Summer is on the way, bringing with it warmer weather, long evenings outdoors, and mosquitoes.
Warm, wet weather presents a breeding ground for mosquitoes, and with so much recent rain around the region, that could mean the valley is in for more of the blood-sucking insects this summer.
The best way to prevent the pests from multiplying is to eliminate any stagnant water from their yards, said Dr. David Gaines, state public health entomologist for the Virginia Department of Health.
Northern house mosquitoes, prevalent around the valley, love water mixed with organic material such as grass clippings, leaf litter and animal manure, making them a concern in areas of standing water on lawns, in gardens or on nearby farmland.
Though annoying, mosquitoes pose a greater risk of spreading diseases like West Nile virus.
The Centers for Disease Control and Prevention describe West Nile as “the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito.”
There are no vaccines to prevent it or medications to treat it, the CDC reports at https://www.cdc.gov/westnile/index.html.
The CDC said: “Fortunately, most people infected with WNV do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness.”
In addition to reducing sources of standing water, Gaines said people can prevent the spread of disease by making sure their windows and doors are properly screened, wearing appropriate clothing while outside, and using insect repellents.
“If sitting out at night, sit in a well-lit area,” he said. Northern house mosquitoes prefer to bite in the dark.
Wear long pants, a long-sleeved shirt and a hat. “You’re less likely to be bitten,” he said.
“Certainly we do recommend the use of repellent,” he added. “Northern house mosquitoes, they do like to go for the face and the neck. The upper part of the body.”
Many repellents containing DEET or picaridin ward off northern house mosquitoes.
“I’m partial to picaridin, because I don’t like the smell of DEET,” Gaines said.
But not all mosquitoes act the same – some fly at night and others during the day. Gaines said it’s important to have a plan of action for any time of day.
“Northern house mosquitoes are given that name because they have a tendency to fly into open doors and windows at night,” Gaines said.
“They’re the mosquito that pesters you all night long.”
The National Institutes of Health classify the northern house mosquito as the primary carrier of West Nile Virus to humans along the East Coast.
“This species is an urban container-breeding mosquito … [having a] close contact with humans and flexibility in host choice,” the NIH writes in a 2016 report at its website.
“Last year,” Gaines said, “we had an extremely wet year, and we saw a lot of West Nile virus.”
To help prevent mosquito bites, he said it’s important to keep homes well-screened and maintain outdoor containers that may collect standing water as well as ponds and swimming pools that can easily fill with grass and leaves.
Homeowners should also fill in any depressions in their yards where water might otherwise pool.
Yard maintenance, he said, “is probably the most important thing you can do to prevent northern house mosquitoes.”
He said larvicides can be used to treat large areas of standing water on farms or in fields.
Asian tiger mosquitoes, also a threat in Virginia, are less likely to carry disease, but more likely to bite people because they fly during the day.
“I can’t say what this year will be like,” Gaines said. “It’s anybody’s guess. It could be a bad year. It could be a not so bad year, and only time will tell.”