Excerpts from Jim Conrad's
from the September 11, 2005 Newsletter issued from the Sierra Nevada foothills
somewhat east of Placerville, California, USA
For the most part insects here are only fractionally as pestiferous as they were in Mississippi. Still, for the last couple of weeks we've been visited with a tiny black fly, a gnat, that I'd rather do without.
When Diana takes her walks she plugs her ears with cotton because those gnats dive into one's ears and bounce about. When Bonnie the dog returns from accompanying Diana on the walks her lower eye-rim looks as if it has a false eyelash plastered to it, but that eyelash is a line of gnats supping her eyeball fluids. Sometimes on my hikes I must put a bandana over my nose and mouth or at least filter my inhalations through mustache whiskers, and even still I manage to inhale a gnat about once a day. When I wave my hand to knock them away from before my face I feel the fly-body resistance as my hand moves through the air. One day, before I figured out a little about them, I had such a dark, swirling cloud of gnats about me and I was so hot and tired that the thought crossed my mind that maybe I'd just fall down and drown in inhaled gnat bodies.
But, then I discovered that all you have to do is to sit down, stop moving, and they'll go away. That suggests that they're less attracted by carbon dioxide and/or heat than by slow movement and/or moisture.
When these creatures land on the binoculars hanging vertically on my chest they instantly start climbing upwards. When they reach the top of the binoculars' body there's a crack between the body and the oculars, and the flies begin aggressively probing into that crack exactly as when they reach Bonnie-the-dog's lower eyelid, where eyeball fluid awaits. I think these flies are programmed to locate a slowly moving mammal, land on it, and climb upwards until they reach a moist eye, nose, mouth or ear. They cluster around my raw leg scratches, too.
After hours of studying their wing venation and head- bristle disposition I've decided that they're probably called -- get this -- Eye Gnats. They're probably members of the Frit Fly Family (not Fruit Fly), the CHLOROPIDAE. My Peterson field guide says the larvae of this large family often live in grass stems or decaying materials, while adults of a few species are "attracted to the eyes or to sores."
If you have a good hand lens or a dissecting scope, I recommend to your attention gnat identification. It's amazing how many species of small fly and gnat there are, and how they can be separated into a surprising number of insect families based on the patterns of veins in their wings and the location and orientation of bristles on the fly's head and body. There's such unexpected and elegant order in these features that it's like discovering that snowflakes have a crystalline structure and that, though every flake is different, they are all based upon certain simple and elemental geometric principles. You can see a page showing close-ups of these features on a Chloropidae at http://www.hadleyweb.pwp.blueyonder.co.uk/Chloropidae/6/chloropidae_6.htm.
When I'm gagging over an inhaled gnat, however, it's hard to think of gnats in terms of snowflake classiness. Still, the point is that many things reveal unexpected beauty if you just make the effort to look at them closely.