Testing fungus impregnated cloths for the control of adult Aedes aegypti under natural conditions

Adriano R Paula,Richard I Samuels,Carlos P Silva,Aline T Carolino,César R Pereira

doi:10.1186/1756-3305-6-256

Adriano R Paula, Richard I Samuels + Show 3 more

Open Access

https://doi.org/10.1186/1756-3305-6-256

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Abstract

BackgroundEntomopathogenic fungi could be useful tools for reducing populations of the dengue mosquito Aedes aegypti. Here the efficiency of fungus (Metarhizium anisopliae) impregnated cloths (with and without imidacloprid [IMI]) was evaluated against adult A. aegypti in simulated human dwellings. Behaviour of mosquitoes in the presence of black cloths was also investigated.FindingsWhen mosquitoes were released into the test rooms, the lowest survival rates (38%) were seen when five black cloths impregnated with conidia of ESALQ 818 + 10 ppm IMI were fixed under tables and chairs. This result was significantly lower than the survival rate recorded when cloths were impregnated with ESALQ 818 alone (44%) or ESALQ 818 + 0.1 ppm IMI (43%). Blood fed A. aegypti had lower landing frequencies on black cloths than sucrose fed insects during the first 24 h following feeding, which may have been due to reduced flight activity. Few mosquitoes (4-5%) were observed to land on the cloths during the hours of darkness. The landing pattern of sucrose-fed mosquitoes on non-treated and fungus-treated cloths was similar.ConclusionThe synergism between M. anisopliae and IMI significantly reduced Aedes survival in simulated field conditions. The use of fungus impregnated cloths is a promising point source application method for the control of adult A. aegypti.

Highlights

Entomopathogenic fungi could be useful tools for reducing populations of the dengue mosquito Aedes aegypti
We show under field conditions that black cotton cloths impregnated with fungal conidia, when deployed in the presence of mosquitoes, significantly reduced the survival of female A. aegypti
A non-lethal concentration of 0.1 ppm was established which was combined with conidia of M. anisopliae, resulting in significant decreases in mosquito survival rates when compared to the use of the fungus alone

Summary

Conclusion

The synergism between M. anisopliae and IMI significantly reduced Aedes survival in simulated field conditions. One such alternative is the use of entomopathogenic fungi for biological control of adult A. aegypti. The use of fungus impregnated black cotton cloths has been shown to be effective at reducing adult Aedes survival under field conditions when tested in large cages [4,8]. In the current study we tested the effectiveness of fungus impregnated black cloths in simulated human residences as the step in the process of developing an integrated vector management program for the control of adult A. aegypti. Experiments were carried out to observe the behaviour of mosquitoes in the presence of black cloths with and without fungus

Methods

Results and discussion

Dengue and severe dengue