Richard W. Baumann

The Holarctic winter stonefly genus Isocapnia, with an emphasis on the North American fauna (Plecoptera: Capniidae)

Abstract This paper presents descriptions, diagnoses, figures, and keys for 12 western North American species of the Holoarctic genus Isocapnia Banks. Complete known distributional records and a cladistic analysis are included for the Nearctic species. Isocapnia fraseri and I. missourii are synonymized with I. integra, and 3 new species are described: I. eichlini n. sp., I. palousa n. sp., and I. rickeri n. sp. Representatives of 5 of the 7 known Palearctic species of Isocapnia were examined and are compared with the Nearctic species. Type localities and distributional data are listed for all 7 Palearctic species.

A review of the Nearctic genus Prostoia (Ricker) (Plecoptera, Nemouridae), with the description of a new species and a surprising range extension for P. hallasi Kondratieff & Kirchner

Abstract The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensis sp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensis sp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given.

Stoneflies (Plecoptera) of Southern Utah with an updated checklist of Utah species.

Abstract Southern Utah comprises 4 major physiographic divisions: the Great Basin, Colorado Plateau, Central Rocky Mountains, and Southern Rocky Mountains, which have been partitioned into faunal regions. We discuss the uniqueness of southern Utah and the amount of land set aside for recreation and preservation, and we encourage the study and preservation of its water resources. The stonefly (Plecoptera) fauna of 13 counties in southern Utah was surveyed. We found 58 species representing 34 genera and 8 families. Three new state records for Utah and many new county records for southern Utah are presented, along with a discussion of distribution patterns and faunal affinities of each species. Distribution patterns indicate a historical connection between the Sevier River and the Colorado drainage and a separation of faunal areas within the Central Rocky Mountains at boundaries between the Wasatch Mountains, Wasatch Plateau, and the Southern High Plateau. The uniqueness of the isolated Abajo and LaSal Mountains, the Virgin River valley, and other faunal areas in southern Utah is presented.

Studies on Distribution and Diversity of Nearshore Ephemeroptera and Plecoptera in Selected Lakes of Glacier National Park, Montana

ABSTRACT Surveys were performed to examine the diversity of Ephemeroptera and Plecoptera in selected lakes in Glacier National Park, Montana, and to generate data for use by the National Park Service. Shallow shoreline sites were sampled by disturbing the bottom and examining the substratum. Published records and previously collected reference specimens were examined. Data were obtained from a total of 29 lakes, but 3 yielded no mayflies or stoneflies. Twelve genera and 21 species of Ephemeroptera, and 11 genera and 5 species of Plecoptera, were found. Most lakes sampled had a diverse fauna of both orders.

Studies on Oemopteryx vanduzeea (Claassen, 1937) and a new species in the O. vanduzeea species group (Plecoptera: Taeniopterygidae) from the Pacific Northwest, USA

The Holarctic genus Oemopteryx is represented in the Nearctic region by three species groups, including the far western O. vanduzeea group. In this paper, we redescribe and illustrate O. vanduzeea (Claassen, 1937) and describe O. leei sp. n. from California and Oregon, USA. The new species is distinguished in the male from O. vanduzeea by the epiproct complex having a tongue-shaped prong that is hood-like at the apex, by the sleeve containing a filament that bears a terminal hook, and by a ventral, elongate, finger-like process that inserts into the apex of the prong. The female of O. leei sp. n. exhibits a large, wide subgenital plate that terminates in a narrow notched apex, whereas the subgenital plate is smaller and trapezoidal, with a flat, truncate margin in O. vanduzeea.

A Review of the Western North American Genus Triznaka (Plecoptera: Chloroperlidae) with A New Species from the Great Basin, U.S.A

Abstract The Nearctic genus Triznaka is reviewed with T. sheldoni, n. sp. described from White Pine County, Nevada, U.S.A. The new species is compared to T. pintada and T. signata. The distinctive armature of the aedeagus and color of the pronotum distinguish the male, while the emarginate to notched subgenital plate and color pattern of the pronotum distinguish the female. The new species is primarily restricted to the Great Basin biogeographic region.

Variation in the epiproct of Arsapnia decepta Banks, 1897 (Plecoptera: Capniidae), with comments on Arsapnia coyote (Nelson & Baumann 1987)

Epiprocts and tergal processes were examined using scanning electron microscopy for scattered populations of Arsapnia decepta Banks, 1897 and A. coyote (Nelson & Baumann, 1987) from throughout their known ranges. Epiproct lengths ranged from 379-578 μm among A. decepta males from 19 sites, and from 575-618 μm for A. coyote males from two sites. Among A. decepta males, the numbers of thick spine-like epiproct setae ranged from 10-34 per cluster. We conclude that A. decepta, as currently defined, shows considerable variation in epiproct dimensions, numbers of epiproct setae per cluster, and width of the dorsal process on tergum 7. In addition, the limited data from our small sample of A. coyote specimens, and the molecular data published recently by colleagues, support continued recognition of this closely related species. SEM images are presented to document the observed variation in these structures from various populations in western North America.

A review of eastern Nearctic Zapada (Plecoptera, Nemouridae) with a new species from the Great Smoky Mountains

We describe a new species, Zapada fumosa n. sp., from the southern Appalachian Mountains. In addition, we collected the rare species Zapada chila (Ricker) for the 1st time in 35 y. We reviewed the eastern Nearctic Zapada (Plecoptera, Nemouridae) fauna and give brief, amended descriptions for Z. chila and Z. katahdin Baumann and Mingo. We illustrated males and gills of all 3 eastern Zapada species with scanning electron microscopy (SEM) and provide a key to the adult stage. Zapada fumosa n. sp. appears to be closely related to Zapada cinctipes (Banks), a broadly distributed western Nearctic species. Unlike most widely distributed and common western Zapada, eastern Zapada are uncommon or have restricted ranges. Rarity and the potential for impending extinction of Z. chila and Z. fumosa n. sp. are discussed in light of altitudinal range reduction and climate warming issues.

Discovery of a large population of the rare winter stonefly Isocapnia mogila Ricker in the Mad River, California (Plecoptera, Capniidae)

Abstract Isocapnia mogila, a rare winter stonefly, is found in good numbers in Humboldt County, California. In the 50 years since this species was described, very few specimens were recorded from only 4 sites in California and Oregon. Emergence seems to be higher in the fall and early winter than in the late winter and spring.

Stoneflies (Plecoptera) of Nevada

Abstract. Stoneflies (Plecoptera) are a dominant group in running freshwaters. We report 104 stonefly species from Nevada. The fauna contains species with Sierra Nevada—Cascade range affinities, few of which penetrate far eastward, and Rocky Mountain species extending to western Nevada. Endemics, species associated with the large interior Humboldt River, and species with northern or southern boundaries in Nevada add zoogeographic complexity. From 3531 stonefly records in Nevada, we provide an annotated discussion and collection data for the species present. This material is a foundation for continuing research on Plecoptera and for monitoring vital stream ecosystems in this arid region of western North America. Collection records from this study are compiled in the Nevada Stonefly Database, which is archived and accessible at http://scholarsarchive.byu.edu/mwnan/vol10/iss1/1.