Laboratory Evaluation of Effcctivc dosc of Dimcthyl phthalatc (UMP) against Anopheles stephensi and Cidexpipiens with two Standard and Modificd mcthods

The most common mosquito repellent formulations available on the market contain deet (N, Ndiethyl-m-toluamide), which has shown good repellency against biting insects. Although effectiveness, deet is not the ideal product, as allergic and toxic effects have been documented. To avoid these adverse effects, research on repellents derived from plant extracts and some other chemical repellents, to replace deet. The repellent dimethyl phthalate (DMP) is again attended due to its safety to human. This study investigates the repellency and effective dosage of DMP, which is synthesized and formulated in Iran, comparing with Germany dimethyl phthalate against Anopheles stephensi and Culexpipiens using human bait methods. Two repellents includes Iranian and Merck dimethyl phthalate (DMP) were evaluated against Anopheles stephensi and Culex pipiens, using American Society for Testing and Material (ASTM) standard procedure, a free choice method based on the variable dose-fixed time. Also a modified of ASTM method we used for determination of effective dosages of the repellents. In laboratory repellent test, dimethyl phthalate was evaluated against An. stephensi and Cx. pipeins when applied to human skin. The experiments with two models of cages conducted twice on each of the four human volunteers (4 males). In ASTM method there were no significant differences between the two repellents (Iranian and Merck’s DMP) as indicated by the ED50 and ED95 values (P>O.05). But, there were significant differences in repellent sensitivity between An. stephensi and Cx. pipiens at the ED95 level. In modified ASTM method there were no significant differences between the two repellents against An. stephensi, as indicated by the ED50 values (P>O.05). But, there are significant differences between the two repellents against Cx. pipiens based on ED50 value. Disclussion: Results of this study showed that the Iranian synthesized DMP has necessary potential and specificity to compare with Merck manufactured product. With both methods relative difference of effective dose of different repellents can be indicated, but standard method is better than modified method. Based on the result of our study, An.stephensi was distinguished as ideal species for repellents test in the laboratory.