Crazy About Bugs This Idaho Professor Has An Itch For Researching The Life Of Mosquitoes

When it’s time to feed them, he unbuttons his shirt and places large containers of the beasts against his abdomen. Hundreds burrow into his skin and begin to suck out his blood, injecting their own saliva to do so.

It’s not quite as gruesome as it sounds. The animals in question are tiny mosquitoes - disease-free ones. The scientist is Marc J. Klowden, a professor of entomology at the University of Idaho.

Klowden loves his work. His laboratory has a screen door on it - to keep the insects in.

Decorating his office are the high-frequency mosquito repellers and burning coils that he says don’t work. An official Idaho mosquito trap, fashioned after a miniature bear trap, hangs from a wall. Gary Larson cartoons featuring mosquitoes are recalled quickly in conversation.

Klowden is a serious scientist in a serious business funded by the National Institutes of Health. Natural History magazine billed him as a “mosquito psychologist,” owing to his extraordinary knowledge of their behavior.

He is quick to remind that mosquitoes carry diseases - bad ones such as malaria, St. Louis encephalitis, filariasis, canine heartworm, yellow fever and dengue.

“Worldwide, about 300 million people contract malaria each year,” said Klowden. “Some two million of them die, most of them children.”

Klowden explained that in the United States, the 200 or so species of mosquitoes are more of a nuisance than a danger. But worldwide, some of the other 3,300 species are a significant health risk.

About 100 to 1,000 cases of St. Louis encephalitis still appear in the United States each year. A recent Florida outbreak killed 11 people. Houston reported a malaria outbreak just last summer.

Why does a mosquito need that one-millionth of a gallon of blood?

Not all of them do, Klowden said. In those species that do, blood provides an essential protein source to support egg-laying. Males don’t need to ingest blood. Their energy comes from the nectar of flowers.

Not all species seek a blood meal from mammals either. Some go exclusively for birds or reptiles.

“Most people just think of a hypodermic needle being inserted into their skin and the blood getting sucked out,” explained Klowden. “In reality, there is a tube, and within the tube are two small stylets with backward-pointing barbs that saw into the skin as the insect searches for a capillary.”

Animating the process, Klowden holds his two index fingers extended in front of his nose and rubs them together to simulate the action of the oscillating stylets.

Once a capillary is pierced, he said, mosquitoes inject their own saliva to continually flush the system and keep the blood cells flowing.

The saliva contains proteins and perhaps anticoagulants and anesthetics. It is the foreign protein in the saliva that is responsible for the itchy welt felt by the blood host.

Since the welt is an allergic-type reaction, not all people respond the same to a bite.

“I had a graduate assistant who would put cups of mosquitoes against his abdomen and let them feed and you absolutely could not tell he had been bitten,” said Klowden.

Do insect repellents work?

“Mosquitoes normally find a host for a blood meal by sensing increasing concentrations of naturally-released chemicals that surround animals in an invisible plume,” Klowden said. “Carbon dioxide, lactic acid, body odors and certain foods can all serve as beacons to them.

“What you spray or rub on your skin … is actually a chemical mask. It only provides a chemical signal that does not allow them to identify you as a host. Leave one spot uncovered and they’ll find it.”

Klowden says DEET, the component of most repellents, is the only really effective mask available. Skin-So-Soft skin moisturizer does work he says, just not very well.

The most effective way to control mosquitoes is to remove sources of standing water where the insects lay their eggs, Klowden said.

“In Chicago, an outbreak of St. Louis encephalitis was traced to a city cemetery,” he said. “Once workers went in and picked up all the vases and such on graves that hold water, the mosquitoes disappeared, and so did the outbreak.”

With all this knowledge about mosquitoes, one would think Klowden has the problem of controlling mosquito bites licked. But as he related his experiences on a summer backpacking trip into the Mallard-Larkins, nature’s humbling powers became apparent.

“We were eaten alive!” he said. “I’ve never seen so many mosquitoes.”

MEMO: This sidebar appeared with the story: WSU insect museum awaits visitors

By Charlie Powell Correspondent

Washington State University officials aren’t kidding when they say the Food Science and Human Nutrition Building is bugged. The James Entomology Collection is one of the most extensive among all universities. “Insects in the collection date back more than 100 years,” said Richard Zach, curator and director of the collection since 1982. “The collection contains more than 1.5 million insects representing roughly 30,000 species, some of which I collected just yesterday.” Zach says the flies and aquatic insects are among the finest parts of the collection, but it also includes some extinct butterflies. Each year, the collection grows by up to 25,000 insects. Right now Zach is part of a team surveying bio-diversity among the Hanford Nuclear Reservation’s insects. “Hanford is nearly an ancestral habitat since it has been out of normal human use for 50 years,” he said. The collection is open to the public weekdays by appointment during business hours. Call Zach, (509) 335-3394.