Worms on our trees

web worm

This year it seems we have a lot of caterpillars on our trees. They are consuming most of the leaves, and some of our neighbors are concerned.

We reached out to Parks, and were told the following:

The fall webworm is native to our region and the impact of these insects on our urban forest is minimal. The worm rarely causes other than aesthetic damage as trees can recover from defoliation, especially when it occurs toward the end of summer. Chemical treatment on trees is not recommended, as it may not be effective and may harm predators such as squirrels and birds that consume the insect.

It is rare that an infestation continues beyond a single season. The webworms will leave host trees by mid-September to pupate (form cocoons) in the soil, so you may consider raking up the leaf litter and placing fresh mulch in the tree bed as a deterrent.

For more information on webworms and their impact to vegetation, please visit USDA.

If you have other concerns similar to this, never hesitate to ask.


Photo courtesy of Roy Leonard