Pre-reproductive females are membranous and reddish-brown, once females begin to lay eggs they are globular or kidney-shaped become light to dark brown, and eventually heavily
sclerotized. The adult females resemble the
bud of their coniferous hosts, hence the name bud scale.
Physokermes are difficult to identify to species, as only pre-reproductive females can be used. Once females begin to
oviposit, their bodies become distorted and it is not possible to detect the morphological features necessary to identify them to species. ==Species==