What Time is it in Nature: Common Whitetail Dragonfly
Summer is nearly here, and the dragonflies have returned to Prairie Ridge! On any given day, you might see 15 or 20 species of dragonflies and damselflies at the pond, but some species are more common than others. The Common Whitetail (Plathemis lydia), as the name suggests, is one of the most commonly spotted dragonflies at Prairie Ridge.
Common Whitetails are found throughout the US and in every county in North Carolina, so they are one of the most common species in the country. They are medium-sized dragonflies that reach lengths of just under 2 inches with wingspans of about 2.25 inches and have relatively broad abdomens. Males, as seen in the image above, have wide black or dark brown bands along the center of each wing and a bright white abdomen. Females look quite different, sporting three black spots along the upper edge of each wing and brown abdomens with broken white lines along each side.
As in other dragonflies, male Common Whitetails are very territorial and will fiercely defend their territory from other males. You will most often find males along the banks of ponds, sitting on vegetation where they can look out over patches of open water. If a male flies into another male’s space, the territory holder will fly out from his perch with his white abdomen held above his head and attempt to chase away the intruder. If successful, the defensive male will return to his territory. If not, he will be usurped and the challenger will take his place.
Territories are important to males because females choose their mates based on the territories they defend. Female Common Whitetails are most commonly observed flying around the prairie and visit the water only when they wish to mate or lay eggs. Females flying over the pond are almost immediately greeted by the male who defends the territory she enters and the pair will mate if the female is receptive. Afterwards, the female will lay her eggs in the water, bouncing up and down so that the tip of her abdomen repeatedly breaks through the surface and her eggs are released into the pond. Because there are typically far more males around the pond than females, an egg-laying female is at risk of being grabbed by another male and taken to another territory to mate again before she finishes laying her eggs. In an attempt to prevent this from happening, a male who has just mated will hover over his mate while she lays her eggs and protect her from incoming males. While this behavior ensures that the eggs laid are his offspring, the behavior also benefits the female as she is protected from harassers and is able to lay her eggs without interruption.
Immature Common Whitetails develop in the water as nymphs and go through several molts before they become adults. This species is one of the first dragonflies to emerge from the water as adults in the spring, though you may see them any time from late March through late October in North Carolina.
Next time you visit Prairie Ridge, take a stroll down to the pond and look out for Common Whitetails! On sunny, calm days you may see several dozen males flying about over the water. On your walk to the pond, be sure to keep an eye out for Common Whitetail females as they are often spotted flying along the trails. Though common, these are very beautiful and interesting dragonflies, well worth a trip to see them!
What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Musuem’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!
(Photos by Chris Goforth)