- Scientific name: Hansonoperla appalachia
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
Description
The Appalachian stonefly is a small slender insect belonging to the order Pelocoptera (stoneflies), family Perlidae (common stoneflies or the stones) and genus Hansonoperla. Adults have contrasting yellow and brown color patterns on head and legs, and brown wings lying flat along abdomen when at rest. Nymphs are 14-20 mm (0.55-0.8 in) in length. Refer to keys from Stark (2004) for adults, and Stewart and Stark (2002), Stewart and Stark (2008) for nymphs and adults at the genus-level for definitive identification.
Life cycle and behavior
Little is known about the life history of Appalachian stonefly but can be inferred from species from shared genus, family, and/or order taxonomic levels. The life cycle of the swamp forestfly is >1 year consisting of an egg, nymph (i.e. larva), and adult life stages. Eggs cling to substrate via a gelatinous film and other stabilizing mechanism and may undergo diapause during summer months. Eggs hatch into nymphs growing and molting for years. Nymphs are predators and can be found clinging on rocks or leaf packs, mosses, root wads in various mesohabitats. The nymphs emerge from the water onto stable substrate (e.g., rocks, vegetation) and transform into winged adults. Adults may be present from late spring to summer, live for about 1-4 weeks, and disperse upstream, downstream, and into other streams (i.e., <1km; 0.6 mi) within forested upland corridors. For reproduction, males mount females and release sperm internally or externally of the female’s genital pore. After mating occurs, females either release eggs over the water surface or dip their abdomens and deposit them into the water.
Distribution and abundance
The Appalachian stonefly range extends from South Carolina and Tennessee, northeast New Hampshire. In New England the species has been recorded in Massachusetts and New Hampshire. In Massachusetts, the species has been recorded in the western part of the state at one location. The species distribution and abundance are data deficient in Massachusetts. Elsewhere, the species has been recorded at low abundances and at few and scattered localities in its range.
Appalachian stonefly is a 2023 Regional Species of Greatest Conservation Need of moderate conservation concern.
Habitat
Appalachian stonefly inhabits small to moderate-sized cold-water streams with cobble and gravel substrate, and typically at higher elevations. The species has been collected in pools with woody debris, along root mats, and undercut banks and may occupy the hyporheic zone.
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Threats
Degradation of water quality, alteration of streamflows, and upland habitat loss are primary threats to Appalachian stonefly. Potential threats to water quality include pollution and sewage overflow, salt and other road contaminant run-off, herbicides and pesticides, and siltation from construction or erosion. The disruption of natural flow regimes by water withdrawals, damming, and stream channelization may have a negative impact on populations. Warming stream temperatures and changes to precipitation regimes from climate change may reduce suitable habitat. Additional threats illegal or accidental industrial discharge and hardening of channel banks and siltation that creates unstable stream habitat.
Conservation
Survey and monitoring
Standardized and targeted surveys for Appalachian stonefly is needed to determine its status in Massachusetts. Surveys should target stream sites to determine species occupancy and population status, particularly in western Massachusetts. Multiple site visits (e.g., ≥3) may be required to detect this species. Routine monitoring of prioritized sites is needed estimate occupancy trends overtime.
Management
Upland and stream habitat protection is critical for the conservation of Appalachian stonefly. Protection of forested upland borders of these river systems are critical in maintaining suitable water quality and are critical for feeding, resting, and maturation. Development of these areas should be discouraged, and the preservation of remaining undeveloped uplands should be a priority. Alternatives to commonly applied road salts should tested to minimize freshwater salinization. Hardened and channelized stream segments should be restored to promote natural sediment dynamics.
Research needs
Through standardized surveys, effort is needed to define habitat requirements, distribution, relative abundance, phenological timing (e.g., adult emergence), and breeding sites. Research effort is needed to estimate detection and occupancy rates and how other environmental variables (e.g., sample timing, weather) affect these rates. Other research efforts include projections of species distribution under climate change scenarios and climate vulnerability analysis in Massachusetts, since this species occupies cold-water streams.
References
Beaty, S. R. 2015. The Plecoptera of North Carolina: A Biologist’s Handbook for the Identification of Stonefly Nymphs with Standard Taxonomic Effort Levels. Version 4.0. North Carolina Department of Environmental Quality, Division of Water Resources, Biological Assessment Branch. Raleigh, North Carolina. iv + 91 pp.
DeWalt RE, Hopkins H, Neu-Becker U, and Stueber G. Hansonoperla appalachia Nelson, 1979. Plecoptera Species File. Retrieved on 2025-04-08 at https://plecoptera.speciesfile.org/otus/895854/overview
Earle, J.I. 2009. New state stonefly (Plecoptera) records for Pennsylvania, with additional records and information on rare species. Illiesia 5(16):169-181.
Hogan, P.N. 2021. Predictive distributional modeling of rare and uncommon stoneflies (Insecta: Plecoptera) of the central Appalachian mountains using maximum entropy. Western Kentucky University, M.S. thesis, 118 pp.
Hogan, P.N., and S.A. Grubb. 2022. Distributional trends and species richness of Maryland, USA, Stoneflies (Insecta: Plecoptera), with an emphasis on the Appalachian region. Ecologies 3(3):395-421.
Kirchner, R. F. and B. C. Kondratieff. 1985. The nymph of Hansonoperla appalachia Nelson (Plecoptera: Perlidae). Proceedings of the Entomological Society of Washington 87(3): 593-596.
Nelson, C.H. 1979. Hansonoperla appalachia, a new genus and a new species of eastern Nearctic Acroneuriini (Plecoptera: Perlidae), with a phenetic analysis of genera of the tribe. Annals of the Entomological Society of America 72(6):735-739.
Stark, B. P. 2004. Perlidae (The Stones). In Stark B. P and B. J. Armitage (eds). Stoneflies (Plecoptera) of Eastern North America. Volume II. Chloroperlidae, Perlidae, and Perlodidae (Perlodinae). Ohio Biological Survey Bulletin, New Series. 14 (4). vi + iv p.
Contact
| Date published: | April 11, 2025 |
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