House buck
| House buck | ||||||||||||
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House buck ( Hylotrupes bajulus ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Hylotrupes | ||||||||||||
| Audinet-Serville , 1834 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Hylotrupes bajulus | ||||||||||||
| ( Linnaeus , 1758) |
The house longhorn beetle ( Hylotrupes bajulus , also known as barbell or large woodworm ) is a member of the longhorn beetle (Cerambycidae) of the genus Hylotrupes . (This word is composed of (Greek) hyle → wood and a Latinized form of trypetes → Bohr (end) er; baiulus (Latin) is a carrier.)
description
The fully grown beetle reaches a body length of 8 to 26 millimeters and is relatively flat. It varies not only in size but also in color and drawing considerable, but nevertheless hardly be confused with other species. The basic color is brown (especially newly hatched animals) to black, with fine gray hairs, antennae and legs are often lighter than the rest of the body. On the wing covers are two pairs of more or less distinct white hair spots. The pronotum is strongly rounded with two smooth shiny calluses on the top. The head is significantly narrower than the pronotum. The thighs are clearly thickened towards the tip, the claws have a small tooth at the base. The front hips are widely separated from each other by the protrusion of the front chest. The eyes are deeply rimmed by the antennae. The latter are relatively short for a longhorn beetle, the third antennae is significantly longer than the fourth.
The house billy beetle is the longhorn beetle, which is incorrectly (in colloquial language) called the wood buck. However, a wooden tick is understood to mean different genera of ticks , e.g. B. the common trestle .
Occurrence
The beetles lay their eggs in dead coniferous wood , but they also like to lay their eggs in buildings, especially in the roof structure .
The development cycle of the longhorn beetle
The larvae of the house billy goat are colored ivory white and reach a body length of about 30 millimeters. The hardly hairy body is structured by creeping bulges. The head capsule is characterized by strong, sclerotized (hardened by protein deposits) and dark colored mandibles , with the help of which they can eat tunnels in the wood. It also has a row of three larval eyes (stemmata) on the side of the small antennae.
The heat-loving beetles fly at temperatures above 30 ° C, in Central Europe from June to August. The males flying first look for a suitable wooden substrate, always in coniferous wood, for laying eggs and then lure the females with a pheromone , and the females also react to the smell of the wood itself. The eggs are attracted by the female with their long, extendable laying tube Cracks and placed in crevices of the wood, on average about 200 per female. The young larvae are very warmth-loving, therefore preferred in roof trusses. They clearly prefer the more nutritious sapwood and can hardly develop on heartwood alone. Under favorable conditions, the development takes three to four years, but under unfavorable conditions it can extend up to ten years. The larvae always leave the outermost edge of the wood intact and are therefore usually not visible. The infestation can be detected through the feeding noises of the larvae. Pupation takes place in the colder winter. Beetles that fly out of the doll's chamber leave exit holes of oval shape with a longitudinal diameter of 5 to 10 millimeters.
The beetle only has a very short life span (approx. 4 weeks) and does not eat any food during this time.
In contrast to the woodworm ( Anobium punctatum ), activity cannot be recognized by wood flour oozing out. The billy goat clogs its passages with the meal and does not enter them again. The infestation therefore remains undetected for a very long time, since, apart from oval escape holes about four to seven millimeters in size, an infestation cannot be detected from the outside. The infestation is only noticeable after a remaining paper-thin wood skin has been scratched. An active infestation can be z. B. by audible feeding noises, fresh larvae or beetle finds, fresh egress holes, etc., but a reliable evidence of activity is extremely difficult. The house goat larva requires a minimum wood moisture content of approx. 12%, with the ideal development moisture being approx. 30%. This is why an infestation by house buck larvae hardly ever occurs in the exposed wooden components of centrally heated rooms. The situation is completely different with built-in wood in relation to the outside area (e.g. expanded roof structure), here a microclimate develops within the wood cross-section, which meets the climatic requirements of the larvae. The infestation is therefore mainly concentrated on roof trusses and wooden houses.
When assessing the risk to wood from insect infestation, the opinion is often expressed that 60 to 80-year-old conifers can no longer be infested by longhorn beetles. It is assumed that essential reserve substances in the wood change over time in such a way that they are no longer bioavailable to the insect larvae and that in this way protection against insects is achieved. Investigations by A. Körting in 1961 showed, however, that a development in very old wood is quite possible and also takes place. Here is the summary of the test results:
- The longhorn beetle larvae showed weight gain in wood that was 5 to 360 years old; Successful development is therefore possible in all age groups. As the wood ages, the nutritional value of the wood decreases, but not to the point where larval development becomes impossible. The larvae compensate for the decrease in nutritional value by increasing the amount of wood they eat.
- If older wood is attacked, the damage in 60 year old wood is about twice as high, in 100 year old wood it is 3 times higher and in wood over 350 years it is about 5 to 6 times as strong as in fresh wood.
- The declining new infestation of older wood is mainly due to an age-related decrease in attractiveness due to the loss of volatile wood constituents. Younger woods are clearly preferred when laying eggs; If there is a high pressure of infestation, however, very old woods are also used, which have largely lost their attractiveness. Also, especially when renovating the roof structure through the installation of new wood, an increased attractiveness of the roof structure can be determined. The nutritional value of the wood is not checked by the parent animals and is not a selection criterion when laying eggs.
Compared to approx. 55,000 annual new infestations from 1910 to 1960 by house buck in Germany, the number of infestations has meanwhile decreased considerably. Currently (as of 2016), an order of magnitude of approx. 6000 new cases per year can be estimated in Germany. A comparable decrease in the frequency of infestation was also demonstrated for Sweden. The reasons for the decline are assumed to be: the effect of preventive and combative chemical wood protection, changed construction methods and the expansion of attic storeys, a reduced proportion of tree edges in standard-compliant structural timber and a decrease in the introduction of wood that is already infected with larvae.
Technically dried wood is apparently only very rarely attacked by the roebuck, as all larvae that may be in the wood are killed during the drying process. The risk of an introduction with already infected timber is therefore particularly low with technically dried wood.
Combat
The determination of infestation activity is a prerequisite for combating damage caused by the house billy larvae. However, this usually encounters massive difficulties:
- During the expert inspection, the hidden areas with a high probability of infestation (layers in the dew point zone, eaves etc.) B. not be examined in detail by obstructions.
- The active infestation of the roebuck does not necessarily make itself noticeable through the throwing of flour and can only be reliably verified by sporadic noises, fresh egress holes or larvae finds. Any omissions indicate an infestation by parasitoid or predatory insects, which in turn is a reliable indication of the presence of the wood-damaging larvae.
- The lack of feeding sounds can, however, also be attributed to the still small size of the larva or to an existing stage of pupation.
- The lack of fresh egress holes can be due to the hidden location or a metamorphic cycle that has not yet been completed.
- Larval finds can often only be made visible by splitting the affected wood.
The house buck can be fought with the following methods ( standardized in Germany according to DIN 68800/4):
- Chemical combating of wood pests by curing and impregnating the surfaces
- Chemical control of wood pests by means of pressure or pressure-free injections
- Hot air process; small objects such as watch cases can be sufficiently heated in a sauna
- Fumigation (e.g. sulfuryl fluoride )
- Microwave: A magnetron with a connected horn radiator shines through the wood for a few minutes and overheats all living things that contain water.
distribution
The species probably comes from the Mediterranean region (possibly from North Africa), where it occurs on conifers in the wild. It was abducted far from there and occurs today almost worldwide, in all of Europe, North and South America, South Africa, and East Asia. In Australia, it was possible to eradicate an introduction in the 1950s by means of severe control measures. Another importation in 2004 in the Perth region was at least contained. Information about an introduction to New Zealand has been given in error.
In Germany, as in all of Europe, the species shows a clearly declining population trend, presumably due to the better wood conservation in buildings and the control measures.
Systematics
The species was first described by Carl von Linné as Cerambyx bajulus . It is the only recent species of the genus Hylotrupes Audinet-Serville , 1834. A fossil species, Hylotrupes senex from the Rott fossil deposit , was assigned to the genus by Carl von Heyden in 1859. This very old and never verified information requires confirmation. The genus belongs to the tribe Hylotrupini Rose, 1983 (earlier often incorrectly attributed to Zagajkevich, 1991) in the subfamily Cerambycinae. According to genetic data, the genus Rosalia is closely related to the Alpine buck .
literature
- H. Joy, KW Harde, GA Lohse: The Beetles of Central Europe. Volume 9, Spektrum Akademischer Verlag, 1966, ISBN 3-8274-0683-8
- Simon Aicher, Boromir Radovic, Gerhard Volland: House ram infestation in glulam . Building research, T 2954. Otto Graf Institute, University of Stuttgart, Research and Materials Testing Institute for the Building Industry (FMPA). Fraunhofer-IRB-Verlag, Stuttgart 2001, 240 pages, ISBN 3-8167-5977-7
- Jochen Müller: Wood protection in building construction . Fraunhofer IRB Verlag, Stuttgart 2005, ISBN 3-8167-6647-1
- Dietger Grosser: Plant and animal construction and timber pests. DRW-Verlag, Leinfelden-Echterdingen 1985, ISBN 3-87181-312-5 .
- Hans-Peter Sutter: Recognizing and combating wood pests on cultural assets . Paul Haupt Verlag, Bern Stuttgart Vienna 2002, ISBN 3-258-06443-1
- G. Becker: Studies on the nutritional physiology of the longhorn beetle larvae . In: Journal of Comparative Physiology . 29/3, 1942, pp. 315-388.
- W. Behrenz, G. Technau: Investigations on the immunization of wood by hot air treatment . 1956
- Dirk Lukowsky: Mechanisms of action of the technical drying of construction timber as protection against the house buck (Hylotrupes bajulus). Proceedings of the German Wood Protection Conference, September 2016, pp. 120–142.
See also
Web links
- Hylotrupes bajulus (L.) - House billy goat ( Memento from July 5, 2008 in the Internet Archive )
- Holzfragen.de
- Hausbock profile
Individual evidence
- ↑ Uwe Noldt: Insects . In: Johann Müller (Ed.): Wood protection in building construction . Fraunhofer IRB Verlag, Stuttgart 2005, ISBN 3-8167-6647-1 , p. 79
- ↑ a b Wolfram Scheiding, Peter Grabes, Tilo Haustein, Vera Haustein, Norbert Nieke, Harald Urban, Björn Weiß: Holzschutz. 2nd edition 2016, fv Fachbuchverlag Leipzig, ISBN 978-3-446-44844-5 , p. 113.
- ↑ Graphic: developing moisture
- ↑ see also Körting A. 1961: On the development and harmful activity of the longhorn beetle (Hylotrupes bajulus L.) in roof trusses of different ages. In: Schädlingskunde , 34/10, pp. 150–153 and recent investigations by the Federal Institute for Materials Testing.
- ↑ a b Dirk Lukowsky: Mechanisms of action of technical drying of construction timber as protection against the house buck (Hylotrupes bajulus) . Ed .: Proceedings of the German Wood Protection Conference 2016. S. 120-142 .
- ↑ The fight against wood-destroying insects - leaflet on the necessity, implementation and restrictions of treatment with gases ( Memento of July 31, 2007 in the Internet Archive )
- ^ A b Ivan Löbl, Ales Smetana: Catalog of Palaearctic Coleoptera. Vol. 6 Chrysomeloidea. Apollo Books, Stenstrup 2010. ISBN 978-87-88757-84-2 , p. 187.
- ^ Qiao Wang: Cerambycidae of the World: Biology and Pest Management. CRC Press, Boca Raton etc. 2017. ISBN 978 1 315313245 , p. 606.
- ^ John Bain (2009): Hylotrupes bajulus - setting the record straight. Forest Health News 196.
- ↑ Dirk Lukowsky (2017): The decline of the house longhorn beetle (Hylotrupes bajulus) in Europe and its possible causes. International Wood Product Journal 8 (3): 166-171. doi: 10.1080 / 20426445.2017.1338548
- ↑ Miguel A. Monné, Frank T. Hovore: Checklist of the Cerambycidae of the Western Hemisphere. 2005 version (updated through 01 January 2006)
- ^ Samuel Hubbard Scudder: Index to the Known Fossil Insects of the World, Including Myriapods and Arachnids. Bulletin of the United States Geological Survey no.71, Washington 1891. p. 542.
- ↑ Seunghyun Lee, Seunghwan Lee (2020): Multigene phylogeny uncovers oviposition-related evolutionary history of Cerambycinae (Coleoptera: Cerambycidae). Molecular Phylogenetics and Evolution 145: 106707. doi: 10.1016 / j.ympev.2019.106707
