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Tramea lacerata

What do they look like?

Black saddlebags, although fairly common, are striking insects. The hind wings are long and wide, with irridescent black bands on the parts of the wings closest to the body. This gives them their common name "black saddlebags," because the black patches make them look like they're wearing saddlebags. The rest of the wing is clear. Black saddlebags are medium to large dragonflies, about 5.33 cm. The body has a streamlined, teardrop shape. Males are mostly black, with deeper coloring than females. Females are larger, and have a whitish-yellow spotted pattern on the back of their abdomen. Recently emerged (newly metamorphosed from their larval state) males look similar to females. Females and newly emerged black saddlebags also have light colored or yellowish faces. Both males and females have black legs.

  • Sexual Dimorphism
  • female larger
  • sexes colored or patterned differently
  • Average length
    5.33 cm
    2.10 in

Where do they live?

Black saddlebags are found throughout much of Mexico and the United States as far north as Maine, northernmost Vermont, and Montana. This species ranges south to Baja California and Quintana Roo, Mexico, and is also found on the Hawai'ian islands, the Florida Keys, Bermuda, and Cuba. In Canada they are found in Quebec, Ontario, and British Columbia.

What kind of habitat do they need?

Black saddlebags prefer stagnant or slow moving bodies of water, like those found in ditches, ponds, and small lakes. They flourish in areas where there are no predatory fishes. Still waters allow females to lay their eggs in a characteristic "dipping" manner, without the eggs being swept away. Adults are often seen gliding in wetlands and grasslands near water.

  • Aquatic Biomes
  • lakes and ponds
  • temporary pools

How do they grow?

Larvae are aquatic. Their gills are folded inside the abdomen to avoid harm. They take in water through their anus and pass it over their gills to breath. After internal metamorphosis occurs, with the adult body forming under the skin, an adult black saddlebags will emerge from the water and grasp a branch where it will complete the rest of its transformation. The cuticle begins to split apart due to the pressure exerted through a series of air intakes. The newly emerged adult, which is quite delicate until the new cuticle hardens, will then crawl out of its old skin (exuviae), allow the wings to open and harden, and then fly away. (Dunkle, 2000)

How do they reproduce?

Black saddlebags males and females meet to mate on tree branches near a source of water. They are sometimes called "dancing gliders" because of their mating behavior. The male will grab a female by the head, then they will adjust their abdomens to be joined. The male often spends a lot of time removing any sperm that may already be in the female before transferring his own sperm. The male then stays with the female as she flies above the water and dips her abdomen into the water repeatedly. Each time she dips her abdomen she is releasing a few eggs into the water. Because the male and female seem to dip together, they are called "dancing gliders."

Females lay their eggs in stagnant or very slow moving waters. They will dip down to the water and drop the eggs into the water. Some of them migrate to the north in the spring, where they will breed.

  • Breeding season
    Breeding occurs during warm weather.

Once the female lays the eggs there is no more parental involvement in the young.

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female

How long do they live?

No information was found on the lifespan of black saddlebags.

How do they behave?

Larvae are aquatic and adults spend much of their time flying. Adults may either mate in the area where they emerged or will begin to migrate. Black saddlebags migrate from August to September. Very little is known about migration routes and life cycles during migration. Male black saddlebags seem to be somewhat social because they are often seen in large feeding swarms.

How do they communicate with each other?

Dragonflies have exceptionally good vision and use it to communicate with other dragonflies, to catch their prey, and to avoid being eaten. They may also communicate with touch when mating.

What do they eat?

Black saddlebags are members of the common skipper family. They use a gliding feeding style, using their long, broad hind wings to glide as they pick insect prey from the air. Black saddlebags are rarely seen perching, but will sometimes rest on the tips of branches between feeding glides. When there is lots of food in a particular area, swarms of large numbers of feeding black saddlebags may form. These swarms are often made up of only males but can have females in them as well. No feeding swarms of only females have been observed.

  • Animal Foods
  • insects

What eats them and how do they avoid being eaten?

Dragonflies are preyed on by aquatic predators, such as fish, when they are larvae. As adults, they may be eaten by birds such as American kestrels and common nighthawks. Their maneuverability and their exceptional sense of vision keeps them safe from most predators when they are flying adults. Larvae are usually aggressive and well-armed predators as well. They can rapidly eject water from their abdomen to shoot out of the way of predators underwater.

What roles do they have in the ecosystem?

Dragonflies are important predators of insects in the ecosystems in which they live. Larvae and adults also provide food for predatory fish and for birds.

Do they cause problems?

There are no negative impacts of black saddlebags for humans.

How do they interact with us?

Black saddlebags adults and larvae eat large numbers of insect pests, such as mosquitoes. Dragonflies in general are also important indicators of healthy, aquatic habitats.

  • Ways that people benefit from these animals:
  • controls pest population

Are they endangered?

Black saddlebags are abundant and widespread. They are not currently considered species of concern in any area they live.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Ginger Dixon (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Dunkle, S. 2000. Dragonflies Through Binoculars. New York City, NY, USA: Oxford University Press.

May, M. "Dragonfly Migration" (On-line). Accessed March 12, 2001 at http://www.hsrl.rutgers.edu/BOB/migrant/may_txt.html.

Paulson, D. June 1, 1984. Odonata from the Yucatan Peninsula, Mexico. Notulae Odonatologicae, Vol.2 No.3: pp. 33-52.

Trial, L. "Pond Dragons" (On-line). Accessed March 12, 2001 at http://www.conservation.state.mo.us/conmag/2000/07/1.htm.

 
University of Michigan Museum of ZoologyNational Science Foundation

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Dixon, G. 2001. "Tramea lacerata" (On-line), Animal Diversity Web. Accessed October 31, 2014 at http://www.biokids.umich.edu/accounts/Tramea_lacerata/

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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