Brown sapwood beetle
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Lyctus brunneus (brown sapwood beetle) |
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| Lyctus brunneus | ||||||||||||
| Stephens , 1830 |
The Brown Powder post beetle ( Lyctus brunneus ) is a kind from the family of borer (Bostrichidae). It comes from tropical regions and is often found in timber import warehouses. It is now one of the most important and most common dry wood destroyers and is widespread worldwide.
Appearance
The beetle is red-brown, dark-brown or yellow-brown in color, with the head usually being darker. It has a slim and rod-like shape and is 2.5 to 7 millimeters long. Characteristic is the head with two humps in front of the eyes and the antennae with clubs at the tip. The wing cover is very finely dotted, the pronotum trapezoidal.
The larvae are ivory in color, curved and have three pairs of legs. It is very similar to the larvae of the common rodent beetle . They reach a length of 6 millimeters. There is a large oval stigma at the end of the abdomen .
Occurrence and distribution
The brown sapwood beetle originally comes from Southeast Asia , but was abducted and distributed worldwide through the timber trade.
It was first spotted in Germany in the 1950s. It has been found in France, Belgium and England since the beginning of the 20th century. In Europe, it is most commonly found in Switzerland. With African imported wood or finished wood products and packaging wood, new imports occur regularly. The naturalization of the brown sapwood beetle was also promoted by its resistance to winter cold. Susceptible wood can be attacked by the brown sapwood beetle in any form, from raw and sawn wood to veneered parquet and plywood . The most common cases of damage are found in furniture, moldings, picture frames, door and window panels, wall and ceiling paneling, parquet wood and shop racks. The origin of the infestation can be at the location of the damage, with the importer, timber dealer or the processor. If the infestation occurs during processing of the wood, damages can be charged against the processor, as the infestation of the beetle is usually visible during the warranty period (according to VOB 4 years and BGB 5 years).
Living conditions and way of life
Expectations
The brown sapwood beetle ( Lyctus brunneus ), like the other species of the genus Lyctus , prefers hardwood in particular . In addition to tropical woods , native wood species such as oak ( Quercus ssp.), Ash ( Fraxinus excelsior ), walnut (Juglandaceae ssp.), Elm ( Ulmus ssp.) And sweet chestnut ( Castanea sativa ) are often attacked . It is mostly brought in with wood species that come from Africa, such as Abachi ( Triplochiton scleroxylon ), Limba ( Terminalia superba ) and Ilomba. Furthermore, the pest infestation occurs repeatedly in Germany on Afzelia ssp., Koto, Meranti ( Shorea ssp.), Ramin ( Gonystylus ssp.), Sipo ( Entandrophragma utile ), mahogany ( Swietenia ssp.), Rattan , bamboo tubes and root wood . The brown sapwood beetle is active at dusk. At a temperature of 26 to 27 ° C and a wood moisture content of 16%, the climatic optimum is achieved.
nutrition
A sufficient starch content is necessary for the infestation and a high protein content of the wood is an important prerequisite for larval development. Heartwood trees are characterized by a low starch content and thus only the sapwood is attacked. Conifers and beech trees are poor in strength and protein , so they are excluded from infestation.
development
The brown sapwood beetle is one of the dry wood insects. These are characterized by the fact that their larvae can develop at a wood moisture content of 7 to 16% and absorb the water when the starch is digested. For this reason, it is possible for them to damage dry wood for several generations and thus their damage exceeds that of the rodent beetle (Ptinidae). Before laying eggs, the female gnaws at the wood surface for nutrient content. Tropical woods such as abachi and limba are particularly strong . The eggs are then placed in cut-off vessels, old larval ducts, cracks or crevices in the hardwood. The female lays between 30 and 50 eggs and larval development usually takes 5-18 months. The larvae hatch after 1–2 weeks and pupate in 2 to 4 weeks. The larvae look like an angel and have a strongly arched chest, three pairs of legs and a large breathing opening on the second rearmost part of the body. The cream-colored larvae live directly below the tree bark and create irregularly shaped tunnels in the longitudinal direction of the wood fibers, which have a diameter of 0.9–1.7 millimeters. In addition, they leave behind a fine, powder-like meal, which often trickles out of holes and open vessels. The color of the meal and the edge of the passage is identical to the color of the healthy wood. When the brown sapwood beetle is fully grown, it bites its way through the bark and gets outside between June and August. Because the females are faithful to their location, the same wood is often attacked, so that several generations follow one another. In addition to tropical sawn timber, the damage can also occur to interior fittings of newer buildings made of corresponding timber, as well as to tropical souvenirs (including bast items, masks).
Infestation characteristics
On the processed wood, the infestation of the brown sapwood beetle can be seen from the cut feeding tunnels that are clogged with nails . If you scratch the nail, it turns out to be a fine talc-like powder, which was created when the beetles hatched. The feeding ducts running in the direction of the fibers have a diameter of 2 millimeters. Furthermore, the living beetles and larvae in the wood, as well as eating and knocking noises are criteria for determining an infestation. The infestation is usually not visible from the outside. After repeated infestation, the wood surface is paper-thin and the interior has now been converted into a powder-like mass. An active infestation can, however, also be simulated by the penetration of solitary bee larvae or storage pests into the feeding tunnels of the brown sapwood beetle and the ejection of the drill dust. Old wooden facades, barns and granaries can be affected by the deception.
Combat
Solvent-based protective agents
There are a few precautionary measures to review before fighting. It should u. a. no materials (cables, insulation materials, etc.) are damaged by the protective agent, contact with feed, food and farm animals should be avoided and the water should not come into contact with the protective agent during bridge work, as this could endanger the fish . Effective protective agents can be found in the LIGNUM directory. Wood vinegar products are ineffective for combating. In Switzerland, you must also ensure that the products are registered with the Federal Offices for Health (BAG) and the Environment (BUS) . The treatment can be carried out by painting or spraying, whereby the wood is painted two to three times with a soaked brush or sprayed onto the wood with an air pressure device or a hand pressure syringe. Further methods are borehole impregnation and injection with pressure equipment.
Hot air process
The environmentally friendly method has been used successfully to control house longhorns , brown sapwood beetles and rodent beetles for over 40 years . During the process, the wood up to and including the core is heated to at least 55 ° C with a special high-performance hot air machine for 5–12 hours at a room temperature of 80 to 120 ° C. The temperature is recorded in a measurement report every hour. In order to achieve preventive protection, a chemical protective agent should be applied to the cleaned wood using the hot air method. The advantages of the hot air process include: a. the active ingredient-free killing of the pests and the safety and cleanliness of the execution. The hot air process is ideal for combating pests in agricultural food operations and is also gentle on the substance.
Fumigation
The fumigation process is mainly used to treat objects of cultural history and rarely for furniture or sawn timber. A gas consisting of hydrogen cyanide and methyl bromide is used for the process . In a well-sealed room, the gas acts on the wood for one to three days. Due to the absorption and the release of the gas from the material, the room must then be well ventilated for three days. After proper treatment, no toxic substances are released from the wood, so the pests have been fought, but there is no preventive protection. In the case of paints with a high iron content, the hydrocyanic acid can cause a blue discoloration. Color changes can also be caused by methyl bromide in certain pigments, as well as a long-lasting odor nuisance in various leather and upholstery materials.
Economical meaning
The brown sapwood beetle is the most damaging dry wood destroyer and, from an economic point of view, is a serious problem, especially since it is now spread worldwide through the timber trade and is very adaptable. It is not uncommon to find it in wood import warehouses and reaches the end consumer via further processing. The infected timber import stores can become the cause of mass infestation, whereby large amounts of expensive and valuable wood are destroyed or can only be thermally utilized. The climate change with mild winters usually harms the native insects, but causes a long-term establishment of the warmth-loving brown sapwood beetles. Due to the discovery of a permanent free-range colony in the sub-Mediterranean Upper Rhine area, it is assumed that the Mediterranean region, which is even more strongly influenced by climate change, represents an even better prerequisite for spreading in the open. If the brown sapwood beetle makes the leap into the temperate terrain and nests in fresh dead wood, there is a potential danger for all openly stored valuable wood stocks in forest production areas, urban trade areas and wood exports. As a result, the forest and timber industries will be forced to draw conclusions.
Damage to the railway infrastructure can also occur. On December 17, 2015, it became known that 600 wooden railway sleepers in the Wehrhahn tunnel of the Düsseldorf Rheinbahn were destroyed by larvae of the brown sapwood beetle. These had to be replaced. In addition, all sleepers were treated with boron salts to prevent renewed infestation.
literature
- Hans Schmidt: Animal pests in timber and timber . Paul Parey Publishing House, Hamburg and Berlin 1962.
Individual evidence
- ↑ a b c d e Brown sapwood beetle (Lyctus brunneus). Retrieved January 10, 2014 .
- ↑ a b Sapwood beetle (Lyctidae). Retrieved January 11, 2014 .
- ↑ a b c d e f Brown sapwood beetle (Lyctus). Retrieved January 11, 2014 .
- ↑ a b c d e f g Lyctus brunneus (Steph.) - Brown sapwood beetle. Archived from the original on July 5, 2008 ; accessed on January 11, 2014 .
- ↑ a b c d Brown sapwood beetle (Lyctus brunneus). (No longer available online.) Archived from the original on February 23, 2016 ; accessed on February 23, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b Expensive life in the parquet. (PDF; 153 kB) Accessed February 23, 2016 .
- ↑ a b c d e f g Directive on wood-destroying insects and their control. (No longer available online.) Archived from the original on March 4, 2016 ; accessed on January 11, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b c Distribution and infestation characteristics of the brown sapwood beetle and other sapwood beetle genera. (No longer available online.) Formerly in the original ; accessed on January 11, 2014 . ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Damage characteristics of important animal wood destroyers. (No longer available online.) Archived from the original on March 2, 2013 ; accessed on January 11, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Sapwood beetle (Lyctus spp.). Retrieved January 12, 2014 .
- ↑ The hot air process - the physical alternative. Retrieved January 12, 2014 .
- ↑ Fight sapwood beetles. (No longer available online.) Archived from the original on November 29, 2013 ; accessed on January 12, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ A Neozoic sapwood beetle under the influence of global warming. Retrieved January 13, 2014 .
- ^ Rheinbahn: Pest infestation near sleepers , Eisenbahnjournal Zughalt.de, December 17, 2015, accessed on January 1, 2016
