Bug bites: The lowdown on no-see-ums

Bug bites: The lowdown on no-see-ums-attachment0

Photo courtesy of CDC

Yes, Caroline, there are no-see-ums, and they do bite. These tiny flies — commonly known as sand flies — have a lot in common with mosquitos.

In body shape they look like a mosquito, says Paul Bartels, a professor of Invertebrate Biology at Warren Wilson College. Pointing to an enlarged photo, he explains that these insects fall under the classification Diptera — meaning they have two wings and are attached to a thorax.

They also have a needle-like sucker and a separate injector tube. Using the latter, these flies squirt a small amount of anticoagulant to keep the blood flowing. It is our body’s allergic reaction to this anticoagulant that produces the itch, which can linger for many days in some people.

You can actually see the no-see-ums, although they are very small — about the size of a sharp pencil point.  They can go straight through window screens but usually fly low and stay outdoors. There are many species, so individuals would have to be identified under a microscope. 

These, and mosquitos of course, are the usual culprits that sting exposed body parts of creatures that exhale carbon dioxide (including humans). The females seek out blood as a source of protein for their eggs. Males of these species do not bite humans.

Professor Bartels says no-see-ums like the backs of human legs because they are protected from the airflow created by walking, which can affect their flight. 

They live in the grass and low vegetation, especially around coastal areas. They must have constant moisture for their larva, and Asheville’s wet spring and summer has suited them to a tee.

The good news is that a commonly available lotion, Avon’s “Skin So Soft,” is an excellent repellent for no-see-ums. They are also repelled by insect repellants containing DEET, or more natural alternatives like Citronella. The best protection is long sleeves and long legs on pants (tightly cuffed) to prevent them from finding your skin. Wilderness fabrics are deliberately woven so tightly that even no-see-ums can’t penetrate them.

No-see-ums are grouped with gnats and midges because of their size and body form. There are thousands of species of these insects, but most of them don’t bite humans, although they can be quite annoying.

There are other critters that do bite humans, like chiggers, which are mites. The larval form of chiggers seek tight, protected spots between skin and clothing, to bite and inject its saliva, loaded with irritating enzymes.

Chiggers do not lay eggs in human skin (according urban legend) so painting the wound with nail polish will not protect you. The itch is long lasting because it takes time for the enzymes to fade.

Professor Bartels also cautions humans to protect their pets — dogs and cats especially — from ticks and fleas. These cause agony to pets, who can’t tell you what’s wrong, and these pests transmit several diseases. Lyme disease is tick-borne, infects humans and is lurking in the North Carolina woods. 

DeWitt Robbleloth is a freelance writer.

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