Spruce beetle of the bark beetle subfamily is native to North America, covering Alaska, Arizona, Maine, Wyoming, Saskatchewan, Quebec, Ontario, and Northern Manitoba. They are known to be a serious pest of several spruce tree varieties, which has resulted in their name.
Size: 4 – 7 mm
Color: The adult beetles have a reddish-brown or black body.
Other Characteristic Features: They are stout with a hard, cylindrical body.
The creamy white larva varies in size, being about 6 mm long when fully developed. The larva, like the adults, is also cylindrical without any legs.
Like the larva, the pupa is also creamy white, with some of its features closely replicating an adult spruce beetle. They remain enclosed within the larval galleries made within the inner bark of the host plants.
The eggs are 1.5 mm long, replicating tiny pearls. The female lays eggs in groups of three or four in the galleries.
| Adult Lifespan | About 2 weeks |
| Distribution | Different parts of North America including Alaska, Arizona, Colorado, Saskatchewan, Maine, Montana, Wyoming, Yukon, Quebec, Ontario, Northern Manitoba, Novas Scotia, British Columbia |
| Habitat | Mostly in spruce forests throughout North America |
| Common Predators | Woodpeckers |
| Seasons active from | May – July |
| Host Plants | Different spruce trees like Colorado blue spruce, Sitka, Engelmann |
| Diet of larvae and adults | Bark and wood |
The beetles mostly infest stumps and logs that have been freshly cut but may even attack standing trees. As the adults bore into the barks for making the egg galleries, they do a lot of harm to the tree. A few of the common signs of infestation include the needles of the spruce tree turning from green to a pale yellow and the formation of red globule-like pitch tubes near the beetle attack spots. Woodpeckers, known to be common predators of these beetles, scrape the bark upon sensing its existence nearby, so that is another warning sign, signaling its presence. Constant attacks also cause the barks to loosen and finally fall off.
Removing infested trees, spraying insecticides, and setting traps are some of the preventive measures.
Image Source: forestpests.org, blogs.agu.org, images.glaciermedia.ca, bugguide.net, fs.usda.gov
Spruce beetle of the bark beetle subfamily is native to North America, covering Alaska, Arizona, Maine, Wyoming, Saskatchewan, Quebec, Ontario, and Northern Manitoba. They are known to be a serious pest of several spruce tree varieties, which has resulted in their name.
Size: 4 – 7 mm
Color: The adult beetles have a reddish-brown or black body.
Other Characteristic Features: They are stout with a hard, cylindrical body.
The creamy white larva varies in size, being about 6 mm long when fully developed. The larva, like the adults, is also cylindrical without any legs.
Like the larva, the pupa is also creamy white, with some of its features closely replicating an adult spruce beetle. They remain enclosed within the larval galleries made within the inner bark of the host plants.
The eggs are 1.5 mm long, replicating tiny pearls. The female lays eggs in groups of three or four in the galleries.
| Adult Lifespan | About 2 weeks |
| Distribution | Different parts of North America including Alaska, Arizona, Colorado, Saskatchewan, Maine, Montana, Wyoming, Yukon, Quebec, Ontario, Northern Manitoba, Novas Scotia, British Columbia |
| Habitat | Mostly in spruce forests throughout North America |
| Common Predators | Woodpeckers |
| Seasons active from | May – July |
| Host Plants | Different spruce trees like Colorado blue spruce, Sitka, Engelmann |
| Diet of larvae and adults | Bark and wood |
The beetles mostly infest stumps and logs that have been freshly cut but may even attack standing trees. As the adults bore into the barks for making the egg galleries, they do a lot of harm to the tree. A few of the common signs of infestation include the needles of the spruce tree turning from green to a pale yellow and the formation of red globule-like pitch tubes near the beetle attack spots. Woodpeckers, known to be common predators of these beetles, scrape the bark upon sensing its existence nearby, so that is another warning sign, signaling its presence. Constant attacks also cause the barks to loosen and finally fall off.
Removing infested trees, spraying insecticides, and setting traps are some of the preventive measures.
Image Source: forestpests.org, blogs.agu.org, images.glaciermedia.ca, bugguide.net, fs.usda.gov
