Ergates spiculatus (Cerambycidae)

the timberworm


Adult Ergates spiculatus, the timberworm.

Pinned Ergates spiculatus specimen with elytra spread to show membranous hindwings used for flight.
Family characteristics + generic features of large size, slightly flattened, sides of thorax spiny.


Large grubs with very small thoracic legs and abdomen with ambulatory ampullae above and below. Largest borer in British Columbia (60-70 mm in length).


Grubholes made by Ergates spiculatus, packed with frass or with shredded wood. Large grubholes packed with frass or with shredded wood.

Principal Hosts:

Douglas-fir and ponderosa pine.

Economic Importance:

Larval mines speed deterioration and limit the amount of salvage from large burns.

References and Links:

EAG: 530-532; FC: 288-289.