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Over 50 years ago nymphs of the Plecoptera species, Paraperla frontalis Banks, 1906 (Plecoptera: Chloroperlidae), were shown to exist in a shallow floodplain aquifer of the Tobacco River, a gravel‐bed river in western Montana and later they were documented throughout the main stems of the Flathead River system. Nymphs are almost never found in surface waters, until they emerge on the river shorelines. As teneral adults, they mate and subsequently deposit fertilized eggs into the river. This novel life cycle is termed "amphibitic." Over the years we and others have found P. wilsoni Ricker, 1965 (Plecoptera: Chloroperlidae), Kathroperla perdita Banks, 1920 (Plecoptera: Kathroperlidae), and five species of Isocapnia Banks, 1938 (Plecoptera: Capniidae), including long‐winged and brachypterous adults and wingless dwarfs (male and female), occupying amphibitic niches in the alluvial aquifers of rivers in Washington, Idaho, Colorado, Alaska and British Columbia. These stoneflies are remarkably tolerant of hypoxia which allows them to exist as abundant consumers in aquifer food webs subsidized by ancient methane. Indeed, stonefly tissues contain carbon that is up to 7000 years old, underscoring the existence of a strong interaction involving the uptake of labile carbon derived from methanogenic and methanotrophic process in aquifers. Details of life cycles, trophic relationships, distribution and abundance have been documented by a suite of studies on the Nyack Floodplain of the Middle Flathead River, Montana. In this paper we review the ecophysiology and ecology of these unique stoneflies in the context of their functional role in gravel‐bed river ecosystems. This article is categorized under:Water and Life > Nature of Freshwater EcosystemsWater and Life > Conservation, Management, and Awareness [ABSTRACT FROM AUTHOR]

Snow algae contribute to snowmelt by darkening the surface, reducing its albedo. However, the potential consequences of algae under the surface (such as after a fresh snowfall) on albedo reduction is not known. In this study, we examined the impact of sub-surface snow algae on surface energy absorption. The results indicate energy absorption across all analysed wavelength ranges when snow algae are snow-covered, an effect that was correlated with both cell densities and chlorophyll-a concentrations. These findings suggest that snow algae lower albedo and thus increase snow melt even when snow-covered. [ABSTRACT FROM AUTHOR]

Comparative population genetic studies provide a powerful means for assessing the degree to which evolutionary histories may be congruent among taxa while also highlighting the potential for cryptic diversity within existing species.In the Rocky Mountains, three confamilial stoneflies (Zapada glacier, Lednia tumana, and Lednia tetonica; Plecoptera, Nemouridae) occupy cold alpine streams that are primarily fed by melting ice. Lednia tumana and L. tetonica are sister species diagnosed from systematic morphological differences, and they are endemic to areas surrounding Glacier National Park and Grand Teton National Park, respectively, in the U.S. Rocky Mountains. Zapada glacier is also present in alpine streams from Glacier National Park to the Teton Range, sometimes co‐occurring with either Lednia species.We used mitochondrial sequence data to clarify species boundaries, compare population genetic patterns, and test demographic models in a coalescent framework for the three stoneflies. We addressed four questions: (1) Is there genetic support for the morphology‐based species boundaries in Lednia? (2) Is there genetic support for cryptic, or as‐yet undescribed, diversity within Z. glacier? (3) Do similar geographic distributions and ecological requirements yield spatial congruence of genetic structure between high‐elevation Lednia and Z. glacier populations? (4) Is there evidence for contemporary gene flow among isolated populations in either group?Our results supported the existing taxonomy with Z. glacier and the two Lednia species differing in their depths of divergence among study regions (e.g. maximum sequence divergence within Z. glacier = 1.2% versus 5% between L. tumana and L. tetonica). However, spatial population genetic patterns were broadly congruent, indicating stonefly populations isolated on mountaintop islands. Coalescent modelling supported the possibility of rare, extremely limited contemporary gene flow among Z. glacier populations, with no support for gene flow between L. tumana and L. tetonica.The focal stoneflies and associated assemblages occupy the highest elevation, coldest permanent alpine streams in the study region. This lotic habitat type faces an uncertain future under a diminishing alpine cryosphere. Given spatial congruence of genetic structure demonstrating unique biodiversity associated with individual alpine islands, we encourage conservation management strategies be developed and applied at corresponding spatial scales. [ABSTRACT FROM AUTHOR]

Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snow melt-driven alpine streams. Although progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects - the meltwater stonefly ( Lednia tumana) and the glacier stonefly ( Zapada glacier) - were recently proposed for listing under the U.S. Endangered Species Act due to climate-change-induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park ( GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (24 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming-induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid-latitude regions. [ABSTRACT FROM AUTHOR]

Rhyacophila bifurcata sp. nov. is described from males collected in Olympic National Park, Washington. The new species is most similar to R. milnei Ross, 1950. A diagnosis and discussion of the R. vagrita group are given. [ABSTRACT FROM AUTHOR]

A diverse Oligocene insect and plant Lagerstätte has been identified recently from paper shales in a sequence of fine-grained deposits exposed on the west side of Canyon Ferry Reservoir, southeast of Helena, Montana. Limited excavation and preparation thus far has led to the discovery of at least 37 families of insects and more than 40 taxa of plants (leaves, seeds, and stems). Preservation of the insect fossils is outstanding, with color patterns, feeding and reproductive structures commonly present. Quality of the preservation compares favorably with that of other Tertiary insect and plant Lagerstätten, such as Green River, Florissant, and Republic. The geologic affinities of the site are not certain, although the deposit has been regarded broadly as Oligocene, based on the mammalian biostratigraphy and an ash-flow tuff stratigraphically well below the insect horizon that has a U-Pb radiometric date of 32.0 ± 0.1 Ma. [ABSTRACT FROM AUTHOR]