On these 90 to 100 degree days, it’s pleasant to get home in the afternoon, exchange slacks for Bermuda shorts and allow your legs to cool off with the rest of you. Walk out in the back yard, check the dog, cat and children – not necessarily in that order. Then sit a while under your big river birch, magnolia or pecan tree. Still a little warm but so-o-o pleasant.

Ouch! Something stung you under the thigh. Scratch, wait a few seconds. Eeee! Another bite. Got you below the knee. Those lowlife “No-see-ums!”

Another name is biting midges. You should have sprayed before coming out. Look around. Can’t see them!

Chris Evans says they’re less than half the size of a flea. Their true name is “ceratopogonidae,” and they’re not little mosquitoes but a breed of bloodsucking flies.

An Orangeburg-raised boy, Evans is now a medical entomologist (insect expert) with the S.C. Department of Health and Environmental Control. Graduating in biology from Wofford in 1992, he first went to work as a telephone engineer at McCall-Thomas.

“Ernest Rogers, whom I worked with, realized how much I wanted to get into the science field and offered to introduce me to Tom Skelton, head entomologist at Clemson. I jumped at the chance; we drove up for an interview,” Evans said. “Dr. Skelton told me about his project concerning the resistance of tobacco budworms to insecticides. I was blank on budworms. Thank goodness he thought I would fit in. That autumn I began studying for my master’s degree.”

Off to study silkworms

Graduating two and a half years later, Evans flew to Japan and the City of Tsukuba to spend the summer working on a similar study but with a different insect, which, of course, was silkworms.

“By this time I realized that I much preferred the insects to genetics (worms) and got a very lucky break,” Evans says. “In August, Clemson called my parents in Orangeburg to say that a Ph.D. research assistantship in entomology had become available, and they wired me. You bet, I wanted it!

“Back at Clemson I began a project to study a particular species of black flies which transmits a parasite into turkeys. It had nearly devastated that South Carolina industry before they learned to house the birds indoors.”

He earned his Ph.D. in entomology in August 2001.

“Only 10 days later I had accepted this job as director of mosquito-borne disease surveillance with DHEC,” Evans said.

“In this field we learned a long time ago that there’s no way to totally eradicate them. Although the malaria epidemics in the U.S. are gone, we still have to deal with cases of West Nile Virus and “Triple-E,” eastern equine encephalitis. Both can cause brain inflammation and death in people,” he said. “Twenty-one South Carolina organizations including health departments, one university and other control programs send mosquitoes to DHEC for testing.”

$125 million loss

As for the midges, Evans says that nowadays most people call them no-see-ums.

“Their size, (less than 1/16 of an inch) causes them to be overlooked. The females must have blood to nourish their eggs. Their tiny, little sawtooth mouthparts cut the skin and cause blood to seep into the surrounding tissue,” he said. “Often this causes more pain than a mosquito. These females can fly as far as eight miles from their breeding grounds for a blood meal. Fortunately, they only infect humans with two diseases, viruses and filarial nematodes (worms).

“Our animals aren’t so lucky; no-see-ums transmit 38 viruses and eight different nematodes into them. One is bluetongue in cattle, sheep and deer. It causes low birth weight, still births and abortions for calves. U.S. restrictions on exporting infected bulls to other countries has caused an estimated $125 million annual loss.”

No-see-ums infect deer with a disease similar to bluetongue which gives them fever, loss of appetite, weakness, a hanging head and labored breathing with tongue protruding, Evans said. He said in some states the infection rate is usually less than 25 percent of population, but it can climb to more than 50 percent.

“We never stop watching them,” Evans says. “They live and breed in wet mud, sand and waste. They feed on decaying vegetation, particularly near saltwater marshes like those in Beaufort County, where the reeds offer garbage ... to lay eggs in.”

He said local mosquito spraying programs kills the no-see-ums, along with the mosquitoes.

“But, there are too many millions over too many thousands of acres for a total wipeout,” he said. “And we have to be careful not to pollute the good fishing in our streams and ponds.”

Noted Evans, “We humans can protect ourselves with shirts and long pants and keeping a can of spray in our cars to use outside. But, no-see-um breeding and other advantages are going to require many a year to stop all together.”

T&D Correspondent Thomas Langford can be reached by phone at 803-534-2097.

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