If you don’t know much about dragonflies, you’ve come to the right place! This week, Tidbits passes along the facts about these members of the Anisoptera infra-order, of which there are more than 5,000 known species.
• The word Anisoptera has its roots in the Greek language, combining “anisos” meaning “unequal,” and “pteron,” which translates “wing,” because this insect’s hindwing is broader than its forewing.
• A dragonfly has large, multifaceted eyes, containing up to 30,000 individual elements known as ommatidia, each consisting of a lens system and a group of light sensitive cells. The eyes have a 360-degree visual field, able to see completely around the insect. Their eyes meet at the top of the head.
• These amazing insects can travel at 45 mph) — about 100 body lengths per second — flying upwards, backwards, or to either side, and can also hover like a helicopter. They can even mate in midair! This is accomplished all the while the insect is flapping its wings just 30 times per minute. Contrast this with a mosquito that must flap its wings 600 times a minute, and the common housefly that flaps 1,000 times per minute.
• The wings of a dragonfly are truly remarkable! Each of the four transparent wings can move independently, flap up and down or be rotated back and forth on an axis. The wingspan varies between 2 and 5 inches (5 and 12 cm). The largest dragonfly is Australia’s Petalura ingentissima, with a 6.2-inch (16 cm) wingspan.
• Like all insects, dragonflies have six legs, but dragonflies cannot walk.
• Many adult dragonflies have brilliant iridescent or metallic colors, frequently blue or green, colors that change as they age, usually getting even brighter.
• The female lays her eggs on the surface of water. While the dragonflies are in their larval stage, they are known as nymphs, and spend a period of about two years on the water, molting up to 15 times before finally shedding the final skin and taking to the air. They live most of their life as an immature nymphs, since they don’t usually live more than a few months as an adult.
• A typical dragonfly might consume hundreds of mosquitoes per day.
• Dragonflies are symbolic in several cultures. The Chinese believe they represent change and instability. The Chinese practice of Feng Shui places dragonfly statues and artwork in areas of a home or office to bring about positive changes or new awareness. In China, they are also a symbol of prosperity and harmony, and are considered a good-luck charm. It’s especially good luck if a dragonfly lands on your head! To the Japanese, they represent courage, strength, and happiness. Swedish legend maintains that the devil uses the insect to check for “bad souls.” Other folklore claims that the insect detects those who tell lies, speak badly of others, or curse, and stitches up the mouth. In fact, some refer to the dragonfly as the “devil’s darning needle.” In the southern United States, legend has it that dragonflies catch insects to feed snakes, as well as stitching up any of their injuries.