Although bug zappers have been in use for decades, studies have questioned their effectiveness.
In 1996, University of Delaware researchers Timothy Frick and Douglas Tallamy published a study in the journal Entomological News. They had collected and identified the kills from six bug zappers at various sites throughout suburban Newark, Del., during the summer of 1994. Of the nearly 14,000 insects that were electrocuted and counted, only 31 (0.22 percent) were mosquitoes and biting gnats. The largest number (6,670, or 48 percent) were midges and harmless, aquatic insects from nearby bodies of water. The researchers claimed that killing this many harmless insects would disturb nearby ecosystems. According to Tallamy, most species of mosquitoes are not attracted to ultraviolet light, and certain species only bite during the day. Tallamy claims that bug zappers are worthless for reducing biting flies, exact a heavy toll on non-target insects and are counterproductive to consumers and the ecosystem.
Other Bug-zapping Strategies
There are lots of alternative means to control insects, particularly mosquitoes. In fact, traditional electronic bug zappers may be ineffective against mosquitoes, which, as we learned in the last section, are not necessarily attracted to the ultraviolet light. Some electronic bug zappers compensate for this by emitting Octenol, a non-toxic, pesticide-free pheromone mosquito attractant.
Mosquitoes are attracted to the carbon dioxide emitted by humans in our breath and sweat, so several types of mosquito zappers try to take advantage of this. One such product emits a steady stream of carbon dioxide, Octenol attractant and moisture. Mosquitoes are attracted to this mixture, get sucked into a net, dehydrate and die. The device is powered by a propane tank, so no electricity is required. One manufacturer claims that entire mosquito populations collapse in six to eight weeks as egg-laying females are destroyed.
Another device uses a chemical that the manufacturer claims blocks the mosquito's olfactory receptors. The makers of this product say that blocking the insect's ability to "smell" carbon dioxide reduces the number of mosquito landings and bites.
Eradicating the female mosquitoes and their eggs is essential to mosquito control. Since mosquitoes lay eggs in water, you should eliminate all sources of standing water, such as watering cans or old tires. Cover any rain barrels, and if you have a pond, stock it with fish that will eat the mosquito larvae.
Commercial pesticides are available that kill mosquito larvae and adults. Municipalities often spray pesticides, particularly malathion, on a large scale in the spring and summer to eliminate mosquito populations.
For personal protection, you can use a broad-spectrum insect repellant that contains N, N-diethyl-m-toluamide (DEET). DEET repels most ticks, mosquitoes and other biting pests. Be sure to read product labels for usage directions.
Another means of personal protection from biting and flying insects is citronella oil. Citronella oil is a product of several types of plants. It is an effective mosquito repellant in high concentrations, but individual plants do not make enough oil to be effective. Citronella can also be found in candles and torch oil -- both meant to be burned outside.
If you like citronella, citronella wristbands give you an easy way to protect yourself on a personal basis.
Many people erect Purple Martin birdhouses or bat houses in the hopes that these animals will eat lots of mosquitoes. While Purple Martins and bats eat huge quantities of insects, mosquitoes are not a significant portion of their diet.
So, the search for the perfect mosquito-control device continues.
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