The Delicate Damselfly

by Forrest M. Mims III

Recently the Holden Arboretum in Ohio asked me to provide a selection of insect photographs for their "Big Bugs" exhibit. One of their selections was the nearby photograph of a Doubleday's bluet damselfly (Enallagma doubledayii).

The bluet damselfly is among the most beautiful creatures along Geronimo Creek. They are bright blue and about the size of a small matchstick. Their wings are clear with faint black veins. When they are not floating above the grasses and flowers, they can be found perched on a reed or twig.

Damselflies are distinctively different in appearance from dragonflies. They are smaller, and they look quite different when viewed up close. When resting, the damselfly folds its wings back over its body. This distinguishes damselflies from dragonflies, which rest with their wings wide open.

Recently I was walking back from the creek when I ran into a spider's web. That wasn't particularly unusual for this time of the year. But I was surprised to find that a dead bluet was suspended from a strand of silk. The spider must have just captured and paralyzed the bluet, for it was not yet wound with silk. Both bluets and spiders eat insects, but spiders also eat bluets.

Less common on our place is an equally attractive black damselfly. The body and wings are black with the exception of a clear section near the end of the wings. Allen Rhodes found the name of this online. It's called the smoky rubyspot (Hetaerina titia).

Like many dragonflies, damselflies are loyal to their mates. Male bluets and some other male damselflies even help their mate lay her eggs!

The bluet does this by clutching the female's neck by a clasper at the very end of his abdomen while the female is perched on an object just above the surface of a pond or slow-moving stream. The female presses the end of her abdomen into the soft tissue of an underwater stem and inserts eggs. When she is through, the male helps pull her from the water like a miniature helicopter!

This is an astonishing example of cooperation during egg laying. How do the male and female each know what to do and how to do it?

All the instructions for this highly complex interaction and cooperation, to say nothing about the construction of the creatures themselves, are precisely programmed in its genes just as our ability to photograph, study and appreciate this remarkable insect is programmed into ours.

Forrest M. Mims III and his science are featured online at www.forrestmims.org.

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise, Seguin, Texas. The column is written for a general audience.