Cherry bark beetle
| Cherry bark beetle | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Cherry bark beetle ( Polygraphus grandiclava ), left and middle female, right male. |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Polygraphus grandiclava | ||||||||||||
| ( Thomson , 1886) |
The cherry bark beetle ( Polygraphus grandiclava ) is a weevils 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 2.5 to three millimeters long and have a black-brown body. The head is visible from above, the pronotum is constricted at the front and not broadly indented at the front edge. It's dotted, matte, and has a keel-shaped center line. The basal edge of the wing covers has a low tooth crest, is slightly curved and barely interrupted in the middle by the shield . There are no rows of grains in the spaces between the rows of dots. The body is covered with close, short and light-colored scales. The front rails are serrated on the outside. The first and fifth sternite are the same length and larger than the second to fourth. The flattened, large and egg-shaped antenna lobe , bluntly rounded at the end, has no seams, the antennae flagella is six-membered. The eyes are divided into two parts. The third foot member is cylindrical in shape. The antennae and tarsi are yellowish in color, while the legs are brown to black.
The male has two humps on the domed, short haired forehead, the female, on the other hand, wears a fine, short ring of hair on the rather flat forehead ( sexual dimorphism ).
distribution
The species is widespread in Central , Northern and Western Europe as well as in Poland and as far as southern European Russia .
Way of life
Polygraphus grandiclava occurs and cherry trees ( Cerasus ) and Swiss stone pine ( Pinus cembra ), less often on Norway spruce ( Picea abies ) and pines ( Pinus ). The colonization of deciduous and coniferous trees is unusual for bark beetles and represents a special feature. So far, no genetic differences have been found between individuals caught from cherry trees or from Swiss stone pines. The animals colonize the bark of the trees and live polygamously . The corridors of the brood pattern are located in the bark and also intervene in the sapwood of the trees. The almost horizontal larval ducts and the vertical mother ducts can be seen on the inside of the bark . One generation is trained every year.
Harmful effect
The beetle can contribute to the death of the trees or parts of the crown in orchards, especially in old cherry trees. However, this is rarely associated with real economic damage, so that control is not necessary.
Pieces of bark often fall off due to woodpecker work , where the feeding pattern is clearly visible. Otherwise, the boreholes with a diameter of 1.5 millimeters indicate an infestation.
Systematics
Synonyms
The following synonyms are known from the literature for Polygraphus grandiclava :
- Polygraphus grandiclava Thomson, 1886
- Pseudopolygraphus cembrae Seitner, 1911
swell
Individual evidence
- ^ Polygraphus grandiclava (Thomson, 1886). Fauna Europaea, Version 1.3, April 19, 2007 , accessed on October 10, 2008 .
literature
- Sabine Grüne : Handbook for the determination of the European bark beetles . M. & H. Schaper Verlag, Hannover 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
