Interesting Facts And Information On the Dragonfly
Male Widow Skimmer Dragonfly
Dragonflies have been in existence for over 300 million years. Long before the dinosaurs walked the earth, Griffenflies, which were their prehistoric ancestors, flew the skies. The largest dragonfly fossil found had a wingspan of 2 ½ feet. The largest known now is said to live in Costa Rica and has a wingspan of 7 ½ inches. Today, there are approximately 3000 species of dragonflies, and they can be found all over the world (except for Antarctica and Arctic Alaska).
Dragonflies represent grace and beauty and are often used in art and poetry. Other names for dragonflies are “water dipper” in England, “old glassy” in China, and the ancients Celts called dragonflies “big needle of wings” because of the needle-like shape of their bodies. In some Native American cultures, dragonflies are believed to be the “souls of the dead.” Dragonflies were once called the "devil’s darning needles," and it was said that the dragonfly would find misbehaving children during the night and come sew their mouths shut. In southern parts of the U.S., the dragonfly is known as the “snake doctor.” The folklore belief is that the dragonfly follows the snakes and will sew them back together if they become injured.
Many people confuse dragonflies and damselflies. The easiest way to tell them apart is the fact that the dragonfly will hold its wings flat, away from its body, at rest. The damselfly will fold its wings close to its body when resting. The damselfly also has a slimmer body than the dragonfly.
Adult dragonflies have the same typical head, thorax, and abdomen divisional bodies as other typical insects. Their head is large compared to the rest of their body, and they have very short antennae. The have two large ball shaped compound eyes which have approximately 30,000 ommatidia, or “lenses,” allowing them to see in a complete 360 degree span. They also have a “flattened” area in front of its eyes with eye cells that see directly in front allowing it to zoom in on its prey. Compared to other insects, the dragonfly has excellent vision.
The mouth of the dragonfly is adapted for biting with a toothed jaw, which is where they get their “dragon” name. However, the dragonfly is harmless to humans: their jaw is too small and they have no “stinger.”
The dragonfly has two sets of very strong wings. Although its wings are transparent and appear very delicate, they are much stronger than they appear. They are not jointed like butterfly wings, and each of their four wings work independently of each other. This allows the dragonfly the agility it has in the air. They can fly straight up or down, make hairpin turns, fly backwards, and hover like a hummingbird. The fastest dragonfly recorded flew at an amazing speed of 30 miles per hour, but their cruising speed is more around 10 mph.
Once the dragonfly has zoomed in on its prey, it grabs it with its set of six legs. The legs are positioned so they form a pouch-like shape that helps it hold on to its prey. They also use their legs for climbing on plants, perching, and walking, but it is rare for a dragonfly to walk.
Dragonfly Wings in Slow Motion
Dragonflies will be found near water. The female dragonflies may lay their eggs on the surface of water or deposit them on aquatic plants. When the eggs hatch, the nymph remains in the water and will hunt and eat aquatic invertebrates. The dragonfly will spend most of its life as a nymph, depending on the species, that could be anywhere from 3 months to 5 years in larger species.
Dragonflies, like all insects, are ectotherms, which means they cannot regulate their body temperature themselves and rely on their surrounding environment to cool or warm themselves. Their flight muscles have to be kept at a fairly warm temperature for them to be able to fly. Some dragonflies “patrol,” meaning they fly back and forth, as compared to those that tend to perch. In order for the “patrolling” dragonflies to warm up their bodies, they will fire up their wings using a rapid whirring motion. “Perching dragonflies rely on the sun for warmth and will skillfully position their bodies to gain the maximum exposure of the sun for warmth. Some dragonflies even use their wings as reflectors, either positioning their wings to reflect the suns warm rays towards their bodies or deflect the sun away from them to cool their bodies."
Dragonflies are carnivorous and usually hunt during flight. They eat a wide variety of insects including:
- even smaller dragonflies.
Just one dragonfly can eat up to several hundred mosquitoes per day. The adults will catch and carry their prey to a perch where they will discard any wings and then ingest their prey, usually starting with the head first.
In the nymph stage, they will eat mainly bloodworms and insect larvae, but are also able to catch and eat tadpoles and very small fish.
Life Span And Predators
Once the dragonfly’s eggs hatch, the nymph will remain in the water and molt between 9 and 17 times before reaching adulthood. During the last molting, the nymph will crawl out of the water and the exoskeleton will crack open to release its abdomen. Its wings will straighten out and begin to dry. It can take from several hours to several days for the “teneral” adult’s body to harden and its wings to strengthen enough for it to fly. It is during this time that the dragonfly is very vulnerable to predators.
The dragonfly is a fast and agile flyer, but can be caught by birds such as falcons, hawks, swifts, flycatchers, and swallows. There are some species of ducks and herons that eat dragonfly larvae as well as newts, frogs, and fish. Once the nymphs have reached the adult stage, as a dragonfly, they have a short life span. Some living for only a few weeks, while others may live up to a year.