Mosquito Control Options for Homeowners

Do those new devices really work?

Mosquito season has arrived! And with it comes more outdoor time, and a concern about how best to protect ourselves from mosquito bites. With the spread of the West Nile virus, more of us concerned about the possibility of mosquitoes as disease carriers, and so we want to keep mosquitoes off of our property and lessen the likelihood of mosquito bites.

Currently consumers are inundated with advertisements for several devices that promise to reduce or eliminate mosquito populations. One model generates carbon dioxide (CO2) that acts to lure mosquitoes to the device, and then another part of the device collects them into a bag where they will die. Several spin-offs of this model use other Aattractants@ such as octenol (another chemical attractant for biting insects), to lure the mosquitoes into the trap. These have recently appeared on the market targeting homeowners. These devices retail for $300.00 to $1,400.00 for the initial investment. At 21 B 30 day intervals, the fuel that generates the CO2 and the octenol must be replaced at the buyers expense.

At this time there are no published scientific studies to support the claims from the manufacturers of the these products. The CO2 baited traps will, indeed, catch mosquitoes - a bag full every night in some locations. But can they Adecimated a population of mosquitoes@ as the advertisements claim? Reduce West Nile virus transmission to humans? Control mosquitoes on an entire acre? Researchers at the University of Florida/Florida Medical Entomology Lab will be working to study the devices this summer.

Here are some things to think about and consider when making an educated decision about spending money on mosquito control products and devices.

• Female mosquitoes are indeed attracted to carbon dioxide (CO2). This is the cue they follow to find a Ahost@ (blood-meal). Entomologists have been using CO2 as Abait@ for years to attract mosquitoes for research purposes. Evaporating dry ice is an excellent mosquito lure. The devices that are on the market take advantage of this known aspect of mosquito behavior and the WILL capture mosquitoes. When you see a half-gallon collection bag that is full of mosquitoes, the perception is the device Aworks great.@ Salt-marsh mosquitoes emerge as adults by the millions. One impressively large collection, a Abag full@ is a minute percentage of all the host-seeking females and will not likely impact these very large populations.
• There are 77 different species of mosquitoes in Florida Each species varies in what host they bite, the time of day they feed, and how far they can fly. Not all of the mosquitoes that bite humans are attracted to these traps. An important example of this is Aedes albopictus, the AAsian Tiger Mosquito@ that spends its immature stages in tires, vases, bowls, and other water-holding devices that may be found around the yard. This species is a primary biting pest for homeowners, and one that most Florida residents will encounter. This species is not attracted to these advertised traps. The best recommendation for reducing this species is to dump out the water every 3-4 days or to remove the container.
• Advertisements claim that the trap will decimate a mosquito population in 4-6 weeks. The life span of an adult mosquito varies with species and temperature, but populations of many mosquitoes that are the target of these devices will often begin to decline naturally within a few weeks if left alone, particularly if rainfall is intermittent and sooner if mosquito control is conducted in the area. There is no evidence that these traps can play a noticeable role in the decline of mosquito populations.
• Taxpayers who live within a mosquito control district in Florida pay considerably less per year for mosquito control than they would pay for the initial investment and continued attractant supply and maintenance of these traps.
• There may be certain circumstances where the mosquito trapping devices can indeed reduce mosquito-biting activity in a small area for a specific time period. Several factors would have to be optimal for this to be true:

1. There should be little wind to disrupt the attractive CO2 cloud
2. The mosquito numbers are manageable to begin with
3. The attractant plume is more substantial than large numbers of people

As with all consumer products, the Abuyer beware@ attitude is always good advice. The only available results of how well these devices work are testimonials from those who have purchased them. Such testimonials do not incorporate controlled studies or proper data analysis. As the University of Florida Medical Entomology Lab completes their scientific testing, the results will be released, and added to this page.

For information on how to control mosquitoes on your property contact the Broward County Extension Education Division and request the publication AMosquito Control for the Homeowner.@ You may contact the division at 954-370-3725 or by e-mailing mpeters@broward.org.

This information is based on that provided by Dr. Roxanne Rutledge, Medical Entomologist at the University of Florida Medical Entomology Lab in Vero Beach, Florida.