Northern Bluet Damselfly - Enallagma cyathigerum
Order Odonata / Suborder Zygoptera
/ Family Coenagrionidae -- narrow-winged damselflies
Live adult damselflies photographed at DuPage County, Illinois, USA
Northern Bluet Damselfly
Insects | Odonata Index | Dragonflies | Damselflies | Bugs Index | Spiders

Northern bluet females usually come in two colour forms, either sharing the male’s same blue-and-black colouration (known as homeochromatic morph), or being different, typically brown to olive-coloured (known as heterochromatic morph), and therefore easily distinguishable from the male. [1]

Northern Bluet Damselfly

Damselflies complete a life cycle in one or two years. The adults mate over the shallow water, sometimes in flight but often while clinging to the exposed portions of weed beds or shoreline vegetation. Immediately after mating, the female will crawl down the vegetation, and 'into' the water to lay her eggs on the submerged portion of the vegetation. Once the eggs are laid she will crawl back up the vegetation and repeat the process. When the eggs hatch they do not go through the larva and pupa transformations. The newly hatched damsel is just a smaller version of the later immature stages. Thus they are simply called 'nymphs' until they actually hatch into adults.

The damselfly nymph is predacious. Usually it lies in wait for other aquatic bugs to get within range and then grabs them with its 'labium' which is modified lower jaw. The nymph will proceed through 10 to 12 instars, or molts, before becoming fully developed and ready to emerge as an adult. With each molt the nymph becomes somewhat darker in color. Finally the nymph will swim towards the shore and crawl into shoreline vegetation. While clinging to this vegetation the nymph's skin breaks along the wing case and out crawls a shortened version of the adult. Before taking flight, the new adult must pump body fluids into its abdomen and wings. Depending on the species, the adult will live for several weeks to several months before mating and dying.

The adult has four wings that fold over the back. The male of the most common variety in the interior is blue while the female is more of a slate color. For the nymph, a fairly large and bulbous head sits on a tubular shaped body. The eyes of the damsel are fairly pronounced but not as large or pronounced as the eyes of a dragonfly nymph. The tail is three feathery looking appendages. The tail is called the "caudal lamellae" and is actually three gills at the end of the abdomen.

Order Odonata: Dragonflies and Damselflies date back 300 million years, to the Carboniferous Period of the Paleozoic Era. Today, there are about 450 North American species, and 5,000 in all. They have evolved in to highly efficient hunters; their freely moveable heads sport huge compound eyes -- in the case of the dragonfly, the eyes nearly cover the entire head -- and their sharp biting mouthparts, coupled with their four powerful, independent wings make them extremely agile flyers capable of snatching prey in midair. These insects cannot fold their wings flat against the body - dragonflies hold them straight out to the sides, damselflies hold then vertically toward the rear. Both families mate in flight and lay their eggs in or close to the water. The mating ritual involves some peculiar acrobatics called a mating "wheel."

References
  1. Klaas-Douwe B Dijkstra, Field Guide to the Dragonflies of Britain and Europe (British Wildlife Publishing, 2006).
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Order Odonata: dragonflies and damselflies date back 300 million years, to the Carboniferous Period of the Paleozoic Era. These colorful, enchanting insects are revered second only to the butterflies in the popular psyche. Explore detailed close-up photographs of live, adult dragonflies and damselflies photographed in the wild.
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