European Pine Sawfly Fact Sheet

Fact Sheets > Insect Fact Sheets > European Pine Sawfly

  The European Pine Sawfly, Neodiprion sertifer (Geoffroy), as its name suggests, is native to Europe and affects pines in landscapes, ornamental nurseries and Christmas tree plantations. Feeding by the larval stage of this pest will not kill the host plant, but can affect its aesthetic value.

Plants Attacked

The european pine sawfly has a preference for mugo (Pinus mugo), Scotch (Pinus sylvestris), red (Pinus resinosa), jack (Pinus banksiana) and Japanese red(Pinus densiflora) pines. It feeds to a lesser extent on white (Pinus strobus), Austrian (Pinus nigra), ponderosa (Pinus ponderosa), shortleaf (Pinus echinata) and pitch (Pinus rigida) pines.

Insect Identification

The mature larvae have shiny black heads and are grayish-green. They have a light stripe down the middle of their back, and a light stripe along each side followed by a dark green stripe running parallel down the length of their body. Newly hatched larvae are 1/8" long but measure one inch long when mature. The adults are brownish black and wasp-like. The cream colored eggs are deposited by the female in the current season's needles, but are not easily seen until they increase in size just prior to larvae emergence in spring.

European pine sawfly eggs in April	Later instar larvae devouring pine needles

Life History

Winter	The eggs over-winter in slits along the edge of the needle.
Spring	Hatching occurs in late April in southwest Pennsylvania and the larvae feed until late May and early June. When mature, most larvae drop to the ground and spin brown cocoons.
Summer	In late summer the adults pupate inside the cocoons.
Fall	The adults emerge from the cocoons and mate. In September and October the female slits the edge of the needle and lays her eggs inside the opening. There are 6 - 8 eggs in a single needle and she lays eggs in 10 - 12 needles.
One generation occurs each year in Pennsylvania.

Damage Symptoms

Initially, the larvae feed only on the needle surface, causing the needle to turn brown and wilt. As the larvae mature, their feeding becomes more extensive and needles are stripped. Complete defoliation of the tree may occur, stunting the plant's growth. The larvae, however, do not feed on new growth, so the trees usually survive. They feed in colonies with as many as 3 or 4 on one needle and will move to a new host when their food supply is exhausted.

First instar sawfly larva	Later instar larvae

Management Options

Cultural	When possible, species more resistant to the European pine sawfly should be used. For example, northern cultivars of Scots pine are known to be more resistant to attack than southern ones.
Biological	There are several parasites and native birds that feed on European pine sawfly larvae. Also, rodents often eat the pupae in the soil. However, these biocontrols do not usually provide adequate control of the pest in the landscape and the nursery.
Mechanical	If detected, the needles containing over-wintering eggs can be removed from the host and destroyed. Colonies of young larvae can also be eliminated by removing and destroying infested branch terminals.
Chemical	Horticultural oils and insecticidal soaps are effective if used when the sawfly larvae are small. Control Measures for European Pine Sawfly

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Authored by:
Katherine Mazzey, Penn State Extension Program Assistant
Michael Masiuk, Extension Agent, Penn State University - Allegheny County

Sources
Cornell Cooperative Extension (2003). Pine Sawflies. http://www.cce.cornell.edu/suffolk/grownet/tree-insect/pine-saw.html

European Pine Sawfly. The Ohio State University Fact Sheets. http://bugs.osu.edu/~bugdoc/Shetlar/factsheet/christmasstree/european_pine_sawfly.htm

Hoover, G.A. (2000). Woody Ornamental Insect, Mite, and Disease Management. Penn State College of Agricultural Sciences. pp.45. http://woodypestguide.cas.psu.edu/Insects.html

Hoover, G.A. (2002). European Saw Fly. Department of Entomology. Penn State. http://www.ento.psu.edu/extension/factsheets/eupinesawfly.htm

Johnson, W.T. & Lyon, H.H. (1976). Insects That Feed On Trees And Shrubs, pp.16, 18. Comstock Publishing Associates. Cornell University Press.

Shetlar, D. J. (2000). European Pine Sawfly. Ohio State University Extension Fact Sheet. http://ohioline.osu.edu/hyg-fact/2000/2055.html