A study on bionomics of malaria vectors in three different eco-epidemiological settings in Upper Krishna Project...

Understanding of malaria vector distribution and influence of climatic environments is essential for devising control strategies. The aim of the study was to study the bionomics of prevalent malaria vectors in three different settings for development of evidence-based sustainable malaria control strategy with special reference to vector control.

Three villages with different eco-epidemiological settings like riverine-low malarious, riverine-high malarious and non-riverine high malarious villages were selected after baseline studies. Entomological aspects such as man hour density, per structure density, mosquito landing collections, sibling species identification, insecticide susceptibility status, parity rate, etc. were studied in these three villages following standard methods and techniques. The effect of these variables was analysed statistically.

Mosquito collections revealed the presence of three malaria vectors in the study villages, namely Anopheles culicifacies s.l., An. fluviatilis s.l. and An. stephensi (Diptera: Culicidae) with varying proportions and seasonal abundance. Densities of the principal malaria vector, An. culicifacies varied seasonally. Anopheles culicifacies was found resistant to DDT (4%), malathion (5%), lambda-cyhalothrin (0.05%) and alpha-cypermethrin (0.1%). Peak density of An. culicifacies was found during post-monsoon months starting from August-September to December in the high malarious villages.

The main vector control interventions should be planned in the post-monsoon months in these villages and suitable insecticide resistance management strategy should be followed as An. culicifacies was found resistant to DDT, malathion, alpha-cypermethrin and lambda-cyhalothrin in the study area.