Spatterdock Darner

Rhionaeschna mutata (Hagen, 1861)

Rhionaeschna mutata
Blair Nikula

Class
Insecta (Insects)
Family
Aeshnidae (Darners)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S2
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or 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 genus Rhionaeschna is made up of mostly tropical dragonflies, and the bright blue Spatterdock Darner (Rhionaeschna mutata, formally Aeshna mutata) is the only representative in New York. It believed the Spatterdock Darner is a relict species which colonized northward over 30 million years ago (Von Ellenrieder 2003)!

State Ranking Justification

This species is extant at 25 locations in New York. The distribution of these records is widespread and the species' principal habitat, vegetated ponds, pools and bogs (Nikula et al. 2003, Dunkle 2000), is also widespread, but localized. These considerations suggest that existing collection locations are not an accurate representation of the actual number of populations. However, the species is thought to be fairly local in New York and other states, and the apparent preference for fishless ponds with Spatterdock Water Lilies may also indicate that the number of undiscovered populations may not be large. It is likely that there are particular qualities such as water depth, bottom substrate type, amount and type of aquatic vegetation, pH, and the absence of certain types of fish, that make some lakes and ponds suitable while others are not suitable. In addition, there are a number of actual or potential threats to the types of waters occupied by this species.

Short-term Trends

Prior to the onset of the New York Dragonfly and Damselfly Survey from 2005-2009 (White et al., 2010), this species was known from seven counties in New York, primarily in the southern tier and Catskills. During and after the survey it has been found in 11 additional counties. However, there are no formal population estimates at individual localities and formal population trends cannot be assessed at this time. It seems likely that at least some occupied sites are being lost due to changes in hydrology and water quality at some lakes and ponds across the species' state range.

Long-term Trends

There is no information on long-term population trends for this species, although it seems likely that at least some occupied sites are being lost due to changes in hydrology and water quality at some lakes and ponds across the species' state range. There is, however, speculation that this species is generally increasing in range northward (Cook & Bridgehouse, 2005 as cited in White et al., 2010). The increasing number of sites in New York supports this view, although it cannot be untangled from increased survey effort.

Conservation and Management

Threats

Little published information is available citing specific cases of negative impacts to this species or other lake-dwelling odonates, but any activities that degrade the sensitive hydrology of these habitats would threaten populations of these species. Examples include eutrophication and changes in dissolved oxygen content, direct effects of pesticides (e.g. for mosquito control or from agricultural runoff), increases in the sediment load of the lake (such as might result from agricultural runoff or removal of vegetation from the adjacent uplands), chemical contamination by runoff of agricultural or other discharge, and acidification of lakes by airborne industrial emissions. Groundwater withdrawal is also a likely threat at suitable sites on Long Island. Removal of large areas of forest or shrub habitats adjacent to occupied lakes and ponds could also threaten populations, as these adjacent habitats are important for recently emerged adults until they reach maturity.

Any activity which might lead to water contamination, siltation, warming of waterways, or the alteration of natural hydrology could directly and indirectly impact lentic habitats and Spatterdock Darner populations. Such threats might include roadway and agricultural runoff, industrial pollution, dams, logging activities, and development (NYS DEC 2005). In addition, siltation decreases the amount of sunlight that reaches aquatic plants (EPA 2005) and lowers the quality of habitats needed for a variety of aquatic species (NYS DEC 2005). Point source pollution, such as effluents from municipal and industrial facilities, contribute to the degradation and pollution of aquatic habitats (EPA 2022, NYS DEC 2005, Mahar and Landry 2013, Strayer et al. 2004). While modern day agricultural and silvicultural practices are an important aspect of the New York State economy, it is important to consider the effects on ecosystems and species. Excessive fertilizer use can lead to algal blooms that can be deadly to aquatic life and overgrazing of livestock in fields could introduce pathogens, oxygen-demanding organics and solids, and invasive species to aquatic ecosystems (EPA 2005).

Approximately 10% of introduced, non-native species could have an impact on the health of ecosystems (McCormick et al. 2009). Invasive plants tend to outcompete native plants and can change natural processes (NYS DEC 2005). Aquatic invasive plants and animals can alter the water chemistry, change the nutrient regime, or decrease the dissolved oxygen levels. Introduced fish can alter trophic relationships resulting in changes to native fish populations and decreased water quality (McCormick et al. 2009), as well as long-term persistence issues for species evolved to live in fish-free systems.

Climate change is another threat that is likely to have lasting effects on riverine systems. Irregular weather patterns can cause extreme drought, flooding, and temperature fluctuations. Heat waves are expected to be more intense (Frankson et al. 2022). The Northeast Region of the United States is expected to experience an increase in precipitation, more frequent storms, and higher than normal temperatures (EPA 2016, EPA 2022). Precipitation is expected to increase 10% to 15% in southern New York and 15 to 20% in northern New York by 2050 (Frvankson et al. 2022). Extreme flooding can cause widespread erosion and runoff with added risk of contamination if flooding occurs at remediation sites, industrial sites, or wastewater treatment facilities (EPA 2016, EPA 2022). Temperature increases can significantly alter ecosystems. As water temperatures rise, the amount of dissolved oxygen decreases and evaporation increase potentially lowering lake and stream levels (EPA 2022). Any combination of these events could change species distributions (EPA 2022) and those that cannot adapt or migrate may be extirpated from some areas (NYS DEC 2005).

Conservation Strategies and Management Practices

Any measures to protect water quality and reduce water contamination or hydrological alteration (such as agricultural or road runoff, shoreline development, and damming) should be considered when managing for spcies that depend on aquatic habitats like Spatterdock Darners (NYS DEC 2005). Lakeshore practices such as natural buffers that promote shoreline integrity of forests and healthy stands of native emergent and floating vegetation should serve to benefit populations of this species.

There is no single recommendation for BMPs for agricultural practices, but in general, management plans should be tailored to local conditions (e.g., soils, slope, land use). Often these plans aim to reduce pollution and increase farm productivity, but incentives could also be used to encourage sustainable farming practices. According to EPA (2005), proper management typically reduces runoff by 20-90%. Consider using Integrated Pest Management (IPM) as an alternative to pesticide use. If pesticides and fertilizers are used, they should only be applied as needed, in the proper amount, and timed appropriately. In addition, livestock should be rotated to avoid overgrazing and to allow for vegetation regrowth. If needed, alternative water sources could be provided along with shade to keep animals out of sensitive areas (EPA 2005).

Public outreach is an important tool for conservation. Many of the threats to aquatic habitats and species can have direct and indirect effects to human health and recreation. In addition, outreach and incentives for various industries would be valuable. Improvements to municipal and industrial treatment facilities was noted by NYS DEC (2005) and further improvements and plans to deal with spills should continue to be encouraged.

Climate change is a global challenge and will require partnerships outside of the New York State border (NYS DEC). However, there are local actions that can help mitigate extreme weather events. Industrial and municipal infrastructure should be improved or replaced to be more resilient to flooding events (EPA 2016, NYS Comptroller 2023). Some suggested actions include installing or improving pumps to remove floodwater from facilities and installing protective structures, such as floodwalls. Ensure that existing bridges, dams, levees, seawalls, retaining walls, and wind barriers are prepared for extreme weather (NYS Comptroller 2023). Runoff and erosion severity can be decreased by installing large culverts, planting vegetation along riverbanks, and protecting and restoring wetlands (EPA 2016, NYS Comptroller 2023).



Invasive species management can be time consuming and costly. Steps should be made to reduce the likelihood of non-native species being introduced into waterways. Boat-washing stations at boat launches can reduce chances of invasive plants and animals being transported to new waterbodies. Public outreach that educates the anglers about the risk of releasing unused baitfish would be beneficial. If there are vulnerable species present, consider a baitfish ban. Mechanical removal of some invasive plants may be needed in some rivers and streams. The use of pesticides to remove invasives can have a negative effect on ecosystems (McCormick et al. 2009) and should be a last resort to control invasive species.

Research Needs

Research aimed at obtaining information on population size at occupied sites would be useful in determining the overall population for this species in the state. Research on larval habitat requirements may provide a better understanding of why the species is uncommon.

Habitat

Habitat

The habitat of this pond/lake species has been described as "fishless ponds, usually with water lilies" (Dunkle 2000) or "vegetated ponds and pools, open marshes and bogs, often with Spatterdock [water lilies]" (Nikula et al. 2003). A recent rangewide review found that Spatterdock water lilies and heavy vegetation were the most commonly reported habitat characteristics for species, and that the fish free association, while often noted, does not appear to be obligate (Schilling et al. 2019). Most New York locations are small ponds with abundant vegetation, including Spatterdock (Nuphar lutea, Yellow Water Lily). As new populations are discovered in New York we are learning more about the habitat use of this species. While several New York populations occur in ponds, lakes and bogs, others represent less typically reported habitats. For example, on Long Island this species has been reported from a coastal plain pond (which may not be the breeding habitat), and in Saratoga County, they have been reported from ephemeral pools that lack the eponymous Spatterdock water lilies. While previous reports questioned the need for fishless ponds (New York Natural Heritage Program 2006), at least some sites in New York are now thought to have fish (New York Natural Heritage Program 2023).

Associated Ecological Communities

  • Coastal plain pond* (guide)
    The aquatic community of the permanently flooded portion of a coastal plain pond with seasonally, and annually fluctuating water levels. These are shallow, groundwater-fed ponds that occur in kettle-holes or shallow depressions in the outwash plains south of the terminal moraines of Long Island, and New England. A series of coastal plain ponds are often hydrologically connected, either by groundwater, or sometimes by surface flow in a small coastal plain stream.
  • Eutrophic pond* (guide)
    The aquatic community of a small, shallow, nutrient-rich pond. The water is usually green with algae, and the bottom is mucky. Eutrophic ponds are too shallow to remain stratified throughout the summer; they are winter-stratified, monomictic ponds.
  • Oligotrophic dimictic lake (guide)
    The aquatic community of a nutrient-poor lake that typically occurs in a deep, steeply-banked basin. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall), they are thermally stratified in the summer, and they freeze over and become inversely stratified in the winter.
  • Oligotrophic pond (guide)
    The aquatic community of a small, shallow, nutrient-poor pond. The water is very clear, and the bottom is usually sandy or rocky.

* probable association but not confirmed.

Associated Species

  • Mottled Darner (Aeshna clepsydra) (guide)

Range

New York State Distribution

This species is extant at 25 locations in New York. These records come from 21 counties in various regions of the state including the southern tier, Catskills, Hudson Valley, northwestern Adirondacks, and Long Island. The wide distribution of these counties suggests that the species is likely to occur in other counties in these regions of the state. However, as in other portions of the species' range, it is expected that this darner will be spotty, or local, in its distribution and a large number of populations will not be found. The number of known counties has roughly doubled since 2005 (from seven to 14) in large part due to increased survey effort via the New York Dragonfly and Damselfly Survey (White et al. 2010).

Global Distribution

This species is uncommon and local within a range restricted to the northeastern United States and southern Ontario. Specifically, the range extends from Maine and southern Ontario, south and west to southern Michigan, southeastern Wisconsin, eastern Illinois, Kentucky, and northern Tennessee, and east to northern Virginia and New England (Dunkle 2000).

Best Places to See

  • Birdseye Hollow State Forest (Steuben County)

Identification Comments

General Description

Spatterdock Darners are an early summer darner with bright blue eyes (Paulson 2011). Males can be easily distinguished from similar species by bright sky-blue markings on the face and body, although this is most useful close up as the species can appear dark or dull from a distance (Paulson 2011). Females are polymorphic and harder to identify (Paulson 2011).

Identifying Characteristics

Like other blue or mosaic darners, adult Spatterdock Darners are large dragonflies with large eyes, a brown thorax with two blue stripes on the front and two on the side, and a long slender brown abdomen marked by two rows of sky blue spots. Unlike simila looking species in the genus Aeshna, the eyes of this species are bright blue, and males have peculiar-shaped, forked terminal appendages. Adult Spatterdock Darners average approximately 2.8 in (7.1 cm) in length. The wings are clear. Females are similar to males, but the thoracic markings are generally duller, and the occasional female has yellowish thoracic stripes and greenish abdominal spots (Nikula et al. 2003, Dunkle 2000). The larvae are elongate, cylindrical-shaped aquatic insects that are usually patterned in drab brown and greenish colors. They climb and crawl among aquatic vegetation. The antennae are composed of seven small, slender segments. Body length is approximately 1.4 in (36 mm) at maturity (Walker 1958), which may be at 1-3 years.

Characters Most Useful for Identification

Close examination of the thoracic pattern is helpful in identification, although the eye color and, for males, the shape of the terminal appendages, are conclusive.

Best Life Stage for Proper Identification

Mature adults are the best life stage for the identification of all dragonflies. Larval identification requires the use of detailed taxonomic keys, can be very difficult, and can be very unreliable, especially in the case of larvae that are not yet mature. Larval identification is best done by people with a great deal of expertise in this area.

Behavior

Adults hunt along forest edges, dirt roads, and fields, often in the vicinity of the wetland where eggs are laid. Females lay their eggs, on the undersides of aquatic and emergent vegetation, especially Spatterdock (Yellow Pond Lily; Nuphar spp.). Males chase other males and patrol for females while flying low along the wetland shoreline or over the open water, often with a leisurely erratic flight. As with other darners, Spatterdock Darners rest by hanging vertically on tree trunks or branches where they can be difficult to detect (Nikula et al. 2003, Dunkle 2000).

Diet

Adult darners feed on flying insects. Tropical members of Rhionaeschna feed on tadpoles as larvae (Jara 2008), and it is likely Spatterdock Darners do as well.

Best Time to See

Spatterdock Darners are an early season species with a flight season of early June to early July. Based on New York records, more than 80% of New York observations occur in June (Donnelly 1999; White et al., 2010). Nikula et al. (2003) show a similar flight season for Massachusetts, but with the season beginning a bit earlier, in late May. The flight season in New York may actually be later than the season in Massachusetts, or the lack of records in late May in New York may simply reflect the overall lack of records for this uncommon species.

  • Present
  • Active
  • Reproducing

The time of year you would expect to find Spatterdock Darner present, active, and reproducing in New York.

Similar Species

  • Springtime Darner (Basiaeschna janata)
    The Springtime Darner (Basiaeschna janata) has bluish abdominal spots and flies in early summer, but has pale yellow to white (rather than blue) lateral thoracic stripes, has small dark patches at the base of the wings, lacks the sky-blue eyes of the spatterdock darner, and is noticeably smaller in overall body size.
  • Cyrano Darner (Nasiaeschna pentacantha) (guide)
    Like the Spatterdock Darner, the Cyrano Darner (Nasiaeschna pentacantha) flies in early summer and has blue eyes, but this species has a projecting forehead, green thoracic stripes, and is noticeably heavier in the body.

Spatterdock Darner Images

Taxonomy

Spatterdock Darner
Rhionaeschna mutata (Hagen, 1861)

  • Kingdom Animalia
    • Phylum Arthropoda (Mandibulates)
      • Class Insecta (Insects)
        • Order Odonata (Dragonflies and Damselflies)
          • Family Aeshnidae (Darners)

Synonyms

  • Aeshna mutata Hagen, 1861

Additional Resources

References

Cook, C. and D. Bridgehouse. 2005. Aesha mutata Hagen (spatterdock darner) in Nova Scotia, a new provincial record, and significant range extension. Agia 16:5.

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.

Dunkle, S.W. 2000. Dragonflies through binoculars: A field guide to dragonflies of North America. Oxford University Press: 266 pp.

Environmental Protection Agency (EPA). 2005. Protecting water quality from agricultural runoff. https://www.epa.gov/sites/default/files/2015-09/documents/ag_runoff_fact_sheet.pdf.

Environmental Protection Agency (EPA). 2016. Adapting to climate change northeast. https://www.epa.gov/sites/default/files/2016-07/documents/northeast_fact_sheet.pdf.

Environmental Protection Agency (EPA). 2022. Region 2 climate adaptation implementation plan. https://www.epa.gov/system/files/documents/2022-10/bh508-R02%20Climate%20Adaptation%20Implementation%20Plan%209.19.2022%20HQ%20OP%20Copy.pdf

Frankson, R., Kunkel, K.E., Champion, S.M., Stewart, B.C., Sweet, W, DeGaetano, A.T., & Spaccio, J. (2022). New York State Climate Summary 2022. National Oceanic and Atmospheric Administration National Centers for Environmental Information. https://statesummaries.ncics.org/chapter/ny/

Jara, F. G. 2008. Tadpole–odonate larvae interactions: influence of body size and diel rhythm. Aquatic Ecology, 42, 503-509.

Mahar, Amy and Jenny Landry. 2013. New York State Department of Environmental Conservation species status assessment for Lasmigona subviridis (Green Floater).

McCormick, Frank H., Glen C. Contreras, and Sherri L. Johnson. 2009. "Effects of nonindigenous invasive species on water quality and quantity." A dynamic invasive species research vision: opportunities and priorities 29 (2009): 111-120.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

New York State Comptroller. 2023. New York's local governments adapting to climate change: challenges, solutions, and costs. https://www.osc.state.ny.us/files/local-government/publications/pdf/climate-change-2023.pdf

New York State Department of Environmental Conservation. 2005. A strategy for conserving New York's fish and wildlife resources. Final submission draft.

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.

Schilling, E. G., Lawrenz, R., & Kundel, H. 2019. A review of the reproductive habitat preferences and conservation challenges of a rare, transient, and ecologically restricted darner dragonfly: Rhionaeschna mutata. International Journal of Odonatology, 22(1), 1-9.

Strayer, David L., J.A. Dowling, W.R. Haag, T.L. King, J.B. Layzer, T.J. Newton and S.J. Nichols. 2004. Changing perspectives on Pearly Mussels, North America's most Imperiled Animals. BioScience 54:429-439.

Walker, E.M. 1958. The odonata of Canada and Alaska. Volume 2, Part III: The Anisoptera - four families. Univ. of Toronto Press. 318 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.

von Ellenrieder, N. 2003. A synopsis of the Neotropical species of Aeshna Fabricius: Genus Rhionaeschna Förster (Odonata: Aeshnidae). Tijdschrift voor Entomologie (Leiden) 146:67-207.

Links

About This Guide

This guide was authored by: Paul G. Novak and John P. Vanek

Information for this guide was last updated on: September 29, 2023

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Rhionaeschna mutata. Available from: https://guides.nynhp.org/spatterdock-darner/. Accessed June 23, 2024.