Flood waters usher in latest ‘plague’ of mosquitoes
As a wave of floodwater recedes from area communities and residents get their first sense of relief, officials are warning of another coming wave, this time of mosquitoes.
The Wisconsin Department of Natural Resources issued a statement Wednesday warning the late-summer rainstorms had caused mosquito populations to soar in areas affected by flooding.
DNR Invasive Forest Insects Program Coordinator Andrea Diss-Torrance said the notice is “to give people some ideas about what they can do to reduce the number of mosquitoes, because we know it can be really frustrating trying to do anything about this horrible plague.”
It has been a banner year for mosquito populations.
“The first part of the spring was ugly because we had all that rain and they were terrible in the country,” said UW-Extension Agriculture Educator George Koepp, “They weren’t bad for a little while, but now they are back and they are none too afraid to come after you even in the sunlight.”
To combat the hordes of flying insects, the DNR recommends residents eliminate breeding sites for the pests.
“Mosquitoes can breed even in small amounts of water, so go around your house and tip plant dishes over and check anything that could be harboring water — old tires can be particularly a place for them,” said Diss-Torrance. “I had a tarp in my yard that had some water so I had to dump that out.”
Although adult mosquitoes can make it difficult, as clouds of mosquitoes burst out of long grass, mowing the lawn also helps.
On a larger scale, city spray and bug bomb operations are an option, though not common in part due to environmental concerns.
Sauk County Parks and Recreation Department Director Matt Stieve said he has noticed a significant uptick in the mosquito population.
“There are a lot of them, I can tell you that.”
Neither Columbia nor Sauk counties have taken any broad steps such as spraying for the insects to combat them. Dealing with the pests primarily has been left to residents, who can use sprays, repellents and mosquito larvae-killing water tablets.
“Typically, if they are used properly over the counter, you need to follow the instructions and that’s the main recommendation,” Koepp said. “Always follow the directions. It is important to keep it out of our rivers, lakes and streams, unless it is designed to be there.”
Conditions should improve as water continues to drain from the Wisconsin and Baraboo river basins. The greatest solution will come from Mother Nature as autumn temperatures arrive.
“As soon as we stop having so much standing water and cooler temperatures the mosquito populations will drop,” Diss-Torrance said. “And we saw that earlier this summer in some areas. We’ve had a terrible problem in my area, but the flood waters have receded and it is much better.”
Late Wednesday afternoon the Wisconsin River at Portage had dropped from a Saturday crest of 16.62 feet to 13.2 feet. About the same time the Baraboo River east of Baraboo had dropped from a major flood stage at 24 feet to the bottom end of the minor flood stage at 17.2 feet.
Koepp doesn’t anticipate a rapid decline in mosquito numbers.
“Anecdotally, there are a lotta, lotta little ones and that makes me nervous,” Koepp said. “But they’ll be around for a while, at least until there is a good frost.”