Where mosquitoes, flies and ticks are biting this summer

Excited for bikini and boardshort season? So are the biting bugs of summer. Mosquitoes and other nipping flies, such as horse, black and greenheads, thrive in warm environments (80 degrees is ideal) near a water source, such as a lake, river or baby pool. Ticks are also out in full force, hitching rides on passing hikers. Basically, every summer vacation destination is full of bugs.

"In terms of mosquito season, I think it's here. It's upon us," said Michael Raupp, an emeritus professor of entomology at the University of Maryland.

In tropical locales, bug season is always in full swing. In cooler climes, it is shorter but no less intense. Alaska and Maine claim the mosquito as their unofficial state bird, after all. Though colder spring temperatures can delay the insects’ arrival, once the weather starts to heat up, the pests will get busy, breeding and biting.

"Every year is kind of bad no matter what, and certainly for people traveling locally as well as internationally," said Laura C. Harrington, a professor of entomology at Cornell University. "There are heightened concerns about mosquito- or tick-borne diseases."

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Experts say global warming has been a boon to insects notorious for crashing summertime outings. Unfortunate for us, they have been expanding into new regions and sticking around for longer.

"With climate change, we’re definitely noticing changes in activity," Harrington said. "We’re seeing shifts in the movement of mosquitoes and ticks into areas where they hadn't been before."

Jessica Ware, associate curator of invertebrate zoology at the American Museum of Natural History in Manhattan, urged summer lovers to not vilify all insects. Some are actually on our side, such as dragonflies, which eat mosquitoes. But she understands our antipathy for the blood suckers.

"It's okay to hate mosquitoes and to not want to be bitten by black flies," said Ware, who helped develop the museum's new insectarium, "but those are just a tiny fraction of the million and a half insect species out there."

Here is how to avoid becoming an all-you-can-eat buffet for some of the worst biters of summer.

Mosquitoes are incredibly annoying. They’re also dangerous.

The females — the biting half of the duo — can transmit a number of diseases, such as dengue, Zika and chikungunya. The Centers for Disease Control and Prevention has detected all three illnesses in the United States and its territories within the past year, including Florida, Hawaii, Texas, Puerto Rico and the U.S. Virgin Islands.

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Malaria is less common in the States. Of the 2,000 annual cases reported domestically, the CDC said most of the patients contracted the parasite while traveling in such malarial hot spots as sub-Saharan Africa or South Asia. West Nile, however, is widespread. Only four states — Alaska, Hawaii, Montana and Maine — are free of the virus, according to a CDC map current through Jan. 10.

"West Nile is the most common mosquito-borne pathogen in the United States," Harrington said.

Across the Atlantic, the European Center for Disease Prevention and Control (ECDC) warns of the rise of mosquito-borne diseases spread by such invasive species as the Asian tiger, Asian bush and yellow fever. In 2021, the organization reported cases in Greece, Italy, Hungary, Romania, Spain, Germany and Austria. Ten people did not survive.

Last year, Northern Italy suffered a rash of West Nile infections, with the Veneto region experiencing the brunt of the outbreak. This year appears more promising: As of May 31, no E.U. country or neighboring nation has reported a human case of West Nile.

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With more than 3,000 species of mosquitoes worldwide, and about 200 in the United States, your bare skin is rarely safe. Some mosquitoes bite at dusk and dawn; others prefer dining during the day.

"We call them day-biting mosquitoes and night-biting mosquitoes," Ware said. "That means you probably can be bitten any time of the day."

To help people prepare for the outdoors, AccuWeather created a seven-day mosquito forecast, which factors in breeding conditions, gestation periods and weather. Values range from "extreme" (e.g., Miami) to "low" (Provincetown, Mass.).

"We developed an index that really looks at what the life cycles are and how many mosquitoes there are going to be at any given time," said Marshall Moss, vice president of operations quality and innovation with AccuWeather. "How long they’ll last varies a bit on weather. So that is factored in, too."

Last May, the company that makes Off! bug repellent introduced a similar tool called Off!Cast Mosquito Forecast, a collaboration between SC Johnson's Center for Insect Science, Google Cloud and Climate Engine. The service debuted with U.S. destinations and expanded to Brazil in February, with plans to add more markets in the future.

Tom Mascari, an entomologist at the Center for Insect Science, provided an early summer projection: "Over the past several weeks, areas of Florida, including Fort Myers, Naples, West Palm Beach, Miami and Fort Lauderdale, have seen severe mosquito activity while states such as Texas and Louisiana are beginning to experience very high activity."

Protect yourself from mosquitoes, and their future generations, by disrupting their breeding grounds: Dump vessels containing standing water, such as grill covers, sand pails or red Solo cups. To deflect bites, wear light-colored clothes that cover as much exposed skin as possible. (Mascari said mosquitoes are drawn to dark garments, the carbon dioxide you release while breathing, body heat and lactic acid.) Before heading out, liberally spray yourself with a bug repellent approved by the Environmental Protection Agency.

Raupp chooses his repellent based on his setting and amount of exposure. He uses oil of the lemon eucalyptus, a botanically based product, if he's puttering around the yard for several hours. For tromping through salt marshes, he will spray on picaridin, which provides six to eight hours of protection. In a tropical rainforest, where he is at risk of contracting dengue, yellow fever or malaria, he will pull out the hard stuff: DEET.

When choosing a DEET product, look for 30 percent concentration. You don't need to go much higher. The CDC said levels above 5o percent do not provide additional protection.

The pros of black flies: They are not disease vectors. The cons: Their bites feel like a hard pinch from the meanest kid on the playground.

"Black flies are really good at feasting on us," Ware said. "They have mouth parts like a cheese grater. They make a little scrape and dab up the blood. It's very painful."

Black flies are found all over the world. They often congregate in areas with moving water, such as streams and rivers, where they lay their eggs. Only the females bite, and they dine indiscriminately.

"You can be bitten anywhere, but you’re less likely to be bitten by a horse or black fly in downtown Manhattan than you would in the Pine Barrens of New Jersey or on a river in Upstate New York," Ware said.

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Harrington said deer flies, horse flies and greenheads often terrorize beach areas, and stable flies breed in seaweed and debris that washes up on the shore.

"There's a whole bunch of non-biting flies that get in your eyes," she added.

Black fly season can run for weeks or months, depending on the variety. Many species are out and about from mid-May to late June or early July. In New Hampshire, one species arrives in August and September, but their method of torture is swarming, not biting.

In general, black flies are most active a few hours after sunrise and before sunset, and on windless and cloudy days. They are partial to woodsy areas, and like vampires, they shy away from bright sun.

To repel black flies, follow the same advice as mosquitoes. In addition, seal up your clothing: Black flies will wriggle into any opening for a bite, such as the gap between your shirt buttons.

With warmer temperatures, ticks have been branching out, including the blacklegged or deer variety that transmits Lyme disease. They often perch on tree limbs, low shrubs and grass blades and grab onto passing hosts, one reason hikers shouldn't stray from the groomed route.

"In the Northeast, we’re seeing movement of the blacklegged tick into Upstate New York, into Vermont, Maine and Canada, in areas where it wasn't before," Harrington said.

Though ticks are typically prevalent from April through September, some have been surviving deep into the shoulder seasons. Others never leave. The American Kennel Club, of all organizations, has a good map of tick seasons by state.

Internationally, the CDC has documented Lyme disease in a wide swath in Europe, from southern Scandinavia to Italy, Spain, Portugal and Greece, and from the British Isles to central Russia. Central and Eastern Europe are the biggest trouble spots.

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One reassuring fact: Only a few species of ticks cause diseases in humans and dog. Even so, you should always take precautions when playing outdoors. Raupp follows a principle he calls "AIR": Avoid, inspect and remove.

"If you’re out for a hike, stay in the center of the trail," he said of the first step. "You’re not going to find ticks along a paved pathway or mulch bed."

If you trek through tick-infested terrain, he recommends wearing long pants and "doing the geeky thing" by tucking them into your socks. Harrington suggests spraying your shirt cuffs, hat, socks and shoes with repellent. Or buy pretreated clothing.

"I treat my shoes like my hiking boots with permethrin," she said.

If you are worried that you brought home a highjacker, throw your clothes into the washer and dry them for 20 to 30 minutes at moderate to high heat. "This will kill any ticks that came back with you," Raupp said.

Next, conduct a full-body search for ticks. Raupp said that if you can remove a blacklegged tick within the first 24 hours, your chances of contracting Lyme disease are "infinitesimally small."

To extract the tick, pick up a pair of tweezers and show no remorse.

"Grab the tick firmly behind the head and twist," Ware said.

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