While we’re still in the thick of the wet, muddy havoc of Winter Melt-Off 2019—and the Cannon River is still receding from its escape from its banks—the minds of optimists are deep in dreams of warmer spring and hotter summer weather. The ongoing joke claims Minnesota has only two seasons: Snow and Construction. I thankfully don’t drive often enough through construction zones to have it impact my life in such an acute and disparaging way, but I do have my own, rural version of our state’s two-season condition: Snow (there’s always snow) and Mosquito.
I had hopes that the record-breaking freeze would wipe out most of this year’s mosquito population, only to be corrected by a friend who said the mosquito population will be in full-swing, if not extra potent, this year due to the resulting wetness of the still-lingering snow. Even folks in Georgia are expecting bad mosquito populations this year, so it’s not just us Mid-Westerners suffering. Drat.
I have my own, rural version of our state’s two-season condition: Snow (there’s always snow) and Mosquito.
In my last Local Wild column, I discussed the snow midge, a wintry mosquito doppelganger. Midges are unlike mosquitos in that they have no biting proboscis, don’t carry disease, and, other than being annoying when they swarm, are harmless to humans. However, like midges, mosquitos are surprisingly hardy over-wintering insects.
Exactly how a mosquito endures cold weather differs by species, but most of them will go into diapause—a state akin to, though different from, hibernation—when temperatures drop below 50°F. According to Pestworld.org, “The mosquito responsible for transmitting Zika…overwinters in the egg stage. … [Eggs stay] in water-holding items [and] enter a state of diapause, a process that suspends their development during the coldest months.” For some species, adult females die after a final spout of winter egg-laying and the eggs go into diapause; adult females of other species may not die, but will instead hide (in the ground, a tree hollow, a barn, etc.) and go into diapause themselves.
Diapause is activated by hormones that pause an organism’s development until better conditions ensue. Adult female mosquitoes who go into diapause can extend their usual 6 to 8-week lifespan to up to 6 months, allowing them to wait out most winters unscathed and ready to propagate when they warm enough to awaken, like this week when we’re expected to hit 50+°F.
But enough about the wonders of mosquito over-wintering. What about how to control them in the spring and summer?
Standing water from overflows of the Cannon River could result in unanticipated ponding, creating massive breeding grounds for mosquitos. / Jessica Woken
First, the obvious: Get rid of any standing water or containers that might catch and hold water, including recesses in the ground that may turn into long-standing puddles.
Next, kill or deter the existing mosquitoes by use of chemicals, electric zappers, or a combination of natural methods, like chickens and plants.
If you’re not one to spray vast areas with pesticides and are hesitant to invest in an electric mosquito trap—they can range from $50 to $900—consider planting (in a garden), potting (around the house), or pruning (native plants) the following to help keep mosquitos at bay:
- Plant or pot: Citronella, lemongrass, lavender, peppermint, basil, lemon balm, rosemary, sage, marigold, chrysanthemums, garlic, catnip
- Prune: Wild Mint, Sweetgrass*
Wild Mint. Image: Wikimedia Commons. Lazaregagnidze (photographer), 11July2011.
As a bonus, mosquito-repellent plants offer up a side of landscape beautification as well as opportunity to attract beneficial insects we actually want around, like bees and butterflies.
Keeping chickens may also help control the mosquito population, as the birds will do their able share of eating as many mosquitoes as they can. (I’ve seen members of my own flock race across the yard in hot pursuit of a mosquito snack.) Some researchers believe chickens may be the next big thing in mosquito control and malaria prevention! Keep in mind, though, that having chickens can also backfire if their run is prone to muddy puddles or the coop isn’t kept clean and dry, both of which serve as excellent mosquito housing.
Good luck, and Happy Mosquito Season! (I think?)
*Author’s Note: Sweetgrass is a natural insect repellent traditionally used by Native Americans. It’s key chemical, coumarin, is also the special ingredient that makes Avon’s ‘Skin So Soft’ a popular insect-repellent lotion!
 Walker, Doug. “Mosquitos could be a big problem this spring.” Rome News-Tribune, 01Mar2019. URL: http://www.northwestgeorgianews.com/rome/news/local/mosquitoes-could-be-a-big-problem-this-spring/article_905cd592-3c47-11e9-a80d-3fa27c05430e.html. Accessed: 21Mar2019.
 Horowitz, Kate. “Could Chickens Be The Mosquito Repellants of the Future?” MentalFloss.com, 20July2016. URL: http://mentalfloss.com/article/83461/could-chickens-be-mosquito-repellents-future. Accessed: 21Mar2019.
 “Using Sweet Grass To Repel Mosquitoes”. CBS MN, 19Aug2015. URL: https://minnesota.cbslocal.com/2015/08/19/using-sweet-grass-to-repel-mosquitoes/.