Journal of Medical Entomology (2009) 46, 1407-1414

Kanutcharee Thanispong, Nicole L. Achee, Michael J. Bangs, John P. Grieco, Wannapa Suwonkerd, Atchariya Prabaripai and Theeraphap Chareonviriyaphap (2009)
Irritancy and repellency behavioral responses of three strains of Aedes aegypti exposed to DDT and alpha-cypermethrin
Journal of Medical Entomology 46 (6), 1407-1414
Abstract: This study quantified both contact irritancy and noncontact repellency behavioral responses of three strains of Aedes aegypti (L.) (one long-term colony and two F1-F2 generation field-caught strains) to field application rates of DDT (2g/m²) and alpha-Cypermethrin (ACyp) (0.025 g/m²) by using an excito-repellency test chamber. The colony The colony strain (USDA) was completely susceptible to DDT and ACyp. One field strain was collected from Chiang Mai (CM) Province, northern Thailand, and was characterized as tolerant (reduced susceptibility) to DDT and completely susceptible to ACyp. The second field strain, collected from Kanchanaburi (KAN) Province, western Thailand, was highly resistant to DDT but fully susceptible to ACyp. All three strains exhibited marked irritancy to contact with ACyp, with more pronounced escape responses occurring in the two field strains. With DDT, the KAN strain demonstrated the lowest escape response during both contact and noncontact trials, whereas a greater response was seen in trials conducted with CM and USDA strains. With exposure to ACyp, repellency was less profound than irritancy but still resulted in a significant escape response compared with paired controls without insecticide (P < 0.05). DDT elicited both irritancy and repellency responses but comparably greater spatial repellency than ACyp. Findings indicate ACyp functions primarily as a strong contact irritant, whereas DDT functions as a relatively strong noncontact repellent in the strains tested. The higher the degree of physiological resistance to DDT, the greater the apparent suppression of both behavioral avoidance responses. Most importantly, observations using susceptible, tolerant, and resistant Ae. aegypti strains show that behavioral responses that can interrupt human-vector contact still occur regardless of degree of physiological susceptibility to compounds tested.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Theeraphap Chareonviriyaphap, Michael J. Bangs

Research topic(s) for pests/diseases/weeds:
control - general
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aedes aegypti		Thailand