Brown Spruce Longhorn Beetle

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French Common name: Longicorne brun de l'épinette
Scientific name: Tetropium fuscum (Fabricius)
Order: Coleoptera
Family: Cerambycidae

The Brown Spruce Longhorn Beetle (Tetropium fuscum (Fabricius); BSLB) is native to northern and central Europe, western Siberia and Japan (CFIA, 2016). BSLB was likely introduced to North America on ships transporting wood packaging from Europe, and it was first discovered in 1999 in Point Pleasant Park, Halifax, Nova Scotia. The beetle is now found in the provinces of Nova Scotia and New Brunswick (CFIA, 2016).

The BSLB attack healthy white, black, red, and Norway spruce trees in Canada (CFIA, 2016), but prefers and performs better in stressed, dying and wind fallen spruce (Flaherty et al. 2011, 2013 a,b). Mature, larger diameter spruce trees (>10cm dbh, diameter at breast height) are more commonly infested (Nelson et al. 2017). BSLB has the potential to spread throughout the range of spruce in Canada where it threatens spruce forests undergoing stress due to drought, defoliators, and wind damage, and could impact the wood products industry. Since 2000, the CFIA (Canadian Food Inspection Agency) has regulated the importation and movement of spruce wood products to limit the spread of BSLB from infested areas.

Figure 1. Adult BSLB. Jon Sweeney, Natural Resources Canada, Bugwood.org

Learn about the Brown Spruce Longhorn Beetle

The Insect

Physical Description

Eggs: white with a slight green tint in colour, oblong shape, 1 mm long, and are laid under bark scales of spruce trees (Figure 2a)

Larvae: white with a tint of yellow and a red to brown head, measures between 1-mm (newly hatched) and 28 mm (mature) (Figure 2b)

Pupae: white in colour and measures 10 – 17 mm long and 3.8 mm wide (Figure 2c)

Adult: brown to red in colour with a flat looking body, dark brown legs, antennae and head, reddish eyes, measures 0.8 - 1.8 cm (Figure 2d)

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