Exotic beetle on the move but is it a symptom or a cause of red spruce decline?

Brown spruce longhorn beetle. Source: CFIA
Male Brown Spruce Longhorn Beetle (Source:  Canadian Food Inspection Agency)
The exotic brown spruce longhorn beetle (BSLB) was reported in Kouchibouguac Park, New Brunswick. in Aug 2011, the first report for a site outside of N.S. It was first discovered in Canada in Point Pleasant Park (Halifax, Nova Scotia) in 1999. An article by entomologist Chris Majka in the current (Jan/Feb) issue of Rural Delivery provides a good overview of the spread of BSLB and related issues. Majka says that in N.S., BSLB attacks only red spruce but only trees that are unhealthy to begin with. He asks why the Canadian Food Inspection Agency (CFIA) has still not commissioned the "relatively simple and inexpensive trials" required to answer the question of whether BSLB beetle inflicts any more damage than native wood and bark boring insects. If it doesn't, then the extraordinary regulations the CFIA has imposed in (unsuccessful) efforts to restrict its movement, beginning with the pre-Hurricane Juan efforts in Point Pleasant Park, are not justified. There is evidence for declines in the health of red spruce associated with unusual climatic variations, unfortunately of a sort that is predicted to continue with climatic warming. Thus the BSLB may be a symptom, rather than a cause of deterioration in the health of red spruce. But why not do the science to find out?

Posted by David P. (JackPine) at versicolor.ca, 7 Feb. 2012