Mosquitos meet their match in pyrethrum

Joel Stottrup / Union-Eagle A city public works employee drives the city’s mosquito spray truck down an alley in north Princeton the evening of July 9, spraying a pyrethrum mist into residential yards.

Joel Stottrup / Union-Eagle
A city public works employee drives the city’s mosquito spray truck down an alley in north Princeton the evening of July 9, spraying a pyrethrum mist into residential yards.

The city of Princeton is spraying more regularly for mosquitoes this year than in past years, according to city Public Works Director Bob Gerold.
Gerold said the extra spraying is needed to stay ahead of the “overabundance of mosquitoes” following this year’s rainy and cool spring.
The city’s first spraying this year was June 17. Ten sprayings  had taken place as of late last week.  The mosquito population typically needs three consecutive days of 70 degree temperatures to hatch, and public works needs temperatures above 55 degrees, along with calm to light winds to spray, Gerold added. It is usually after 7 p.m., when the conditions are conducive to a good kill, as that is when the mosquitoes come out from the shade, Gerold said.
The city sprays pyrethrum, a derivative of the chrysanthemum flower, typically at a rate of about a half ounce per acre, according to Gerold. The city has one mosquito spray vehicle and it takes the operator two to three hours to spray the city, Gerold said.
The spray truck is driven down alleys as much as possible to get the spray into backyards, and the direction of travel is chosen according to the wind direction to most effectively get the spray onto properties, Gerold said.
Public works has also been using a second method of mosquito control – the placing of mosquito pucks into oxbow lakes formed when a wide river meander gets cut off from the river. The larvicide in the slowly dissolving puck kills the mosquito larvae before it can mature. Public works has been placing the pucks in  Pioneer and Riebe Parks.
“We’re struggling to stay ahead (of the hatching of mosquitoes),” Gerold said. “They are hatching like crazy.”
“They’re horrendous,” Princeton resident Wayne Fritz said. Fritz said that he knows of other residents in the city who feel the same way.
The city has at least one resident appreciative of the city’s mosquito control efforts in Barb Anderson. She had heavily criticized the city many years ago for lack of mosquito spraying.
Anderson recalled how about 20 years ago she was not able to stand still on her property because of the mosquitoes.
Now this year she can sit out on her deck until about 9 p.m. and not worry about the pests, she added.
“You can’t get them all,” Anderson said. “God bless them (public works). They’re doing a good job.”
The backwaters of the Rum River to the east of Fifth Avenue North where Anderson lives is a mosquito breeding ground, Anderson added. Gerold agreed.
Mosquitoes are noticed more this year not just in the city. Linda Evans, who lives along the Rum River in rural Princeton, said this has been one of the worst years for mosquitoes at her residence.
Gerold has one suggestion for how residents can help prevent the breeding of mosquitoes. Look around where rain water can collect, such as parts of playground equipment, and old tires and buckets. Remove any water and keep it from collecting, if possible, Gerold suggested.

  • dLine

    The easiest way to get rid of these mosquitoes is to use a repellent and I found one very effective on Amazon it’s called Sweetly Citron. It has a pleasant smell and all natural so it’s safe for the whole family.

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