- This family is known
as the Darners, because the females lay their eggs in plants, and their abdomens
look like a sewing needle as they cut into plant stems to insert their eggs.
- In North America there
are 41 species in 11 genera that belong to this family. In Idaho this family
contains genera Aeshna and Anax, both of which are commonly known as darners.
There are seven species of Aeshna and one of Anax that occur in Idaho.
- This family includes
the largest and most powerful dragonflies. They vary in length from 2 inches
to almost 5 inches long from head to tail, with the majority of species about
3 inches long. The abdomen is long and slender, and the thorax is robust.
The abdomen is very narrow just behind the thorax.
- The wings are almost
- Members of this family
have the largest eyes and most highly developed nervous systems of any family
of dragonflies. The eyes cover most of the head and meet along a broad seam
on the top of the head.
- These are the fastest
fliers among the dragonflies, and they are almost always on the wing during
the day. They do all of their hunting while on the wing, and will capture
and eat almost any soft-bodied insect that is smaller than themselves. Adults
are often found feeding miles from water.
- These dragonflies have
a highly developed ability to control their body temperature, thus can fly
in colder temperatures than most other dragonflies. They also occur farther
north than most other dragonflies.
- The naiads are very
long and slender. They are voracious hunters and climb actively over submerged
vegetation looking for prey. They will eat anything smaller than themselves,
including mosquito larvae, damselfly nymphs, other dragonfly nymphs, tadpoles,
and small fish. In warmer climates the naiads mature in one year or even less,
but in the most northerly areas where they occur, they may take up to 8 years
- When the naiad has reached
the proper size, it crawls out of the water onto a plant stem or anything
that projects out of the water. In a slow, fascinating process it emerges
from a split in its naiad skin to become a dragonfly. The naiads are vulnerable
to predators during this time, thus they emerge at night when the number of
predators is low. They usually crawl vertically onto vegetation and emerge
- The naiads in this family
swim by jet propulsion. They do this by squirting water out of the end of
Members of this genus have
a brown base coloration, with blue or yellow stripes on the side of the thorax,
and blue, green or yellow spots on each segment of the abdomen. They are medium
to large sized dragonflies. Females in this genus fly singly, without the male
attached, and lay their eggs alone in the stems of aquatic plants or in decaying
wood that has fallen into the water.
Aeshna constricta- Lance-tipped
Aeshna interrupta- Variable
Aeshna multicolor- Blue-eyed
Aeshna palmata- Paddle-tailed
Aeshna sitchensis- Zigzag
Aeshna umbrosa- Shadow darner
These are our largest
dragonflies. The smallest member of this genus is the largest dragonfly found
in Idaho! The other members are found further south. These dragonflies have
a solid green thorax with no stripes. Females fly singly or in tandem with the
male to lay their eggs in the stems of aquatic plants.
Anax junius- Common
Written by Mark Lung and Stefan
Photo by Dennis Paulson
Page design by Ean Harker 2001.