Stephen Diehl and Vici Zaremba


Stephen Diehl and Vici Zaremba

Class
Insecta (Insects)
Family
Corduliidae (Emeralds)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S1
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
G5
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).

Summary

Did you know?

Forcipate Emeralds are not easy to observe due to their elusive behavior of perching in trees up to 20 feet above ground (Paulson 2011). They can best be observed when foraging in flight over roads or clearings or when females come down to open water to oviposit in breeding habitat.

State Ranking Justification

In New York, Somatochlora forcipata is known from nine sites in six counties mainly in northern NY, with one location in Rensselaer County (New York Natural Heritage Program 2018). It has a small known range in the state, mainly found in bog habitats with some flowing water, where threats to habitats could include climate change and hydrologic alteration.

Short-term Trends

During the 1990s, Forcipate Emerald was discovered in large bog complexes in Franklin and St. Lawrence Counties as well as sites in Essex and Lewis County (Donnelly 1999, 2004). Additional new sites in the Adirondacks were added recently in Hamilton, Franklin, Essex, and Lewis Counties and at least two of the known sites have been extant for 10-15 years. In 2007, the range was extended significantly southward in New York to the Rensselaer Plateau and records are known from nearby in western Vermont and Massachusetts (Donnelly 2004).

Long-term Trends

The species was first documented in New York in the 1980s (New York Natural Heritage Program 2018). Since observations are fairly recent, and the full extent and size of the populations have not been determined, long-term trends are unclear. A recent new county record in NY could reflect a recent range expansion, but more likely reflects an increase in survey efforts.

Conservation and Management

Threats

Any activity which might lead to water contamination or the alteration of natural hydrology could affect Forcipate Emerald populations. Such threats may include roadway run-off, industrial pollution, the building of dams, peat mining, forestry, or development activities near their habitats (NYS DEC 2005). Both emergence rates and/or species ranges may shift for odonate species as a result of climate change (Corser et al. 2014).

Conservation Strategies and Management Practices

Any efforts to reduce siltation of habitats, reduce alteration of the bogs from activities such as peat mining, and any ditching and filling activities should be considered when managing for this species (NYS DEC 2005).

Research Needs

Appropriate bog/fen habitats should be searched in Sullivan and Orange Counties and along the central Southern Tier in Steuben, Tioga, Chemung and Broome counties because there are known records in adjacent New Jersey and Pennsylvania (Donnelly 2004). In addition, research is required to understand the habitat requirements and threats to this species, and to create appropriate management guidelines for its persistence in known locations (NYS DEC 2005).

Habitat

Habitat

This species inhabits small spring-fed boggy streams, feeding in sunny glades and along roads and perching in trees 15-20 feet high. Both larger bog/wetland complexes and smaller boggy swales can be occupied as long as some moving open water with pools is present (Walker and Corbet 1975).

Associated Ecological Communities

  • Black spruce-tamarack bog (guide)
    A conifer forest that occurs on acidic peatlands in cool, poorly drained depressions. The characteristic trees are black spruce and tamarack; in any one stand, either tree may be dominant, or they may be codominant. Canopy cover is quite variable, ranging from open canopy woodlands with as little as 20% cover of evenly spaced canopy trees to closed canopy forests with 80 to 90% cover.
  • Dwarf shrub bog (guide)
    A wetland usually fed by rainwater or mineral-poor groundwater and dominated by short, evergreen shrubs and peat mosses. The surface of the peatland is usually hummocky, with shrubs more common on the hummocks and peat moss throughout. The water in the bog is usually nutrient-poor and acidic.
  • Inland poor fen (guide)
    A wetland fed by acidic water from springs and seeps. Plant remains in these fens do not decompose rapidly and thus the plants in these fens usually grow on older, undecomposed plant parts of mostly sphagnum mosses.

Associated Species

  • Delicate Emerald (Somatochlora franklini)
  • Incurvate Emerald (Somatochlora incurvata) (guide)

Range

New York State Distribution

During the 1990s, it was discovered in large bog complexes in Franklin and St. Lawrence Counties as well as sites in Essex and Lewis County (Donnelly 1999, 2004). Additional new sites in the Adirondacks were added recently in Hamilton, Franklin, Essex, and Lewis Counties and at least two of the known sites have been extant for 10-15 years. In 2007, the range was extended significantly southward in New York to the Rensselaer Plateau and records are known from nearby in western Vermont and Massachusetts (Donnelly 2004). It is likely that this species breeds on small streams primarily within larger bogs (more infrequently at smaller ones) throughout the Adirondacks and perhaps the Tug Hill and Rensselaer Plateaus.

Global Distribution

The center of Forcipate Emerald's distribution lies in north-central Ontario in the central Canadian Shield forest ecoregion and ranges northwestward to the Northwest Territories, south to northern Wisconsin and West Virginia, northeastward to Newfoundland and Labrador (Donnelly 2004). New York lies near the center of the range, but this species was not discovered in the state until 1980 in Hamilton County (Donnelly 1999).

Best Places to See

  • Bloomingdale Bog

Identification Comments

Identifying Characteristics

Male Forcipate Emeralds have a metallic green and brown thorax with two oval-shaped pale yellow spots of similar size on both sides. Their face is black and they have bright emerald green eyes. Their abdomen is dark with a whitish ring on segment 2 and small yellow spots on the side of segments 5 through 8. Males have a distinctive clasper that is arched in profile, long cerci that are slightly incurved with sharply pointed tips. Females are similarly colored with a distinctive broad subgenital plate that projects downward obliquely and is about as long as abdominal segment 9. The female's lateral abdominal yellow spots are found on segments 3 to 7 (Mead 2003, Paulson 2011).

Characters Most Useful for Identification

The characters most useful for identification are the yellow thoracic spots and unique terminal appendages on the adults.

Best Life Stage for Proper Identification

Adult.

Behavior

Boreal Somatochlora nymphs take at least 4 years to develop and they occupy shallow water meadows, sedge-filled pools, and sedge-filled shallows of small ponds. During this time, they are drought resistant and can survive dry conditions for up to 4-9 months through certain physiological adaptations and by actively burrowing in mud and seeking out sheltered locations in moss, cracks in mud, crevices in rotting logs, and sedge root clumps (Wiley & Eiler 1972). Somatochlora almost always occur at low densities, they often fly high (30-50), and adults are extremely elusive and difficult to capture (Packauskas 2005).

Diet

Forcipate Emerald larvae feed on smaller aquatic invertebrates and adults feed on insects which they capture in flight.

Best Time to See

Donnelly (1999) reported the flight season in New York as June 23 to July 11. This is significantly shorter than reported in Maine (Brunelle and deMaynadier 2005) and Massachusetts (Nikula et al. 2003) which runs from the end of May to early-September, which is also similar to the flight season reported by Walker and Corbet (1975), who stated that July was the peak flight season. NYNHP phenology data show a more protracted flight season in New York, with most records between June 23 to July 15 and one August 27 sighting (New York Natural Heritage Program 2018).

  • Reproducing
  • Larvae present and active

The time of year you would expect to find Forcipate Emerald reproducing and larvae present and active in New York.

Similar Species

  • Delicate Emerald (Somatochlora franklini)
    Delicate Emeralds do not have two prominent yellow thoracic spots, or lateral spots after abdominal segment 3 (Jones et al. 2008).
  • Ocellated Emerald (Somatochlora minor)
    Ocellated Emeralds have two spots on the thorax as well, but their overall size is much smaller than Forcipate Emeralds (Paulson 2011).
  • Brush-tipped Emerald (Somatochlora walshii)
    The female Brush-tipped Emerald has a similar genital plate to the Forcipate Emerald, but can be distinguished using field guides such as Jones et al. 2008.

Forcipate Emerald Images

Taxonomy

Forcipate Emerald
Somatochlora forcipata (Scudder, 1866)

  • Kingdom Animalia
    • Phylum Mandibulata (Mandibulates)
      • Class Insecta (Insects)
        • Order Odonata (Dragonflies and Damselflies)
          • Family Corduliidae (Emeralds)

Additional Resources

References

Brunelle, P.-M. and P. deMaynadier. 2005. The Maine Dameslfly and Dragonfly Survey: A Final Report. 2nd edition. Report prepared for the Maine Department of Inland Fisheries and Wildlife (MDIFW), Bangor, Maine. November 1, 2005. 31 pp.

Corser, J.D., E.L. White, and M.D. Schlesinger. 2014. Odonata origins, biogeography, and diversification in an Eastern North American hotspot: multiple pathways to high temperate forest insect diversity. Insect Conservation and Diversity 7:393-404.

Donnelly, T. W. 1992. The odonata of New York State. Bulletin of American Odonatology. 1(1):1-27.

Donnelly, T.W. 1999. The dragonflies and damselflies of New York. Prepared for the 1999 International Congress of Odonatology and First Symposium of the Worldwide Dragonfly Association. July 11-16, 1999. Colgate University, Hamilton, New York. 39 pp.

Donnelly, T.W. 2004. The Odonata of New York State. Unpublished data. Binghamton, NY.

Jones, Colin D., Andrea Kingsley, Peter Burke, and Matt Holder. 2008. The dragonflies and damselflies of Algonquin Provincial Park and the surrounding area. The Friends of the Algonquin Park. Whitney, ON.

Mead, K. 2003. Dragonflies of the North Woods. Kollath-Stensaas Publishing, Duluth, MN. 2003 pp.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

New York State Department of Environmental Conservation. 2005. Comprehensive Wildlife Conservation Strategy Planning Database. New York State Department of Environmental Conservation. Albany, NY.

Nikula, B., J.L. Loose, and M.R. Burne. 2003. A field guide to the dragonflies and damselflies of Massachusetts. Division of Fisheries and Wildlife, Natural Heritage and Endangered Species Program, Westborough, MA. 197 pp.

Packauskas, R.J. 2005. Hudsonian emerald dragonfley (Somatochlora husonica): A technical conservation assessment. A report prepared for USDA Forest Service, Rocky Mountain Region, Species Conservation Project. 38 pp.

Paulson, D. 2011. Dragonflies and damselflies of the east. Princeton University Press, Princeton, New Jersey, USA.

Walker, E.M. and P.S. Corbet. 1975. The odonata of Canada and Alaska, vol. 3: The Ansioptera - three families. University of Toronto Press, Toronto.

Wiley, R.L. and H.O.Eiler. 1972. Drought resistance in subalpine nymphs of Somatochlora semicircularis Selys (Odonata: Corduliidae). The American Midland Naturalist 87:215-220.

Links

About This Guide

This guide was authored by: Erin L. White

Information for this guide was last updated on: March 15, 2019

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Somatochlora forcipata. Available from: https://guides.nynhp.org/forcipate-emerald/. Accessed November 17, 2019.

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