Physokermes


Physokermes are a genus of scale insects known as the bud scales. They are restricted to the Holarctic, though Physokermes hemicryphus has been introduced to North America. Some species are plant pests.

Morphology

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

There are 13 described species in the genus Physokermes: