"Trees that are stressed are more vulnerable to defoliation and the opportunistic organisms that frequently attack them, so efforts should be made to keep trees in a good state of health or vigor."
That's according to a gypsy moth handbook created for the U.S. Department of Agriculture.
- Cutting, filling, grading, paving and other construction can hurt a tree's soil and root system.
- Keep the forest floor surface as natural as possible in wooded backyards. Removing organic leaf litter can hurt oak trees, which thrive in acidic soil. Also, layers of natural leaf litter provide a natural habitat for mice and shrews that prey upon gypsy moth larvae and pupae.
- Mulch or ground cover plants may be good for isolated trees, but dense grass over feeder roots will compete for moisture and nutrients.
- Water, fertilize and prune stressed trees during a drought.
- Remove bark flaps, dead branches, stumps and debris, which can protect gypsy moth larvae and pupae.
- Tulip or yellow poplar, honeylocust, ash, maple, hickory and dogwood are among the trees less popular with gypsy moths.
- Inspect sheds, garages, tree houses, stone walls, wood piles and lawn chairs for hidden egg masses.
- A sticky band around a tree - such as grease, tar or another petroleum product - may trap gypsy moth larvae, but may also hurt thin-barked trees.
Source: "The Homeowner and the Gypsy Moth: Guidelines for Control" by Michael L. McManus, David R. Houston and William E. Wallner