Sampling the Adult Resting Population

Animal bait catches (see Chap. 6) usually catch only unfed females in search of a blood-meal and the choice of bait species will in many cases determine the species of mosquito sampled. Attractant traps (Chap. 11) also predominantly sample host seeking females, and may often attract only certain species. Non-attractant traps (Chap. 8) give less biased collections of mosquitoes and, at least theoretically, should sample all species more or less equally. However, they only sample the proportion of the population that is active and airborne, which again mainly comprises unfed females, although these may not all be actively host seeking. Non-attractant traps also sample the active proportion of the male population better than attractant traps. Adult mosquitoes probably spend a majority of their time resting in natural or man-made shelters, and are thus unavailable to be sampled using bait catches, or attractant and non-attractant traps. Resting collections sample unfed females, including those not actively host seeking, both blood-fed and gravid females and also males. Resting collections therefore provide much additional information and will yield samples of the population that more accurately represent the sex ratio, age structure and physiological condition of the population as a whole.