Wading for Bugs: Exploring Streams with the Experts

15. Way Cool Mountain Midges

83 15 Way Cool Mountain Midges Gregory W. Courtney “Deuterophlebiids (du-ter-o-fle-bee-ids) are set up as a demonstration at the front table,” read an announcement from Dr. Norm Anderson in our aquatic entomology lab at Oregon State. “These are rare flies, so be very careful when you handle the specimens.” Hewascertainlymakingafussoverthesefliescalled“mountain midges.” This was the first time he’d placed a demonstration up front, next to his desk. Perhaps he wanted to keep an eye on the specimens? Keep an eye on us? Make sure we didn’t damage those precious specimens, or walk off with one or two for our own collections (bonus points!)? I had seen drawings before but could not have anticipated how exciting it was to see actual specimens of larval deuterophlebiids. 84 Truly Flies They were odd indeed! The body was dorsoventrally flattened, as though someone had stepped on the rock that harbored those larvae. Each of the first seven abdominal segments had a pair of large, lobe-like structures that could be turned inside out, and each of these prolegs, or “false legs,” had several rows of hooks (called apical crochets). Way cool! The head, with those elongate forked antennae, had odd, comb-like mandibles and other weird mouthparts with enlarged spatulate (spoon-shaped) hairs. For a moment I wondered, “This can’t be a real insect; is it a trick by Dr. Anderson?” I soon dismissed that idea. Nevertheless, I believed those larvae certainly looked more like something from a sci-fi movie than from some river in Oregon. “Where were these collected?” I asked. “The Marys River,” replied Dr. Anderson. That was the river that ran out of the Oregon Coast Range into the Willamette River a short bicycle ride away. “No, where exactly were they collected? When? Are these specimens all you have? What is the purpose of . . .” and here I would inquire about any number of the morphological features I might be considering. Dr. Anderson had come to expect a barrage of questions from me (perhaps he began regretting that the demonstration was so close to where he sat). He knew me well enough to be able to see the path ahead. I had already volunteered in his lab, where I’d shown some competence and interest in identifying Diptera (fly) larvae. At the time I hadn’t fully realized that nobody else in the lab, especially Dr. Anderson, wanted to identify “maggots,” so the niche was wide open (and my filling it would be encouraged). Besides, he knew that anything he called “rare” would tweak my interest. So, the combination of “odd,” “rare,” and “Diptera” meant the Way Cool Mountain Midges 85 inevitable: I had to learn more about these flies, and of course collect some! Although it seemed a rather onerous task at the time, collecting has become less of a challenge after nearly thirty years of studying deuterophlebiids. We now know that mountain midges are widespread in western North America, found throughout the Sierra, Coast, and Cascade ranges, and in the Rocky Mountains from New Mexico to the Yukon. However, when I was a student in Dr. Anderson’s course, these flies had been collected from only a handful of locations. As it turned out, the specimens from the Marys River were collected just west of Philomath, Oregon, a mere seven miles from campus. This was the obvious destination for my next collecting trip. So, less than two days after that fateful laboratory introduction, I was at the Marys, picking up rocks, taking kick samples, even “washing” rocks into my kick net. Although I found lots of interesting aquatic insects, there wasn’t a single deuterophlebiid. I was crushed. Might these flies be as rare as Dr. Anderson suggested? The river was a bit high, so perhaps I simply hadn’t been able to sample the best habitat. Regardless, it was back to the lab with the disappointing news. I asked him if there were other places in Oregon where these flies occurred. “I’ve heard that Mike Stansbury, an aquatic biologist and avid insect collector, found them in the South Umpqua River. Part of an environmental assessment study,” he told me. The South Umpqua drains out of the southern Cascades in a warmer, more southerly part of Oregon, about two and a half hours away. “Time for a road trip!” I decided. About a month after my failed attempt...