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Knight, J.C. and Corbet, S.A., 1991. Compounds affecting mosquito oviposition: structure-activity relationships and concentration effects. Journal of the American Mosquito Control Association 7: 37-41 At concentrations tested and in containers tested (5cm x 20cm diameter. i.e., not standard oviposition jars), methyl hexanoic acid and 5-methyl-2-hexanone gave statistically higher egg counts than controls. They suggest that dose-response curves need to be generated for any compound believed to be an oviposition attractant or repellent. This work was done in Kenya with Aedes aegypti, formosa. Corbet, P.S. and Chadee, D.D., 1990. Incidence and diel pattern of oviposition outdoors of the mosquito, Aedes aegypti (L.) (Diptera: Culicidae) in Trinidad, W.I. in relation to solar aspect. Annals of Tropical Medicine and Parasitology 84: 63-78. Experiment design: Unshaded traps, some get light from east, some from west. 22 sites with 2 ovitraps each. Each placed on the ground, 1-15 m from nearest house, within 5 mm of, but not touching, a concrete or brick wall (minimum width 20 cm) and unshaded from above. So, shaded by the wall but gets light at some times. About 1.5 m apart along 3 parallel walls separating 4 adjacent residences. Results: Oviposition was "usually greater in the west than the east, regardless of the measure of comparison adopted. West-facing sites received 59.2% of eggs and featured 57.1% of occurrences; and on 64.3% of occasions this ovitrap had more eggs than its east-facing counterpart." p.66. (They note that other researchers did not find this difference elsewhere.) Key point may be that a body of water has a different temperature than the surrounding land at dawn and dusk and it gives off a stream of water vapor the mosquito can follow. Uncovered, not shaded, west-facing water would be ideal for generating such a gradient in the evenings. Zahiri, 1998. I NEED TO PUT IN FULL CITATION HERE Presence of larvae is both attractant and repellent for egg-laying. Too many or too few inhibit egg-laying. Optimum number in their study was _____ larvae per ml in containers that were _____ x ______. Chadee & Corbet, 1990 I NEED TO PUT IN FULL CITATION HERE Crowding of larvae impairs fitness. How does female know larvae will be there? In this study, Chadee and Corbet found that females preferred laying eggs in pots in which they had not previously laid eggs. So, the presence of eggs (not larvae) acted as a repellent for egg-laying. Strickman, 1993 I NEED TO PUT IN FULL CITATION HERE Sometimes a simple modification makes a huge difference. In this study, aluminum lids for covering water jugs were test-modified to deter mosquitoes from laying eggs in the jars. The foam needed to be in a certain orientation (on the vertical side of the lid) to be effective. Pavlovich, 2000 I NEED TO PUT IN FULL CITATION HERE Mosquitoes prefer to lay eggs in black containers, preferably that contain some bacteria (Bacillus cereus being preferred to others tested) The Mosquito Atlas at The University of Arizona Copyright © 2002 E. Willott. All rights reserved. Last update October 2, 2002. Mail to: willott@u.arizona.edu |