Insect Identification
Insect Identification

Western Flying Adder - (Cordulegaster dorsalis)

Authored By Staff Writer | Last Updated: 2/10/2014

Western Flying Adders are long, hairy dragonflies that are quite at home in the Pacific Northwest.

Picture of Western Flying Adder

The Western Flying Adder is part of the very common summer flying insect generically grouped as "dragonflies". They appear quite large when compared to most insects measuring about 70mm to 85mm in length. With their wings spread, they can hit widths of up to 135mm. Coloring on these creatures is quite impressive, yielding an almost brown to black surface with accents of yellow at intervals.

Western Flying Adders, like most other dragonflies, can be found near streams and woods. This particular species is "western" thanks to a range that lies west of the Rocky Mountains and north into Canada. Unlike other dragonflies, Western Flying Adders are not particularly aggressive toward other species of dragonflies.

In early spring, females will insert their eggs into soft wood or plants near creeks or streams using a long syringe-like ovipositor. The young, hairy naiads (juveniles) hatch and then make their way to into water and burrow into the sandy or silty bottom. They emerge from these hiding spots to feed on other aquatic insects using their large spoon-shaped lower lip. They mature rather quickly and are fully developed adult by late spring.

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Category: Dragonfly or Damselfly
Common name: Western Flying Adder
Scientific Name: Cordulegaster dorsalis
Other Names: Pacific Spiketail

  Kingdom: Animalia
   Phylum: Arthropoda
    Class: Insecta
     Order: Odonata
      Family: Cordulegastridae
       Genus: Cordulegaster
        Species: dorsalis

Adult Size (Length): 70mm to 135mm (2.76in to 5.31in)

Identifying Colors: green; black; yellow

Additional Descriptors: flying, hairy

North American Reach (Though Not Limited To*): California, Idaho, Montana, Nevada, Oregon, Washington

* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.