypti (Diptera: Culicidae)

• Published in: Journal of medical entomology 2006-01, Vol.43 (1), p.55-60
• Main Authors: Paul, Ayesa, Harrington, Laura C., Scott, Jeffrey G.
• Format: Article
• Language: English
• Subjects: adult insects; Aedes - drug effects; Aedes - growth & development; Aedes aegypti; Animals; Biological and medical sciences; cytochrome P-450; cytochrome P450 monooxygenases; dengue; Dengue - prevention & control; Dengue - transmission; Drug Synergism; Female; Fundamental and applied biological sciences. Psychology; insect growth regulators; Insect Vectors - drug effects; Insect Vectors - growth & development; Insecta; insecticides; Insecticides - pharmacology; Invertebrates; Juvenile Hormones - pharmacology; larvae; Lethal Dose 50; Life Cycle Stages - drug effects; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; metabolic detoxification; Mosquito Control; new insecticides; pesticide synergists; piperonyl butoxide; toxicity; vector control; VECTOR CONTROL, PEST MANAGEMENT, RESISTANCE, REPELLENTS; Vectors. Intermediate hosts
• ISSN: 0022-2585; 1938-2928
• DOI: 10.1603/0022-2585%282006%29043%5B0055%3AEONIFC%5D2.0.CO%3B2

Insecticides are one of the major tools for controlling vector populations and for reducing the transmission of human pathogens. However, there are few new insecticides being developed and marketed for vector control. Herein, we report on the toxicity of six novel insecticides to both adult and larval Aedes aegypti (L). and the toxicity of three novel insect growth regulators (IGRs) to larvae. Four insecticides were highly or moderately toxic to larvae with LC50 values of 16 (chlorfenapyr), 70 (hydramethylnon), 79 (indoxacarb), and 84 ng/ml (imidacloprid). Diafenthiuron and chlorfenapyr were moderately toxic to adult mosquitoes with LC50 values of 13 and 92 ng/cm2, respectively. Imidacloprid was strongly synergized by piperonyl butoxide (PBO) in Ae. aegypti adults, suggesting that neonicotinoids are intrinsically very toxic to adult mosquitoes (in the absence of detoxification). The effect of PBO on the toxicity in adults and larvae was considerably different, both in terms of the insecticides that were synergized (or antagonized for chlorfenapyr versus adults) and in terms of the degree of synergism. This result implies that the cytochrome P450s involved in metabolism of these insecticides are different between adults and larvae. Pyriproxyfen was confirmed as a potent IGR (EC50 of 0.0017 ng/ml) for mosquitoes, although tebufenozide lacked activity. The potential for use of these materials in mosquito control is discussed.