Wednesday, July 15, 2009

Nature Guide: Dragonflies

Dragonflies play an important role in nature. They are valuable predators because they help control populations of harmful insects like mosquitoes and other small insects like flies, gnats, ants and bees. Our Nature Guide Jon Latimer gives us some background on dragonflies and describes some of the species we might see in our area right now.

"A dragonfly is a flying insect with two pairs of strong transparent wings and an elongated body. It is a master of flight, able to fly forward and backward, and even hover for a short time. Although it has six legs like any other insect, a dragonfly seldom walks. Instead, it uses its legs to catch prey in midair. Immature dragonflies, known as nymphs, are also an important food source for fish, frogs and birds.

"Adult dragonflies are usually found flying around lakes, ponds, streams and wetlands. Females lay their eggs in water. Males are territorial and sometimes patrol along the water's edge. They can often be seen engaging in quick aerial battles with intruders.

"The Common Green Darner is one of the largest and fastest-flying dragonflies, able to reach speeds of over 50 mph. Adult males are green with a blue abdomen. Females and juveniles have a reddish abdomen. A green darner may be seen far from water, but it breeds in small ponds, lakes or other still water. It is sometimes called a 'Darning Needle' or 'Mosquito Hawk.'

"The Blue Dasher is a small blue dragonfly found almost everywhere there is water. The male has a white face, a black tip on its abdomen and black and yellow stripes on its thorax. A female has narrow yellow stripes on its abdomen.

"Found in a variety of habitats, the Eastern Pondhawk can often be seen perching on the ground. The male is powder blue with a green face. Females and juvenile males are green with black spots on their abdomen.

"The base of the wings of both the male and female Widow Skimmer are marked with prominent black bands. The adult male develops broad white spots at the middle of its wings, which are unmistakable. Their body is a steely blue color.

"The adult male Common Whitetail is also unmistakable. It has large brownish-black bands on its wings and a chalk white abdomen. Females are dull brown all over.

"A dragonfly can be confused with a damselfly, but they are easy to tell apart. When resting, a dragonfly holds its wings perpendicular to its body. A damselfly hold its wings parallel to its body. A dragonfly's flight is swift and direct; a damselfly's flight is fluttery and random."

0 comments: