Black pine wasp
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Black pine wasp ( Xeris spectrum ) |
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| Xeris spectrum | ||||||||||||
| ( Linnaeus , 1758) |
The black pinewood wasp ( Xeris spectrum ) is a species of wood wasp that lives on conifers .
features
The species is slender and gracefully built, with long legs and an elongated, cylindrical abdomen, which (typical of plant wasps ) sits broadly on the thorax . As with many wood-dwelling insects, the size of the adults is extremely variable and can vary between about 10 and 30 millimeters in length depending on the environmental conditions. Males and females are the same size, but differently colored. The long and slender ovipositor ( ovipositor ) is immediately noticeable in the female, and with a length of around twenty millimeters it is almost the length of the body; it is carried straight backwards at rest in extension of the abdomen. As with many wood wasps, the rather small head is very flexible and attached to a narrow neck (cervical) region. Typical for the genus are two keels on the back of the head, which give it an angular appearance. The leading edge of the pronotum is also edged. In the wing veins a closed anal cell is missing in the hind wing, otherwise it corresponds to that of the related genera and species. The wings are clear and have no pterostigma . In both sexes, the abdomen ends in a stepped, coarsely toothed point (cornus) that is relatively narrow and somewhat widened in the middle.
The body of the species is predominantly black in color. There are always two white spots on the back corners of the head (distinguishing feature from the genus Sirex ). The long, thread-like antennae are also black. The legs of the male are also predominantly black (with a red "knee" joint and tarsi ), while the female has an extensive red color.
Way of life
The species develops in the wood of dead or ailing softwoods without a clear preference for a genus or species. According to some observations, at least in Europe (and contrary to the naming), it should prefer spruce and fir to pine . The development period is one year, in higher mountain areas or northern latitudes two or even three years. The adults hatch in mid to late summer. Eggs are laid on standing or freshly felled, lying wood; wood that has been lying down for a longer period of time or that has been built in is not accepted. Behavioral experiments have shown that the species prefers strains that have already been occupied by other wood wasps species. Since the black pine wasp, an exception among the wood wasp species, does not have its own symbiotic fungi of the genus Amylostereum , but needs them for development, it is probably dependent on another species that it also supplies with the fungus. The larva gnaws a short passage with a chamber-like extension into the wood.
The species is of little economic importance and is not considered a special forest pest. Neither healthy trees nor construction or timber are attacked. Damage is occasionally reported on trees that show bark damage from planting or logging work at the base of the trunk. However, the animals are quite widespread when they are brought into human homes with wood (especially firewood).
distribution
The species has a very large distribution area that includes the entire northern hemisphere. There are three subspecies. In Europe the type subspecies Xeris spectrum spectrum occurs. The species colonizes almost all of Europe, north to southern Norway, but is absent in England for unknown reasons. In Europe it is the only species of the genus.
supporting documents
Individual evidence
literature
- Nathan M. Schiff, Steven A. Valley, James R. LaBonte, David R. Smith (2006): Guide to the Siricid Woodwasps of North America. Published by Forest Health Technology Enterprise Team. Morgantown, West Virginia.
- Robert M. Benson (1943): Studies in Siricidae, especially of Europe and southern Asia (Hymenoptera, Symphyta). Bulletin of Entomological Research 34: pp. 27-51.
- Hideshi Fukuda & Naoki Hijii (1997): Reproductive strategy of a woodwasp with no fungal symbionts, Xeris spectrum (Hymenoptera: Siricidae). Oecologia 112: pp. 551-556.
