''Physokermes'' are a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
scale insects
Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the ...
known as the bud scales. They are restricted to the
Holarctic
The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...
,
[
] though ''Physokermes hemicryphus'' has been introduced to
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
.
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
Sclerosis (also sclerosus in the Latin names of a few disorders) is a hardening of tissue and other anatomical features. It may refer to:
* Sclerosis (medicine), a hardening of tissue
* in zoology, a process which forms sclerites, a hardened exo ...
.
The adult females resemble the
bud
In botany, a bud is an undeveloped or Plant embryogenesis, embryonic Shoot (botany), shoot and normally occurs in the axil of a leaf or at the tip of a Plant stem, stem. Once formed, a bud may remain for some time in a dormancy, dormant conditi ...
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
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
, 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
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
in the genus ''Physokermes'':
*''
Physokermes coloradensis''
Cockerell 1895
*''
Physokermes concolor''
Coleman 1903 - fir bud-scale
*''
Physokermes fasciatus''
Borchsenius 1957
*''
Physokermes hellenicus''
Kozár & Gounari 2012
*''
Physokermes hemicryphus''
(Dalman) 1826 - small spruce bud-scale
*''
Physokermes inopinatus''
Danzig & Kozár 1973 - Hungarian spruce bud-scale
*''
Physokermes insignicola''
(Craw) 1894 - Montery pine scale
*''
Physokermes jezoensis''
Siraiwa 1939
*''
Physokermes picaefoliae''
Tang 1984
*''
Physokermes piceae''
(Schrank) 1801 - spruce bud-scale
*''
Physokermes shanxiensis''
Tang 1991
*''
Physokermes sugonjaevi''
Danzig 1972
*''
Physokermes taxifoliae''
Coleman 1903 - Douglas fir scale
References
Sternorrhyncha genera
Coccidae
{{Coccidae-stub