Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2008
Publication Date: 1/1/2009
Citation: Barnard, D.R., Xue, R. 2009. Bloodmeal mass and oviparity mediate host avidity and deet repellency in Aedes albopictus (Diptera: Culicidae). Journal of Medical Entomology. 46(5)1235-1239.
Interpretive Summary: Deet is a repellent that is used to protect humans from mosquito bites and in some cases to interrupt the transmission of mosquito-borne disease agents. The effectiveness of deet against mosquitoes that obtain a partial blood meal then continue to seek blood from the same/another host has not been determined. This is an important question for female mosquitoes that have passed through one or more blood feeding/egg laying cycles because only those (parous) females can be infective with a disease agent. Thus, when deet effectiveness against such mosquitoes is below expectation, the repellent user is unknowingly exposed to increased risk for contracting mosquito-borne disease. In this study, scientists from the ARS Medical, Agricultural, and Veterinary Entomology Center in Gainesville, FL and tha Anastasia Mosquito Control District, St. Augustine, FL examined the effects of partial blood meals and parity status on the host seeking activity of the Asian Tiger mosquito and the repellency of deet. They found that the protection time from mosquito bite afforded by deet was higher against parous female mosquitoes than against mosquitoes that had not passed through a blood feeding/egg laying cycle. These results showed that deet protection times established in laboratory bioassays (which use mosquitoes that have not laid eggs) provide a reliable measure of deet repellency to parous female mosquitoes.
Technical Abstract: This study was made to determine the effects of blood meal mass on host seeking activity relative to the repellency of deet (N,N-diethyl-3-methylbenzamide) and to determine the importance of oviparity in this process. There was a curvilinear relationship between blood meal mass in partially fed Aedes albopictus and host avidity, with a threshold for reduction of host seeking activity between 0.8 and 1.0 mg of ingested blood. There was also a relationship between blood meal mass and reproductive parameters in the mosquito, including a significant difference in the mean host seeking rates of nulliparous and parous females. The effect of blood meal mass/host seeking on deet repellency depended on the parity status of the female with repellent failure observed more quickly in nulliparous than in parous mosquitoes.