seyedhassan nikookar health sciences research center, department of medical entomology and vector control, faculty of health, mazandaran university of medical sciences, sari, iran. seyedhassan moosa-kazemi department of medical entomology and vector control, school of public health, tehran university of medical sciences, tehran, iran. mohammadreza yaghoobi- ershadi department of medical entomology and vector control, school of public health, tehran university of medical sciences, tehran, iran. hassan vatandoost department of medical entomology and vector control, school of public health, tehran university of medical sciences, tehran, iran and institue for environmental research, tehran university of medical sciences, tehran, iran. mohammadali oshaghi department of medical entomology and vector control, school of public health, tehran university of medical sciences, tehran, iran. abolfazl ataei department of medical entomology and vector control, school of public health, tehran university of medical sciences, tehran, iran.