How to identify winter moths
The most visible sign of a heavily infested tree is that it will be completely defoliated. The complete defoliation can reduce the annual growth rate of some oak species and successive defoliations can kill branches or entire trees.
If your tree suffered heavy defoliation, then water is crucial for the tree to have a second flush of leaves. Take a look at these options:
It is a pesticide-free option where you place a sticky band around the tree's trunk in early to mid-November. The sticky band prevents the female moths from crawling up the tree to lay their eggs. The band should be monitored and replaced over the course of a month, as the band becomes full.
Use dormant horticultural oil from November to January for effective moth prevention.
Use insecticides containing Spinosad, Indian, or Sevin to treat the newly hatched caterpillars. For feeding caterpillars, homeowners can use DiPel or Biobit, Javelin, and others containing B.t.k., which are applied to leaves that kill them when ingested by the caterpillars.