Title

Study on CIPAC (Collaborative International Pesticides Analytical Council) wash-resistance on pirimiphos-methyl and chlorpyriphos-ethyl and deltamethrin impregnated bednets using cone bioassay tests against An.stephensi at laboratory condition

Principal Investigator

Dr. Hassan Vatandoost

Abstract

Results:
The sufficient efficacy was observed on the LLINs impregnated with pirimiphos methyl at 250-500 mg/m2 resulted 79.9% and 90.7% for mean of the knockdown and mortality rates. The LLINs impregnated with chlorpyrifos ethyl at 250-350 mg/m2 showed the acceptable efficacy using knockdown and mortality rates 68.9% and 97.5% respectively. Based on the results and considering the knockdown and mortality values, the dosage 350 and 500 mg/m2 was recommended for impregnating LLINs to pirimiphos methyl and chlorpyrifos ethyl. In this research, with attention to application of fixed dosage for deltamethrin (25 mg/m2), the bioassay resulted unexpected low values for mortality and knockdown rates. Hence the evaluation of the higher dosage recommended for the future research.
Conclusion:
The mean of knockdown and mortality rates were increased after one washing of LLINs which may be due to releasing of insecticide from impregnated fibers. Both rates were decreased after increasing the washing times. The findings indicated the suitability of organophosphorus insecticide tested for combined use with a pyrethroid for impregnating LLINs in order to manage the insecticide resistance within the malaria vectors

Year

2018