Master of Disguise: Mexican Walking Sticks
Tara A. Spears
It’s not the tequila nor are you imagining that the branch just walked away. It’s an insect- you know the ones, those subtropical and tropical bugs that look just like branches—until those twigs get up and walk away from you.
The body and legs of these insects are long and thin. Generally, they are wingless. Their antennae are also long and thin. They live in trees and bushes, where their color and shape camouflage them very effectively. Diapheromera femorata only eat leaves and stems of plants and usually only eat at night.
One weird fact about the Stick insect is that they are a nation of Amazonians, mighty females, that can reproduce almost entirely without males. Unmated females produce eggs that become more females. Another interesting feature is that some stick insects can change color, like a chameleon, depending on the background where they’re at rest. The species that I have in my yard does this: it will be green on the scrub but turns tan if I place on my beige patio tile. 
Most stick insects live in a warm, tropical climate where it doesn’t freeze. Some species are quite large – more than 15 cm long! They do not bite, but large stick insects can inflict wounds with the sharp spines on their legs. Males are slightly smaller than the females.
Walking sticks go through three stages of development: egg, nymph and adult. The female can lay up to 150 eggs, dropping them one by one to the ground. The walking stick’s egg is also camouflaged and resembles a brown seed that hatch in the spring. The nymph stage walking stick (immature) resembles a tiny adult when they hatch from the egg. Depending on the species, they molt several times before reaching sexual maturity. The walking stick has a lifespan of only one season.
The eggs of some stick insects are collected by ants. The ants hide the eggs in their underground nest, away from parasites. In exchange for this service, the ants feed on an edible substance that covers the eggs.
In addition to their protective camouflage, some stick insects are able to spray a noxious chemical on birds that attack them. The chemical’s composition and effects are similar to tear gas.
Young stick insects have another useful method of defense. If one of their legs is caught by an enemy, they leave it and escape. Their leg grows back the next time they molt. Adult insects can’t regenerate a limb, however.
Take time to sit quietly around shrubs and you’re certain to enjoy the bobbing walk of these interesting insects.