White-spotted sawyer beetle of the longhorn beetle family is a wood-boring species indigenous to different parts of North America. The white spots on the wings of both males and females earn them their name.
Size: 20 – 25 mm (0.78 – 0.98 inches)
Color: They have a metallic black body, withwhite spots near the base of their elytra.
Other Characteristic Features: The antennae in males are twice the length of their body, while it is comparatively shorter in females. In both the sexes, a spine is seen to the col3 of their prothorax.
Their body and head are creamy-white and reddish-brown. A full-grown larva reaches 40 – 50 mm (1.57 -1.96 inches), burrowing in the cambium and phloem upon hatching, remaining there till they pupate.
The pupae reach a length of 20 – 25 mm (0.78 – 0.98 inches), initially pale white, later turning to reddish-brown. Their legs, mouthparts, wings, and antennae are incomplete then. The appendages, too, are less prominent, eventually developing as they mature. Upon complete development, the pupae harden and become darker. The pupation stage lasts for a week, and the adults emerge from the tunnel chewing through the barks.
The elongated white eggs appear cylindrical and a little flattened, rounded towards the ends. They grow to about 3mm (0.11 inches).
| Other Names | Spruce bug, spruce sawyer |
| Adult lifespan | A few weeks |
| Duration of larval stage | 2 – 3 years |
| Distribution | Throughout North America |
| Habitat | Pine and spruce forests |
| Common Predators | Birds, and bats |
| Seasons active from | May – early September |
| Host Plants | Black spruce, white spruce, balsam fir, jack pine |
| Diet of larvae and adults | Larvae: Tissues of damaged or diseased coniferous species Adults: Soft bark of the young conifer branches |
While feeding on the bark of the twig’s undercol3s, the adults go on to damage the tips, making them turn red and die eventually. The larvae chew the woods and even bore holes in them to make galleries. Those created by the younger larvae on the tree’s outer bark are removable in the sawmills. However, the matured ones do more damage as they make deeper U-shaped tunnels in the wood, which is visible when the lumber is longitudinally cut. It is challenging to eliminate these galleries upon sawing the wood in the mills. Their presence makes way for fungal accumulation giving the wood a bluish tinge and reducing its value. One could find several wood chips near their tunneling spots, mostly close to the trees’ base.
Image Source: lh3.googleusercontent.com, bugguide.net, tidcf.nrcan.gc.ca, lh3.ggpht.com
White-spotted sawyer beetle of the longhorn beetle family is a wood-boring species indigenous to different parts of North America. The white spots on the wings of both males and females earn them their name.
Size: 20 – 25 mm (0.78 – 0.98 inches)
Color: They have a metallic black body, withwhite spots near the base of their elytra.
Other Characteristic Features: The antennae in males are twice the length of their body, while it is comparatively shorter in females. In both the sexes, a spine is seen to the col3 of their prothorax.
Their body and head are creamy-white and reddish-brown. A full-grown larva reaches 40 – 50 mm (1.57 -1.96 inches), burrowing in the cambium and phloem upon hatching, remaining there till they pupate.
The pupae reach a length of 20 – 25 mm (0.78 – 0.98 inches), initially pale white, later turning to reddish-brown. Their legs, mouthparts, wings, and antennae are incomplete then. The appendages, too, are less prominent, eventually developing as they mature. Upon complete development, the pupae harden and become darker. The pupation stage lasts for a week, and the adults emerge from the tunnel chewing through the barks.
The elongated white eggs appear cylindrical and a little flattened, rounded towards the ends. They grow to about 3mm (0.11 inches).
| Other Names | Spruce bug, spruce sawyer |
| Adult lifespan | A few weeks |
| Duration of larval stage | 2 – 3 years |
| Distribution | Throughout North America |
| Habitat | Pine and spruce forests |
| Common Predators | Birds, and bats |
| Seasons active from | May – early September |
| Host Plants | Black spruce, white spruce, balsam fir, jack pine |
| Diet of larvae and adults | Larvae: Tissues of damaged or diseased coniferous species Adults: Soft bark of the young conifer branches |
While feeding on the bark of the twig’s undercol3s, the adults go on to damage the tips, making them turn red and die eventually. The larvae chew the woods and even bore holes in them to make galleries. Those created by the younger larvae on the tree’s outer bark are removable in the sawmills. However, the matured ones do more damage as they make deeper U-shaped tunnels in the wood, which is visible when the lumber is longitudinally cut. It is challenging to eliminate these galleries upon sawing the wood in the mills. Their presence makes way for fungal accumulation giving the wood a bluish tinge and reducing its value. One could find several wood chips near their tunneling spots, mostly close to the trees’ base.
Image Source: lh3.googleusercontent.com, bugguide.net, tidcf.nrcan.gc.ca, lh3.ggpht.com
