2.2. SUSCEPTIBILITY OF AN. DIRUS TO INSECTICIDES THE MAIN VECTOR AN....
4.2.2. Susceptibility of An. dirus to insecticides The main vector An. dirus at test sites was still sensitive to alpha-cypermethrin 30 mg/m
2
and lambda-cyhalothrin 0.05% in northern Thailand. An. dirus s.l was still susceptible to deltamethrin 0.05% (mortality of 100%) [56]. In Thailand, An. dirus was sensitive to bifenthrin 0.09% and deltamethrin 0.05% with the mortality of 100% [101]. In Laos, WHO susceptibility test showed the two main vectors An. dirus, An. minimus had not been resistant to pyrethroid [98]. So far, in Vietnam as well as other countries with the presence of An. Dirus, no resistance of this species to insecticides used in malaria control has been reported. However, some studies have recorded the insecticidal avoidance of these mosquitoes [35], [51], [113]. In fact, insecticidal avoidance is also a kind of behavioral resistance caused by the presence of insecticides. Behavioral resistance also makes it difficult for vector control because the efficacy of chemicals is limited due to a decreased chemical exposure of vectors [51]. An. dirus is a species living in the forest habitat. It only comes to a host when needing blood, so its exposure to insecticides is limited, resulting in its weak insecticidal resistance compared to An. epiroticus and An. Minimus which live near humans. Thus it can be said that no insecticidal resistance of An. dirus populations has been found, and available insecticides can be used to contain this species. CONCLUSIONS