Forest Invasive Alien Species
www.exoticpests.gc.ca
Established Insects
- Ambermarked birch leafminer
- Balsam woolly adelgid
- Beech scale
- Birch casebearer
- Birch leafminer
- Black stem borer
- Common pine shoot beetle
- Eastern spruce gall adelgid
- Elm leaf beetle
- European pine sawfly
- European pine shoot moth
- European pineneedle midge
- European spruce sawfly
- Gypsy moth
- Introduced pine sawfly
- Larch casebearer
- Larch sawfly
- Lombardy leafminer
- Mountain ash sawfly
- Pear thrips
- Rusty tussock moth
- Smaller European elm bark beetle
- Winter moth
European spruce sawfly
Position of eggs on needles
Mature larva (length: 20 mm)
Cocoon (length: 10 mm)
Female laying eggs on a white spruce needle
Dorsal view of the female (length: 8-9 mm)
Old spruce forest infested
Taxonomy
Description
Distribution Map
Main host(s)
Black spruce, Norway spruce, white spruce
Diet and feeding behavior
Phytophagous / Phyllophagous / Free-living defoliator
Micro-habitat(s)
Needle
Distribution
Eastern Canada, Manitoba
Damage, symptoms and biology
During outbreaks, this insect causes defoliation of variable severity. This damage results from larvae feeding mainly on old foliage and, on same rare occasions, on new needles. Severe defoliation reduces the tree’s growth and vigour, and can even kill the tree if it becomes completely defoliated.
The European spruce sawfly produces only one generation per year in the northern part of its geographic range, but may produce two generations in southern Quebec. The larva overwinters as a cocoon and transforms into a pupa the following year, or may prolong its diapause and become an adult one or two years later.
The European spruce sawfly produces only one generation per year in the northern part of its geographic range, but may produce two generations in southern Quebec. The larva overwinters as a cocoon and transforms into a pupa the following year, or may prolong its diapause and become an adult one or two years later.
Comments
Native to Europe, the European spruce sawfly was first reported in Canada in 1922 and in the United States in 1929, but did not really attract the attention of foresters until 1930, when it caused severe damage to spruce stands in Quebec’s Gaspé peninsula. The infestation spread rapidly throughout northeastern North America. The discovery of this infestation led to the development of a national forest insect inventory network consisting of the states in the northeastern U.S.
Sawfly populations began to decline in 1938 with the emergence of a viral disease that affects the larvae, returning to endemic levels in 1945, where it has since remained throughout Canada. Its current Canadian range extends from the Atlantic provinces to Manitoba.
Sawfly populations began to decline in 1938 with the emergence of a viral disease that affects the larvae, returning to endemic levels in 1945, where it has since remained throughout Canada. Its current Canadian range extends from the Atlantic provinces to Manitoba.
