Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico

Abstract

BackgroundCar tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance.ResultsSpinosad treatments at 1 or 5 ppm (mg a.i./liter) provided 6–8 weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis) was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments.ConclusionThe present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes.

Efficacy and non-target impact of spinosad, Bti and temephos larvicides for control of Anopheles spp. in an endemic malaria region of southern Mexico

“…that develop in water containers or abandoned car tires in urban or peri-urban habitats in Mexico [12-15]. These findings have been substantiated and expanded upon by others that have studied container and pool dwelling mosquito species across different parts of the world [16-22].…”

Estudo experimental sobre a ação de larvicidas em populações de Aedes aegypti do município de Itabuna, Bahia, em condições simuladas de campo*

“…aegypti, confirms the results of other studies. [19][20][21][22] This finding is important: the three alternative larvicides tested are on the list of products which the Health Surveillance Secretariat/ Ministry of Health can buy, as alternatives to other chemical insecticides used by vector-borne disease control programs which, given their toxicity, can affect non-target organisms as well as the environment.…”

Effects of Bacillus thuringiensis israelensis and spinosad on adult emergence of the non-biting midges Polypedilum nubifer (Skuse) and Tanytarsus curticornis Kieffer (Diptera: Chironomidae) in coastal wetlands

“…quinquefasciatus, Aedes aegypti and Ae. albopictus (Marina et al, 2011, Marina et al, 2012 which are efficient vectors of human pathogenic viruses (Rezza et al, 2007, Fontenille et al, 2009, Butler, 2012, Vega-Rua et al, 2013.…”