Do Bug Zappers Work?
Many a summer’s night I would sit on my back deck and rejoice at hearing one of the most beautiful sounds on earth: the electric crackle of a mosquito that was no longer going to be feasting on my blood. Well, my fond memories of banishing mosquitoes from my backyard have now come into question. Last year while researching a tip submitted by Tip Hero Joy, Woman Outsmarts Mosquitoes with Beer, I came across this nugget on Mosquito.org:
Black light insect electrocution devices (Bug Zappers, etc.) are purchased in huge quantities by homeowners due to their demonstrated ability to attract and kill thousands of insects over a 24 hr. period. One industry representative estimates that over 1.75 million of these devices are purchased annually in the U.S.
But do they really control pest insects? Bug zappers do indeed kill some mosquitoes. However, the only two controlled studies conducted to date by independent investigators at the University of Notre Dame showed that mosquitoes comprised merely 4.1% and 6.4% respectively of the daily catch over an entire season. Even more important was the finding in both studies that there was no significant difference in the number of mosquitoes found in yards with or without bug zappers.
In fact, not only are bug zappers’ effectiveness at killing mosquitoes called into question, but they also end up killing many beneficial insects:
What is particularly disconcerting, however, is the number of non-pest insects that comprise the vast majority of trap catch. Many of these insects are beneficial predators on other insect pests. They in turn constitute a major part of the diet of many songbirds. Indeed, reduced numbers of moth and beetle prey species have contributed significantly to the decline of songbird populations in many affluent suburbs. Insect electrocution devices undoubtedly bear some responsibility for this phenomenon. source: Mosquito.org
While digging deeper into this question I came across this 1997 article from Science Daily containing an interview with Jonathan Day, associate professor of entomology with the University of Florida. Day lays out why bug zappers are ineffective:
“The main reason bug zappers don’t work is that mosquitoes are extremely sensitive to carbon dioxide,” Day said. “They see the UV light in your yard, but once they pick up even the slightest trace of carbon dioxide from people, they change direction and zero in on the source of that odor. They are expert at detecting carbon dioxide at levels as low as 50 parts per million.”
So bug zappers may have the direct opposite effect intended — by attracting more mosquitoes to you. The light attracts the mosquitoes to your general area and, once they sense carbon dioxide in the air, they make a bee-line for you.
Day also brings up another interesting point about bug zapper producers’ latest efforts to get people to enlist them in their fight against mosquitoes:
Even some of the new electric bug zappers that have been fitted with an octenol packet — which he described as “the latest marketing gimmick” — are virtually useless for controlling mosquitoes. Compared to the powerful attraction carbon dioxide has for mosquitoes, octenol is a minor chemical insect attractant and will not improve the overall performance or effectiveness of the device. source: Science Daily
It looks like I’ll be pulling the plug on my bug zapper this season.
Tip Heroes, what do you use to fight off mosquitoes? Please share your experiences in the comments below.
Photo credit: Fly Again
