Daily News-Record, October 1, 2022
We usually think of insects as being creatures of the summer, and thus expect to see large numbers of them during warm weather and a decline in their populations as cool weather arrives. While this holds true for many species of insects, there are others that appear seemingly out of nowhere in fall. The walkingstick is one of them, which you may have noticed.
Walkingsticks mate in fall, and it’s their search for mates that brings them out into the open where we can marvel at how much they really do resemble sticks. If you watch one, you may observe it gently swaying. This motion imitates the movement of a twig in a breeze and helps to deceive birds, such as Carolina Wrens, that feed upon them.
Lizards and spiders also prey upon walkingsticks, and parasitic wasps and flies lay eggs on them that develop within their bodies. To avoid detection, walkingsticks remain almost motionless during daylight hours unless disturbed, in which case they might drop to the ground. A “twig” that walks will instantly betray its disguise!
Most folks think of walkingsticks as having slender brown bodies, but a careful observer will spot some that are completely light green, or that have brown bodies and green legs. Nevertheless, they mate with each other and are the same species.
A female lays eggs until cold weather sets in, when she will die. She ejects the tiny eggs from high up in trees, and they fall into the leaf litter below. The tough-skinned brown or black eggs remain on the ground throughout the winter and will not hatch until late spring.
The reason you don’t often see walkingsticks during spring and summer is because the nymphs (sexually immature insects that resemble the adults) are doing their best to remain inconspicuous as they feed on plants. Until midsummer they might be found on understory shrubs (those shrubs that grow in the shade of trees), but then they move up into tree crowns where they move slowly along during the night, feeding on the green leaves of their chosen host plant.
Walkingsticks feed mostly upon oak, basswood and wild cherry leaves, but may also eat apple, birch, hickory, locust and dogwood. Since these trees are common in Virginia, it’s easy to understand why walkingsticks are also common here.
As a rule, there’s only one generation per year in our area because it takes most of the season for the young insects to develop. Walkingsticks are unlikely to reach dense enough population levels to defoliate plants.
Because Walkingsticks are such perfect imitators of twigs, you would think that they would stay put on plants where they are so wonderfully camouflaged. However, at this time of year, they can be found on all sorts of surfaces. I’ve seen them mating on car doors and porch railings, and resting on sliding glass doors, carport ceilings, and trash cans. Perhaps they are much less wary now because their lives are about to end, and they may sense it.
Marlene A. Condon is the author/photographer of The Nature-friendly Garden: Creating a Backyard Haven for Plants, Wildlife, and People (Stackpole Books; information at www.marlenecondon.com). You can read her blog at https://InDefenseofNature.blogspot.com