We’ve been monitoring spongy moth egg hatch and found eggs began hatching throughout Grand Rapids during the second week of May, 2022.
We expect it will take at least two weeks for all eggs to hatch. Once eggs hatch, caterpillars may remain on the masses several days before dispersing. Spongy moth caterpillars disperse by ballooning - sending out a silken thread and then carried by a breeze. It may take several days for caterpillars to find a suitable host.
Just after caterpillars have hatched, when they are small and young, barrier bands will prevent them from climbing back into trees after ballooning or when they have fallen. Barrier bands can be made using duct tape and/or a waterproof, sticky material such as the Tanglefoot or petroleum jelly.
When the bark is dry, wrap duct tape around the tree, shiny side out, pressing the tape firmly into the bark cracks to prevent caterpillars from slipping under the bands. Then, turn the tape over and wrap once more with the sticky side up. The tape should be wrapped a few inches wide and placed around the tree trunk at chest height – about four feet above the ground. If possible, spread additional sticky Tanglefoot or vasoline onto the lower portion of the barrier.
Throughout the next months we will continue to monitor and track the spongy moth population. Below are our previous Spongy Moth Updates: