Summer means mosquito season. There are over 3,000 different species of mosquitoes in the world, and about 200 in the U.S. alone, . Typically, mosquito activity starts when overnight temperatures start to stay above 50 degrees or so. Not all mosquitos carry diseases, but several species like Zika and West Nile Virus. Mosquito species have different activity patterns and feeding preferences (some bite birds; others prefer mammals like us humans), but they all share the same basic life cycle and habitat preferences, which means you can control them all the same way. The techniques that work best have one thing in common: they make your home inhospitable to pests.
All mosquitoes lay eggs in water, and they need precious little of it. Reducing, if not eliminating, standing water is the first step in eradicating the mosquito threat. "We create all sorts of areas for water to collect, which provides a breeding ground for mosquitoes," says Ross Jundt, a mosquito and tick expert who owns several Mosquito Squad franchises in the Twin Cities area.
A 6-inch-diameter plant saucer with only 1/2-inch of water can be enough for mosquitoes to reproduce. "All they need is eight to 10 days for eggs to turn into adult mosquitoes," Jundt points out. "It doesn't take long."
He advises dumping out any item that contains stagnant water, such as plant saucers, dog bowls, and bird baths, on a regular basis. Then, if needed, fill them with fresh water. Replace water in sources like dog bowls and bird baths at least daily; most mosquito eggs hatch within 48 hours (plus, your dog will thank you).
Kid's toys, buckets, wading pools, and anything else that holds water but you don't want to throw out should be flipped over when not in use so they don't fill with any water.
"Really, we're our own worst enemy. We create mosquito habitats close to our house," Jundt says. If your yard has items you don't need and that hold water, get rid of them. Old tires are a notorious culprit. They not only retain water, but provide a warm, sheltered environment that's perfect for mosquito breeding. Throw them out. If you're using a tire for a swing, drill a hole in the bottom so water can drain freely.
The best time to look is right after a rain storm, when water collects in small items you might not think of as problematic.
Over winter, your gutters may have filled up with debris and won't drain properly. Clean out gutters and downspouts to make sure water doesn't pool and create a welcome breeding environment.
Fix holes in window and door screens so that any mosquitoes that are around don't become an inside problem. Finally, pull weeds near foundations and keep your lawn mowed to a low height to reduce habitat.
Mosquitoes like still or stagnant water, so make sure that pools are properly chlorinated and maintain the filter. Clean filters in fountains and run them frequently, which helps deter mosquitoes from laying eggs there.
For water that accumulates in fish ponds, ditches, or rain barrels, use "mosquito dunks" to kill mosquito larvae. Roughly the diameter of a quarter, a dunk is dropped into standing water and releases a natural larvicide called Bti (a bacteria: Bacillus thuringiensis) that kills only mosquito larvae—it won't harm fish, birds, or other animals. You can buy the dunks at home centers. They cost about $10 for a six-pack, which kill larvae for 30 days in 100 square feet of stagnant water.
If you're using a tarp to cover a pile of firewood, a speedboat, your grill, or any other large items, make sure it's pulled tight. Otherwise, rainwater pools in the folds and the low spots. If the tarp can't be pulled tight, remove it so the water drains.
Most garden supply and hardware stores sell sprays or granules for insect control in the landscape. Use them sparingly, and only if necessary; most feature pyrethrins or their synthetic version, pyrethroids. Pyrethrins are natural insecticides derived from chrysanthemums, but natural does not mean non-toxic, and pyrethrins , according to the National Pesticide Information Center.
Pyrethrins also kill a variety of insects: mosquitos and ticks, but also pollinators like honey bees and beneficial insects like ladybugs. If you decide to spray on your own, pick a calm day to reduce drift. If you hire a pro, ask to see a license, and what chemicals they'll be using.
If you're outside when mosquitos are active, insect repellant and long sleeves are the best way to avoid getting bitten. You can use repellants like citronella and fans, but they're not a complete solution.