Bug of the Week
Sedge Sprite (Family Coenagrionidae)
The BugLady is looking forward to chasing sedge sprites again this year. They hang out in the kinds of low, dark, inaccessible places that require contortions by photographers – places that both need a flash and are overpowered by one. And no, the BugLady has not started chasing faeries; the Sedge Sprite (Nehalennia irene) is a tiny, shiny damselfly in the Family Coenagrionidae, the narrow-winged damselflies.
There are only six species of sprites (genus Nehalennia) worldwide (the genus name is taken from one of the river goddesses of the Rhine). One is Eurasian, one lives in Central and South America (there have been a few sightings in extreme southern Florida), and the other four are North American. Sedge sprites and sphagnum sprites (Nehalennia gracilis) are found here in God’s Country, although Sedge sprites are far, far more common. Telling the two apart requires a hand lens, and the sprites are so very fragile that handling them is not recommended.
The Nehalennia have in common their ridiculously small size (often less than an inch), metallic coloration, and love for dense stands of plants around quiet, clean wetlands like marshes, bogs, fens and ponds. They typically fly below the radar and do not venture out over open water. Unlike many of their brethren, they are not extraordinarily camera shy.
Sedge sprites are found across southern Canada and the northern half of the U.S. Although they are more common in the eastern part of their range, Mead, in his Western-Great-Lakes-centric Damselflies of the North Woods calls them, surprisingly, “perhaps the most abundant damselfly in the north woods.” Because they spend most of their time flitting among the stems of sedges and other emergent vegetation, they’re easy to miss. Stokes, in the Beginners Guide to Dragonflies and Damselflies describes them as “skulking low in dense vegetation.”
While the last 2 ½ segments of a male sphagnum sprite’s abdomen is totally blue, there is some black/metallic green on the tip of the sedge sprite’s abdomen. Female sedge sprites show little or no blue at the tip and are generally pale white or yellow below; female sphagnum sprites are similar to their males.
There’s not a lot known about the life history of sedge sprites. Females lay eggs in floating, dead plants like cattails and sedges. Like other sprites, the male sedge sprite continues to clasp the front of the female’s thorax while she oviposits (it’s called “contact guarding;” other species of dragons and damsels may guard their ladies from a perch or from the air or not at all); her body is horizontal and his tilts at about 45 degrees. As Dennis Paulson says in his encyclopedic Dragonflies and Damselflies of the East, “in temperate species, pairs oviposit with male held up like little blue-tipped stick.”
She uses a blade on her ovipositor to slice into plant tissue and then she inserts one or more eggs. According to one source, the eggs hatch in just a few days; another says it takes a few weeks. The naiads must grow and shed a dozen times before they are ready for adulthood, and their growth rate is influenced by water temperature (the warmer, the faster). They overwinter as almost-grown naiads and complete the job in early summer of the next year. Adults may feed away from water until they are ready to mate.
Damselflies, young and old, are carnivores. Paulson says that their “long tibial (leg) spines, and wings held over abdomen when perched may indicate they are flycatchers.” Midges are probably a big part of their diet, and the aquatic naiads feed on any small critters they can catch.
The BugLady is thrilled that she’s finding more bugs than she saw last year. This is either a testament to Nature’s ability to rebound or a sign that she needed bifocals more than she thought she did.