Ponderous Borers can be found in forested areas of Douglas fir and ponderosa pine (their principle hosts) throughout the Rocky Mountain region. Females lay eggs in cracks of suitable logs or stumps from trees that have recently been felled or killed by fire. They do not attack live trees. The larval stage typically takes 3 to 5 years until pupation and the emergence of the adults that garner so much attention. And at up to 3.5 inches in length, that attention is well deserved. Interesting fact—the mature larvae have gnawing jaws that inspired the invention of the chainsaw.

Size: Up to 3.5 inches in length

Photo by: Glenn Marangelo on 6/21/22 in Missoula, MT