Effect of triflumuron, a chitin synthesis inhibitor, on Aedes aegypti, Aedes albopictus and Culex quinquefasciatus under laboratory conditions

Ademir Jesus Martins,Thiago Affonso Belinato,José Bento Pereira Lima,Denise Valle

doi:10.1186/1756-3305-6-83

Abstract

BackgroundResistance to traditional insecticides represents a threat to the control of disease vectors. The insect growth regulators (IGR) are a potential alternative to control mosquitoes, including resistant populations. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. In the present study, we evaluated the efficacy of the CSI triflumuron on Culex quinquefasciatus, Aedes albopictus and against several Ae. aegypti field populations.MethodsThe efficacy of triflumuron, against Cx. quinquefasciatus and Ae. albopictus was evaluated with laboratory strains through dose–response assays. Additionaly, this CSI was tested against seven Ae. aegypti field populations exhibiting distinct resistance levels to both temephos and the pyrethroid deltamethrin. Aedes aegypti populations were exposed to both a dose that inhibits 99% of the adult emergence of mosquitoes from the susceptible reference strain, Rockefeller, (EI99 = 3.95 μg/L) and the diagnostic dose (DD), corresponding to twice the EI99.ResultsOur results indicate that triflumuron was effective in emergence inhibition (EI) of Cx. quinquefasciatus (EI50= 5.28 μg/L; EI90= 12.47 μg/L) and Ae. albopictus (EI50= 1.59 μg/L; EI90= 2.63 μg/L). Triflumuron was also effective against seven Ae. aegypti Brazilian populations resistant to both temephos and deltamethrin. Exposure of all the Ae. aegypti populations to the triflumuron EI99 of the susceptible reference strain, Rockefeller, resulted in complete inhibition of adult emergence, suggesting no cross-resistance among traditional insecticides and this CSI. However, a positive correlation between temephos resistance and tolerance to triflumuron was observed.ConclusionThe results suggest that triflumuron represents a potential tool for the control of disease vectors in public health. Nevertheless, they point to the need of constant monitoring of the susceptibility status of vector populations to CSIs.

Highlights

Resistance to traditional insecticides represents a threat to the control of disease vectors
Chitin synthesis inhibitors (CSI) are insect growth regulators (IGR) that interfere with the insect moult
This work deals with the chitin synthesis inhibitors (CSI) triflumuron efficacy against Ae. aegypti field populations, as well as laboratory colonies of Ae. albopictus and Cx. quinquefasciatus

Summary

Introduction

Resistance to traditional insecticides represents a threat to the control of disease vectors. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. Aedes albopictus and Culex quinquefasciatus mosquitoes are widely distributed across the globe, mainly in tropical and subtropical regions [1] The presence of these species is considered a public health problem, In Latin America, the presence of these mosquitoes involves an additional risk, as they are potential vectors of chikungunya and the West Nile virus, two arboviruses not yet reaching this continent [5,6,7]. Organophosphates (OP) and pyrethroids (PY) still play an important role in vector control Their effectiveness has been hampered due to resistance [8,9,10,11]. CSI exposure results in deformities of the larval cuticle, which often become unable to survive to the moult [15,16,17]

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Conclusion