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Ophiogomphus susbehcha

What do they look like?

Adult St. Croix snaketail dragonflies are large, at 5 cm in length. Their eyes are large and gray. Their middle body section, called the thorax, is dark bluish-green with a single black stripe down the side. They have 6 black legs. Their long, slender tail section, called the abdomen, has yellow spots going down the back. Their tail ends in a club-shape, which gives them the "snaketail" name, since it looks like a cobra snake. Females have horns just behind their eyes that males do not. Dragonflies have two pairs of long wings with many veins on them.

Larvae of this species are slightly flattened. They have an oval body that is also rounded and slightly pointed at the end. They also have brownish-black spots. St. Croix snaketail larvae are much larger than other dragonfly larvae that live in the same areas. Dragonfly larvae have large lower lips that they can shoot out to grab prey. They also do not have gills on the outside of the body; instead the gills are located inside the rectum at the end of their body. ("Ophiogomphus susbehcha", 2013; Borror and White, 1970; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965; Sabet-Peyman, 2006; Wellhouse, 1926)

  • Average length
    5 cm
    1.97 in

Where do they live?

The St. Croix snaketail dragonfly, or Ophiogomphus susbehcha, is a rare dragonfly species that is only found in several places in the United States. It was first discovered in two rivers in Wisconsin and Minnesota in the United States, the St. Croix river, and the Chippewa river. It is also thought to live in the east, to Pennsylvania, and it has also been discovered in the Potomac River in Maryland. Researchers also think that another species in Pennsylvania, Ophiogomphus edmundo is probably a subspecies of the St. Croix snaketail dragonfly. There dragonflies are very rare wherever they are found. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

What kind of habitat do they need?

St. Croix snaketail larvae are aquatic, and live in large rivers. The larvae live in the bottoms of the rivers or streams, which have fast-flowing, clear water. The bottoms of the rivers are usually made up of gravel, sand and rocks.

Adults live on land and in the air, and are usually near rivers and streams. They hunt for food in fields, forests, and wetlands. The areas they live are usually undisturbed by humans, often in land preserved by the government.

  • Aquatic Biomes
  • rivers and streams
  • Range elevation
    244 to 305 m
    800.52 to 1000.66 ft

How do they grow?

St. Croix snaketail dragonflies probably have a 2-year life cycle. They go through incomplete metamorphosis, and have the life stages of egg, larvae, and adult. After hatching, the larvae burrow into the bottom of the riverbed and spend the winter there. Larvae go through several stages called instars. The following spring, larvae become mature between late May and late June. They get out of the water in mid-morning, and crawl away on land and stop on rocks, vegetation, or on large tree trunks. The larvae molt into adults by shedding their skin. While the new adult sits there and waits for its wings to dry, it is called a teneral. After several hours, the adult flies away. (Gibbs, et al., 2004; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

How do they reproduce?

Males fly along rivers, looking for females. Males compete with each other to mate with females. Males and females mate while perched on the shoreline on bushes and trees. Before mating, a male has to bend the end of his abdomen forward to transfer sperm to an organ on his abdomen. When he finds a female, he holds her by the back of the head with the end of his tail. The female bends her abdomen up to the body of the male to take his sperm and fertilize her eggs. (Lyons, 1999; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965; Sabet-Peyman, 2006)

After mating, the males leave and the females lay their eggs in rivers by dipping the end of their abdomen in the water. The current of the water carries the eggs away. The larvae will live in the river bottom over the winter until the following spring and summer, when they emerge and become mature adults ready to mate. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965)

  • Breeding season
    Breeding takes place in the summer.

To provide for their offspring, females put nutrients in the eggs that the offspring can use to develop and grow before hatching. Females also lay the eggs in rivers where the larvae can survive after hatching. However, after eggs are laid, the parents do not give any more care. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • female

How long do they live?

St. Croix snaketail dragonflies likely live for about 2 years. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

  • Average lifespan
    Status: wild
    2 years

How do they behave?

Adults are predators, and spend much of the day flying around, looking for food and mates. They often perch in treetops in the evening and early morning. While resting, they hold their wings outstretched. While flying, adults have a regular route that they fly along. (Borror and White, 1970; Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965)

Home Range

Adults usually stay within about 30 meters of the river or stream where they lived as larvae. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

How do they communicate with each other?

Most members of Odonata have large heads with large, well developed eyes that give them excellent vision. Vision is their most important sense, since it allows them hunt very well, and also to find mates. During mating, males and females also communicate by touch, since the male holds onto the female with the end of his abdomen. (Sabet-Peyman, 2006)

What do they eat?

Both St. Croix snaketail adults and larvae are predators and feed on insects. Larvae eat other aquatic insects, such as midge and mayfly nymphs. Adults eat flying insects that they hunt for in forests. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)

  • Animal Foods
  • insects

What eats them and how do they avoid being eaten?

Dragonflies are preyed upon by birds, lizards, frogs, spiders, fish, water bugs, and other large dragonflies. However, they have good eyesight and are fast fliers, which allows them to avoid many predators. Larvae avoid predators due to their brownish-black spots and colors, which work as camouflage in their rivers and streams. (Sabet-Peyman, 2006)

  • These animal colors help protect them
  • cryptic

What roles do they have in the ecosystem?

St. Croix snaketail dragonflies are predators to many other insects, and are prey to many other organisms. This makes this dragonfly species an important part of its ecosystem and food web. They have been seen in large numbers along medium-sized, clear and clean rivers that have a high number of other animals species. This means that these dragonflies probably interact with many other species.

The spread of the invasive zebra mussel, Dreissena polymorpha, in the Lake Superior basin may cause problems for St. Croix snaketail dragonflies as the zebra mussel change the ecosystem. ("Resource Brief: Dragonflies & Damselflies", 2009; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Sabet-Peyman, 2006)

Do they cause problems?

St. Croix snaketail dragonflies do not cause any problems for humans.

How do they interact with us?

Dragonflies act as bioindicators of ecosystem health. If something causes changes in an ecosystem, such as pollution, there will also be changes in dragonfly populations as a result. If researchers look for changes in dragonfly populations, they will know if something happens to an ecosystem. They are important organisms for research. Dragonflies also feed on pest insects such as mosquitoes. (Lyons, 1999; Schultz, 2009; Wellhouse, 1926)

  • Ways that people benefit from these animals:
  • research and education

Are they endangered?

Nationally, St. Croix snaketail dragonflies are not an endangered species. In Wisconsin, it is an endangered species, and in Minnesota it is a species of special concern, since populations there are small and rare. ("CITES", 2013; "Endangered Species Program", 2013; "IUCN Red List of Threatened Species Version 2012.2", 2012)


Ann Horner (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Angela Miner (editor), Animal Diversity Web Staff.


2013. "CITES" (On-line). Accessed March 27, 2013 at

2013. "Endangered Species Program" (On-line). U.S. Fish and Wildlife Service. Accessed March 27, 2013 at

2012. "IUCN Red List of Threatened Species Version 2012.2" (On-line). Accessed March 27, 2013 at

2013. "Ophiogomphus susbehcha" (On-line). Wisconsin Odonata Survey. Accessed March 26, 2013 at

Minnesota Department of Natural Resources. 2013. "Ophiogomphus susbehcha/St. Croix Snaketail" (On-line). Minnesota DNR. Accessed March 25, 2013 at

2009. "Resource Brief: Dragonflies & Damselflies" (On-line). National Park Service. Accessed March 27, 2013 at

2013. "Saint Croix Snaketail (Ophiogomphus susbehcha)" (On-line). Wisconsin DNR. Accessed March 26, 2013 at

Borror, D., R. White. 1970. A Field Guide to the Insects. Boston, USA: Houghton Mifflin Company.

Dunkle, . 2013. "Ophiogomphus susbehcha" (On-line). NatureServe. Accessed March 25, 2013 at

Gibbs, E., B. Bradeen, D. Boland. 2004. Spatial and Temporal Segregation Among Six Species of Coexisting Ophiogomphus (Odonata: Gomphidae) in the Aroostook River, Maine. Northeastern Naturalist, 11: 295-312.

Lyons, R. 1999. "Damsels and Dragons - the Insect Order Odonata" (On-line). Accessed March 27, 2013 at

Ross, H. 1965. A Textbook of Entomology 3rd edition. New York, USA: John Wiley & Sons, Inc..

Sabet-Peyman, J. 2006. "Introduction to the Odonata" (On-line). UCMP Berkely. Accessed March 27, 2013 at

Schultz, T. 2009. Diversity and Habitats of a Prairie Assemblage of Odonata at Lostwood National Wildlife Refuge, North Dakota. Journal of the Kansas Entomological Society, 82: 91-102.

Wellhouse, W. 1926. How Insects Live. New York, USA: The Macmillan Company.

University of Michigan Museum of ZoologyNational Science Foundation

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Horner, A. 2014. "Ophiogomphus susbehcha" (On-line), Animal Diversity Web. Accessed April 24, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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