As spring comes into full bloom, flowers aren’t the only thing popping up. Mosquitoes are also spawning in small, mostly natural pools of standing water.
After those pools dry out, a cousin moves in. And it’s known to be an aggressive biter.
The Asian tiger mosquito, an invasive species first introduced to the U.S. in 1985 via used tire shipments, loves nothing better than laying eggs in the standing water of small containers. And that means it has a tendency to show up much closer to people.
“They breed in artificial containers almost exclusively,” said Chris Hooper, director of Dauphin County’s West Nile Virus Control Program. “We find most of ours in and around Harrisburg, in more-urban areas.”
Hooper said the tiger mosquito, native to southeastern Asia and readily identifiable by the white striping on its legs and body, has been in Dauphin County since 2016. In Allegheny County, it was first spotted in 2010, according to the county health department.
Marcus Snyder is a public health technician in Cumberland County, and he said when he gets a call about tiger mosquitoes, he usually tracks them to a small container a homeowner hasn’t spotted.
“Something that also really contributes is the corrugated downspouts with black plastic ridges,” Snyder said. “There’s enough water there for them to lay eggs after a rainfall. Then when the next (rain) comes, the eggs will hatch.”
In Dauphin, the number of county-set traps that caught at least one tiger mosquito went from zero in 2006 to more than 1,600 in 2011. And Hooper said the insect’s behavior has helped it proliferate.
“They are aggressive when it comes to biting humans,” he said. “And, they’ll do it pretty much any time of day. Other mosquitoes, it’s usually dawn and dusk when they’re out, but these will come out in the full sun.”
And typically, once they get a blood meal, female tiger mosquitoes will head off to lay eggs, up to 300 in their lifetime.
The good news? Despite being aggressive, they are also lazy travelers, according to Zachary Smith, owner of Pest Dude, a California insect- control business.
“If you’re getting bitten, it most likely means you’re close to the water source,” Smith said. “So look carefully for those hidden spots that are holding water. It can be less obvious than you think.”
Hooper said even an old soda bottle cap can hold enough water for them to lay eggs.
He recommended the same basic measures as with other mosquitoes, wear long sleeves at dawn and dusk and use an EPA-registered repellent, to avoid being bitten.
In southeast Asia, they are believed to have served as vectors for the Zika virus, Eastern equine encephalitis and Chikungunya. But in the U.S., that is much less of a concern, according to Emily Struckhoff, a vector-borne disease specialist with the Penn State Extension.
“It’s not involved in any locally transmitted mosquito diseases,” Struckhoff said. “It you get bitten by one in Pennsylvania, you’re not likely to get sick or develop any diseases from it. But it gets on people’s radar because of how aggressive it is.”
“It’s one that people notice quite a bit,” she said.
Patrick Varine is a Tribune-Review staff writer. You can contact Patrick by email at pvarine@triblive.com or via Twitter .
