Consistent rains keep mosquito-fighting crews busy
FARGO – Heavy rain this week has also meant heavy hours for mosquito-fighting crews in the metro area.
“It’s made life a little miserable for staff here,” said Ben Prather, director of Cass County Vector Control.
His crew of about 40 had already hit 35 work hours for the week when he sent them home at about 11 p.m. Wednesday, and they were back out at it again Thursday, slogging through the hard-driving rain to treat standing ditch water all over the county.
That’s because the intermittent rainstorms had washed away the 3 tons of pesticides crews applied the preceding three days.
Despite the hard work, it is bound to get worse on the skeeter front in the next few weeks and aerial spraying is likely, Prather said.
Average trap counts across Fargo and West Fargo on Thursday “crested” at 76.3 mosquitos, which led to crews spraying in both cities that night, Prather said. The average trap count Friday was down to 33.5 mosquitos.
“So now we’re back on the other side of the ridge,” he said.
Historically, Prather said a 76-bug count is “run of the mill,” and that trap counts have been double, triple or quadruple that.
“Contextually, we’re doing very, very well,” he said. “People probably don’t absolutely agree with that. One mosquito bite is too much for some folks, but, all things considered, it’s coming down.”
Cass County Vector Control has been applying residual pesticide treatments to standing water this week to destroy the larvae that grow up into floodwater mosquitoes, which can carry diseases.
Moorhead hasn’t needed to do a citywide fogging yet, instead focusing on larvacide and spot spraying in parks and recreation areas, said Steve Moore, the city’s public works director.
Although the bug count is coming down, Prather and Moore said they expect a spike soon, and an aerial spraying across Fargo, West Fargo and Moorhead is in the planning stages.
“This rain that’s been falling all over the place is going to make consistent, repetitive kinds of treatment absolutely necessary over the next 10 to 20 days,” Prather said.
There is no set date for that aerial spraying yet, Prather said, and Moore said trap counts will be done again Monday to see if Moorhead needs a fogging with trucks.
It’s all culminating in a perfect storm of sorts for vector control workers – because every time the metro gets an inch of rainfall, crews essentially have to start over, Prather said.
“The last couple of shifts have been 10, 12, 10, 12, 13 hours,” he said Thursday. “There’s some heavy eyes today.”
Even with all those hours, though, according to Prather, it’s more cost-effective than switching to a different, longer-lasting kind of pesticide.
The alternative treatments range from a longer-term, 30-40-day type to the 90-to-100-day, long-lasting residual product that communities like New Orleans and other swampy Southern regions use.
But those treatments are prohibitively expensive, said Prather, at about $700 an acre for the longest-lasting type versus $15 an acre for the ones predominantly used here.
It doesn’t make sense cost-wise to use the longest-lasting ones here in Cass County because the weather is only spottily soggy, said Prather.
They do use the midrange pesticides over about 20 percent of the county’s standing water, mostly in areas that tend to stay wet, such as near Hector International Airport.
“We go with a little more labor-heavy product,” Prather said.
Still, he hasn’t lacked for volunteers for 10- to 12-hour shifts, even though workers know more rain is certain to wash their work away.
“Whoever is a glutton for punishment,” said Prather, as a mosquito lurks midair in the rain. “It’s a common enemy.”
Forum reporter Erik Burgess contributed to this report.