Pit wood beetle
| Pit wood beetle | ||||||||||||
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Pit wood beetle ( Hexartrum exiguum ) ♂, museum specimen from the collection of the Cologne Zoo |
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| Scientific name | ||||||||||||
| Hexarthrum exiguum | ||||||||||||
| ( Boheman , 1838) |
The mining timber beetle ( Hexarthrum exiguum , Syn. : Rhyncolus culinaris ) is a weevil (Curculionidae) of the subfamily of Faulholzrüssler (Cossoninae) who live in rotten wood. The beetle is considered a secondary wood pest, the larvae of which destroy the sapwood area of construction timber that has already been attacked by fungi, especially in mines.
features
The pit wood beetle is a red-brown and 2.8-3.4 mm long, typical representative of the weevil . It has the head shape characteristic of the family with a trunk-shaped extension. The proboscis in the male is conical and slightly longer than wide at the base. In the female it is 1.5 times as long as it is wide, narrower and longer than in the male and of rectangular shape. The trunk is finely dotted, the points are connected to one another in a longitudinally wrinkled manner. The antennae sit on the side of the trunk and bend almost at right angles to the front. The eyes do not protrude from the head. The shiny pronotum is not shagreened or is only indistinctly shagreen, which means that it has no grain pattern. The wing covers have parallel edges and, as in all species of the genus, have strong point stripes and teeth on the rear edges.
The male's aedeagus is elongated, trough-like and strongly curved. Its tip is cut off at an angle. The upper sides of the aedeagus are bulged in the middle; the only feature that definitely distinguishes the pit wood beetle from the sometimes very similar Hexarthrum capitulum . The latter has an aedeagus with straight tops.
Occurrence and way of life
The pit wood beetle occurs in southern and central Europe, but is rapidly becoming rarer in the north and is already completely absent in north-western Germany. Its diet consists of conifers and hardwoods, which are exposed to high levels of moisture and often already fungal damage. In Italy it was found in horse chestnuts and European hackberry trees . It is important for wood protection because its larvae can attack spruce pistils in mines, but also construction timber in buildings. The larvae develop particularly well at a temperature of around 23 ° C, and the species occurs all year round. Recently an occurrence in Turkey was described.
literature
- Heinz Joy , Karl Wilhelm Harde , Gustav Adolf Lohse : The beetles of Central Europe. Volume 11: Curculionidae II. Spektrum Verlag, Heidelberg / Berlin 1999. ISBN 978-3-8274-0685-9 .
Web links
- DHBV: Pit wood beetle (PDF; 161 kB)
- H. Huseyin Cebeci, Klaus Hellrig, Paul F. Whitehead: First Record of the Pit-Prop Beetle Hexarthrum exiguum (Coleoptera: Curculionidae) in Turkey. In: Florida Entomologist 94 (3): 404-406. 2011, doi : 10.1653 / 024.094.0304
Individual evidence
- ↑ German Wood and Building Protection Association: Pit wood beetle. On: www.dhbv.de. ( Memento of the original from April 20, 2015 in the Internet Archive ) 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. (PDF; 161 kB)
