Dragonflies: Dinosaurs of the Garden

Dragonflies arrived in the garden more than 300 million years ago-a mere 70 million years before the earliest known dinosaur. With expert hunting skills (they are insect eating machines) and the ability to fly at speeds over 30 mph, it's not surprising that their species have been able to achieve such longevity. Dragonflies live, breed, and eat around water.

In recent years, human development and the resulting loss of wetlands have put 15-20% of the world's dragonfly species in danger of becoming extinct. By inviting dragonflies into your garden you can help preserve this important insect predator. They'll show you their appreciation by happily reducing your mosquito population.

Dragonflies vs. Damselflies

There are over 6000 different species of dragonflies and damselflies worldwide, 400 of which live in North America. Like bird watchers, devoted dragonfly watchers enjoy identifying and learning about the species they're watching. Dragonflies belong to an order of insects known as Odonata, which is Greek for "tooth." There are two sub-categories (or sub-orders) of dragonfly, the Anisoptera, which are the dragonflies and the Zygoptera, the damselflies.

Certain characteristics make it easy to distinguish one from another. When perched, dragonflies hold their wings straight out to the side (horizontally), while damselflies hold their wings straight back (vertically). Dragonflies have nearly round heads, while damselfly heads are slightly elongated. Lastly, most dragonflies appear large and robust. Damselflies appear smaller and more delicate.

Darters and Hawkers

Dragonflies are carnivorous and feed on larvae or other flying insects. Depending on the species, the lifespan of a dragonfly can be as short as six months to as long as approximately seven years. They are generally categorized into two groups:

• Darters - Known as 'clingers,' due to their preference for clinging to plant life and quickly jumping away from the plant to catch food.
• Hawkers - Known for flying over water, looking ('hawking') for food; they have long, lightweight bodies which allow them to search for food for long periods of time.

Observing Dragonfly Behavior

One of the best reasons to attract dragonflies to your garden is simply to enjoy hours of entertaining insect behavior. A sturdy bench and a pair of binoculars should always be close at hand. Males defend their territory much like a male red-winged blackbird would, staking claim to an elevated perch near a pond and zooming out to chase away potential challengers. Most people are familiar with dragonfly and damselfly mating rituals, two dragonflies forming a circle or "wheel" in mid-air or in the case of damselflies, flying in tandem-one directly behind another. Much like a predatory bird, dragonflies fly over water to hunt for prey, dive-bombing it and snatching it in mid-air. With 30,000 lenses and the ability to see a full 360 degrees, it's likely that dragonflies will be watching your behavior, too!

Providing Ponds for Dragonflies

A diverse landscape of trees, shrubs, and flowers will attract the insects to your garden that dragonflies prefer to feed on, but garden ponds will provide them with a home. Dragonflies reproduce in ponds, laying their eggs in, near, or under the pond water. They also like to hunt on or near the water. This works out well for gardeners, because they eat unwanted insects, helping to preserve the environment of a pond or garden.

If you don't already have one, creating a large pond to attract dragonflies isn't necessary. A kiddy pool or half barrel is all you need. Ideally, you pond should contain underwater plants and rocks and be a minimum of 2 ft deep. This is so dragonfly nymphs can hide from frogs, birds, predatory fish, or passing raccoons.

Plant reeds, grasses, or shrubs around the pond's perimeter to provide adult dragonflies with perches for hunting and "pond watching" and allow nymphs to crawl up out of the pond. Some species will use surrounding plants as nurseries, inserting their eggs into the more soft-stemmed plants. Dragonflies like basking in the sun, and like butterflies, they are attracted to light colored rocks. A combination of moving and still water in your pond will serve to attract the widest variety of different dragonfly species.