How Mosquito Traps Work

Mosquito traps use attractants to lure insects

Most traps require round-the-clock operation and an electrical outlet, which compromises portability. The CO2 used as an attractant in many mosquito traps is typically produced using standard 20-pound propane tanks that must be replaced every three weeks, on average, and are rarely included in the price of the trap. Some traps use propane to provide both power and a source of CO2. The plume of CO2 mimics human exhalation, making the traps effective for capturing blood-feeding insects while leaving beneficial insects alone. When mosquitoes approach a trap, they are captured by a vacuum or sticky strip. Other chemical attractants, including octenol and Lurex, are provided via a cartridge or strip that must be replaced regularly. Many products purport to significantly reduce or even decimate the local mosquito population, but the American Mosquito Control Association (AMCA) is skeptical of such claims. An article about mosquito traps on the association's website warns consumers that "acre-wide control by these devices may be somewhat overstated," noting that many studies are conducted in controlled, screened-in areas. Many users report that their traps actually cover a much smaller area. In addition, experts caution that most studies are designed to measure the abundance and diversity of mosquito species captured by specific traps (or types of traps) in a set period of time, not whether mosquito traps themselves can control or eliminate the mosquito population in a given area.

In an interview, AMCA technical advisor Joe Conlon says that when setting up a mosquito trap, "there's a million things that can go wrong." Many factors influence how many mosquitoes are trapped; these include the mosquito population's size and feeding behavior, the trap's proximity to the breeding habitat, weather conditions such as rainfall and wind, and what species are present. Conlon recommends that traps be used in well-defined breeding habitats, such as swamps or near standing water. Most people can get protection by slathering on repellents rather than investing in a trap, he adds. In the end, most experts recommend that people who use traps also use low-tech means of mosquito control, such as larvicides and personal insect repellents.