by Karin Apfel
As West Nile continues to expand in North America, a considerable amount of interest is being generated by the new devices designed to attract, then either trap or kill, mosquitoes. Their goal is to significantly reduce or even collapse local mosquito populations by decreasing the number of egg-laying (and blood-sucking) females. Power supplies for each type of trap varies. Those that are totally self-contained utilize propane to provide both power and a source of carbon dioxide as an attractant. One model, the GobblinTM uses methyl alcohol (fondue fuel). These units can be set a considerable distance from buildings and riding areas, drawing the mosquitoes away from human or equine activity. Other units rely on household power and must be plugged into extension cords.
All traps utilize some form of attractant that lures the female mosquito to a capture or killing device. In some cases mosquitoes are captured by an impeller fan that draws them into a net where they dry up. Other traps have sticky surfaces or electrocuting grids. All traps require maintenance.
Attractants used are generally variations of mammalian exhalations, scents and body heat. Most use carbon dioxide (CO2) produced either through the combustion of propane or alcohol or via a CO2 cylinder. This makes the devices specific for drawing blood-sucking insects. Non-target insects such as moths and beetles are largely unaffected. The CO2 is often synergized with 1-Octen-3-ol (a derivative of gasses produced in the rumen of cows) to increase attractiveness.
Some devices, such as the Sonic WebTM, attract mosquitoes through a combination of 1-Octen-3-ol and a sound pulse that mimics a human heartbeat.
According to the American Mosquito Control Association, advertising claims for acre-wide control “may be somewhat overstated, in most cases being based upon best-case extrapolations… Nonetheless, these devices will indeed trap and kill measurable numbers of mosquitoes. Whether this will produce a noticeable reduction in the mosquito population in your case will depend upon your tolerance level, absolute mosquito population size, proximity, size and type of breeding habitat producing re-infestation, wind velocity and direction and species of mosquito present”. Cost for mosquito traps range from $200 to $1800 CDN. Canadian sources include Pestalto www.pestalto.com (866) 648-7773 and Davros Developments www.mosquitoeater.com (905) 238-8150.
