Prionus Root Borer
Prionus sp.
Coleoptera: Cerambycidae

Host plants visited by this beetle include pecan, oak, apple, cherry, dogwood, maple, pine, etc. (usually younger or weakened trees).

To identify, the adults are large (1 ½ to 2 inches long), robust, reddish brown to black with long antennae (up to length of their bodies). The larvae are creamy white or yellow with brown heads. Mature larvae may be as long as 4 inches. Adult beetles emerge from the soil in late spring and early summer and are often attracted to lights at night. Eggs are laid in the soil near the host trees. Mature larvae pupate in earthen cells 8 to 12 inches below the soil surface. The adults emerge from these cells and burrow to the soil surface. A single generation may take 3-5 years to complete.

The beetle usually attacks young trees or older trees that are noticeably weakened. There will be a gradual thinning and yellowing of foliage throughout the crown and gradual limb-by-limb mortality. The larvae chews away large patches of bark and feed on the inner tissue of roots.

Use BACK button to return to Index