The phrase “damsels in distress” conjures images of a helpless female in imminent danger: Ann Darrow in the clutches of King Kong, Pauline tied to a railroad track, Nell Fenwick in the grasp of Snidely Whiplash. Well, the damsels of the insect realm must not have seen the same movies that we did. The damsels in this Bug of the Week are predators much more the ilk of the Terminator than of Tinker Bell! Damselflies are meat-eaters; highly efficient predators whose deadly skills belie their delicate appearance. As adults these aerial hunters capture flies, leafhoppers, and small moths. Damselflies are close kin of the dragonflies we met previously in Bug of the Week. They belong to a group of ancient carnivorous flying insects in the suborder Zygoptera. The prefix zygo- comes from the Greek word meaning “yoke,” or “forming pairs”; the suffix –ptera means “wings”.
The gorgeous ebony jewelwing is often found near small streams.
They actually have two pairs of wings, and the fore and hind wings are similar to each other in size and shape. Unlike their dragonfly counterparts, which hold their wings outstretched to the side at rest, most damselflies perch with their wings neatly folded upright along the length of their abdomen. Damselflies are more delicate in body shape and form than their robust dragonfly cousins. They are also relatively weak fliers, whereas dragonflies race past like fighter helicopters on the attack. Courtship in damselflies is a complex affair with males of some species performing courtship flights to win the attention of the female. The nuptial pair will fly in tandem for long periods of time. This is likely a way for the male to ensure that his sperm are the ones to fertilize his partner’s eggs. Coupling often continues even when the female deposits her eggs on or in emergent or submerged aquatic vegetation. Some damselflies actually go beneath the surface of the water to lay eggs. Other species use sharp appendages on their tail to slice open plants and deposit eggs within. Damselfly eggs hatch into curious looking nymphs that live the life aquatic. They obtain oxygen from water using beautiful leaf-like gills called lamellae arrayed on the last segment of their abdomen. Unlike dragonfly nymphs that jet about by squirting water from their anus, demure damselfly nymphs propel themselves by wriggling their abdomen with snakelike motions.
Leaf-like gills on the tail of the damselfly nymph allow it to remove oxygen from the water.
Like their parents, damselfly nymphs are predators and consume small insects, crustaceans, worms, and other invertebrates. For adult damselflies life is short and sweet. It lasts only a few weeks and it is filled with pursuing mates and eating other insects. However, youth for damselflies may be long and, in some species, nymphs may take several years to develop. Although damselflies are not as showy as their dragonfly relatives, they are fantastic creatures. On a warm summer day it is worth a trip to the edge of a pond or a woodland stream to glimpse these delicate, deadly damsels.
The following BBC Worldwide video, “Damselfly: A Battle for Paternity,” reveals the mating rituals of damselflies (use audio):
References
We thank Bill Lamp for providing the gorgeous damselfly nymph featured in this Bug of the Week. Information was gleaned from “An Introduction to the Study of Insects” by D.J. Borer, D.M. De Long, and C.A. Triplehorn; and “Beginner’s Guide to Dragonflies” by B. Nikula, J. Sones, D. and L. Stokes.
For more information on damselflies, please visit the following websites:
http://www.ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html
http://stri.discoverlife.org/20/q?search=Odonata
http://www.uky.edu/Ag/CritterFiles/casefile/insects/damselflies/damselflies.htm