The woolly covering varies from creamy white to yellowish-white when older, and the inner capsule is light brown.

The sexual generation male, similar in coloration to the female, measures 1.2–1.6 mm in length.

[1] Upon emerging from catkin galls in mid-March to early April, the sexual generation mates and lays eggs in the mid-rib of new leaves.

The woolly galls develop from mid to late summer through the fall and winter, with asexual females emerging from September through February.

This emergence period coincides with catkin bud production, where the asexual females lay their eggs.