Description of walking sticks
A walkingstick looks like a long, slender, cylindrical stick on 6 spindly legs and with 2 long, thin antennae. This makes them immediately recognizable to almost everyone, in spite of our limited opportunities to see them. One of the reasons we seldom see a walkingstick is their effective camouflage. Walkingsticks and their relatives the leaf insects mimic their natural background to a degree rarely matched by other insects. Apparently, this mimicry provides excellent protection from predators that would otherwise pounce upon these sluggish (and presumably tasty) insects.
The USDA Forest Service has compiled an exhaustive list of fanciful nicknames for walkingsticks. A walkingstick may be called stickbug, specter, stick insect, prairie alligator, devil's horse, witch's horse, or devil's darning needle, depending on locality. Most of the nicknames conjure images of malice or dread, neither of which is necessary for walkingsticks in the U.S.
There are approximately 2,500 species of walkingsticks in the world. Unfortunately for Iowans, only four species are known from the upper Midwest and only one species is common. Most walkingsticks are found in the tropics, with the greatest diversity in the Oriental region.
Our walkingstick is an impressive 2 2/3 to 4 inches in length. Unfortunately, it is a piker compared to some tropical species that reach almost a full 12 inches in length. All walkingsticks in the upper U.S. are wingless in the adult stage, while some tropical species have showy wings they can flash as further defense against predators.
Life cycle of walking sticks
The walkingstick starts life as an egg. Eggs are produced in late summer and autumn and drop from the treetops to spend the winter on the ground. The hard, flat, round, eighth-inch long eggs are described as seed-like. Even the eggs are camouflaged!
Walkingsticks have a simple life cycle. Eggs hatch in May or early June into quarter-inch long, green nymphs that look like miniature versions of the adult. Nymphs feed near the ground on the leaves of shrubs and small trees until about mid-summer when they move to the upper canopy. There they continue feeding until they reach their final full-grown size in late July or August. Adults are brown expect the top surface that is green or gray. Females lay eggs until frost, often producing up to 150 eggs per female.
Damage caused by walking sticks
Walkingsticks are herbivores. They have chewing mouthparts and eat the leaves from the tress, shrubs and other plants on which they hide. Walkingsticks are generally not considered to be a pest, though large populations may defoliate plants to a noticeable degree. Occasional defoliations in northern Wisconsin and Minnesota have been reported.
Walkingsticks can be picky eaters. The adults prefer to feed on the leaves of oaks, basswood, and wild cherry. Leaves are eaten from other trees growing among preferred hosts. These include ash, paper birch, hickory, locust, apple, and chestnut. Maple trees and conifers (such as pine and spruce) are avoided.
Management of walking sticks
Walking sticks seldom cause enough damage to warrant management.
Do you live in Iowa and have an insect you would like identified?
The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them. Please see our website for current forms, fees, and instructions on preserving and mailing insects.
Contact information for each states diagnostic laboratory for U.S. residents. If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic