Monday, August 23, 2010


By Susan Thurn,
CNHM Director of Education

“Ouch!” I exclaim. I look down to my arm ready to swat the mosquito I am sure just bit me. Yet nothing is there. Moments later, the itch begins, and the welt soon after is at least penny sized. These are the no-see-ums, a tiny biting fly that I hate to love. Aptly named, no-see-ums are less than ¼ inch long, a little black dots the size of a period that is very difficult to see. Boy, do we feel them though!
No-see-ums often stay in shrubs or the dead leaf litter across the ground. Just walking along can stir them up. They stay close to home, though, usually not flying more than about 350 feet from their breeding area. These flies, or midges, are just like many of the other flies or mosquitoes. They are active mostly at dawn and dusk. Only the females bite us. They need the protein in our blood to make their eggs. Yet how does such a small creature do this much “damage”? No-see-ums and other flies puncture the skin with mouthparts that look like scissor blades. Their tube-like mouth is called a proboscis, and is made up of several different parts. At the end of this mouth they have receptors to sense where to begin feeding. A pair of mandibles (the scissors) cuts the skin back and forth. Another part with backward facing teeth helps to move their mouth into their prey’s body. They then inject an anticoagulant saliva into our bodies, and finally begin to draw in blood from a blood vessel. These tiny creatures feed on mammals, birds, or reptiles. Males feed on nectar.

The no-see-um larvae hatch from eggs in water, mud, or moist leaf litter. The larvae eat dead plant or animal matter. During this part of their life cycle the larvae have a spiny “tail” that entomologists use to identify them. As adults, they have two wings with dense hairs that have special pigmentation that also allows biologists to identify them.

The reaction my body has is an allergic reaction to the proteins in no-see-um saliva. Thank goodness, for me, the itching subsides in a short time. In spite of my discomfort, these small insects do provide food to other creatures, making them just as important in the food chain. In tropical forests there is one species of biting midge that helps to pollinate chocolate, which helps in my mind to negate the irritation I sometimes have at their bites. Everything has its place, after all! For chocolate alone, perhaps it is worth loving them!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at

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