Have you been wondering what these webs in your trees are? This is the second year in a row that I noticed significant numbers of them.
When I first saw them popping up, I assumed they were just late tent caterpillars, those demonic, hairy creepy crawlies that eat all the leaves off of trees in late May and June.
However, after poking around, I discovered that they aren’t actually tent caterpillars. Turns out, these webs are from a different moth called a fall webworm, and, in many cases, they’re less harmful than their tent caterpillar counterparts.
About Fall Webworms
Like tent caterpillars, webworms enjoy eating the leaves off of trees after they hatch. However, they’re eating leaves at the end of the season, when the leaves have already done their job and are dying off anyway. That means the trees are generally unharmed and will grow back just fine next year. Of course, if you have a very small tree or really hate the look of the webs, it could still be a problem.
In addition to appearing later in the year, another way webworms differ from tent caterpillars is that their nests appear at the end of branches and encompass the leaves there, rather than near the base of branches like tent caterpillars.
Webworms have a unique life cycle. They emerge from their eggs and begin webbing immediately, which they expand to include more leaves as they grow. They can go through 11 growth stages before pupating in old leaves, soil, or bark for the winter. The next spring and summer, they emerge and begin laying eggs to begin the process again.
They are not picky eaters. Webworms can be found in over 90 species of deciduous trees!
In case you’re wondering, full-grown moths are almost fully white up here when we see them. Further south, they have more brown spots.
How to Deal with Fall Webworms
So, what can you do about them? Well, like tent caterpillar nests, they can be cut from the tree and set on fire. Always a good time, but if you don’t want to worry about accidentally starting a backyard tent inferno, there are better options.
The simplest option is to just leave it if it doesn’t bother you. Chances are, the webworms aren’t harming your tree, so aside from not liking the look of it, there’s not too much reason to dislike them. The webs will turn brown once the caterpillars go into their pupa stage, and will fall out of the tree altogether from the wind and snow of winter.
If you want it gone pronto, you can remove it pretty easily yourself. Just like spider webs, you can grab a stick and make caterpillar cotton candy out of it. After you’ve gotten all the webbing and webworms out of the tree, you can make an offering out of it for the birds. The birds are big fans, in fact, there’s one out pecking at a web in our apple tree as I write this.
If you don’t want to wait for birds, you can dump your fuzzy stick in a bucket of soapy water.
It’s not a good idea to try using pesticides on them. Apparently, the web won’t let pesticides through to kill them, and the other methods are more effective.
Hopefully, you can now make an informed decision on how to deal with fall webworms! If you’d like to learn more scientific facts about them, check out this article.
These caterpillars are interesting, but not a lot of fun… but Monarch caterpillars are! Here’s how to raise them.