Maple cottony scale (Pulvinaria innumerabilis) found on this green ash (Fraxinus pensylvanica) is a pest that in sufficient numbers can cause significant stress to trees. It is a soft scale which is an insect in the “true bug” family of hemiptera that uses piercing and sucking mouthparts to feed on the fluids in the vascular tissues of the tree. The egg mass is the white cottony material that has formed underneath the female scale.














