Anopheles: indicators and influences

May 16, 2013, 12:49 p.m.

 

Anopheles species associations in Southeast Asia: indicator species and environmental influences

Valérie ObsomerMarc DufrenePierre Defourny and Marc Coosemans

  •  

For all author emails, please log on.

Parasites & Vectors 2013, 6:136 doi:10.1186/1756-3305-6-136

Published: 4 May 2013

Abstract (provisional)

Background

Southeast Asia presents a high diversity of Anopheles. Environmental requirements differ for each species and should be clarified because of their influence on malaria transmission potential. Monitoring projects collect vast quantities of entomological data over the whole region and could bring valuable information to malaria control staff but collections are not always standardized and are thus difficult to analyze. In this context studying species associations and their relation to the environment offer some opportunities as they are less subject to sampling error than individual species.

Methods

Using asymmetrical similarity coefficients, indirect clustering and the search of indicator species, this paper identified species associations. Environmental influences were then analysed through canonical and discriminant analysis using climatic and topographic data, land cover in a 3 km buffer around villages and vegetation indices.

Results

Six groups of sites characterized the structure of the species assemblage. Temperature, rainfall and vegetation factors all play a role. Four out of the six groups of sites based on species similarities could be discriminated using environmental information only.

Conclusions

Vegetation indices derived from satellite imagery proved very valuable with one variable explaining more variance of the species dataset than any other variable. The analysis could be improved by integrating seasonality in the sampling and collecting at least 4 consecutive days.

<< News Archive