Ryan Johnson, Published June 12 2013
As skeeter numbers jump, Vector Control crews out in full force
But Cass County Vector Control Director Ben Prather said while the number of pesky insects in the city has jumped in recent days, it’s nothing “extraordinary” – even if it feels that way to residents who had a mostly mosquito-free summer last year because of drought conditions.
“It’s not like I’ve seen in the past,” he said. “But definitely the perception for most everybody out there is yeah, it’s not comfortable.”
A few dozen mosquito traps are placed around Cass County, including more than 20 within the city limits of Fargo and West Fargo. Each weekday, Vector Control employees pull the traps and count the number of females – males don’t bite – to come up with an average number.
Prather said the average jumped from two mosquitoes per trap on Monday morning to 35 by Tuesday morning. Thirty-five is the threshold for when they consider a citywide spraying of a light mist of pesticide that kills adult mosquitoes.
Because of the increase in trap numbers, the Cass County team planned to ground-spray Wednesday evening in Fargo, West Fargo, North River and Leonard by a fleet of 21 trucks, weather permitting.
The effort will typically knock down the number of mosquitoes by 80 to 90 percent, Prather said.
Moorhead Director of Operations Chad Martin said 2012 was a “premium year” for mosquitoes in the region.
“We never sprayed at all last year,” he said.
But weather permitting, Moorhead workers will be out tonight for their first citywide spraying of the year to get the mosquitoes under control, Martin said.
He said the city tries to work closely with Cass County Vector Control and bases its decision to spray on the North Dakota trap counts because Moorhead doesn’t operate its own.
Prather said this week might mark the summer’s first brush with mosquitoes for many residents, but the work to keep the pests to a minimum started more than a month ago. That’s when crews worked on the first line of defense – larval control – when they applied concentrated chemicals to standing bodies of water to kill mosquitoes before they start to look for blood.
“They can’t escape standing water until they emerge as adults, and literally you can kill 1,000 mosquitoes with just a couple granules of our product,” Prather said.
Workers have also visited areas perfect for mosquitoes – damp, shaded, humid spots, especially in wooded areas. Prather said a longer-lasting pesticide is sprayed by backpack units for a more targeted killing, with the chemical sticking on plants for up to four weeks.
Prather said the pesticide his crews use is nontoxic and breaks down rapidly, usually within 30 minutes. It kills mosquitoes, but doesn’t harm other animals and plants.
Watching for West Nile
Prather said Vector Control’s work is about more than dealing with the nuisance of mosquitoes. Even last summer, when dry conditions meant low mosquito numbers, crews were busy spraying in August because of confirmed cases of West Nile virus that can be passed to humans from mosquitoes. The disease can be deadly and often has symptoms similar to the flu.
So far, the species of mosquito that transmits West Nile in the region hasn’t been found, Prather said, adding that they’ll keep a close eye on the traps. He said mosquito control efforts may be ramped up if the virus makes it way here again later in the summer.
Fargo Cass Public Health environmental health practitioner Miles Schacher said there are some easy precautions to limit the chance of being exposed to West Nile virus.
“You hate to tell people not to be outside because we have a short enough summer as it is, but if you have to be outside, dress accordingly,” he said.
That includes wearing a long-sleeved shirt if it’s cool enough and making sure to wear a shirt of some kind – even on sunny days – to limit how much skin is a potential target for mosquitoes.
Schacher said the U.S. Centers for Disease Control and Prevention also recommends applying an approved repellent to minimize the risk of a bite. He said to look for a product with 10 percent DEET for those who will be outdoors for a couple of hours, 15 percent for two to four hours and 20 to 50 percent DEET concentration for longer periods of time.
Approved insect repellents are safe to use on children with concentrations of up to 30 percent DEET, but the American Academy of Pediatrics says parents shouldn’t use any product with DEET on children younger than two months.
“Basically, if you have a child under 2 months, really you shouldn’t be exposing them to any potential for mosquitoes,” Schacher said.
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Readers can reach Forum reporter Ryan Johnson at (701) 241-5587