Cordulegastridae

Family of dragonflies

The Cordulegastridae are a family of Odonata (dragonflies) from the suborder Anisoptera. They are commonly known as spiketails. Some vernacular names for the species of this family are biddie and flying adder. They have large, brown or black bodies with yellow markings, and narrow unpatterned wings. Their bright eyes touch at a single point, and they can be found along small, clear, woodland streams, flying slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly. They usually hunt high in forest vegetation, and prefer to capture prey resting on leaves or branches (known as gleaning).

Within the family Cordulegastridae there are 51 species amongst three different genera. These genera include Anotogaster, Cordulegaster, and Neallogaster, which have 15, 30, and 6 species respectively

The name Cordulegastridae comes from the Greek kordylinus, 'club shaped' and gaster, belly. The common name spiketails refers to the females' prominent ovipositors.

A typical lifespan of Cordulegastridae dragonflies is 3–5 years. The Cordulegastridae usually lay their eggs in the sand in shallow water, the female hovering just above the water with her body in a vertical position, and making repeated dips into the water with her abdomen. The females trap air bubbles with hairs along their bodies to allow them to reach the bottom of the water and deposit eggs into the substrate. Males are remarkably territorial and their territorial behavior varies based on the oviposition of the females. Nymphs will consume any prey they can capture, going as far as eating smaller larvae of the same species. This family captures their prey by extending their labium, categorizing them as ambush predators.

Since nymphs are aquatic and adults are terrestrial, their habitats are quite different. The preferred habitat of Cordulegastridae nymphs are small lotic or flowing streams with clean sand and silt substrates. All eight species in North America belong to the genus Cordulegaster. There are five species of concern according to the International Union for Conservation of Nature and Natural Resources (IUCN), Cordulegaster bidentata, Cordulegaster heros, Cordulegaster trinacriae, Cordulegaster helladica and Cordulegaster sarracenia. C. bidentata, C. trinacriae and C. heros are identified as Near Threatened and found in Europe. Most threatened however are C. helladica and C. sarracenia which are Endangered on the IUCN Red List due to significant habitat loss.