Sword wasps
| Sword wasps | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Xiphydriidae | ||||||||||
| Leach , 1819 |
The sword wasps (Xiphydriidae) are a family of plant wasps whose larvae live in wood.
features
The sword wasps are similar to the wood wasps (Siricidae), with which they were formerly combined in a superfamily. In contrast to these, the neck (cervical) region is remarkably elongated with long cervical sclerites, so the head is clearly and well separated from the trunk. This feature is the easiest way to distinguish them from other plant wasps. The body length is between 4 and 25 millimeters (without ovens). The body usually appears stocky, not as narrow and elongated as the other wood-dwelling plant wasps. The antennae are elongated and consist of 13 to 25 segments, the first antenna segment is often elongated and slightly curved. The characteristic point into which the abdomen of the wood wasps is pulled out at the end is missing in this family. The abdomen is elongated, cylindrical and keeled on the sides. In the wing veins one vein, the subcosta, is completely missing. As with related families, a long ovipositor is noticeable in the female, which is carried straight out at rest as an extension of the abdomen. The actual stinging bristles (first and second blades) are softer and more flexible than those of the other wood-dwelling plant wasps. The enveloping third valves are much wider, which is what the name refers to.
Most species are black in color, often with yellow, red or white markings. The wings are tinted clear or smoky gray.
Larvae
The build of the larvae is shaped by the way of life inside the wood. The larva is white in color and, with the exception of the head capsule, soft-skinned, and the mandibles of the mouthparts are particularly well developed. One-part antennae sit on the head, the larval eyes have receded. The three pairs of thoracic legs are short and partially receded, the abdominal legs on the abdomen are completely absent. They can be distinguished from the larvae of the wood wasps by the labrum , which is symmetrically structured (in the Siricidae it is strikingly asymmetrical).
Way of life
The larvae of the sword wasps live inside wood. The female lays eggs in the wood of the host tree with its strikingly long and straight ("sword-shaped") ovipositor, mostly at a shallow depth, directly under the bark, with several eggs being applied to each hole, each separated by a small space. In contrast to the wood wasps, the female curves her abdomen towards the wood when laying eggs, so not only spreads the ovipositor on the belly side. The hatching larva digs a passage in the wood with its mouthparts, which it later expands into a small chamber. The passage behind the larva is usually densely clogged with food. Similar to the wood wasps, the larva can only live on wood as food if it has previously been partially decomposed by wood-dwelling fungi. Every species of sword wasp therefore lives in symbiosis with a species of fungus, the spores of which the female carries in specialized cells (so-called mycangia or mycetangia) and releases them into the wood when the eggs are laid. The mycangia lie at the base of the ovipositor, under the subgenital plate. The fungus species are different from those found in wood wasps; DNA analyzes have so far found two species, Daldinia decipiens and Entonaema cinnabarina ( hose mushrooms , family wooden club relatives ) both in one species ( Xiphydria longicollis ). The sword wasp larva gnaws a passage up to the wood surface before the pupae rest, but below the bark, where it pupates in a small chamber. Pupation does not take place in the family in a cocoon. The imago hatches out of the wood in the Central European species in late summer or early autumn.
Killer wasps only exceptionally infest tree trunks. The larvae are more often found in branches with a relatively thin cross-section or in very young stems. Almost without exception, dead or ailing branches are attacked. The species are often host-specific in one or a few related tree species, although the biology and host species of many species are unknown. Deciduous tree species are mainly infested, evidence from conifers is mostly uncertain and dubious (in the meantime a type of Derecyrta auraucariae has been found in the Brazilian araucaria in South America ).
Systematics
The family Xiphydriidae is divided into two subfamilies:
The relationship of the sword wasps within the plant wasps has not been clarified with certainty. Traditionally, they were run together with the other families living in wood in the superfamily of wood wasps (Siricoidea). However, according to recent studies, this placement is not justified; it is based on characteristics converged by the way of life. Today the family is mostly classified in isolation in the monotypic superfamily Xiphydrioidea. The Xiphydrioidea, together with the stem sawflies (Cephidae, Cephoidea), the Siricoidea, the orussidae (Orussoidea) and apocrita (Apocrita) a kinship group whose exact phylogeny is still uncertain. The grouping is sometimes referred to as "Unicalcarida".
distribution
The Derecyrtinae live in South America (a genus Australocyrta with two species in Australia). The Xiphydriinae occur almost worldwide, but they are absent in Africa.
Five types of the family have been identified in Germany:
- Xiphydria camelus (Linne, 1758). In dying hardwoods of numerous species, especially alder ( Alnus ) and birch ( Betula ).
- Xiphydria longicollis (Geoffroy, 1785). In deciduous trees that are dying, especially oaks ( Quercus ).
- Xiphydria prolongata (Geoffroy, 1785). Detected in poplar, willow and elm wood.
- Konowia megapolitana Brauns, 1884. Detected in birch and alder. Raspberry ( Rubus idaeus ) isalso specified.
- Konowia betulae (Enslin, 1911). Detected in birch. Possibly just a synonym for megapolitana
Economical meaning
In general, sword wasps are not considered to be significant forest pests. Since they almost only infest wood from dead and dying trees and prefer branches or trunks of small diameter, the damage they cause is usually minor. In some cases, the killer wasps, in particular Xiphydria camelus on alder and Xiphydria longicollis on oak, killed damaged young trees of already reduced vitality. In some cases there is also devaluation of wood as timber and construction timber through the larval bores. The importance of the sword wasps, however, never approaches that of the real wood wasps. Laying eggs on dry and debarked wood, e.g. B. Lumber, never occurs. As a rule, trees that are still standing are occupied.
The larvae are often brought into human dwellings with wood (especially firewood), where the adults that hatch later can be noticed.
Enemies
The sword wasps are attacked by a large number of hymenoptera parasitoid. Numerous parasitic wasps of the family Aulacidae (superfamily Evanioidae) specialize in orca wasps and can severely limit the population locally. Parasitic rates of 50% and above are not uncommon. Aulacus striatus locates the sword wasp larva based on the hole left by the host female. She drills through the wood into the host egg, in which she lays her own egg. The parasitoid larva grows within the host larva, which it kills and leaves when it wants to molt into a pupa. Other parasitic parasitic wasps include z. B. to the true parasitic wasps (Ichneumonidae, tribe Rhyssini, e.g. genus Rhysella ) and Xiphydriophagus (family Pteromalidae). There is a scientific film about the parasitoids of Xiphydria camelus that is shown very often at universities and educational institutions.
Orca wasp larvae, along with wood wasps and wood-dwelling beetles, are the most important food for numerous woodpecker species.
swell
- Wolfgang Schedl: Hymenoptera, subordination Symphyta: plant wasps, manual of zoology: Arthropoda: Insecta. Volume 4. Verlag Walter de Gruyter, 1991, ISBN 3-11-012739-3 .
- Andreas Taeger, Ewald Altenhofer, Stephan M. Blank, Ewald Jansen, Manfred Kraus, Hubert Pschorn-Walcher, Carsten Ritzau (1998): Comments on the biology, distribution and endangerment of the plant wasps in Germany (Hymenoptera, Symphyta). In: Taeger, A. & Blank, SM 1998 (Ed.): Plant wasps in Germany (Hymenoptera, Symphyta). Annotated inventory. - Goecke & Evers, Keltern, 364 + 3 p.,
- ↑ Hisashi Kajimura (2000): Discovery of Mycangia and Mucus in Adult Female Xiphydriid Woodwasps (Hymenoptera: Xiphydriidae) in Japan. Annals of the Entomological Society of America 93 (2): 312-317. doi : 10.1603 / 0013-8746 (2000) 093 [0312: DOMAMI] 2.0.CO; 2
- ↑ Petr Srutka, Sylvie Pazoutova, Miroslav Kolar (2007): Daldinia decipiens and Entonaema cinnabarina as fungal symbionts of Xiphydria wood wasps. Mycological Research 111: 224-231. doi : 10.1016 / j.mycres.2006.10.006
- ↑ Roland Mecke, Maria Helena M. Galileo, Márcia Silva Barbosa, Rafael S. Araújo (2001): Insects associated with araucaria trees. Interim report 2000 on the BMBF - DLR project 01LT0011 / 7 Araucaria forest, research focus Region 4: Mata Atlântica. 39-43.
- ↑ Michael J. Sharkey, James M. Carpenter, Lars Vilhelmsen, John Heraty, Johan Liljeblad, Ashley PG Dowling, Susanne Schulmeister, Debra Murray, Andrew R. Deans, Fredrik Ronquist, Lars Krogmann, Ward C. Wheeler (2012): Phylogenetic relationships among superfamilies of Hymenoptera. Cladistics 28 (2012) 80-112. doi : 10.1111 / j.1096-0031.2011.00366.x
- ↑ John T Jennings, Andrew D Austin, Nathan M Schiff (2009): The Australian endemic woodwasp genus Austrocyrta Riek (Hymenoptera: Xiphydriidae) Australian Journal of Entomology (2009) 48, 29-35. doi : 10.1111 / j.1440-6055.2008.00680.x .
- ↑ Dimitry E. Shcherbakov (2008): New records of Hymenoptera from the Moscow Region and other parts of Russia, with notes on synonymy of Konowia species. Russian Entomological Journal 17 (2): 209-212.
- ↑ Klaus Hellrigl (2006): About occurrence of wood insects in houses. Forest Observer 2/3 (2006): 33-348.
- ^ GH Thompson & ER Skinner (1961): The alder wood wasp and its insect enemies. Commonwealth Forestry Institute film. [1]
- Museum of Natural History Berlin: Fauna Europaea
- Ottesen, PS: Norske insecter og deres artsantall. , NINA Utredning 55, pp. 1–40 (1993, revised 1999) (Norwegian / English)