ANNAPOLIS – The days are getting warmer, the cherry blossoms have bloomed, the first pitch has been thrown, and . . . the mosquitoes have hatched.
Mosquitoes have moved beyond a simple annoyance in recent years, as West Nile Virus spreads across the nation, and malaria-carrying mosquitoes were found in Montgomery County last year.
While it’s too early to predict how large the summer mosquito population may be, the spring population is already shaping up to be larger than last year’s, said Patricia Ferrao, an entomologist with the Maryland Department of Agriculture’s Mosquito Control Section.
This spring has been wet enough to revive eggs left without enough moisture to hatch last year, meaning that there’s effectively a backlog of mosquitoes, she said.
Right now, the division is spraying B.t.i pesticide in swamps where mosquitoes breed, trying to kill the larvae before they can mature, and contacting areas that had mosquito problems last year to see if they want be sprayed with permethrin when the adults begin to swarm, she said.
But home and business owners can play an important part in mosquito control as well, by taking steps to eliminate areas of standing water on their property, Ferrao said.
Mosquitoes require only a quarter-inch of water to breed, and some species, such as the Asian tiger mosquito, breed exclusively in small, shaded pools of water, which aren’t easily targeted by large spraying campaigns, she said.
“This is the time you need to be a little more vigilant,” Ferrao said, suggesting that people should seek and empty standing water in gutters, flower pots, garbage cans and elsewhere.
Although many people regard mosquitoes as little more than an annoyance, they shouldn’t be complacent about the bugs, she said.
“The reason that mosquitoes do not pose a public health threat in Maryland right now is because there is an active mosquito control program,” she said.
In Maryland, the disease most people think of in conjunction with mosquitoes these days is West Nile virus, which is a threat during the entire mosquito season, although the state didn’t identify its first infected mosquito until July last year, Ferrao said.
Last year, 35 people in Maryland contracted West Nile virus, and seven died, out of 4,161 cases and 277 deaths nationwide, according to figures provided by the Centers for Disease Control and Prevention.
Because the spread of West Nile virus is dependent on the range of animals that carry the disease, the CDC don’t try to predict what a given season will bring, said Llelwyn Grant, a spokesman for the centers.
It’s more important to recognize that the disease is here to stay, and will continue to spread, he said.
And while West Nile virus isn’t a threat on the order of influenza, and efforts to track its spread have gotten better since the virus first arrived in North America, “there’s always room for improvement,” and more to learn about the virus, Grant said.
Malaria also became a concern last year when two Loudoun County, Va., residents were discovered to be ill with the disease, and infected mosquitoes were found on islands in the Potomac River in Maryland.
A third Loudoun teenager was found to have malaria on March 12 of this year, but she was likely infected last year, said Marilyn Piety, a program manager with the Montgomery County Public Health Services. Montgomery County hasn’t decided yet how to proceed with its mosquito control program for this year, Piety said, but the county still has some time to develop a plan.