Tetropium fuscum F.
A longhorned beetle new to the western hemisphere attacking trees in Nova Scotia
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Name: Tetropium fuscum F.
Animalia: Arthropoda: Insecta: Coleoptera: Cerambycidae
Common Names: brown spruce longhorn beetle; BSLB
This new pest to the western hemisphere is considered a decomposer in its native range, but is apparently attacking healthy trees in this infestation.
Issues of Concern:
BSLB has been found in Halifax, Nova Scotia. The highest populations are found in Point Pleasant Park, where approximately 5000 trees are infested. Other infested trees are all within a 15km radius of the park. This park is adjacent to a large maritime port, which is suspected to be the point of introduction.
Currently, BSLB is attacking healthy trees and appears to be reinfesting the same trees each year instead of dispersing to new trees. This behavior may increase the chances of successful eradication.
When longhorned beetles reach outbreak levels, they have the potential to persist for a decade and continually cause damage over extensive tracts of vulnerable conifer forests.
BSLB is acting as a primary pest of trees in Canada, but is considered a secondary pest in its native range (see distribution). There is concern that this type of adaptive behavior, i.e. increased "pestiness" demonstrated by introduced species, is becoming more common. No effective treatment is available for infected trees; cutting, chipping and incineration is the best current option.
Hosts: spruce (Picea); fir; pine (Pinus); larch; occasionally hardwoods
Throughout Europe; Japan; new to Halifax, Nova Scotia
Symptoms observed in attacked trees include streams of resin scattered along the trunk, holes in the bark (approx. 4 mm diam.), and networks of feeding tunnels under the bark (up to 6 mm diam.). Tunnels in the wood appear L-shaped when cut in cross section, and may be 6 mm wide and 4 cm deep. Coarse sawdust may be found in and around tunnels or plugging the entrance/exit holes. BSLB seems to prefer large trees greater than 10 cm DBH.
Point Pleasant Park is in close proximity to the Port of Halifax, suggesting introduction through dunnage.
Source: Canadian Food Inspection Agency (CFIA)
Smith, G., and J.E. Hurley. 2000. First North American record of the Palearctic species Tetropium fuscum (Fabricius) (Coleoptera: Cerambycidae). Coleopt. Bull. 54: 540.
Longhorn Beetles of the Western Palearctic Region Website Posting
CFIA Website Information
Natural Resources Canada Website
Halifax Regional Municipality News Release