IN LATE SUMMER, it’s fairly common to find weird-looking webs (like the one pictured above) on crabapple and other hard-wood trees. Who weaves these horrid things? Meet Hyphantria cunea, the “Fall Webworm.” More about this caterpillar, and why you needn’t go out on a limb to eradicate it:
Hyphantria lives a well-protected life in the silken, water-proof tent it spins around the leaves it eats. Birds and parasitic wasps are rarely able to penetrate the tents. As the caterpillars require more foliage, they simply expand their tent until an entire branch is enclosed.
What do I do about this furry worm? Basically nothing. You see, here in the Northeast, the webworm emerges only in late summer or early fall. Trees at this time have already prepared themselves for winter dormancy, and couldn’t care less if they have leaves or not. They always recover without a hitch the following spring.
However, the webs are unsightly. To remove them, I either prune off the effected limbs, or sweep the webs with a broom or a stick. As the web comes off the tree, the caterpillars remain attached to it. Webs and their inmates are then disposed of.
Again, you need only remove such a tent for aesthetic reasons. If permitted to live, the colony will feed for 4-8 weeks, then migrate downward and pupate in the soil. In spring they will emerge as dusky-white nocturnal moths.
Their are two races of Hyphantria: blackheaded and redheaded. I have the blackheaded type. Both have yellowish bodies. The black dots on their tent are from the waste they produce.
Have you seen the tell-tell signs of the Fall Webworm in your garden? You can let me know in the comments field below.
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