''Xeris spectrum'' is a kind of

horntail Horntail or wood wasp are any of the 150 non-social species of the hymenopteran family Siricidae, a type of wood-eating sawfly. The common name "horntail" derives from the stout, spine-like structure at the end of the adult's abdomen, which is ...

or wood wasp, that lives in

coniferous forest Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...

s. It is large wasp with a powerful

ovipositor 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 typica ...

in females. Unlike other Siricid Wood wasps, ''Xeris spectrum ''does not have symbiotic fungi to aid its larvae as they burrow in the wood of fir and other conifer trees making it unique in the Siricidae. It is widespread and is found in large parts of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and North America.

Appearance

The body of ''Xeris spectrum'' is cylindrical. The head is broadest behind the eyes, and antennae are thread-shaped. Both sexes are equal in length, between . The body is black or dark brown and shiny with white spots behind the eyes and on the sides of the

prothorax The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

. ''Xeris spectrums legs are orange-red. Males have brown rings around the leg. The body of the

larvae 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. T ...

is cylindrical and slightly flattened and is up to long. The

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

is in length. The antennae of the pupa extend beyond the wings at the level of the eighth segment.

Behavior

''Xeris spectrum'' are found in open pine forests. Males often begin to fly a few days earlier than females. The females drill their ovipositors into the tree, just under the bark, and deposit their eggs. Females lay eggs in coniferous trees, usually

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ( taiga) regions of the Earth. ''Picea'' is the sole genus in the sub ...

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

and

larch Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains furt ...

. Although ''Xeris spectrum'' does not have any symbiotic fungi, it often takes advantage of the fungal symbionts of other wood wasp species. A study of the reproductive strategies of ''Xeris spectrum'' showed that the females often lay their eggs on wood where other wood wasps of species with symbiotic fungi have already laid their eggs. This allows the ''Xeris spectrum'' larvae to benefit from the fungi. In addition, adult ''Xeris spectrum'' emerge from their holes at two different times: one group emerges in summer with the species of other wood wasps, while the other group emerges the next spring. The larvae are very different from the adults, both in lifestyle and appearance. The newly hatched larvae have access to food in the wood of damaged trees. As the larvae gnaw on the wood, the holes grow wider and deeper. Evidence of the larvae is noticeable in the deposits of wood chips and faeces that are left behind by the larvae. Just before the chrysalis stage larva boring a small chamber about into the tree. ''Xeris spectrum'' belongs to the group of insects with complete metamorphosis (

Endopterygota Endopterygota (from Ancient Greek ''endon'' 'inner' + ''pterón'' 'wing' + New Latin ''-ota'' 'having'), also known as Holometabola, is a superorder of insects within the infraclass Neoptera that go through distinctive larval, pupal, and adult ...

), who undergoes a metamorphosis during development. Between the larval stage and the adult stage is the

chrysalis A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

stage, a rest period, in which wasps inner and outer bodies change. The larvae's pliable and soft body is transformed into a

with a hard shell. When the shell is hard starting transformation from larva to the adult. The internal organs are lost in varying degrees down to a cell mass. A reorganization takes place and the animal transformed. The length of the pupa phase varies according to temperature. The entire development from egg to adult takes several years.

Damage

''Xeris spectrum'' is considered to be a

pest Pest or The Pest may refer to: Science and medicine * Pest (organism), an animal or plant deemed to be detrimental to humans or human concerns ** Weed, a plant considered undesirable * Infectious disease, an illness resulting from an infection ** ...

in the

timber Lumber is wood that has been processed into dimensional lumber, including Beam (structure), beams and plank (wood), planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as fini ...

industry. The damage caused by the wasp damages the wood and decreases its value. ''Xeris spectrum'' is most prevalent in homogeneous stands of

fir Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

and mixed stands of

and

that have been damaged by wind, fire, snow and

pathogenic In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

fungi. The density of the larvae can reach up to 60 specimens in of tree stem.

References

{{Taxonbar, from=Q575956 Siricidae Insects described in 1758 Taxa named by Carl Linnaeus