This time of year in this area, this is more likely to be fall webworm which is native (so is WTC). Defoliation from these insects is unsightly but these trees often rebound because they are targeting deciduous trees that are used to losing leaves and can rebound from this feeding. Especially because they do not tend to completely defoliate the same trees each year. https://www.oregon.gov/odf/Documents/forestbenefits/Webworm_2017.pdf

Christine Buhl
Jan. 8, 2026, 1:41 p.m.