Columbian timber beetle
Corthylus columbianus Hopkins (Coleoptera: Curculionidae, Scolytinae)
Orientation to pest
Columbian timber beetle, Corthylus columbianus Hopkins, is a native North American ambrosia beetle, one of a group of beetles that vector wood-destroying fungi, which the beetle larva then eats. Unlike most ambrosia beetles, Columbian timber beetles attack live trees rather than dead, dying, or newly felled trees. Trees, however, do not die, since trees are able to fill galleries with callus tissue. However, losses occur from lowered quality of timbers cut from infested trees, due to the presence of callus-filled galleries and fungal-stained wood.
Hosts commonly attacked
Columbian timber beetles attack a wide range of hardwoods, including various oaks (Quercus) and maples (Acer), sycamore (Platanus occidentalis L.), poplar (Populus), elm (Ulmus), beech (Fagus), and others.
Distribution
The Columbian timber beetle ranges in the United States from Massachusetts to Georgia, west to Michigan and Missouri.
Images of Columbian timber beetle
| Figure 1. Callow adult (left) and pupae of the Columbian timber beetle, Corthylus columbianus | Figure 2. Egg of Columbian timber beetle in chamber prepared by adult. Note the ambrosia fungus (Ambrosiella eylebori Brader) coating the chamber, which is inoculated into the gallery by the adult. | Figure 3. Galleries of Columbian timber beetle |
| Figure 4. Emergence holes and sap-soaked patches on trunk are signs of Columbian timber beetles | Figure 5. Milled maple timber shows the callus-filled galleries of Columbian timber beetle, and blue staining of associated ambrosia fungus |
Important biological control agents related to this pest species
Natural enemies of Columbian timber beetle have not been reported.
Web links for information on Columbian timber beetle
Articles
- Milne, D. H. and R. L. Giese. 1969. The Columbian timber beetle, Corthylus columbianus (Coleoptera: Scolytidae). IX. Population biology and gallery characteristics. Entomological News 80(9): 225-237.
