Love bites

Associated Press POSTED AT 1:06 PM EDT Wednesday, Aug 4, 2004

CHARLESTON, S.C. — What you long thought to be true is true: Mosquitoes prefer biting some people more than others. "Some people are just more attractive," said Ulrich Bernier, a research chemist with the U.S. Department of Agriculture.

"Mosquitoes are so keen at figuring out who the best people are to have a blood meal," he said. "We still don't understand how they figure it out so well. They know how to do it and we don't know how they know."

Mosquitoes are highly attracted to one in every 10 people. Mr. Bernier is working to discover which of the more than 1,000 chemicals on the skin of people attract and which repel mosquitoes.

Figuring out what attracts mosquitoes has been an easier chore that determining what repels them.

Mosquitoes are attracted to lactic acid in sweat and to carbon dioxide. They're so attracted to the latter that Martin Hyatt, Charleston County mosquito control superintendent, sometimes baits traps with dry ice, which is simply solidified carbon dioxide.

Mosquitoes are also attracted to sweet smells including perfume, hair oil and deodorant. They also are attracted to dark clothing, said Joe Conlon, American Mosquito Control Association technical adviser.

Mr. Bernier has identified some of the body chemicals that repel mosquitoes but wouldn't say which ones. There are patents involved but the research is encouraging, he said.
"I would never say we would be 100 per cent safe," Mr. Bernier said. "I would say we're getting better all the time."

Mr. Bernier's lab in Gainesville, Fla., was created after the Second World War to find repellents for the military. After investigating 80,000 chemicals, scientists developed DEET as an insect repellent.

But it's not only the scent of a person that can cause a mosquito to bite. The pesky insects also have their own quirks.

"We're just scratching our knowledge of it," Mr. Conlon said.
But home remedies like eating brewer's yeast, garlic or vitamin B-12 don't seem to help much.

"I don't care whether you eat them or smear them on the skin, it doesn't make any difference," said Mr. Bernier, who added while diet seems to make a difference, little research has been done on the topic.

Mr. Hyatt said one way to avoid being bitten is prevent mosquitoes from hatching.
He said a lot homeowners could help themselves simply by draining the standing water where mosquitoes breed.