|MURUGAN, KADARKARAI - Bharathiar University|
|XUE, RUI-DE - Anastasia Mosquito Control District|
|Kline, Daniel - Dan|
Submitted to: ACTA TROPICA
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2013
Publication Date: 4/22/2014
Citation: Barnard, D.R., Dickerson, C.Z., Murugan, K., Xue, R., Kline, D.L., Bernier, U.R. 2014. Measurement of landing mosquito density on humans. ACTA TROPICA. 136:58-67.
Interpretive Summary: Surveillance systems for adult mosquitoes rely on mechanical traps for the early detection of vectors and the prevention of mosquito-borne disease epidemics. But the relationship between mosquito data from mechanical traps and the number of mosquitoes in nature is unknown. Past detection failures, that include the exotic Asian Tiger mosquito and mosquito-borne disease agents such as West Nile virus, may be a consequence of the traditional dependence on mechanical traps for vector surveillance. These failures indicate a need for better methods to sample adult mosquito populations. To improve the usefulness of mechanical traps for mosquito detection and population monitoring purposes, ARS scientists developed techniques and procedures that enable safe, efficient, and accurate measurement of the mosquito numbers landing on a human host. Data obtained using these methods and procedures provide a quantitative standard against which mosquito collection data from mechanical traps can be compared and corrected, if necessary, to provide accurate and reliable information about the mosquito population and for vector control purposes.
Technical Abstract: In conventional vector surveillance systems, adult mosquito density and the rate of human-mosquito contact is estimated from the mosquito numbers captured in mechanical traps. However, the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental factors bias mosquito responses such that trapped mosquito numbers may not correlate with landing mosquito numbers. As an alternative to mechanical traps, direct counts of landed mosquitoes on a human subject enable real-time measurement of landing adult mosquito density. Based on this paradigm, we studied methods to measure mosquito landing responses to a human host. Our results showed: (a) an 18% difference (P <0.0001) in the mean number of female Aedes albopictus (Skuse) making initial contact with the skin (9.1 ± 0.6 /min-1) compared with the number remaining on the skin for 5 sec (7.4 ± 0.6 /min-1); (b) an increase (P <0.05) in the mean landing rate (min-1) of Culex nigripalpus Theobald and Cx. quinquefasciatus Say with increased sampling time; (c) no difference (P >0.55) in the average number of Ae. albopictus landing on the arm (8.6 ± 1.6 /min-1) compared with the leg (9.2 ± 2.5 /min-1) of the same human subject; (d) differences among day-to-day landing patterns for the mosquito species we studied but measurable periodicity (P <0.05) when daily patterns were averaged over >4 diel periods; and (e) an effect on landing responses from air temperature (P <0.0001) for Ae. albopictus and Cx. nigripalpus and dew point temperature (P <0.0001) for Cx. quinquefasciatus. Results from this study were used to develop a procedure for safely and accurately measuring the mosquito landing rate on a human subject.