Dendroctonus ponderosae (Scolytidae)

mountain pine beetle

Adults:

Dendroctonus ponderosae, the mountain pine beetle, adult. Rather stout, black cylindrical beetles 4 to 7.5 mm long. Antennae are small, elbowed and have a flattened club. The head is visible when viewed from above.


Larvae:

Dendroctonus ponderosae, larva. White, curved legless grubs with distinct head and mandibles. There are four larval instars.


Damage:

Galleries made in bark by Dendroctonus ponderosae. Adults attack living trees and construct egg galleries up to 90 cm long parallel to the grain of the wood in the cambial region. Larvae hatch and chew feeding galleries at right angles to the parent gallery, thus girdling the tree when attack density is high. A blue-staining fungi is introduced into the sapwood by the adult, further blocking translocating tissues. Attack is indicated by "pitch tubes" on the tree bole. Foliage turns red (forming characteristic red-tops) one year after attack. There is commonly a one year life cycle. Note also circular emergence holes without frass.


Principal Hosts:

Pinus contorta, P. ponderosa, P. lambertiana, P. monticola, and P. albicaulis are its principal hosts. Ten or more other species of pine are recorded hosts.

Economic Importance:

This insect is ranked as the most destructive of the bark beetles. In lodgepole pine, the MPB infests mature forests, often decimating them over extensive areas. In other host species, group killing on large scale occurs in both mature forests and in young, overstocked stands.

References and Links:

EAG: 491-498, 502-504; FC: 353.

For management information, see BC Forest Practices Code Bark Beetle Management Guidebook (1995).

For more general information, see HForest and JP17.

Bark Beetles in BC is the BC Ministry of Forests (provincial) bark beetle website, with updates on recent surveys.

Mountain Pine Beetle is the Canadian Forest Service (federal) mountain pine beetle website.

Beetle-Proofing Research in the East Kootenays was studied in a long-term programme to reduce the susceptibility of mature lodgepole pine stands.

Also, you may wish to check out the CLMA/NFPA Mountain Pine Beetle Emergency Task Force website.

Additional Images:

Pitch tube Mature gallery in bark and larger frass filled oviposition gallery, smaller side galleries made by larvae Bluestain in sapwood
MPB galleries in lodgepole pine bark Red crowns of MPB killed lodgepole pine in Nelson, 1981 MPB infested lodgepole pine forest in the Cariboo, 1984