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Objective: To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica.Methods:cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m2, at 24, 48 and 72 h exposure period. Mortality (number of dead cockroaches) was assessed after 24 h. Other exposed specimens were transferred to the beakers contained food and water for counting the retard mortality rate after 1 week. This cross sectional study has been done on the laboratory strain of German Results: Increasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m2, respectively. The results of the statistical analysis showed no significant difference in the lethality of 50% of DE plus water on the German cockroach nymphs.Conclusions:Due to the resistance of German cockroach against organochloride organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect’s control.
RESUMO
OBJECTIVE@#To evaluate the bioefficacy of α-cypermethrin impregnated into long lasting insecticide treated nets (LLITNs-INTERCEPTOR®) against main malaria vector, Anopheles stephensi (An. stephensi).@*METHODS@#The effectiveness of bed net impregnated with α-cypermethrin (INTERCEPTOR®) with washing was evaluated. The washing procedure and bioassay tests were carried out according to the WHO-recommended methods. Malaria vector, An. stephensi was exposed to impregnated bed net for three minutes and then mortality measured after 24 h recovery period. Knockdown was also measured according to the logarithmic times.@*RESULTS@#Result of cone bioassay method showed that bioefficacy of α-cypermethrin decreased from 100% in unwashed to 15% in 20 washes. KT(50) was measure as one minute in one wash and increased to 40 min in 20 washes.@*DISCUSSION@#Findings of this study provide guideline for malaria vector control authorities and people using pyrethroid-impregnated bed nets.