In my last blog post,
Dragons Still Fly, I dove into the natural history of dragonflies. These speedy creatures truly astonish me. A dragonfly willingly hunts and captures prey larger than its own body and at times, heavier. It performs such aerial feats on the wing and with an exceedingly high success rate. As an interpreter of all things nature, it’s difficult to even mention this prehistoric beast of an insect without paying reverence to its uncommonly delicate cousin, the damselfly. Both animals are placed into the insect order Odonata, from the Greek word odontos, meaning tooth. As you’ve gathered, their mandibles are equipped with teeth. These pseudo-jaws come in handy for restraining squirmy prey such as mosquitoes. Being so closely related, dragonflies and damselflies have many similarities both in appearance and ecology.
So how do you know when you’ve spotted a damselfly? Start with individuals that have landed and are, quite conveniently, holding still. Hurry! The quickest and easiest field trait is to observe how the insect is holding its two pairs of wings. Damselflies hold their wings vertically to the rear, similar to a butterfly. In contrast, a dragonfly typically holds its wings outstretched to the side. Though not always true, a damselfly will generally appear smaller, thinner, and more delicate. The animal’s stature is not a distinguishing field trait, but if a damselfly zooms past you at 20 mph, it may be the only useful trait!
 male Blue-fronted Dancer - RRNC path 650x.ashx) |
This 1.5” male blue-fronted dancer landed directly on a path nearby Rocky River Nature Center. A typical elongate and delicate damselfly, but note the species-distinguishing black line atop its thorax. |
Damselflies prefer habitats with water. Simply put, you are likely to come across a damselfly around any unpolluted body of water, i.e., ephemeral forest-floor pools, streams, rivers, fens, bogs, ponds, and lake shores. This affinity for water is a result of their obligate relationship with the water as they undergo incomplete metamorphosis from egg to nymph and finally to adult. Life begins for a young dragonfly when the adult female lays her fertilized eggs loosely into water or directly into plant material anchored under the surface. Also, their preferred prey items inhabit similar environments, so it pays to hang out near water! You’re now in search of an adult damselfly. Sure, your best chances are spring through fall in Cleveland Metroparks, but if you really want to score, go on a pond prowl when the sun is shining. The radiation from the sun helps their bodies’ thermoregulation and thus, keeps them airborne.
Of greatest interest to me is their contribution to the flow of energy through the ecological systems in which they inhabit. Damselflies package readily available energy in the ecosystem and move it up the colloquial food chain. Transferring energy in and around the food web is of key importance to a sustainably functioning ecosystem. A damselfly puts forth great effort to capture mosquitoes and spiders, but then may end up in the gullet of hungry bird before midday. Gulp!
-Marty Calabrese, Naturalist