Biochemical Basis of Cyfluthrin and DDT Resistance in Anopheles stephensi (Diptera: Culicidae) in Malarious Area of Iran

Background: Anopheles stephensi is a key urban malaria vector in the Indian subcontinent and Middle East includ­ing south and southeast of Iran. Wide application of insecticides resulted in resistance of this species to various insec­ticides in these regions. This study was conducted to reveal the role of metabolic mechanisms in the development of resistance in An. stephensi to DDT and cyfluthrin. Methods: Field mosquito specimens were collected from Chabahar Seaport, southeast corner of Iran, in 2015. Insec­ticide susceptibility and enzyme assays were conducted as recommended by WHO. Results: Mean enzyme ratios were 3.95 and 3.04 for α- esterases and 2.40 and 1.97 for β- esterases in the DDT and cyfluthrin- resistant populations correspondingly compared with the susceptible strain. The GSTs enzyme mean ac­tivity ratios were 5.07 and 2.55 in the DDT and cyfluthrin- resistant populations compared with the susceptible beech strain. The cytochrome p450s enzyme ratios were 1.11 and 1.28 in the DDT and cyfluthrin- resistant populations respectively compared with the susceptible beech strain. Conclusion: Metabolic mechanisms play a crucial role in the development of DDT and cyfluthrin resistance in An. stephensi, therefore, further evaluation of the mechanisms involved as well as implementation of proper insecticide resistance management strategies are recommended

Fauna and monthly activity of sand flies at zoonotic cutaneous leishmanianisis focus in Damghan district, Semnan province (2008)

Introduction: Zoonotic cutaneous leishmanianisis is one of most important health problem in theworld and the disease has been reported from more than 88 countries with 350 million people at the riskof it .The disease has been widespread in several parts of islamic republic of Iran. Sand flies(phlebotominae) are the vectors of the disease that transmit of parasites from the infected rodents tohuman. Knowledge on ecology of Sand flies can help us to design of disease control program. Determineof fauna and monthlyonthly activity of Sand flies was the main objects of this study.Material and Methods: This survey was performed as an experimental and practical study. It wascarried out in Damghan district of Semnan province during 2008. Sand flies were collected from indoorsand outdoors using sticky traps twice in month from early April to late November.Results: Totally 6110 sand flies (6 species of Phlebotomus and 2 species of Sergentomyia) werecollected and identified from indoors (2146) and outdoors (3964). Activity of sand flies were started inApril and ended in October with two peaks in May and September. The dominant species werePhlebotomus papatasi.Conclusion: High density of Phlebotomus papatasi as the dominant specimen indicates that, thisspecies can be the main vector of disease. Collection of P. caucasicus, P.mongolensis and P. ansarii fromrodent burrow show that they can play as the secondary role to transmitting of disease among rodentreservoirs. Dissection of sand flies for finding of parasites and following of them by molecular methods isnecessary to confirmation of proven vector(s). Control of rodents, environmental sanitary as well aspersonal protections and insecticide impregnated bed nets was suggested to prevention of disease