Do mosquito traps work?Do mosquito traps work? What to know before you buy one

Mosquito traps are a crowded, confusing category, and the honest answer to whether they work is that it depends entirely on the type. The dividing line is how the trap attracts mosquitoes. Host-seeking female mosquitoes, the ones that bite, home in on carbon dioxide, body heat, and the smell of skin. A trap that imitates those cues can catch biting mosquitoes. A trap that relies on light mostly cannot, because biting mosquitoes are barely drawn to light. Get that one distinction right and most of the marketing sorts itself out.

CO2 and lure traps, like the Biogents BG-Mosquitaire and the propane Mosquito Magnet, generate carbon dioxide (from a tank or by burning propane), often add heat and a skin-scent lure, and use a fan to vacuum approaching mosquitoes into a net. These target the right cue, and the best of them are used in real mosquito surveillance and suppression programs. In published field trials, networks of Biogents traps have cut biting of container-breeding Aedes mosquitoes by half or more, reaching about 87 percent in one five-week study.

The catch, and it is a big one, is deployment. Those strong results come from multiple traps ringing a property or a neighborhood, well placed and run continuously through the season. A single unit in one backyard does far less, on the order of 10 to 30 percent, and results swing widely with placement and how many people and pets nearby are competing for the mosquitoes' attention. Propane traps like the Mosquito Magnet are the weakest of the group: an independent review found they could not demonstrate a meaningful reduction in biting pressure. Treat a lure trap as a season-long commitment that supplements repellents and source control, not a one-box fix.

UV light and fan traps (DynaTrap, Katchy) and electric bug zappers attract insects with light, which is the wrong cue. Independent university studies are consistent: mosquitoes make up only a few percent of what these devices catch, often under 5 percent, and controlled trials found no difference in yard mosquito numbers with or without them. The overwhelming majority of the catch is moths, midges, beetles, and other non-biting, often beneficial insects. Some, like DynaTrap, claim a titanium-dioxide surface makes trace carbon dioxide, but the amount is trivial next to a person's breath.

Attractant tubes like the Spartan Mosquito Eradicator are a separate cautionary tale: a plastic tube of salt, sugar, and yeast marketed to kill mosquitoes for 90 days. Independent testing found it did not attract or reduce mosquitoes, the maker never submitted efficacy data, and the product has drawn class actions and sales bans in several states. Indoor UV-and-glue traps like Katchy are genuinely useful against fruit flies and fungus gnats, just not mosquitoes.