Dragonflies and Damselflies

Odonata

Classification

Pronunciation

How to pronounce Odonata: /ˌoʊdəˈneɪtə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Erythrodiplax funerea by the Smithsonian. Used under a CC0 license.
Lestes stultus by the Smithsonian. Used under a CC0 license.
Celaenura gemina by the Smithsonian. Used under a CC0 license.
Helocordulia uhleri by the Smithsonian. Used under a CC0 license.
Undetermined undetermined by the Smithsonian. Used under a CC0 license.
Celaenura gemina by the Smithsonian. Used under a CC0 license.

Summary

Odonata is an order of predatory insects encompassing dragonflies and damselflies, characterized by their aquatic nymphs and carnivorous life stages. They are essential predators in their ecosystems and serve as indicators of water quality.

Physical Characteristics

Odonates have large rounded heads with well-developed compound eyes, two pairs of long, transparent wings that move independently, and elongated abdomens. Adults have three ocelli and short antennae, while their mouthparts include simple chewing mandibles. Nymphs have stockier bodies and smaller eyes, and their mouthparts are modified into a labial mask for catching prey.

Identification Tips

Dragonflies are typically bulkier with large compound eyes and wings spread at rest, while damselflies are more slender with eyes apart and wings folded along the body.

Habitat

Odonates are primarily found near bodies of water as both juveniles and adults, often described as aquatic insects, although some species can be found far from water.

Distribution

Approximately 460 species of odonates are present in North America, with about 6000 species distributed worldwide in warmer climates, with diversity notably higher in these regions.

Diet

All life stages of Odonata are carnivorous, primarily insectivorous, feeding on smaller insects, with larvae also preying on small fish and tadpoles.

Life Cycle

Odonate life cycles include aquatic naiads or nymphs that undergo multiple molts before developing into flying adults. They can be voracious predators at the nymph stage, and adults undergo a final transformation into reproductive forms after a teneral stage.

Reproduction

Males have complex genitalia for mating, including claspers for grasping the female during copulation. Eggs are laid in water and hatch into pronymphs. Mating involves a distinctive wheel position for sperm transfer.

Conservation Status

Nearly two-thirds of U.S. Odonata species have been designated as 'Species of Greatest Conservation Need'.

Ecosystem Role

Odonates serve as bioindicators of water quality and are important predators in aquatic ecosystems, reflecting the health of their environment.

Collecting Methods

  • Netting during adult flying periods
  • Sampling in aquatic habitats for larvae

Preservation Methods

  • Drying specimens
  • Ethanol preservation for soft-bodied forms

Evolution

Odonata have a rich fossil record dating back to the Late Carboniferous period, sharing a close evolutionary relationship with mayflies. They exhibit unique flight mechanics and have been studied for insights into insect evolution and adaptation.

Similar Taxa

Misconceptions

The term 'dragonfly' typically refers to the suborder Anisoptera but is sometimes used for all Odonata; enthusiasts prefer 'true dragonfly' for clarity.

Tags

  • odonata
  • dragonflies
  • damselflies
  • aquatic insects
  • insect ecology