Keeping The Buzz At Bay

Bergen County is working hard to control mosquitoes, and there are steps you can take to do the same.
Buzz At Bay


Matthew Bickerton is a trapper, but his quarry isn’t fox or marten, and he doesn’t have to venture into the woods to track it down. In fact, Bickerton doesn’t particularly want to find anything in his traps, though at this time of year they’re never empty.

As an entomologist with Bergen County’s Department of Health, he’s after decidedly smaller game—specifically, mosquitoes—and he’s not out to kill them, but to count them. His discoveries help the county’s Department of Mosquito Control determine where the pests are breeding; what diseases, if any, they’re carrying; and how bad they’re going to be this year—an estimation that depends largely on prevailing weather conditions.

“Warm and wet works for mosquitoes and virus,” he says, referring to West Nile virus, the predominant disease transmitted from mosquitoes to humans. Last year in Bergen County, June was very warm and very wet, as were July, August and September, and the mosquito population was one of the highest in recent memory. Water is a particular problem because it’s where mosquitoes lay their eggs. From the Meadowlands to your backyard birdbath, those eggs are getting ready to hatch into the tiny larvae, known as wrigglers, that will become full-fledged mosquitoes in a matter of days, their sights (or, better put, their proboscises) trained on you and your family.

That doesn’t mean the county isn’t hard at work keeping mosquito populations down, or that there’s nothing you can do to keep the pests from ruining your summer. In both cases, though, diligence is required. Bergen is home to some 40 different species of mosquito, each behaving somewhat differently. “Some,” notes Warren Staudinger, director of the county’s mosquito control department, “are really dependent on rain—those are our floodwater mosquitoes. Others like stagnant water—we call them backyard, container-inhabiting mosquitoes.” Most tend to feed at dawn and dusk, but at least one species—the Asian tiger mosquito, so called for its striking black and white stripes—is perfectly comfortable chowing down (on you) during the day as well.

You probably don’t need this article to tell you that mosquitoes are at their worst in July, August and September. “That’s when the phone rings off the hook,” says Staudinger, “and the Asian tiger mosquito is the cause of most of those complaints.” When asked what residents are complaining about, Grace Grootenboer, the county’s chief mosquito inspector, laughs, but not without sympathy. “That they’re getting chewed alive,” she says. “That they’re being carried away.”

It may be hard to believe, but if it weren’t for the county’s mosquito control efforts, things would be a heck of a lot worse. The chief objective is to get the larvae before they become biting adults. To do that, the county sprays with a bacterium known as Bacillus thuringiensis, or BTI, which is lethal to mosquito larvae but, according to the Centers for Disease Control & Prevention, harmless to people and other mammals, fish, birds and other insects. Some spraying is done by helicopter, especially over large areas like the Meadowlands and the county’s northern flood plains, but it’s also done by hand.

Because it’s impossible to get every mosquito in the larval stage, says Staudinger, the county also sprays for adult mosquitoes, with a class of insecticides known as pyrethroids, synthetic formulations that are similar to the insecticide pyrethrin, derived from the chrysanthemum plant. In safe doses, pyrethroids aren’t toxic to humans and other mammals, but they do kill most insects. To keep them from killing off large numbers of beneficial insects such as bees and butterflies, the county usually sprays between 4 and 5 a.m., when insects other than mosquitoes aren’t likely to be out and flying.

Determining where to spray is crucial. Inspectors rely on an electronic database cataloging known mosquito habitats; after a heavy rain, they’ll check traps in those habitats to see if any of the mosquitoes are harboring West Nile virus. If they find what Staudinger calls a West Nile “hot spot,” the county will spray, usually with truck-mounted units.

It will also spray residential properties, if requested, at no cost. But Grootenboer offers a caveat: “Some people think that the treatment is a preventative, and it’s not. It will only knock down the mosquitoes in flight at that time. The real preventative is for residents and their neighbors to maintain their backyards.”

In fact, many of the mosquitoes that plague us in our backyards were born and bred there, or nearby, on our neighbors’ properties, and container-born mosquitoes—those that hatch from eggs laid in containers such as birdbaths, baby pools, old tires and tarpaulins—represent the county’s number-one mosquito problem. With that in mind, the county developed a program known as Bergen Bites Back (, offering resources for residents who want to learn about, and combat, mosquitoes (and those other backyard menaces, ticks), including links, downloadable materials and a checklist of common mosquito habitats.

Saddle River resident Stephen Wiessner, executive director of Englewood’s Flat Rock Brook Nature Association, notes that “the No. 1 thing I do to discourage mosquitoes in my own backyard is to remove all standing water.” The word “all” is key: Mosquitoes have been known to reproduce in a water-filled soda-bottle cap. Birdbaths are OK, as long as you change the water at least every five days, which is how long it takes a mosquito larva to turn into an adult. Other common traps for standing water are buckets, recycling bins, watering cans, kids’ toys and plant saucers (for a complete list, go to the Bergen Bites Back site). Don’t forget to check your gutters; if they’re blocked, they can accumulate water. And those flexible downspout connectors? If they’re not pitched steeply enough, they can collect water in their ridges (a favorite spawning site for Asian tiger mosquitoes, according to Staudinger). If you have a pond on your property that isn’t stocked with fish (which happily gobble up mosquitoes and their larvae), you can add BTI in the form of mosquito “dunks,” widely available online.

In addition to removing water, advises Debora Davidson, executive director of the Tenafly Nature Center, “remove excess debris, like toys, lawn furniture, leaves, fallen branches and overgrown vegetation from your property so mosquitoes don’t have many places to ‘hang out.’”

For any of these measures to be truly effective, of course, you’ll need to spread the word to your neighbors and get them to join in. Even so, you’re not likely to knock out every mosquito in the neighborhood. That’s where mosquito deterrents and repellents come in. The most effective repellents contain DEET (diethyltoluamide), an oil that’s been proven to repel mosquitoes and other biting insects over a long period of time (the more DEET in the product, the longer it works). A study published in the New England Journal of Medicine found that while other substances, including soybean oil, mineral oil, citronella and some essential oils, do repel mosquitoes, none works for very long and all require frequent reapplication.

Staudinger notes that it’s especially important for older residents and those with compromised immune systems to use an effective repellent in order to protect against West Nile virus. In fact, says Bickerton, “most people who become infected with West Nile don’t even show symptoms. But people who are immunocompromised can get extremely ill with the virus.” The number of serious cases in Bergen County tends to be small: three cases in a typical year, with 10 cases representing an annual record. But for vulnerable people, avoiding contact with infected mosquitoes is critical.

What you wear outside can make a significant difference. Long sleeves and long pants offer great protection against mosquitoes, as long as they’re loose-fitting. Bickerton warns that “mosquitoes can get through tight-fitting clothing,” which allows them to make direct contact with the skin; avoid fabrics like lycra and spandex. In addition, avoid wearing dark colors, which attract mosquitoes. Of course, covering yourself head to toe on a hot and humid day isn’t particularly pleasant—the bugs may not get you, but heat prostration may.

If you’re eating or socializing outside, the solution may be as simple as a fan. A study out of Michigan State University found that a simple house fan was effective at repelling mosquitoes, both because the insects find it hard to navigate in strong winds and because the breeze from a fan disperses exhaled carbon dioxide, a strong mosquito attractant.

Recently, many Bergen yards have sprouted lawn signs advertising that they’ve been treated by a mosquito control service such as Mosquito Shield or Last Bite. If you’re thinking of going that route, Bickerton advises, do your due diligence: Find out what they spray with and whether it can be harmful to you, your pets, or backyard inhabitants like birds and beneficial insects. How do they apply the spray? “I’ve heard of instances where they’re spraying the lawn, which doesn’t make sense because mosquitoes don’t hang out on the lawn,” says Bickerton. You may also want to make sure that your neighbors don’t object, since sprays will inevitably drift to adjoining properties. Finally, advises Staudinger, confirm that the company has a commercial applicator license.

Don’t waste time and money on “solutions” that don’t solve the problem. Some ultrasonic devices, for example, have actually been shown to attract mosquitoes. And citronella, which in large concentrations can repel mosquitoes, doesn’t do the trick when used in candle form. So-called bug zappers, which use light to attract insects and then electrocute them, are great at killing moths and other night-flying insects, but not mosquitoes, which aren’t attracted to light. And Bickerton notes that plants touted for their mosquito-repelling properties—marigolds and eucalyptus, for instance—have been shown to be largely ineffective. On the other hand, they look pretty and smell nice, which can go a long way toward making summer pleasurable, with or without mosquitoes.

The takeaway: If you want to keep mosquitoes out of your yard, be diligent about hunting down and emptying sources of standing water. If you want to keep them off your skin, use an effective, long-lasting repellent. And if you need some good news: Hey, autumn is just a couple of months away.

By Leslie Garisto Pfaff

Categories: Bergen Health & Life, Homepage Features