Residual effects of deltamthrin WG 25% as a new formulation on different surfaces against anopheles stephensi, in Southeastern Iran

Indoor residual spraying [IRS] is functioned as national interventions against malaria in southeastern foci of Iran and deltamethrin WP one of the insecticides have been used since past decade. In this study, the residual activity of the wettable granule [WG] was studied on different surfaces in hut scale trial against Anopheles stephensi in Iranshahr district, southeastern Iran. Three dosages of 25, 40 and 50 mg a.i./m2 of deltamethrin WG 25% formulation were applied on plaster, cement, mud, and wooden surfaces using Hudson[Registered] X-pert compression sprayer having 10 litters capacity. The residual effects of deltamethrin WG 25% on different surfaces was assessed based on reduction of mortality An. stepehnsi from 100% to about 70%. At 25, 40 and 50 mg a.i./m2 the WG formulation of deltamethrin had a bioefficacy for about 2, 3 and 4 months respectively. There was an expectable fluctuation in mortality of An. stephensi at different sprayed surfaces as well as dosages. The proposed 50 mg/m2 WG is the longest activity for up to 4 months which needs to be applied for two spraying cycles per year at the climatically condition of southwestern Iran

[ study of physical and chemical factors affecting breeding places of anopheles in Iranshahr]

Malaria is one of the most important health problems in many countries as well as Iran, especially in southern Iran. Considering the role of Anopheles in transmission chain of the disease, this study aims at determining effective physical and chemical factors in breeding places of Anopheles' larve in Iranshahr. 68 samples including 63 from breeding places of larve and five samples from ponds with no larve were collected from different regions of Iranshahr as control group. Each sample of the study contained one from those of water and the other from larve group which were collected scientifically. Experiments conducted on water sample included PH, electrical conductivity, Nitrate, Nitrite, Sulphate, Chloride, Calcium, rigidity, salinity, darkness, and Phosphate. In this study 8 out of 13 species of Anopheles which had already been reported in the region were collected. The results obtained indicate that there is significant difference between mean physical and chemical factors of control group samples and samples. Collected from breeding places of larve. The range of variables such as electrical conductivity, total rigidity, Calcium, Chloride, Sulphate. Nitrate in breeding places without larve is more than 2 and xometimes 20 times while in regard with darkness and phosphates it is the reverse. Components such as Phosphate, electrical conductivity, and Calciumin larve life of anopheles were of great influence as the most important carrier of Malaria in the region. The results showed that large quantities of the above agents can play inhibiting role for any kind of Aanophelines species. Whereas existence of nitrite in large quantities in water was one of the few components that plays positive role in mosquitoes life