Have you noticed some interesting things happening on the ends of the limbs of persimmon, pecan or about 90 other deciduous tree species? I found it interesting articles began popping up the middle of July in 2016, 2015, 2014 and 2013 describing webs covering branches and even entire small towns. Just seeing if you were paying attention. If nothing else, the webworms are pretty predictable. Each fall webworm is officially known as a Hyphantria cunea. Hyphantria is Greek for weaver and cunea is Latin for wedge. A wedge weaver? Weaver comes from the massive webs the caterpillars create. The caterpillar metamorphoses into a white moth the shape of a wedge or triangle. This is an imaginative elegant combination of words to describe the fall webworm. Moths and butterflies are in the order Lepidoptera, second largest in the insect world.
The female moth lays hundreds of eggs that appear covered in short white hair on the bottom of a leaf. The eggs hatch into larvae with either black heads and yellow-green bodies or red heads with tan bodies. Both have long gray hairs and black spots. The hairs are attached to nerve cells that are sensitive to touch. At this point they continually spin their webs into gigantic proportions as they feed from within the protection the silk provides. Fittingly, the web is called a nest. All the nestlings, if spooked, will start to jerk in a coordinated effort designed to frighten or startle potential consumers.
Chickadees, barn swallows, purple martins, mockingbirds, robins and wrens may attempt to tackle the webs to get to the juicy protein packets. Wildlife ecologists think the development of large numbers of caterpillars in the autumn is probably linked to migration of certain bird species. This is similar to the tent caterpillars that show up in the spring, also a food source for migrating birds. Tent caterpillars (Malacosoma americanum) build their webs in the crooks or forks of branches. Another fascinating fact is their Latin name translated into English means soft bodied American…..don’t take offense; we are talking about caterpillars. Malakos is Latin for soft and soma does mean body.
Not only do the songbirds eat fall webworms, but bats, wasps and other insect predators, spiders, bacteria and even viruses can attack. When all is said and done, the trees look ratty, but the effect is basically cosmetic. The defoliation takes place late in the season and the trees are already preparing to go to bed for the winter.
Fall webworms (caterpillars) molt 6 to 11 times in 6 weeks. They then crawl out of the tree and find a nice place in the soil or under bark to spin their felt-like cocoons for the winter. Adult moths emerge in late spring through the summer. They are nocturnal and, yes, drawn to light. They are moths. The Northern moth is all white, but the southern moth is white with cute black spots. Native to North America and Mexico, the small moths have 1.5 inch wingspans and segmented legs black at the feet to knees transitioning into orange or yellow segments at the thigh, if the moth was a person. They have hearing organs at the base of their wings, thus they hear with their wings. At the base of the antennae are Johnston’s organs that help the moth navigate and keep its balance. The antennae lack clubs at the end but resemble slender black saws. Butterflies have sleek antennae.
Lepidopteran antennae are very sensitive to odors. The Cecropia moth, using his feathery antennae, can smell his mate 7 miles away. Moths can also smell with their feet. As a matter of fact, moths are studded all over with sense receptors. Think you can outrun the Sphinx moth? It is the fastest moth in the world and has been clocked at speeds exceeding 30 mph. You think you have talents.
In the realm of mythology, the moth as a totem represents the energy of whirlwinds, the ability to transform, to move in darkness or hear messages. Next time you see the fall webworms covering your landscape, remember….they not only can transform into something that can fly, but are probably as unique as each of us humans.