Megasemum asperum, a Cerambycid Beetle
Here is a new-to-me Cerambycid (longhorn) beetle. I haven’t added one of these to my photo collection in the 15 years I’ve lived on San Juan Island, so note here that they are “UNCOMMON” and not populous in number.
This species is the only one in its genus in North America. It is Megasemum asperum. I see in perusing iNaturalist.org that there have been 67 reported observations dating back to 2007.
Location: San Juan Island, WA
ID: Megasemum asperum
From Bugguide.net –
Size: 18-25mm
Season: July to August (this is when you could see an adult)
Numbers: a single species in the New World & in NE Asia
It was described by John Lawrence LeConte in 1854
From Beetles of Western North America – “Larvae mine Douglas-fir (Pseudotsuga menziesii) and fir (Abies). Adults are attracted to lights during the summer. Found in coniferous forests of western North America,” (Dr. Art Evans, entomologist, 2021).
Your take away message – NOT a pest. NOT a tree killer. NATIVE species! Performs important recycling of nutrients role in ecosystems allowing regeneration in our forests. Appreciate Biodiversity.
Thanks for reading!
Bugging You From San Juan Island 