Conophthorus sp. (Scolytidae)

conebeetle

Eleven species in western North America.

Adults:

Small shiny black beetle with barkbeetle features. Adult is one of the injurious stages. Adults often burrow along axis of cone. Females lay eggs.

Larvae:

Legless, small, curved, wrinkled, ivory coloured grubs feed indiscriminately throughout the cone.

Damage:

Adult beetle bores into an immature second year cone in pines. Usually each cone is attacked by one pair of beetles, boring into the stalk of the cone and tunnelling into the axis. The female lays its eggs in the tunnel, which now becomes an egg gallery, then vacates the cone, plugging the entrance hole with frass. Larvae are present July-August, pupate and transform into adults which remain in the cone until the following spring. The attack kills the cone and destroys all potential seeds. Damaged cones drop to the ground in early summer.

Principal Hosts:

Sugar pine, ponderosa pine, and western white pine.

Economic Importance:

Periodic outbreaks may destroy 25-75% of a cone crop over large acreages.

References and Links:

EAG: 547; FC: 375.

Additional Images:

	Life Cycle Diagram