''Hylotrupes'' is a monotypic genus 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 t ...

s in the family Cerambycidae, the longhorn beetles. The sole species, ''Hylotrupes bajulus'', is known by several common names, including house longhorn beetle, old house borer, and European house borer. In South Africa it also is known as the Italian beetle because of infested packing cases that had come from Italy. ''Hylotrupes'' is the only genus in the tribe Hylotrupini

Distribution

This species, originating in Europe, and having been spread in timber and wood products, now has a practically

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

, including Southern Africa, Asia, the Americas, Australia, and much of Europe and the Mediterranean.Bugguide
/ref>Cerambyx
/ref>

Description

CSIRO ScienceImage 1742 The European house borer

''Hylotrupes bajulus'' can reach a body length of about , while mature larva can reach . These beetles are brown to black, appearing grey because of a fine grey furriness on most of the upper surface. On the pronotum two conspicuously hairless tubercles are characteristic of the species. On the elytra usually there are two whitish pubescent spots. Females do not have a real ovipositor, only a little more elongated

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

. The species can be defined polymorphic, having an extreme variability, both in the dimensions and in the aspect. In small specimens the pubescent spots on the elytra disappear almost completely and the legs and antennae turn to a reddish color.

Biology

Adults are most active in the summer (June–September). Only the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e feed on the wood, with a preference for dead wood of pines ( Pinus), fir, spruce ('' Picea abies''),

Araucaria ''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen Conifer, coniferous trees in the family Araucariaceae. There are 20 extant taxon, extant species in New Caledonia (where 14 species are endemism, ende ...

and

Pseudotsuga ''Pseudotsuga'' is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names for species in the genus include Douglas fir, Douglas-fir, Douglas tree, Oregon pine and Bigcone spruce. '' Pseudotsuga menz ...

species . Ecologically it can be quite important as a scavenger of dead pine trees, pine fence posts, and similar objects, hastening their decay and collapse. The life cycle from egg to beetle typically takes two to ten years, depending on the type of wood, its age and quality, its moisture content, and also depending on environmental conditions such as temperature. Larvae usually pupate just beneath the wood surface and eclose in mid to late summer. Once the

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

of the newly emerged adult beetle has hardened sufficiently the adults cut oval exit holes 6–10 mm (¼ to 3/8 in) in diameter, typically leaving coarse, powdery

frass Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...

in the vicinity of the hole. ''Hylotrupes bajulus'' preferentially attacks freshly produced sapwood of

softwood file:Pinus sylvestris wood ray section 1 beentree.jpg, Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main diff ...

timber. Contrary to the name "old-house borer", the species is more often found in new houses; maybe because the beetles are attracted to the higher resin content of wood harvested more recently than 10 years earlier. If old wood is attacked, the damage is usually greater. As the nutrient content of wood decreases with age the larva has to consume larger amounts of wood. In Australia the infection of home construction is mainly caused by the use of wood already infected with the eggs or

e of the beetles if the wood is not properly kiln-dried in production.Grimm, M., et al. (2009)
European House Borer ''Hylotrupes bajulus'' Linnaeus in Western Australia: the anatomy of an eradication program.
The International Research Group on Wood Protection. IRG/WP 09-20403.

Gallery

File:Hylotrupes bajulus (huisboktor) (4).jpg, Larva File: 130312 Tesarik krovovy Hylotrupes bajulus (1).JPG, Larva exposed in infested wood File:Hylotrupes bajulus side2.jpg, Adult. Side view File:Hylotrupes bajulus front.jpg, Front view

References

* * {{Authority control Woodboring beetles Callidiini Building defects Household pest insects Monotypic Cerambycidae genera Insects in culture