Conophthorus sp. (Scolytidae)

conebeetle


Eleven species in western North America.

Adults:

Adult Conophthorus sp. beetle. 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:

Saggital section through cone showing Conophthorus larva feeding. Legless, small, curved, wrinkled, ivory coloured grubs feed indiscriminately throughout the cone.



Damage:

Cone damage caused by Conophthorus sp. 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;

Fact sheet.

Additional Images:

Photo credit: Jon Sweeney Life Cycle Diagram
External symptoms of damaged cone, plus white grubs feeding in cone. Entry holes in young cones. Damage caused by feeding larvae. Emergence holes and deformity of attacked cone.