. Protecting log cabins, rustic work, and unseasoned wood from injurious insects in the eastern United States. Forest insects; Wood Preservation. 10 FARMERS' BULLETIN 2104 ers push it out through the en- trance hole (fig. 12). The compo- sition of these borings varies from fine, white, and powdery ma- terial to coarse, brownish par- ticles (fig. 12) or shreds of wood fiber (fig. 13). These characters, combined with the different patterns made while scoring the wood under the bark, the size and shape of the gallery in the wood, the color of the borings, and the species of wood attacked, make it
. Protecting log cabins, rustic work, and unseasoned wood from injurious insects in the eastern United States. Forest insects; Wood Preservation. 10 FARMERS' BULLETIN 2104 ers push it out through the en- trance hole (fig. 12). The compo- sition of these borings varies from fine, white, and powdery ma- terial to coarse, brownish par- ticles (fig. 12) or shreds of wood fiber (fig. 13). These characters, combined with the different patterns made while scoring the wood under the bark, the size and shape of the gallery in the wood, the color of the borings, and the species of wood attacked, make it possible to determine the type of injury, and usually, the identity of the species of insect responsible for the damage. The mature larva transforms into a pupa and then into an adult beetle. When emerg- ing through the surface of the wood or bark, the beetle makes either a round or an oval hole, depending on the species of insect. Flatheaded Borers The beetles of the group known as flatheaded borers are more uni- form in general appearance than are those of the roundheaded borers. They are slightly flat- tened, metallic-colored, boat- shaped beetles, ranging in length from 14 inch to nearly l1/^ inches (fig. 14). The eggs are laid singly or in a mass on the bark or in crevices in the bark or wood. The larva is a slender, flatheaded grub having conspicuously widened segments next to the head (fig. 15). The young borer mines the inner bark or wood, making a flattened, oval, more or less tortuous mine or wormhole which, when completed, widens into a large pupal or rest- ing cell. This cell connects with the outer surface by a short, oval exit hole through which the new beetle emerges. The larval mines may be in either the bark or the wood alone, or as do many, may. F-480491 Figure 14.—Adult beetle of a flatheaded borer {Chrysobothris octocola (Lec.)). extend throughout the entire piece and will be filled with tightly packed sawdust-like ma- terial (fig. 16). Seasonal Activity
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Keywords: ., bookcentury1900, booksubjectforesti, booksubjectwoodpreservation
