Submitted to: Journal of Vector Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/2/2011
Publication Date: 7/11/2011
Citation: Tisgratog, R., Thananchai, C., Bangs, M.J., Thainchum, K., Prabaripai, A., Chauhan, K.R., Pothikasikorn, J., Chareonviriyaphap, T. 2011. Chemical induced behavioral responses in anopheles minimus and Anopheles harrisoni in Thailand. Journal of Vector Ecology. 36(2):321-331. Interpretive Summary: Evaluation of potential repellent compounds against mosquito vectors of diseases is time consuming and often involves animal or human subjects. We have developed a laboratory modular assay system that can screen candidate compounds without involving human subjects or animals. This assay system is compact in size and only requires small amounts of the test compound. These results from compact assay system supports previous field studies which show that human contact and disease transmission by mosquitoes are interrupted by public health insecticides and repellents. This information can be used by scientists in the private and public sectors that are interested in developing and testing potential repellent compounds and insecticides.
Technical Abstract: Behavioral responses of female mosquitoes representing two species in the Minimus Complex exposed to an operational field dose of bifenthrin or DEET (N,N-diethyl-m-toluamide) were described using an excito-repellency test system. Two test populations of An. minimus, one from the field (Tak Province, western Thailand), the other from a long-established laboratory colony, and Anopheles harrisoni collected from Kanchanaburi Province, western Thailand, were used. Results showed that all test populations rapidly escaped after direct contact with surfaces treated with either bifenthrin or DEET compared to match-paired untreated controls. Greater escape response by exposed females to bifenthrin and DEET were observed in the An. minimus colony compared to the two field populations. Field collected An. minimus demonstrated a more rapid escape response to DEET than to bifenthrin, whereas An. harrisoni showed a converse response. Fewer females escaped from test chambers without direct contact with treated surfaces compared to contact tests; however, the spatial repellency response was significantly pronounced in all test populations compared to match-paired controls. DEET was found to perform as both a contact stimulant and moderate spatial repellent.