Jeff Green | Jun 05, 2008
Outdoors - June 5, 2008
Back toHomeOutdoors in the LandO'Lakes - June 5, 2008 Ebony Jewelwings – Insect Gems of Woodland Streams Outdoors in the Land O'Lakes by Steve Blight As everyone who spends time in the Land o’ Lakes area knows, June is a seriously buggy time of year. Good for the birds, which take advantage of the explosion of life in our forests to feed their hungry nestlings, but not always so enjoyable for humans.
But some of our insects are exceptionally attractive as well, and June is a great time of year to appreciate their beauty. One of the most exquisite creatures to inhabit our area is the Ebony Jewelwing. I recall the first time I saw this relatively common species of damselfly, when I spotted a group of males flitting about in a shaft of sunlight at the top of a shaded woodland stream. An accurate description of the male jewelwing inevitably sounds like exaggeration – its 1 to 2-inch long body is a brilliant metallic teal blue or emerald green colour, and its wings are a slightly translucent jet black. The combination of the black wings and iridescent body is breathtaking. The female is a duller version of the male, but has a conspicuous white spot near the tip of its wings.
Jewelwings are not strong fliers. Unlike dragonflies, with their characteristic efficient helicopter-like flight, Jewelwings flutter, more like butterflies. They are easy to get close to as long as you approach slowly and don't make any sudden movements. Ebony Jewelwings prefer sunny spots in the woods but usually perch only a minute or two before flitting to another nearby spot.
These delicate insects feed by flitting out and returning to a perch along a small stream. You may not see the flying insects it is capturing and eating, for they can be tiny. But a good feeding perch will be used for hours or days, and a territory of six to ten feet along the stream will be defended from other damselflies.
Jewelwings are a species of damselfly, which together with dragonflies make up an order of insects called Odonata. About 160 species of Odonata have been identified in Ontario. Dragonflies and damselflies are usually found around lakes, ponds, streams and wetlands because their larvae, known as “nymphs", are aquatic. Their eggs are laid in water or on vegetation near water or wet places, and hatch into nymphs, which are voracious predators of aquatic organisms, including mosquito larvae and even small fish.
After spending a year or more as nymphs, dragonflies and damselflies crawl out of the water onto vegetation and molt into flying adults, leaving their empty cases clinging ghost-like to the vegetation. Adults typically eat mosquitoes, midges, and other small insects. I have vivid memories of watching dragonflies zooming back and forth though a column of midges, picking them off one at a time. Odonata species generally require clean water, so the presence of plenty of these insects is a good indicator of clean water and healthy ecosystems.
Dragonflies differ from damselflies in several easily recognizable ways. Dragonflies are strong fliers with fairly robust bodies and at rest hold their wings open, out to the side. Damselflies tend to be smaller and less robust, and when at rest most species hold their wings folded together over the abdomen. Dragonfly eyes occupy much of the insect's head, often nearly touching each other across the face. In damselflies, there is typically a gap between the eyes.