Hemlock Wooly Adelgid - Identification and Control

The presence of white cottony masses on twigs and at the base of the hemlock needles is the most obvious indicator and good evidence of a hemlock woolly adelgid infestation. These masses or "sacs" resemble the tips of cotton swabs. They are present throughout the year, but are most prominent in early spring.

The actual insect is not plainly visible as it protects itself and it's eggs with their mass of fluffy white secretion. This "cover" actually makes it hard to control the aphid with chemicals.

HWA display several different forms during their life cycle, including winged and wingless adults. The females are oval, blackish-gray, and about 1mm in length. Newly hatched nymphs (crawlers) are approximately the same size, reddish-brown, and produce white/waxy tufts that cover their bodies throughout their life. The white-cottony masses are 3mm or more in diameter.