The Moab Mosquito Abatement District will fog along the sloughs in the Colorado River, the Matheson Wetlands Preserve and into Moab neighborhoods beginning at 9:15 p.m. Wednesday, June 26, after three traps were found to contain about 10,000 mosquitoes each earlier this week.
A flustered Libby Nance, director of the district, said the threshold is 250. The public, she said, has clamored to have something done.
Nance said the species, aedes vexans, also called floodwater mosquitoes, are a nuisance insect that don’t carry diseases such as West Nile, but they are aggressive daytime biters that have indeed vexed residents and tourists alike.
The wet winter and spring flooded sloughs and when those floodwaters abated millions of mosquito larvae was primed to hatch.
Nance said the cold fog will begin at the river where Canyonlands by Night and Day is located south to the neighborhoods west of Fifth West.
She recommended local residents to keep the pesticide out of the house by turning off AC units and swamp cooler and closing open windows and doors if they hear the fogger approaching.
“We hope to knock them down in their habitat, which is shrubs and trees,” said Nance, who said the decision to fog – which kills all kinds of insects, not just mosquito larvae – was made after she consulted with experts at mosquito abatement districts in northern Utah.
The ultra-low volume cold fog will be released from a truck in 30-micron aerosol bursts that will “completely atomize.” Nance said the fogging is not harmful to humans or pets, but she advises anyone with respiratory disease to remain indoors after 9 p.m. Wednesday.
She said sunlight will photodegrade the fog within three days. The fogging should be completed by midnight, but there is an indeterminate number of linear miles that will be targeted. People will know when the truck-mounted fogger is in the neighborhood, said Nance, because it is a “very loud unit.”
Nance also said she contacted local beekeepers who will cover their hives to protect them. “Really the only danger is to bees,” said Nance.
Note: This story was edited to add information about keeping pesticide out of residences.