By DEBORAH GERTZ HUSAR

Herald-Whig Staff Writer

They're still here, and they might not be leaving anytime soon.

The pesky buffalo gnats, also known as black flies, are still thriving -- and annoying people at the same time -- thanks to a combination of temperature and water spurred by the flooded Mississippi River.

"Everything we could find on them said larva only occur in running water. In Quincy, you have running water," said Dr. Colleen O'Keefe, food safety and animal protection division manager with the Illinois Department of Agriculture.

"Larva numbers decline when water temperatures reach 75 to 80 degrees. With all the water you've got and where it's coming from, it's not 75 to 80 degrees. You've got the makings to have good buffalo gnats."

The buffalo gnats first appeared in May and probably have been in the area ever since but grew more troublesome in recent days.

"They're getting rather annoying. The last couple of days you couldn't go outside," said Mike Roegge, crop systems educator with the University of Illinois Extension Adams/ Brown Unit. "Vanilla isn't working. DEET isn't working. I don't know what's working to keep these things out of your face except not going outside, but you've got to be out there."

Windy conditions for much of the spring may have curbed the pesky bugs, which aren't very strong flyers.

"If you get a good strong headwind against them, they can't keep up," Roegge said.

With many people planning outdoor activities over the Fourth of July weekend, O'Keefe said, using fans to move the air could help control the gnats.

"If you have a picnic close to the house, set up fans. That just physically removes them from the area," she said.

Other control measures have varying levels of effectiveness.

Some people swear by vanilla, Skin So Soft or insect repellents with DEET. The gnats are attracted to dark colors, so light-colored clothing and hats to cover the ears may help.

"The problem is you can't really spray for them," O'Keefe said. "They're hatched far from where you happen to be."

Adults emerge in the late spring to early summer and are known to travel more than 10 miles in search of a meal. In humans, their bites typically cause pain, itching and swelling. Livestock and poultry can die when bitten by large numbers of them.

Linda Garner, patient care supervisor in the emergency department at Blessing Hospital, suggests cleansing bites with mild soap and water and applying anti-itch cream.

The bites can trigger stronger reactions in people with extensive allergic history.

"If you're short of breath, your throat is swelling and heart is racing, then by all means notify your physician or report to the nearest emergency room," Garner said.

The gnats have about a three-week life cycle and will continue hatching under the proper conditions.

"I would expect and hope, really hope, they would be ending their life cycle soon," Roegge said.

But when the waters warm and slow down, the area could see problems with another pest.

"When the water stops flowing, you get mosquitoes," O'Keefe said. "Before mosquitoes, you get black flies or buffalo gnats."

--dhusar@whig.com/221-3379