Common Name: Pear Sawfly Larva or Pear Slug Latin Name:
Caliroa cerasi (Linnaeus 1758) (R. Bercha, det.)
Length: 11 - 12 mm
Range: Throughout Alberta
Habitat:
Various
Time of year seen: June -
September (Additional
Sightings)
Host Plants: Cotoneaster, pin cherry, mountain ash,
hawthorn and plum
Other: Although the Pear Sawfly was originally native to Europe it
now has a global distribution due to the movement of infested goods.
In North America the species is
parthenogenic. The female adult flies emerge from mid-June to July
and oviposite eggs into the bottom of the host plants leaves. In about
2 weeks the larva hatch and begin feeding on the lower and upper surfaces of
the leaf, which they skeletonize, leaving only the veins. Over a
period of 3 weeks the larva pass through 6 or 7 instars before falling to
the ground where they pupate in a cocoon of soil and silk in which they
overwinter. Later instars of the larva are typically dark brown to
black and covered with slime. Larval damage to horticulture stock may
reduce fruit yield and possibly kill young trees, while it is considered
aesthetically displeasing in ornamental trees and shrubs. (Ives et al, 1988
and Eaton et al,2006) |