Western pine bark beetle
| Western pine bark beetle | ||||||||||||
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Western pine bark beetle ( Pityokteines spinidens ) |
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| Pityocteines spinidens | ||||||||||||
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The Western fir bark beetle ( Pityokteines spinidens ), also silver fir bark beetle called, is a species of beetle from the genus Pityokteines in the family of weevils (Curculionidae).
description
Adult male beetles are 2 to 3 millimeters long, while female beetles are 2 to 2.6 millimeters long. The body is cylindrical in shape and colored brown. On the abdomen there are hairs which are twice as long in the female as on the front body. There are three teeth on the fall of the Elytres .
Similar Art
Both the beetle and the feeding pattern resemble that of the crooked pine bark beetle ( Pityokteines curvidens ) with which the species is often associated.
distribution
The western pine bark beetle occurs in Europe wherever its host trees can be found.
Way of life
The first overwintered beetles can be seen from April. As host trees, mainly fir species , especially the silver fir ( Abies alba ), as well as cedars ( Cedrus ) and larches ( Larix ), and less often spruce ( Picea ), are infested in tree wood age. Infested trees can be recognized by their bark peeling, crown discoloration and woodpecker activity. The species has little tendency to mass reproduce.
Reproduction
Two generations are trained per year in the lower areas. Occasionally sibling broods occur. The females first dig a small ramming chamber in the bark. From this, 4 to 10 centimeters long, arched star corridors extend from which the sapwood can graze. The interference is tight. The larval ducts are short and inclined or perpendicular to the grain of the bark. The dolls' cradles are only laid out in the sapwood.
Harmful effect
The western fir-bark beetle causes less economic damage than the crooked-toothed fir-bark beetle. In infested trees, the bark will peel off and the crown will discolour.
Combat
For a successful control it is necessary that infected trees are recognized early and used or debarked. If the animals are already pupated, debarking is no longer useful, as the pupae can also develop in the debarked wood.
swell
Individual evidence
- ↑ a b c d e f Entry at wsl.ch
- ↑ a b entry at forestpests.org
- ↑ Bark-breeding beetles on silver fir in information sheet for practice , p. 7 ( 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. (PDF; 2.1 MB)
