Field comparison of Bermuda-hay infusion to infusions of emergent aquatic vegetation for collecting female mosquitoes.

Field experiments were conducted in east-central Alabama in 2003 and 2004 to compare the attractiveness of selected gravid-trap infusions to ovipositing female mosquitoes. Comparisons were made among infusions of the following plants: Bermuda hay, Cynodon dactylon, and 3 species of emergent aquatic plants typical of Culex larval habitats, i.e., soft rush, Juncus effusus; a common sedge, Rhynchospora corniculata; and broad-leaf cattail, Typha latifolia. Experiments were conducted at a site in Lee County, AL, with an abundance of common nuisance mosquitoes, including Culex quinquefasciatus and Aedes albopictus. Carbon dioxide-baited miniature light traps were operated concurrently with gravid traps to provide an activity index of mosquito species at the site. Gravid traps with hay infusion collected the greatest numbers of Cx. quinquefasciatus and Culex restuans females (2003). The results indicate that hay infusion is highly attractive to Cx. quinquefasciatus and is the infusion of choice for collecting females of this species in gravid traps. In the case of Ae. albopictus, infusions were not determined to be significantly different from one another in their attractiveness to gravid females. In general, females of Cx. quinquefasciatus and Cx. restuans demonstrated selectivity when choosing an oviposition site, whereas Ae. albopictus females did not. Factors associated with the oviposition biology of the latter species most likely account for their lack of preference for any single infusion type.