YELLOW FLY (Family Tabanidae)

Yellow Fly Click the speaker to hear the Yellow Fly

WHAT IS A YELLOW FLY?  In Florida, about twelve different flies are all called “yellow flies” or “deer flies.”   These insects are about 1/2” long with black and yellow bodies and 2 pairs of wings.  The males do not bite.  Instead, they eat flower nectar.  Only the females bite and suck blood.  They need the protein from these blood meals to make their babies.  The female usually lays 50-300 eggs on the grasses above a marsh or pond.  After about a week, the eggs hatch and baby yellow flies, called larvae, drop into the water.  They stay in the water eating dead plants or tiny animals all winter long.  When the larvae get to be 1/2” long, they crawl out of the water and become a pupa.  Inside the pupa, they grow and change, then emerge as adult yellow flies from March to September. 

HOW CAN YOU AVOID YELLOW FLIES? 

1)   Most yellow flies like to be in the shade, so they tend to stay away from bright sunlight.  Twenty or thirty can swarm around your head and shoulders at the same time.  When they bite, it hurts!  Try to stay in bright, sunny areas.

2)   Most kinds of yellow flies are afraid of small spaces, so they won’t follow you inside a car or building.  (However, at least one species will follow you right in and bite hard!)  If they’re really bothering you, try to get inside or at least under an overhang.  If yellow flies get into your car, just roll the window down a few inches.  The ones inside will fly out, and the ones outside won’t come in.

3)   If you must be in the forest or marsh during the summer, try staying fairly still in one area.  If you are hiking around, you continually attract new yellow flies.  However, if you stay in the same spot, after 5-10 minutes, they seem to ignore you.

4)  If you must keep moving, travel at a fast jog.   At about 5mph, you can outrun most yellow flies.  Be sure to wear a shirt, because some can still land on your back.

5)   It’s hard to make yellow flies go away.  If you swish them away, they just come back.  If you swat them, it usually doesn’t kill them.  You have to slap and roll to actually kill them.

6)  Insect repellents that you can spray on your skin often provide little protection from yellow flies.  You can try using a yellow fly patch, a sticky rectangle you attach to the back of a baseball cap.  It has a mild yellow fly attractant and traps the flies as they attack.

RESOURCES:

            McGavin, G. C.  Am. Nature Guides to Insects.  New York:  Smithmark Publishers Inc., 1992.
Milne, Lorus and Margery.  National Audubon Society Field Guide to North American Insects and Spiders.  New York:  Chanticleer Press, Inc., 1995.

Provided by the Pelotes Island Nature Preserve
http://pelotes.jea.com

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