Callidiellum
Callidiellum
*Callidiellum* Linsley, 1940 is a small genus of longhorn beetles (Cerambycinae) native to East Asia, now recognised as an invasive pest in parts of Europe and North America. Commonly known as the Cedar Longhorn, its species feed exclusively on Cupressaceae — including ornamental thujas, junipers, and cypresses — making them a notable quarantine concern for horticulture and urban forestry. Adults are typically reddish, elongate-cylindrical beetles between 8 and 18 mm, active from April through July. Their ability to establish in planted conifer stands outside the native range has prompted EPPO regulatory attention.
Seasonal activity
Flight season: Spring–Summer
Green = active months · Orange = peak
Host plants
Primary hosts: wood
External resources
Field tip: On dead wood or under bark. Hosts: Thuja/Chamaecyparis. Invasive — report any find!