Shadow spongy moth (Lymantria umbrosa) is an insect pest of hardwood trees, shrubs, and plants. It is a native of Asia and was first detected in Washington in 2019.
Defoliation by gypsy moths can weaken trees, making them susceptible to subsequent infection by various pathogens.
For more information about this plant pest, see the CAPS data sheet and the CABI data sheet.