Megasemum
Megasemum
*Megasemum* [auct., verify] is a small genus of spondylidine longhorn beetles characteristic of boreal and montane conifer forests across the eastern Palaearctic region, from Siberia through northeastern China to Japan. Adults are dark, cylindrical beetles ranging from 15 to 30 mm, associated with dead or dying Pinaceae — principally *Picea*, *Abies*, and *Larix*. Largely nocturnal, adults are most active from May to August and are attracted to conifer bark volatiles and smoke, which betray their affinity for recently stressed or burned trees. Larvae develop slowly over two to four years, beginning beneath the bark before boring deep into the sapwood.
Seasonal activity
Flight season: Summer–Autumn
Green = active months · Orange = peak
Host plants
Primary hosts: pine
External resources
Field tip: Under conifer bark or on trunks. Boreal species — northern/montane forests.