Aeshnidae

Common Name

Darners

Overview

Aeshnidae is a family of large dragonflies known for their powerful flight and striking coloration. They are prevalent in many parts of the world and are often seen near freshwater habitats.

Taxonomy

Key Characteristics

  • Large body size, generally ranging from 6-9 cm in length
  • Long and thin abdomen
  • Complex, large compound eyes that almost touch at the top of the head
  • Two pairs of strong, transparent wings
  • Brightly colored bodies, often with blue or green hues

Life Cycle

  1. Eggs: Laid in aquatic plants or directly into the water.
  2. Nymphs: Aquatic stage lasting several months to several years, depending on species and environmental conditions.
  3. Emergence: Nymphs climb out of the water and shed their exoskeletons to become adults.
  4. Adults: Terrestrial stage lasting a few weeks to several months, during which they mate and lay eggs.

Behavior and Ecology

  • Strong fliers, capable of fast and agile maneuvers in the air.
  • Predatory at both nymph and adult stages, feeding on other insects including mosquitoes.
  • Males often establish and defend territories near water to attract females for mating.

Notable Species

  • Aeshna juncea (Moorland Hawker)
  • Aeshna cyanea (Southern Hawker)
  • Anax junius (Common Green Darner)
  • Anax imperator (Emperor Dragonfly)

Conservation

Most species within the Aeshnidae family are not currently threatened, though habitat destruction and pollution pose risks to their populations. Conservation efforts focus on preserving aquatic habitats and maintaining clean water sources.

Significance to Humans

Darners are beneficial insects, playing a role in controlling pest populations, particularly mosquitoes. They also serve as indicators of healthy aquatic systems and are subjects of interest for both amateur naturalists and professional entomologists.

Fun Facts

  • Some species of darners can fly at speeds of up to 56 km/h (35 mph).
  • Darners have excellent vision, with up to 30,000 individual facets in each compound eye.
  • The name "darner" comes from their long, needle-like abdomen, reminiscent of a darning needle.
  • These dragonflies can hover like a helicopter and even fly backward.
  • Darners are known for their migratory behaviors; the Common Green Darner travels thousands of miles.