The spring emergence of Plecoptera (stoneflies) in the Willow Creek drainage, Humboldt Co., CA., April-July, 1984

Plecoptera (stoneflies) were collected during the spring emergence in the Willow Creek basin, Humboldt County, California. Both adults and nymphs were collected using qualitative methods. Water chemistry, substrate size, and riparian vegetation were used as desciptive parameters. Most adults were identified to species. A total of 41 species was recorded in the study. A new species of Paraleuctra was found and the previously unknown female of Paraleuctra divisa was collected. An Arcynopteryx-like nymph (Perlodidae) may represent a new genus, based on the gill number and arrangement. Spring emergence patterns are given for several species.