3541 Author Judson, Sarah W. Author Nelson, C. Riley text Zootaxa 2012 2012-11-06 3541 1 118 journal article 1175­5334 505937B0-9F57-4068-82E6-8553826DD5AA Taeniopterygidae COMMON NAME: Willowflies. SIZE: Small to Medium ( 10–20 mm ). FEEDING GROUP: Shredders (Some Scrapers). TOLERANCE VALUE: 2 (Low). DIAGNOSIS: Both adults and nymphs are distinguishable from other families by the length of the second tarsal segment being approximately equal to the length of the first segment ( Fig. 9 ). Adults resemble those of Nemouridae in overall body shape, although taeniopterygids lack the well defined “X” venation found in nemourids. In males, sternum 10 is long and often visible from the dorsal view, appearing to surround the genitalic structures like a cup ( Fig. 369 ). Sternum 9 in females is likewise long in most genera ( Fig. 370 ), though barely produced in Taeniopteryx ( Fig. 376 ). The nymphs are generally stout bodied with the pronotum considerably wider than the abdomen. The developing wing pads are greatly divergent from the midline ( Fig. 12 ). As with all Euholgnatha, the paraglossae and glossae are subequal and the labial palps are robust ( Fig. 7 ). DISCUSSION: These stoneflies are found in flowing waters in root mats, snags, leaf packs and sometimes on stones. They are usually found at the edges of streams and rivers where the current is reduced. Like Capniidae , the adults often emerge during cold months, though little collecting during this time period has been done in Mongolia due to road accessibility issues. Most species in this family are generally intolerant of pollution, but some species are well-adapted to large polluted rivers.