Apple ermine moth (Yponomeuta malinellus) is an insect pest of apple trees. It is a native of Eurasia and was first detected in Washington in 1985.
Larvae of this moth can cause severe defoliation of apple trees. Feeding and mining begins with leaves followed by gregarious feeding protected by a silken web occurring in May and early June.
For more information about this plant pest, see the CAPS data sheet.