Does Electrifying Mosquitoes Protect People From Disease?

Maybe a little, but that’s not why bug zappers are so popular. An Object Lesson.

I spent my childhood in Addis Ababa, Ethiopia, where I was tormented by mosquitoes day and night. I happen to be one of those people whom the bugs find very attractive. My legs and ankles were perennially so bitten that sometimes I was asked if I had a skin disorder. Now I live in Jamaica, and the mosquito torment continues. Last year, I contracted Zika. For these reasons and others, I must reluctantly admit: I’m a mosquito killer. And I’ve sought methods for revenge.

The bug-zapping racket is a fantasy come true. It is a tennis racket-like device with electrified wires instead of strings. Its wielder waves it through mosquito airspace. Then: a satisfying sizzle. Goodbye pest.

Although invented as an efficient way to snuff out winged enemies, the popularity of these zappers might service human nature (and its dark side) more than human health.

* * *

I first acquired a Chinese-made insect zapper at a grocery store in Kingston, Jamaica. I had already lived in the tropics for about a year, stubbornly refusing to buy what I was sure was a gimmick. But after watching my neighbor wave at mosquitoes with zest, crowing victoriously as she heard the telltale snap of a mosquito meeting its end, I decided to finally give it a try. Zika was spreading and, besides, it looked fun.

Once I brought my zapper home, I spent some quality time happily waving my new magic wand at every flying insect. I was a convert. I wondered about the effectiveness. Could they replace the weekly insecticide sprayings that I had come to dread in my neighborhood?

The idea of electrocuting insects goes back more than a century. In 1911, Popular Mechanics ran an article about an “electric death trap” for killing flies. The device, a squat cage whose wires carried a current of 450 volts, had a bit of meat placed inside as bait. The magazine judged the bulky contraption “too expensive ever to come into more than very limited use.”

This “electric death trap” was a far cry from today’s portable zappers, passing judgment like Zeus with his thunderbolt (a popular design on zappers, it happens). The contemporary bug zapper was invented in 1959, when Thomas Laine envisioned a device that would kill insects on contact, rather than by being “crushed or otherwise mutilated in a messy manner.” This electrified flyswatter would have “a voltage sufficiently great to kill a fly having parts in contact” with its screens.

But Laine’s bug zapper seems to have been a false start. It looked a lot like today’s zappers, but it’s unclear if it ever came to market. Instead, a Taiwanese inventor, Tsao-I Shih, is often credited with inventing the modern bug zapper, an “electronic insect-killing swatter,” in 1996.

While most zappers resemble tennis rackets, they probably owe just as much of their design to the fly swatter. Robert Montgomery, who patented that device in 1900, was the first to come up with using wire netting to give it a “whiplike swing.” It was far more aerodynamic than newspapers or whatever crude implement happened to be at hand to bat at insects. And later, perfect for electrifying.

The golden age of bug-zapper innovation arrived in the mid-aughts. A slew of inventors filed patents for devices with slight variations: adding lights, or flexible, shock absorbent handles. One racket even boasted a bait tray, which according to its inventor was especially useful: When “dead insects fall into the tray, they are now bait for their carnivorous buddies.”

It was also around this time that bug zappers seemed to take off commercially. And in the decade or so since, bug zapping rackets have become ubiquitous—at least in the tropics. They are marketed as “chemical-free” and environmentally friendly, fun, and cheap.

* * *

Do these gadgets work? It depends on what a bug zapper is expected to do.

When a zapper comes into a contact with a fly, mosquito, or other insect, it delivers an almost certain death. Smaller insects appear to be vaporized by the rackets, vanishing without a trace. For me, that’s made the bug zapper a useful aid to domestic sanity. At night, mosquitoes would drive me half-mad buzzing around my head. Ending the nocturnal torture meant getting out of bed and turning on the lights. Then, with sleep-blurred senses, I would fruitlessly try to nab the insect mid-air. When that failed, I would have to grab a swatter and wait for the mosquito to land. With a zapper, I can lie in the darkness, barely waking up, and just wait for unsuspecting mosquitoes to blunder into it.

In that sense, the zapper works: It kills bugs its operator can find, and in a gratifying way. But when it comes to controlling vectors for disease, the zapper is no panacea. “They are more of a toy than anything else,” explains Joe Conlon, a Florida-based technical advisor to the American Mosquito Control Association. “It will knock down a few mosquitoes and your kids might have fun with it … but in these days of Zika virus and chikungunya, or dengue, you need to get serious about this stuff,” he said. The mosquito is responsible for more animal-related deaths than any creature, spreading malaria and West Nile virus, too. The tsetse fly, which transmits sleeping sickness, is only the fifth deadliest, according to the Gates Foundation.

Conlon is a retired military Navy entomologist who has been in the mosquito-control business for over 40 years. He tells me that the zapper’s main flaw is simple: In order for it to work, humans have to be able to see the bug first. Bug zapping rackets work well in an enclosed space, like a room with closed windows or window screens. But they don’t work so well outside where mosquitoes can hide more effectively and more easily approach from behind.

Mosquitoes like the disease-carrying Aedes aegypti like to feed on the lower extremities. Zapper-wielding humans might not notice one until after it has delivered its payload of Zika or malaria. My own case is instructive. Most likely, I contracted the disease at a pool party, where I didn’t have (and probably shouldn’t have had) my electrocuting racket poolside.

There are about 178 different species of mosquitos in the United States. According to Conlon, the bug zapper is probably most effective against the Culex pipiens, the common house mosquito. Culex pipiens can transmit the West Nile virus, so a zapper should never be used as the sole way of controlling mosquitoes. Instead, Conlon suggests using one alongside other mosquito-control methods like repellents, pesticides, and physical barriers—clothing and window screens.

Uli Bernier, a research chemist with the USDA’s Mosquito and Fly Research Unit—and the “world’s foremost authority on repellants,” according to Conlon—says the rackets have worked well for his lab. For his work developing repellants, he goes through around 12,000 mosquitoes weekly. He zaps about 15 to 20 per day, when they escape from their traps.

* * *

Given their dubious effectiveness, mosquito zappers might be best understood as a dark form of insect-slaying entertainment. Like me, Bernier is one of those people who attracts mosquitoes. In fact, he often challenges visitors to compare mosquito attractiveness by putting their arms in a mosquito cage to see who draws the most bugs. So far, he’s only lost once. “It’s fun to electrocute mosquitoes,” Bernier admits. Zappers seem to bring out a particularly bloodthirsty element in their owners, many of whom describe zapping bugs into the afterworld with great relish.

Some brands of bug zapper cater to this murderous tendency with names like “The Executioner”, “The Terminator,” and “Warrior Supreme.” One racket is the shape of a human hand—presumably so that in their final moments bug victims can be clear about the intent and source of the attack. “Have fun killing mosquitos!” reads the advertisement. “Better than Call Of Duty!” says one review, referring to the popular video game.

That amusement extends beyond the murder of bugs. Some people are so attracted to the lure of the zapper that they find it just as fun to try it out on themselves. When Bernier first got a mosquito zapping racket about 10 years ago, the first thing he wanted to do was see how much it would hurt to touch the electrified grid. Powered by two double-A batteries, it couldn’t hurt that much, could it? I confess that, I too, have been tempted, but I haven’t tried it. People report that it stings.

“Sometimes you just can’t help yourself,” says Jamie O’Boyle, an analyst at Philadelphia’s Center for Cultural ​Studies and Analysis who examines the way subconscious thinking drives human choices. He explains that this behavior is driven by human curiosity and our tactile nature. “One of the things that primates do is touch stuff,” he says. Other primates engage in similar behavior such as poking anthills, knowing full well that the ants will come swarming out. With zappers, the probable delivery of a small electric shock adds a “frisson of danger” to the experiment, perhaps making it even more appealing.

Zappers are also a staple of pranksters. Many zapper-related pranks involve intoxication or the element of surprise. In a YouTube video with more than 5 million views, a woman places 100 bug zappers around her sleeping boyfriend. When she wakes him up he leaps from racket to racket, yelping as he gets zapped. Another prank revises the classic wet towel whip in the shower: Conlon, the mosquito expert, reports that some Marines like to use a bug zapper instead. Among teens and office workers, dares to stick a tongue or a finger onto the charged surface are popular.

So yes, the bug zappers do work, just not nearly well enough to make them worthwhile if they weren’t any fun. And given the dour threat of the diseases the insects carry, perhaps a little dark humor at their expense is warranted.

As Conlon puts it, “Killing mosquitoes is one of life’s simple pleasures.”

This article appears courtesy of Object Lessons.