Nance: Fogging helped problem

Moab Mosquito Abatement District Manager Libby Nance said employees fogged the sloughs on the western boundary of Fifth West and nearby neighborhoods Friday through Sunday and again on Wednesday night. After trapping Monday, Nance said the mosquito population has decreased sevenfold.

No West Nile was detected in lab testing of four pools of adult mosquitoes. She said 15 additional pools will be sent to the Salt Lake City Public Health Lab for confirmation.

They took Monday off as that is the day of the week Nance collects samples to test for West Nile virus.

She said the product used is Biomist 4-4, a pesticide used as insecticide and miticide, according to, a website that monitors pollution. Biomist 4-4 is registered for unrestricted use, with a toxicity category of “caution,” which falls before “danger,” and “warning.” The active ingredients are permethrin and piperonyl butoxide.

Permethrin is not toxic to humans and other mammals, and is even used to treat head lice. However, it is highly toxic to cats and fish. It is made of synthetic chemicals that act like natural extracts from the chrysanthemum flower and is commonly used in mosquito control programs, according to the National Pesticide Information Center.

Piperonyl butoxide, according to NPIC, is a manmade pesticide synergist. Alone, it is not designed to harm insects, but it does make pesticides more effective.

Nance said phone calls from often-irate residents have slowed and she believes the fogging has had an effect.