Dragonfly
Dragonfly Facts
| Size | 0.71-4.7 inches (18 mm to 12 cm) |
| Speed | Up to 30 mph (56 km/h) |
| Weight | Unknown |
| Lifespan | 3 month to 5 years (larva), 6 weeks to 11 months (adult) |
| Food | Insects, flies, fleas |
| Predators | Birds, frogs, spiders, wasps, bats |
| Distribution | Worldwide (except polar regions) |
| Habitat | Lakes, ponds, rivers |
| Order | Dragonflies |
| Class | Cobweb Spiders |
| Order | Odonata |
| Scientific name | Odonata |
| Characteristics | Flying insects with a long body and two large pairs of wings |
Main Characteristics
Dragonflies are small flying insects known for their long, slender bodies and two pairs of wings. They have the ability to move their wings independently, allowing for exceptional flight capabilities. They can even hover in the air or fly backward, which is why they are often likened to tiny helicopters. Their elongated abdomen aids in maintaining a steady flight path. Another distinctive feature is their large compound eyes, which are made up of up to 30,000 individual lenses.
Species
There are more than 6,400 species of dragonflies, with approximately 450 to 471 found in the USA. The most common species in the USA include:
- Globe skimmer (dragonfly)
- Common green darner (dragonfly)
- Common whitetail (dragonfly)
- Black saddlebag (dragonfly)
- Blue dasher (dragonfly)
- Black-shouldered spinyleg (dragonfly)
- Meadowhawk (dragonfly)
- Ebony Jewelring (damselfly)
- American Rubyspot (damselfly)
- Bluet (damselfly)
- Fragile forktail (damselfly)
- American rubyspot (damselfly)
- Spreadwing (damselfly)
- Sooty Dancer (damselfly)
- Forktail (damselfly)
History and Evolution
Dragonflies have existed for over 300 million years, predating the dinosaurs. Back then, they were much larger. A fossil discovery of the dragonfly Meganeura monyi shows that they could have had a wingspan of 25.5 inches (70 cm), making it the largest prehistoric insect known to date.
Distribution and Habitat
Dragonflies are found all over the world, except in polar regions where it's too cold and most bodies of water remain frozen for extended periods. They thrive in warm habitats near lakes, ponds, swamps, and streams.
Way of Life
Dragonflies are solitary creatures. Most of them are active during the day and spend the majority of their lives as larvae in water. During this stage, they are primarily active at night. They undergo several molts over the years before becoming adults, at which point they can finally fly. However, most species only live for a few more weeks after reaching adulthood.
Anatomy and Appearance
Size and Weight
Depending on the species, dragonflies can range in body length from 0.71 inches (18 mm) to 4.7 inches (12 cm), with a wingspan varying between 0.69 inches (17.6 mm) and 7.5 inches (19.1 cm).
Legs
Dragonflies have six legs. While they can't walk with them, they can grip onto surfaces like flower stems, blossoms, or branches.
Wings
Dragonflies have a pair of wings on each side, totaling four wings. These wings feature a delicate network of veins that intersect, and they are otherwise transparent. Some species have narrow bands, small spots, or various patterns on their wings.
Color
Dragonflies can come in a variety of colors, such as red, yellow, green, or blue. Their wings shimmer with a metallic sheen in the sunlight.
Dragonfly or Damselfly – What's the Difference?
Dragonflies have a broad, short body with wings that are all the same length and always held open. Their eyes are positioned closely together. In contrast, damselflies have a slender, elongated body, with their front wings longer than the back ones. When at rest, they fold their wings together, and their eyes are spaced further apart.
Diet
Dragonflies are carnivorous. As larvae, they feed on mosquito larvae, water fleas, tadpoles, and young fish. Once they mature, they hunt flies, mosquitoes, and cicadas, capturing between 30 to 100 mosquitoes each day.
Behavior
Hunting
Dragonflies are exceptional hunters. They fly close to the water where many prey animals are found. They catch their food mid-air and eat it while flying. Only larger insects are taken to the nearest branch to be consumed in peace.
Warming Up in the Sun
Dragonflies rely on the warmth of the sun. Before they can take flight, they bask in a sunny spot to warm up. That's why they're seldom seen on cloudy or overcast days.
Winter
What do dragonflies do in winter? Most of them don't live long enough, as they only survive for about 6 to 8 weeks. However, common winter damselflies are different. They can live up to 11 months and survive the winter by hiding in dead plants. On sunny days, they can be seen even during the cold winter months. They are among the first dragonflies to appear in spring, often as early as April and May.
Senses and Abilities
Brain
Dragonflies spend their entire day flying around – to feed and escape from predators. They rely on their ability to perform quick aerial maneuvers at any moment. Their brains are working at full capacity, with 80% dedicated to processing the images captured by their compound eyes.
Speed
Dragonflies are incredibly fast, capable of flying at speeds of up to 30 mph (56 km/h).
Sense of Sight
Dragonflies possess an exceptional sense of sight. Their compound eyes are made up of nearly 30,000 tiny individual lenses, allowing them to see in all directions. These eyes almost wrap around their entire head, providing them with a 360-degree field of vision. But that's not all; they can also detect UV light and polarized light.
Flying Skills
Dragonflies can change direction mid-flight, allowing them to quickly escape from predators. They can also fly backwards and hover in place.
Life Expectancy
Dragonflies can live for several years in total. As larvae, they can survive for a few months up to five years. Adult dragonflies typically live for 6 to 8 weeks, but the winter dragonfly is an exception, as it can live for up to 11 months.
Enemies and Threats
Natural Enemies
Dragonflies face numerous predators. Adult dragonflies are hunted by birds, frogs, spiders, water shrews, wasps, and bats. Their larvae are also preyed upon by ants, water bugs, water mites, and water beetles.
Conservation Status
In Germany, around 29% of dragonfly species are listed as endangered, while only 54% are considered safe.
Are Dragonflies Dangerous?
Dragonflies and damselflies may look intimidating due to their swift flying maneuvers and slender bodies, which can seem a bit scary. But can they sting or bite? Are they poisonous? The good news is that while dragonflies do have mouthparts, they cannot harm humans. They are also not venomous. If a dragonfly lands on your arm or hand, there's no need to panic; it usually flies away after a few seconds.
Importance for the Ecosystem
Dragonflies play a crucial role in nature by keeping insect populations in check. That's why we see them as beneficial creatures: they catch flies and mosquitoes before they become a nuisance. Additionally, they help us monitor the quality and health of our water bodies, as they thrive only in healthy aquatic environments.
How to Attract Dragonflies to Your Garden
The easiest way to attract dragonflies is by having a small, shallow garden pond along with the right flowers. These spots serve as perfect resting places and draw in insects that dragonflies love. Marsh and pond plants are particularly suitable, including mouse-ears, spiked water-milfoil, flowering rush and yellow iris.
Reproduction
Mating Ritual
Female animals only mate with males that have established territories. As a result, there are intense aerial battles among the males during mating season. However, the females do not always agree to mate; if they want to get rid of an overly persistent male, they will dramatically drop to the ground and play dead. When a female is receptive, they form what is known as a 'mating wheel'.
Mating Wheel
During mating, dragonflies curve and connect their bodies, forming a heart-like shape. This occurs because the male's reproductive organs are located at the front of its thorax, while the female's are situated at the back of her abdomen. The male secures the female by gripping her neck with his abdominal claws. Subsequently, the female bends the tip of her body forward towards the male's thorax, and the male assists by curving his body as well.
Eggs and Larvae
Female dragonflies lay their eggs in water after mating. The eggs hatch into larvae, known as nymphs, which breathe using gills and search for food underwater. They are typically a grayish-brown color and do not yet have developed wings.
Molting and Metamorphosis
As they grow into adult dragonflies, they molt 10 to 20 times, shedding their outer skin since it doesn't grow with them. As larvae, they can live for a few months to several years. After their final molt, they become adults and are able to fly, but most species only live for an additional 6 to 8 weeks.
The Dragonfly Is Related To:
- Mayfly
- Neoptera
Animals in the Same Biome:
- Ant
- Carp
- Diving Bell Spider
- Duck
- Frog
- Grass Snake
- Gray Heron
- Microbat
- Shrew
- Wasp
- Water Bug
- Water Mites
- Water Scavenger Beetles
Sources:
- "Preattentive facilitation of target trajectories in a dragonfly visual neuron" (https://www.nature.com)
- "Smallest Dragonfly" (https://www.guinnessworldrecords.com)
- "Largest Dragonfly" (https://www.guinnessworldrecords.com)
- "Largest prehistoric insect" (https://www.guinnessworldrecords.com)
- "Largest wingspan for an insect" (https://www.guinnessworldrecords.com)
- "Libellen (Odonata)" (https://www.rote-liste-zentrum.de)
