Bug FAQSpined Woodborer
Trichocnemis spiculatus · Order: Coleoptera · Family: Cerambycidae
Also called: Long-horned beetle, Ponderous Borer, Western Pine Sawyer Beetle
The spined woodborer is the biggest wood-boring beetle found in Colorado. Its larvae develop inside fallen ponderosa pine and Douglas fir logs, feeding on the wood of dead or dying trees. The species lives in western North America and its life cycle can take several years to complete.
Source: Wikipedia
Size
It is the largest wood-boring beetle species recorded in Colorado.
Source: Wikipedia
Where it lives
The beetle develops on fallen ponderosa pine and Douglas fir trees.
Source: Wikipedia
What it eats
Larvae eat the wood of dead or dying pines, especially ponderosa pine and Douglas fir.
Source: Wikipedia
Life cycle
The life cycle of the spined woodborer spans several years.
Source: Wikipedia
Where it comes from
Its native range is in western North America.
Source: Wikipedia
Lookalikes
A taxonomic synonym for this species is Ergates spiculatus.
Source: Wikipedia
Where it is found in the US
Recorded in 14 of 51 states and DC. Most records: California, Oregon, Washington, Arizona, Idaho, Colorado, New Mexico, Montana.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Cerambycidae)
House LonghornHylotrupes bajulusCan damage your home
Asian Longhorned BeetleAnoplophora glabripennisDamages trees, gardens or crops
Red Milkweed BeetleTetraopes tetrophthalmus
White-spotted SawyerMonochamus scutellatusCan damage your home
Red Pine Longhorn BeetleStictoleptura rubra
Spotted Longhorn BeetleRutpela maculataDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Trichocnemis_spiculatus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.