By Barbara Pleasant
Several synthetic and organic pesticides will poison mosquitoes on contact, but they’ll provide only minimal relief. The best way to reduce mosquito populations in your yard is to eradicate breeding sites and also install both passive and active mosquito traps.
Mosquitoes need water to breed — their larvae are the “wigglers” you can see in neglected buckets of water if you look closely — so you can naturally limit mosquito swarms by eliminating breeding sites in your neighborhood. To do this, always empty water from open containers, old tires and other potential breeding grounds within five days after a heavy rain. Add a product called Mosquito Dunks (made with Bacillus thuringiensis) to rain barrels and other standing-water supplies for a safe and easy way to prevent mosquito larvae from hatching. Or, let fish do the trick — preferably native minnows. You can purchase traps at a sporting goods store that have been designed to collect the minnows from a pond, and then release them to feed on larvae in your rain barrel or water garden.
You won’t need many minnows — fish are some of the best mosquito traps available. One fathead minnow can eat 74 mosquito larvae per day. A study from Rutgers University recommends 10 gambusia minnows for one standard rain barrel, and 35 to 100 for a water garden, depending on its size. Similar stocking rates would apply to arroyo chub minnows or fathead minnows.
Some of the best mosquito traps use multiple attractants — light, carbon dioxide and an attractant called “octenol” — to lure mosquitoes and then suck them in with a fan. A University of North Dakota professor of biology collected data in 2002 showing that the Mosquito Magnet caught 8,000 female mosquitoes per night during peak-summer season. The Mosquito Magnet is pricey, starting at $400. The cheapest Mega-Catch model costs much less — $150 with lures — and is a good fit for smaller yards. Shop carefully: Some anti-mosquito products actually spray chemical pesticides into the air — and those pesticides could be toxic to you, too.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.