Bug FAQBlackspotted Longhorn Beetle
Rhagium mordax · Order: Coleoptera · Family: Cerambycidae
Source: Wikipedia
The Blackspotted Longhorn Beetle measures between 13 and 26 mm in length. Adults are ochre-black with a single black spot on each wing cover and have small yellow hairs plus two hair-free spots on the elytra. It occurs across Europe and extends into Kazakhstan and Russia.
Source: Wikipedia
How to recognize it
Their bodies have fine yellow hairs and two bald spots on the wing covers.
Source: Wikipedia
Size
They grow to a length of 13 to 26 mm (0.5 to 1.0 in).
Source: Wikipedia
Where it lives
The beetle is found throughout Europe and into Kazakhstan and Russia.
Source: Wikipedia
Life cycle
The ichneumonid wasp Ischnoceros rusticus parasitises the beetle’s larvae.
Source: Wikipedia
Where it comes from
Its native range covers Europe, Kazakhstan and Russia.
Source: Wikipedia
Where it is found in the US
Recorded in 1 of 51 states and DC. Most records: Alaska.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
More photos
Questions people ask
How large does the Blackspotted Longhorn Beetle get?
Adults range from 13 to 26 mm long.
Source: Wikipedia
Where can I find this beetle?
It occurs across Europe and into Kazakhstan and Russia.
Source: Wikipedia
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/Rhagium_mordax
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.