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United States Department of Agriculture

Agricultural Research Service

Title: Larval Rearing Water and Pre-Existing Eggs Influence Oviposition by Aedes Aegypti and Aedes Albopictus (Diptera: Culicidae)

Authors
item Allan, Sandra - UNIVERSITY OF FLORIDA
item Kline, Daniel

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 23, 1997
Publication Date: N/A

Interpretive Summary: The mosquitoes, Ae. aegypti and Ae. albopictus, are common pests of humans and livestock throughout the southern United States. These species are not readily collected by light traps and are usually monitored through use of "ovitraps" which collect eggs. Trapping is an important element in mosquito control programs and improvement of trapping sensitivity greatly enhances surveillance for mosquito control. In this study, scientists at the Center for Medical, Agricultural and Veterinary Entomology in Gainesville, FL examined the influence of water used in rearing larval mosquitoes and previously deposited eggs on oviposition by both species of mosquitoes. Oviposition was greatly enhanced in the presence of larval rearing water compared with water controls. Both mosquito species responded equally to larval water from the other species. Previously laid eggs significantly increased oviposition by Ae. aegypti only. Future studies will attempt to identify the attractants from the eggs and larval water. Oviposition attractants have considerable potential for enhancing the sensitivity of ovitraps that are currently used to detect and monitor populations of Ae. aegypti and Ae. albopictus.

Technical Abstract: Oviposition responses of gravid Aedes aegypti and Ae. albopictus were evaluated in two-choice laboratory bioassays to larval rearing water and eggs from prior ovipositions of both species. In bioassays, oviposition responses of female Ae. aegypti were significantly greater to larval water from either species compared to deionized water controls (P < 0.05) and these responses differed by 8.3% (Ae. aegypti) and 12.2% (Ae. albopictus). Oviposition by Ae. albopictus females was also significantly increased in response to larval water from either species compared to water controls (P < 0.0001) with responses differing by 15.1% (Ae. aegypti) and 17.6% (Ae. albopictus). Oviposition responses of gravid Ae. aegypti and Ae. albopictus were evaluated in the presence of pre-existing conspecific and heterospecific eggs on strips of oviposition paper. Significantly more eggs were laid by gravid Ae. aegypti females on oviposition paper containing either Ae. aegypti or Ae. albopictus eggs than on oviposition paper without eggs. In contrast, oviposition responses of gravid Ae. albopictus females did not differ between the presence of pre-existing eggs of either species and oviposition paper without eggs. These results indicate that Ae. aegypti and Ae. albopictus differ significantly in oviposition responses to larval rearing water and pre-existing eggs.

Last Modified: 10/1/2014