Erin L. White


Erin L. White

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
G4
Apparently Secure globally - Uncommon in the world but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors.

Summary

Did you know?

The word incurvate means to curve inward. The Incurvate Emerald is so named because the claspers (terminal appendages) on adult males curve inward at the tip from the dorsal (top) view (Jones et al. 2008).

State Ranking Justification

In New York, Somatochlora incurvata is known from four bogs in three counties in the North Country (New York Natural Heritage Program 2017). It has a small known range in the state, limited to Adirondack sphagnum bogs where threats to habitats could include climate change and hydrologic alteration due to human activities.

Short-term Trends

There is no information on population trends for this species at known locations, as a number of sites have only recently been documented and it was first observed in the state in 1993 (Donnelly 1999, New York Natural Heritage Program 2017). The species seems to be highly ephemeral in New York because it has rarely been observed at a site subsequent to the initial sighting (with the exception of Massawepie Mire), despite numerous visits by experienced surveyors. This pattern is similar to Michigan where the species was first described in 1916, but not seen again until the early 1990s (Lee 1999).

Long-term Trends

Long-term information regarding population size is not available prior to the late 1990s (New York Natural Heritage Program 2017). Since observations are fairly recent, and the full extent and size of the populations have not been determined, long-term trends are unclear.

Conservation and Management

Threats

Any activity which might lead to water contamination or the alteration of natural hydrology could affect Incurvate Emerald populations (NYS DEC 2005). 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 from forestry disruption of habitats, reduce alteration of the bogs in activities such as peat mining, and any ditching and filling activities should be considered when managing for this species (NYS DEC 2005).

Research Needs

Further research is needed to define the distribution and population size of the Incurvate Emerald and inventory in Adirondack sphagnum bogs is needed. An informative distribution model developed by NY Natural Heritage highlighted several large bogs in southern Franklin County that would be worthy of intensive survey efforts including north of the St. Regis River near Whitney Pond and Black Pond Swamp and Bull Rush Bay on Middle Saranac Lake in the Saranac Lakes Wild Forest (New York Natural Heritage Program 2006). 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

In New York this species inhabits large, open, forest-bordered bogs, poor fens, and peatlands with widely scattered tamarack and black spruce, and ericaceous bog shrubs interspersed with sedges and Sphagnum, with abundant shallow, pooled water and rivulets. The water in these pools is clear and cold and moves almost imperceptibly through the sphagnum mat (Shiffer 1993). In Michigan, S. incurvata can be found in patterned peatlands and northern fens associated with marl- or peat-containing flowing alkaline groundwater (Lee 1999). Wisconsin habitats are large wetland complexes on old glacial lake beds, often adjacent to sandy pine uplands. Larvae have only recently been described and were found clinging to the underside of sphagnum mounds at pool edges in partially decomposed dark brown sphagnum and sedges (Wisconsin Natural Heritage Inventory Program 2010).

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

  • Canada Darner (Aeshna canadensis)
  • Variable Dancer (Argia fumipennis violacea)
  • Sphagnum Sprite (Nehalennia gracilis)

Range

New York State Distribution

Incurvate Emeralds have been documented in three counties in northern New York: Essex, Franklin, and St. Lawrence. It has been observed at four bogs in these counties since 1993 (New York Natural Heritage Program 2017).

Global Distribution

The global range for Incurvate Emerald is quite limited and is known from Wisconsin, Michigan, Ohio, Pennsylvania, New York, Rhode Island, Massachusetts, New Hampshire, and Maine in the United States and Ontario, Quebec, New Brunswick, Prince Edward Island, and Nova Scotia (Abbott 2006-2017).

Best Places to See

  • Massawepie Mire (St. Lawrence County)

Identification Comments

Identifying Characteristics

Incurvate Emeralds have bright emerald green eyes when mature. Males have a dark thorax with metallic green iridescence and two lateral spots fading with age (anterior spot is more elongate and posterior spot is shorter and more rounded). Their abdomens are brownish to black and long and slender. There are dull orange-brown lateral spots on abdominal segments 3-8. The male cerci (terminal appendages) are distinctive from other Somatochlora and are strongly curved inward at tips from the dorsal view. Females are similar to males, but have a thicker abdomen and a yellowish ovipositor that is large and scoop-shaped (Nikula et al. 2003, Jones et al. 2008, Paulson 2011).

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). Adult males fly low and erratically over vegetation and occasionally perch on tree branches or hover over open pools.

Diet

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

Best Time to See

Incurvate Emerald adults have been found in New York from July through August (Donnelly 1999, New York Natural Heritage Program 2017). They could possibly be observed later in the season, given flight dates in nearby states and provinces (Paulson 2011).

  • Present
  • Reproducing

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

Similar Species

  • Forcipate Emerald (Somatochlora forcipata) (guide)
    Incurvate Emeralds are also larger and duller than Forcipate Emeralds. The male cerci and female ovipositor are also distinctive and help to separate the species. The cerci arch downward on Forcipate Emeralds. Forcipate Emeralds are smaller with two round yellow spots on the thorax (Jones et al. 2008).
  • Kennedy's Emerald (Somatochlora kennedyi)
    Kennedy's Emerald is less dull in appearance and Incurvate males have cerci that are more forcep-like than Kennedy's from a lateral view (Paulson 2011).

Incurvate Emerald Images

Taxonomy

Incurvate Emerald
Somatochlora incurvata Walker, 1918

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

Additional Resources

References

Abbott, J.C. 2006-2017. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: March 17, 2017).

Bick, G.H. 1983. Odonata at risk in conterminous United States and Canada. Odonatologica 12(3):209-226.

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. 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.

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.

Lee, Y. 1999. Special animal abstract for Somatochlora incurvata (Incurvate Emerald dragonfly). Michigan Natural Features Inventory. Lansing, MI.  Available http://web4.msue.msu.edu/mnfi/abstracts/zoology/Somatochlora_incurvata.pdf.

Needham, J.G. and M.J. Westfall, Jr. 1954. A Manual of the Dragonflies of North America (Anisoptera). University of California Press, Berkeley, California. 615 pp.

New York Natural Heritage Program. 2006. Element distribution model for Somatochlora incurvata. Albany, NY. 3-12-2010.

New York Natural Heritage Program. 2017. Element Occurrence Database.State University of New York College of Environmental Science andForestry, Albany, NY.

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.

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

Shiffer, C.N. 1969. Occurrence and habits of Somatochlora incurvata, new for Pennsylvania (Odonata:Corduliinae). The Michigan Entomologist 2(3-4):75-76.

Shiffer, Clark. 1993. Observatoions on Somatochlora incurvata in Pennsylvania. ARGIA 5:10-11.

Walker, E.M., and P.S. Corbet. 1975. The Odonata of Canada and Alaska. Vol 3. The Anisoptera--Three families. Univ. Toronto Press. 307 pp.

White, Erin L., Jeffrey D. Corser, and Matthew D. Schlesinger. 2010. The New York Dragonfly and Damselfly Survey 2005-2009: distribution and status of the odonates of New York. New York Natural Heritage Program, New York State Department of Environmental Conservation. Albany, NY. 450 pp.

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.

Wisconsin Natural Heritage Inventory Program. 2010. Endandered Resources Program species Information, Somatochlora incurvata. Wisconsin Depeartment of Natural Resources, Madison, Wisconsin. http://www.dnr.state.wi.us/org/land/er/biodiversity/index.asp?mode=info&Grp=12&SpecCode=IIODO32130.

Links

About This Guide

This guide was authored by: Erin L. White

Information for this guide was last updated on: March 31, 2017

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Somatochlora incurvata. Available from: https://guides.nynhp.org/incurvate-emerald/. Accessed July 16, 2019.

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