Dragonflies are large, long-bodied insect
s with two pairs of slender wing
which are held horizontal
ly at rest. Their large compound eye
s enable the adults
to catch their prey
(usually other insects) in flight
, whilst the larvae
. Adults can grow up to 10 inches in length, although
prehistoric fossil record
s indicate extinct dragonfly species of over 2 feet long.
Scientific classification: Class: Insecta, Order: Odonta,
Suborder: Anisoptera, Family: Aeshnidae. Popular
names and nicknames include: dragonfly, damselfly, darner, gomphus, skinner.
The following questions are taken from the FAQ of the
British Dragonfly Society whose web pages are at www.dragonflysoc.org.uk:
Do Dragonflies Bite or Sting?
Dragonflies don't bite or sting people
unless they are handled. They have a lot of
"folk names" which imply that they do (such
as Horse stinger), but they don't use their
egg-laying tube (ovipositor) for stinging.
They also don't bite (people) but they are a
fearsome predator of other flying insects.
How long do Dragonflies live? Is it true that they only live for one day?
At the shortest, a dragonfly's life cycle from egg to death of adult is about 6
months. Some of the larger dragonflies take 6 or 7 years! Most of this time is spent in
the larval form, beneath the water surface, catching other invertebrates. The small
damselflies live for a couple of weeks as free-flying adults. The larger dragonflies
can live for 4 months in their flying stage. No insect has a lifespan of only one day -
even mayflies (not closely related to dragonflies) live for several months
underwater as larvae before emerging as winged adults. Adult mayflies may only live
for a day or so as they are dedicated "breeding machines". They cannot feed as
adults as (most) don't have any functional mouthparts.
How fast do they fly?
The maximum speed of large species like the hawkers is around 10-15 meters/sec, or
roughly 25-30 mph. Average cruising speed is probably about 10 mph. Small species,
and especially damselflies, are generally slower, although many medium-sized species
can probably keep up with the largest ones.
What is the lifecycle of the Dragonfly?
Greatly simplified, the life cycle is Egg (usually laid under water), Larva (free
moving, water dwelling nymph) and Adult. The larva lives for several weeks (or years
depending on species) underwater and undergoes a series of moults as it grows. It
emerges from the water when it is ready to undergo its final moult where the "skin"
splits to reveal the winged adult.
What do Dragonflies eat?
Mainly, adult dragonflies eat other flying insects, particularly midges and mosquitoes.
They also will take butterflies, moths and smaller dragonflies. There is one Asian
species which takes spiders from their webs! The larvae, which live in water, eat almost
anything living that is smaller than themselves. The larger dragonfly larvae are
known to catch and eat small fish or fry. Usually they eat bloodworms or other aquatic
Are there any legends and myths about Dragonflies?
There are many legends and myths about dragonflies and damselflies from all parts
of the world. Many are evident from their common nicknames. In the UK, Dragonflies
were called 'Horse-Stingers'. This name may come from the way a captured dragonfly
curls its abdomen as if in an attempt to sting. An old name for damselflies was 'Devil's
Darning Needles'. This stems from an old myth that if you went to sleep by a stream
on a summer's day, damselflies would use their long, thin bodies to sew your eyelids
shut! Naturally there is no truth in either myth.
Do Dragonflies have antennae (feelers)?
Yes, Dragonflies do have a pair of antennae. They are very tiny and difficult to see.
As dragonflies rely much more on their eyesight than on a sense of touch or
smell, they do not need the large antennae found on some beetles and moths.
Why do Dragonflies sometimes appear in large swarms?
Several species of dragonfly are known to collect in large aggregations or swarms. In
Europe, the Migrant Hawker (Aeshna mixta) and the Four-spotted Chaser (Libellula
quadrimaculata) have been observed to do this.
In most cases this appears to be due to very favourable feeding conditions in the
locality. It may also be a "courting" group with males actively searching for females.
This is less likely as males are much more aggressive to each other when looking for a
The Four-spotted Chaser occasionally collects in these large aggregations before
making a mass movement to another locality (like a bird migration). The reasons for
this are unclear but may be due to population pressures.
There are records from the US of migratory assemblages of species such as the Green
Darner (Anax junius) and various species of Saddlebags (Tramea).