Stormwater Ponds, Constructed Wetlands, and Other Best Management Practices as Potential Breeding Sites for West Nile Virus Vectors in Delaware During 2004

Abstract

We performed longitudinal surveys of mosquito larval abundance (mean mosquito larvae per dip) in 87 stormwater ponds and constructed wetland in Delaware from June to September 2004. We analyzed selected water quality factors, water depth, types of vegetation, degree of shade, and level of insect predation in relation to mosquito abundance. The 2004 season was atypical, with most ponds remaining wet for the entire summer. In terms of West Nile virus (WNV) vectors, wetlands predominantly produce Aedes vexans, culex pipiens pipiens, and Culex restuans. Retention ponds generally produced the same species as wetlands, except that Cx. p. pipiens was more abundant than Cx. restuans in retention ponds. Aedes vexans and Culex salinarius were the most abundant species to Conservation Restoration Enhancement Program ponds. Sand filters uniquely produced high numbers of Cx. restuans, Cx. p. pipiens, and Aedes japonicus japonicus, a newly invasive vector species. Site that alternately dried and flooded, mostly detention ponds, forebays of retention ponds, and some wetlands often produced Ae. vexans, an occasional WNV bridge vector species. Overall, seasonal distribution of vectors was bimodal, with peaks occurring during early and late summer. Ponds with shallow sides and heavy shade generally produced an abundance of mosquitoes, unless insect predators were abundant. Bright, sunny ponds with steep sides and little vegetation generally produced the fewest mosquitoes. The associations among mosquito species and selected vegetation types are discussed.

An examination of the effect of landscape pattern, land surface temperature, and socioeconomic conditions on WNV dissemination in Chicago

“…Many researchers have examined and documented the factors associated with WNV transmission all over the world Balenghien et al 2006;Gingrich et al 2006;Ruiz et al 2007), but the study of the influences of landscape patterns, land surface temperatures, and socioeconomic conditions on WNV dissemination is still undergoing. This study aimed to improve the understanding of how landscape, land surface temperatures, and socioeconomic conditions together influence WNV dissemination in the urban context and to assess the importance of environmental factors in the spread of WNV.…”

“…Wetlands and stormwater ponds, especially those under heavy shade, provide an ideal environment for mosquito development. Ponds with plenty of sunshine and a shortage of vegetation are believed to be a poor environment for mosquitoes growing (Gingrich et al 2006).…”

Asociación de vector del VNO e hidrófito invasor: Culex pipiens Linnaeus, 1758 y Ludwigia grandiflora (Michaux) Greuter and Burdet en el marjal de Xeraco-Xeresa, Valencia

“…y Cx. pipiens (Gingrich et al 2006). Además, algunas especies como L. grandiflora colonizan frecuentemente los arrozales y, por tanto, sus efectos superan el ámbito ecológico y añaden pérdidas económicas.…”

Stormwater control measure (SCM) maintenance considerations to ensure designed functionality

“…The water-vegetation-soil matrix provides multiple pollutant treatment with mosquito populations. Asset managers in response to public health concerns face criticism and danger if CSWs in their jurisdiction become mosquito breeding grounds due to risk of disease (Gingrich et al, 2006). Designers could account for the proliferation of undesirable vegetative species by aggressively planting species they know to be conducive to both rapid growth and attracting mosquito predators.…”