Dendroctonus pseudotsugae | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Infraorder: | Cucujiformia |
Family: | Curculionidae |
Genus: | Dendroctonus |
Species: | D. pseudotsugae |
Binomial name | |
Dendroctonus pseudotsugae Hopkins, 1905 | |
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
- 1 2 Furniss, Malcolm; Kegley, Sandra. "Forest Insect & Disease Leaflet 5" (PDF). USDA Forest Service. USDA Forest Service, Pacific Northwest Region (R6), Portland, Oregon. Retrieved 23 July 2016.
- 1 2 Dekker-Robertson, Donna; Griessmann, Peter; Baumgartner, Dave; Hanley, Don. Douglas-fir Beetle (Dendroctonus pseudotsugae). Washington State University and US Department of Agriculture. pp. 11–12.
External links
- http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5187396.pdf
- http://www.barkbeetles.org/douglasfir/dfb.html