Field Efficacy of New Larvicide Products for Control of Multi-Resistant Aedes aegypti Populations in Martinique (French West Indies)

Abstract

Abstract. World-wide dengue vector control is hampered by the spread of insecticide resistance in Aedes aegypti . We report the resistance status of a wild Ae. aegypti population from Martinique (Vauclin) to conventional larvicides ( Bacillus thuringiensis var israeliensis [ Bti ] and temephos) and potential alternatives (spinosad, diflubenzuron, and pyriproxyfen). The efficacy and residual activity of these insecticides were evaluated under simulated and field conditions. The Vauclin strain exhibited a high level of resistance to temephos, a tolerance to insect growth regulators, and full susceptibility to spinosad and Bti . In simulated trials, pyriproxyfen and Bti showed long residual activities in permanent breeding containers (28 and 37 weeks), whereas under field conditions they failed to curtail Ae. aegypti populations after four weeks. Conversely, diflubenzuron and spinosad showed a residual efficacy of 16 weeks, suggesting that these chemicals may be promising alternatives to Bti and temephos for controlling insecticide-resistant Ae. aegypti populations.

Novel larvicide tablets of Bacillus thuringiensis var. israelensis: Assessment of larvicidal effect on Aedes aegypti (Diptera: Culicidae) in Colombia

“…The use of Bti as a control strategy for A. aegypti larvae has been previously reported using different formulation and doses, particularly in countries where temephos resistance has been reported in A. aegypti populations (25,26).…”

“…In that study, contrary to most other studies, a residual activity of 12 weeks with larval mortality >80% was observed. Several studies conducted under field conditions in different countries with commercially available and experimental Bti tablets have shown that their residual activity is less than a month (25,37,(43)(44)(45)(46). In Colombia, several Bti formulations tested under field conditions (18,24,43,47) have yielded varied results depending on the study site.…”

Statistical Evaluation Of The Larvicidal Effect Of Diflubenzuron On Culex Pipiens Larval Stages

“…Numerous studies followed different habitats of the larvae of mosquitoes that preceded the WHO recommendations for the use of difl ubenzuron at different concentrations and for different types of mosquito larvae. For drinking water, water canisters, and potable water wells, the recommended dose is 0.25 mg difl ubenzuron/ L [21].…”

“…In the earlier period adult mosquito forms were controlled with malathione based compositions, permethrine, lambdacihalotrine and deltamethrine [18]. The long term use of organophosphate larvicides in the Belgrade area, as well as lack of information pertaining the resistance to larvicides, and their removal from the list of allowed biocides had infl uenced the need to study the effects of alternative substances for the control and elimination of mosquito larvae [19][20][21]. In the recent years there is an increased interest in studies on the larvicidal effects of difl ubenzuron based formulations.…”

Using the Bio-Insecticide Bacillus Thuringiensis Israelensis in Mosquito Control

“…Mosquito larvae are particle feeders and Bti tend to sink more or less rapidly in mosquito breeding sites where it is sprayed. In the field, Bti toxicity is lost within a week against Anopheles which feeds in surface (Kroeger et al, 1995), whereas Aedes species are still killed up to 4 weeks after treatment (Marcombe et al, 2010), suggesting that differences in feeding behaviour might explain this difference in susceptibility (Lacey, 2007). Changes in the type and/or level of expression of the midgut proteases can also be involved, as well as modifications in the expression and/or sequence of the specific membrane receptors.…”