Cordulegastridae

Common Name

Spiketails

Overview

Cordulegastridae, commonly known as spiketails, is a family of dragonflies known for their distinctive long and spiny ovipositors and glossy black bodies with yellow markings. These dragonflies are often found near clean, slow-moving streams and rivers where they lay their eggs.

Taxonomy

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Odonata
  • Suborder: Anisoptera
  • Family: Cordulegastridae

Key Characteristics

  • Long, narrow abdomen with spiked ovipositor used for laying eggs in sediments
  • Large, expansive eyes that cover most of the head
  • Glossy black body with vivid yellow patterns
  • Strong, agile fliers often found hovering or patrolling near water bodies

Life Cycle

  1. Egg Stage: Eggs are laid in the sediment of clear, slow-moving water.
  2. Nymph Stage: Aquatic nymphs are predatory and grow for several months to years, undergoing multiple molts.
  3. Adult Stage: Emergence occurs, and adults mate and lay eggs, repeating the life cycle.

Behavior and Ecology

  • Predatory both as nymphs and adults; nymphs feed on aquatic invertebrates, while adults hunt other flying insects.
  • Adults are often seen patrolling territories along streams and rivers.
  • Habitat preference includes clear, well-oxygenated water bodies with abundant vegetation.

Notable Species

  • Cordulegaster boltonii (Golden-ringed Dragonfly): Recognizable by its striking gold and black banded abdomen.
  • Cordulegaster dorsalis (Pacific Spiketail): Found in North American streams, known for its robust build and territorial behavior.

Conservation

  • Habitat degradation, pollution, and watercourse modifications pose significant threats.
  • Preservation of clean water bodies and maintaining vegetative buffers along streams are crucial.

Significance to Humans

  • Indicators of clean, healthy water systems due to their habitat preferences.
  • Contribute to controlling insect populations, aiding in natural pest management.

Fun Facts

  • Some species of Cordulegastridae can fly at speeds up to 30 miles per hour.
  • The intricate yellow patterns on their bodies serve as camouflage against predators.
  • Despite being fierce predators, spiketail dragonflies are harmless to humans.
  • Their eyes are so large and well-developed that they can detect prey and mates from great distances.