Warm winter could cause an increase in mosquitoes, UK professor says

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By Amanda Hancock

Lexington Herald-Leader

Mosquitoes are out for blood in Central Kentucky earlier and in mightier form this summer.

While some experts are predicting this summer to be one of the worst for mosquitoes in decades, Grayson Brown, professor of entomology at the University of Kentucky, said there’s no way of knowing until summer is in full swing. The life span of a mosquito is relatively short, a few months at most, but mosquitoes have been building up their numbers since March and will be noticeable in the upcoming months.

Brown said winter’s higher temperatures are one reason for the spike of mosquitoes this year.

“It just didn’t get cold enough to kill the mosquitoes and their eggs,” he said. During the winter, mosquitoes usually freeze, but Brown said water temperatures stayed higher than normal.

Mosquitoes tend to thrive in warm weather, so they started laying eggs earlier than previous years, said Brown. He also said Western Kentucky will most likely suffer severely from mosquitoes because of heavy flooding last summer.

But the early start in breeding doesn’t necessarily mean record-breaking amounts of mosquitoes. Brown said the actual numbers will ultimately depend on rainfall.

“If there’s a normal amount of rain from this point on, there will be a normal amount of mosquitoes,” he said.

Rain and any source of standing water could increase the mosquito population.

Nathan Powell, senior environmental health specialist at the Lexington Health Department, said the best way to control mosquitoes is to find and empty any areas of standing water in a home or yard, such as a puddle, flower pot, birdbath or clogged gutter. Since most mosquitoes need less than an inch of water to lay eggs, these items could easily turn into a mosquito’s nest.

The health department is conducting annual chemical spraying starting Thursday. Spraying will occur at various times throughout the summer. Spraying starts in the early morning, when mosquitoes are most active. They will use Duet, a spray produced by Clarke Mosquito Control, that is harmless to humans and is not corrosive.

Even though there could be more mosquitoes, the health department plans to continue spraying on the same schedule as previous summers.

In order to better educate residents and public health workers about the species, Brown hosted a mosquito identification course on Tuesday.

Brown informed those in attendance that there are nearly 60 different species of mosquitoes, each having different behaviors and the potential to carry a slew of diseases such as dengue fever or Lyme disease.

Kathy Fowler, director of the state Department of Public Health’s division of protection and safety, was among those in attendance. Fowler said the training will help the department gain competency in mosquito control.

“If there was an outbreak, we don’t have a lot of working knowledge to respond,” she said.

After taking the course, Fowler said being able to identify the different species of mosquitoes can help prevent any potential spread of diseases. She said she didn’t know what to expect from mosquito activity during the summer, but she thought the state needed to be prepared.

“It gives us another tool to build up our basic knowledge and prepare for whatever could happen,” she said.

Brown provided several microscopes to examine different types of mosquitoes and discussed which are most common and threatening in different regions.

The most common disease-carrying species that calls Lexington home is the Southern House mosquito. The house mosquito carries Lyme disease, but it usually isn’t sighted until the middle of August.

Brown said other disease-carrying insects, such as black-legged ticks and sand flies, are also common in Central Kentucky during the warmer months.

The Asian tiger mosquito is Lexington’s most common mosquito. The Asian tiger, named for its black and white stripes, produces the worst itch, Brown said.

“It accounts for about 95 percent of all bug bites in Lexington,” he said.

This “urban mosquito” is more aggressive and tends to bite during the daytime.

“They love Japanese honeysuckle trees and we have a ton of those,” he said.