Great birch sapwood beetle
| Great birch sapwood beetle | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Great birch sapwood beetle ( Scolytus ratzeburgii ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Scolytus ratzeburgii | ||||||||||||
| Janson , 1856 |
The great birch sapwood beetle ( Scolytus ratzeburgii ) is a weevil from the subfamily of the bark beetle (Scolytinae). Since it creates its breeding systems in the bark of the host trees, it is counted among the bark breeders.
features
The beetles are five to seven millimeters long and have a cylindrical, shiny black body. The wing top seam runs parallel to the end. The elytra are reddish and structured with coarse and fine rows of dots. The rails ( tibia ) of the forelegs are smooth on the outside and end in a hook tooth. The neck shield covers the head seen from above not. The forehead has a weak short keel in the male and a strong longitudinal keel in the female. The belly rises diagonally from the second sternite towards the end. The second sternite has no spinous process, but is smooth, the third has a large, button-shaped cusp in the middle of the male.
distribution
The species is distributed in Central and Northern Europe , Northern Italy , Eastern Europe , Russia and Mongolia , and east to Japan .
Way of life
The great birch sapwood beetle lives mainly on birches , whereby the sand birch ( Betula pendula ) is preferred. The species populates the bog birch ( Betula pubescens ) and Ulmus laciniata more rarely . Old, ailing birch trees are preferred. The feeding pattern can be recognized immediately from the outside by the numerous mating holes or air holes, which usually run in a row vertically, more rarely horizontally or diagonally on the trunk. Depending on the size of the animals, they usually have a diameter between two and three millimeters. The mother duct usually begins with a hook-shaped curve and is a single-armed longitudinal duct up to ten centimeters long. Larval ducts arise close to each other and often bend up and down at the beginning or end of the mother duct, mostly 50 to 60 pieces.
The great birch sapwood beetle forms one generation per year that flies from June to July.
literature
- Fritz Schwerdtfeger : The forest diseases. Textbook of forest pathology and forest protection . 4th, revised edition. Parey, Hamburg and Berlin 1981, ISBN 3-490-09116-7
- Sabine Green : Manual for the determination of the European bark beetle Verlag M. & H. Schaper, Hanover 1979, ISBN 3-7944-0103-4
- Edmund Reitter : Fauna Germanica - The beetles of the German Empire. Volume 5, KG Lutz, Stuttgart 1916
- Edmund Reitter: Fauna Germanica - The beetles of the German Empire. 5 volumes, Stuttgart KG Lutz 1908 - 1916, digital library volume 134, Directmedia Publishing GmbH, Berlin 2006, ISBN 3-89853-534-7
