''Polycaon stoutii'', the black polycaon or Stout's branch borer, is a species of
woodboring beetle
The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood (i.e., are xylophagous). In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The ...
in the Bostrichidae family. It is found in North America in
British Columbia
British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...
, the
Pacific Coast states, and
Arizona
Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...
, but has spread elsewhere due to the shipping of wood products.
Relationship with wood
''Polycaon stoutii'' breeds in
hardwoods
Hardwood is wood from angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes ...
. The female bores into the wood and lays its eggs in a tunnel. Usually, these host trees are dead or dying, but they are reported to bore into healthy ones as well. Recorded host trees include
redwood
Sequoioideae, commonly referred to as redwoods, is a subfamily of Pinophyta, coniferous trees within the family (biology), family Cupressaceae, that range in the Northern Hemisphere, northern hemisphere. It includes the List of superlative tree ...
,
coast live oak
''Quercus agrifolia'', the California live oak, or coast live oak, is an evergreen live oak native to the California Floristic Province. Live oaks are so-called because they keep living leaves on the tree all year, adding young leaves and sheddi ...
,
maple
''Acer'' is a genus of trees and shrubs commonly known as maples. The genus is placed in the soapberry family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated si ...
,
manzanita
Manzanita is a common name for many species of the genus '' Arctostaphylos''. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from Southern British Columbia and Washington to O ...
,
madrone,
California laurel,
sycamore
Sycamore is a name which has been applied to several types of trees, but with somewhat similar leaf forms. The name derives from the Ancient Greek () meaning .
Species of otherwise unrelated trees known as sycamore:
* ''Acer pseudoplatanus'', a ...
,
hickory
Hickory is a common name for trees composing the genus ''Carya'', which includes 19 species accepted by ''Plants of the World Online''.
Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve ...
,
mahogany
Mahogany is a straight- grained, reddish-brown timber of three tropical hardwood species of the genus ''Swietenia'', indigenous to the AmericasBridgewater, Samuel (2012). ''A Natural History of Belize: Inside the Maya Forest''. Austin: Universit ...
,
ash, and various fruit trees. Infestation can occur before the trees have been harvested or in a
lumberyard.
Larvae develop inside the wood for at least a year, but can remain there for over twenty years before emerging as adults. They are known for occasionally emerging from wooden furniture.
Description
Adults are 10-23 mm in length. They are cylindrical, hairy, and black. Their heads are slightly downturned.
''Polycaon stoutii'' can be distinguished from the related ''P. granulatus'' by the
antennae having 11 segments and the 2nd and 3rd
tarsal segments being cylindrical. It can be distinguished from ''P. punctatus'' by its black colouration and the 3rd antennal segment being much shorter than the 4th.
References
Further reading
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*
{{Taxonbar, from=Q2409674
Bostrichidae
Articles created by Qbugbot
Beetles described in 1853
Taxa named by John Lawrence LeConte
Beetles of North America