by MATT BUNKE
carver county news
A long winter, late spring and wet summer have combined to create an usual emergence pattern among mosquitoes this summer that has left many Carver County residents dealing with a season’s worth of the pesky insects in a matter of a just a few weeks.
NYA City Administrator Tom Simmons has received complaints this summer from local residents regarding an unusually high number of mosquitoes, and the Metropolitan Mosquito Control District (MMCD) says it isn’t surprised. While the MMCD says the overall number of mosquitoes probably isn’t any higher than normal this year, the emergence of several varieties all at once has been a nuisance for those who love to spend their Minnesota summers outdoors.
As the season wears on, that nuisance could turn into real danger as the risk of the West Nile virus increases later in the summer. A sample of mosquitoes in Carver County was recently the first in the metro area to test positive for the virus this year.
“We’re not necessarily seeing more mosquitoes than is average, but what is happening is that the season was delayed by a couple weeks because of unusually late snow and a very late spring,” MMCD Public Information Officer Mike McLean said. “That’s really collapsed the season down, and we’re seeing big spikes in mosquito numbers throughout the metro area. It’s not so much that there are more of them; it’s that there’s more of them together at the same time. It’s an interesting phenomenon.”
McLean said that different varieties of mosquitoes typically hatch at different times of the year. Usually, an aggressive variety known as spring mosquitoes hatch around Memorial Day, and often trigger the first batch of mosquito complaints. Later, floodwater mosquitoes tend to develop in standing water that is often left over from melted snow.
This year, a late spring followed by torrential early-summer rains have left standing water everywhere. The result was the hatching of spring and floodwater mosquitoes all at once earlier this month, instead of in phases.
“It’s been a challenge,” McLean said. “It’s been a really intense year.”
McLean said the wet weather this year is only part of the reason for the recent swarms of mosquitoes, and truly understand the increase, one must actually look back over the last several years. McLean said that when heavy rains and flooding follow several years of drought — as has been the case in Minnesota in recent years — it can mean a rapid increase in mosquito numbers.
That’s because mosquito eggs can remain viable more than a decade. Floodwater mosquito eggs that were laid during the last flooding incident typically lie on dry land, unhatched, until that area floods again.
“When you have a year where it’s breaking drought and there’s a lot of standing water, a lot of mosquitoes are coming from eggs that were laid the last time the water was that high,” McLean said. “You end up with an explosion in those peskier summer-time mosquito numbers.”
Mosquito concerns haven’t gone unnoticed by NYA city staff, who, for about 10 years prior to this year, contracted with Clarke Mosquito Control, a global company with an office in Clearwater, to provide about eight extra sprays in the summer.
This year though, budget constraints removed the extra sprays, saving the city $9,000 annually, according to Simmons.
“We did away with it in this year’s budget,” he said, adding they will revisit it in the next budget session. “We aren’t doing those extra sprayings.”
The MMCD has been aggressively targeting the pests so far this year. McLean said the organization has covered 150,000 acres so far this year with it’s helicopter treatments, which is already 3/4 of the roughly 200,000 acres it covers each year.
The MMCD, created in 1958 by the Minnesota State legislature, serves the seven-county metro area, including Carver County. The district is governed by 18 county commissioners from those seven counties, including Carver County Commissioner Jim Ische — who is serving as the MMCD chairman this year — and Carver County Commissioner Tom Workman.
The MMCD is funded by taxpayers, with the funding included in the “Special Taxing Districts” portion of property tax statements. The owner of a $250,000 home, for example, pays about $11.50 per year.
The MMCD uses a variety of methods to control mosquito populations, including helicopter treatments, which are used to control larval mosquitoes. Helicopters apply a dry pellet to wetlands, making use of a natural soil bacterium or a mosquito growth regulator to prevent larval mosquitoes from becoming biting adults. The helicopters do not spray insecticides to control adult mosquitoes.
Instead, the MMCD attempts to control adult mosquitoes by fogging cities throughout the metro area by using either ground vehicles or backpacks. Most recently, all streets within city limits of Mayer and NYA were fogged on July 18, with Cologne fogged most recently on July 15. Exact areas that were sprayed can be found on the MMCD website, www.mmcd.org.
Looking ahead to Stiftungsfest, NYA’s town celebration set for Aug. 23 to 25, Simmons said the MMCD will do some extra spraying to limit mosquitoes.
However, Simmons expects to continue to hear concerns from neighbors who get bitten while out in their yards, at ballfields or enjoying some of the city parks.
“I think the worst is when people out in their yards in the evenings,” said Simmons. “That’s what I hear the most. That’s when usually I hear ‘boy, we got eaten alive.’”
Simmons added he has spent less time outside himself, partly because of the mosquitoes.
“Along with the heat,” he said. “If you get out there and it’s a certain time in the evening and they start buzzing…”
Residents can also continue to report troublesome areas to the MMCD.
The MMCD’s control measures are designed in part to relieve metro-area residents of the annoyance that comes with bites, but also to keep the public safe. West Nile season is rapidly approaching, and the virus has already been found in a sample of Carver County mosquitoes.
McLean said that’s no reason to panic — it’s typical to see positive tests this time of year — and that the connection to Carver County doesn’t mean mosquitoes are any more dangerous in this area than any other part of the metro area. It just happens to be where this sample was collected.
However, as the summer wears on and West Nile dangers increase later in the season, McLean also said it’s important to take common sense precautions.
“It’s only a matter of time before humans are exposed,” McLean said. “Bites in May and June are really pesky, but they aren’t carrying the disease yet. Now we’re starting to see signs of West Nile creeping into birds and mosquitoes. … We don’t want to raise unnecessary alarms, but really start taking seriously packing that mosquito repellent.”
Adam Gruenewald contributed to this story.
Contact Matt Bunke at email@example.com and Adam Gruenewald at firstname.lastname@example.org.