The Effect of Ivermectin in Seven Strains of Aedes aegypti (Diptera: Culicidae) Including a Genetically Diverse Laboratory Strain and Three Permethrin Resistant Strains

• Published in: Journal of medical entomology Vol. 49; no. 2; pp. 356 - 363
• Main Authors: Deus, K. M., Saavedra-Rodriguez, K., Butters, M. P., Black, W. C., Foy, B. D.
• Format: Journal Article
• Language: English
• Published: Lanham, MD Entomological Society of America 01-03-2012; Oxford University Press
• Subjects: Aedes - drug effects; Aedes - genetics; Aedes aegypti; Analysis; Animals; Biological and medical sciences; cross-resistance; Culicidae; Diptera; Female; Fundamental and applied biological sciences. Psychology; Genetic Variation; Health aspects; Humans; Insecta; Insecticide Resistance; Insecticides - administration & dosage; Invertebrates; Ivermectin; Ivermectin - administration & dosage; Lethal Dose 50; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Oviparity - drug effects; Ovum - drug effects; permethrin; Permethrin - administration & dosage; Species Specificity; VECTOR CONTROL, PEST MANAGEMENT, RESISTANCE, REPELLENTS; Vectors. Intermediate hosts; Laboratory study; Permethrin; Insecta; Parasite; Laboratory; Arthropoda; Culicidae; Aedes aegypti; Cross resistance; cross-resistance; Ectoparasite; Invertebrata; Diptera; Ivermectin
• ISSN: 0022-2585; 1938-2928; 0022-2585
• DOI: 10.1603/ME11164

Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all strains. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among strains, and all three permethrin-resistant strains were significantly less susceptible to ivermectin than the standard reference strain. The hatch rate after an ivermectin bloodmeal was less variable among strains, and only one of the permethrin-resistant strains differed significantly from the standard reference strain. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among strains suggests that permethrin and ivermectin cross-resistance may occur.