Английская Википедия:Dendroctonus pseudotsugae
Шаблон:Short description Шаблон:Speciesbox
Dendroctonus pseudotsugae, the Douglas-fir beetle, is a species of bark beetle found in western North America. Three subspecies exist that correspond to the subspecies of Douglas-fir. The beetles also infest downed Larch trees.[1] Outbreaks often occur in conjunction with drought, root rot diseases, overcrowding, damage by insects that damage foliage, and environmental disturbance. This insect is part of the western forest ecosystem, playing a role in thinning weak trees in a stand.[2]
Adult Douglas-fir beetles are light brown when young and become dark brown or black with reddish wing covers. They are somewhat hairy and range in size from 4.4 to 7 mm. The larvae are small, legless, the size of grains of rice, and white. Pupae are white to cream colored. Visible evidence of infestation includes patches of orange to reddish-brown boring dust in the bark or at the base of the tree. Resin streamers from attacks higher in the tree may also be present. Inside the bark, 6 to 30 inch egg galleries run parallel with the grain. Eggs are laid on either side of the gallery and when they hatch, the larvae mine perpendicular to the galleries.[1][2]
References
External links
- http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5187396.pdf
- http://www.barkbeetles.org/douglasfir/dfb.html
