Blueberry Sawfly
(Neopareophora litura (Klug) )
Fact Sheet No. 206, UMaine Extension No. 2285

Description

Adults are 1/4 inch long, black, and generally wasp-like in appearance but do not have the narrow waist usually associated with a wasp. They have membraneous wings which they hold flat over their body (Fig. 1). 

The slow-moving, caterpillar-like larvae (Fig. 2) are usually the color of blueberry foliage (grass green), which makes them difficult to detect directly on the foliage.

Fully grown, larvae are about 4/10 inch long.  When feeding, they usually coil their body over the edge of the leaf and chew around the edge.  Pupae are enclosed in a camouflaged cocoon in the litter (Fig. 3).

Life Cycle

Blueberry sawfly adults lay eggs in early to late May inside newly developing, still folded, leaf whorls of lowbush blueberries (Fig. 4).  The eggs hatch and larvae emerge within one to two weeks.  Larvae feed on leaf tissue inside the developing whorl, killing the new leaves and filling the interior of the whorl with their excrement, a flaky brown material. 

Young larvae, which are rarely seen, are white or flesh-colored with black heads and black legs.  Older, green larvae begin to appear on the blueberry foliage in late May or early June when leaves are well-developed. 

The larvae continue to feed on the foliage until mid to late June. After reaching maturity, the larvae move to the ground and spin cocoons in the litter where they spend the winter.

Damage and Economic Importance

Although not usually an economic concern to growers, in large numbers larvae may cause damage by defoliating the plants.  Blueberry sawfly larvae feed on blueberry leaves from late May to late June.  The damaged leaves have a scalloped appearance around the edges. Infestations are usually confined to isolated areas within a field. 

Pest Management

The blueberry sawfly can be controlled with an appropriate pesticide.  Refer to Fact Sheets Nos. 204 and 209 for additional information on monitoring and control, or contact the lowbush blueberry specialist, University of Maine Cooperative Extension, 1-800-897-0757 (toll-free in Maine) or 207-581-2923.

Prepared by Judith A. Collins, Assistant Scientist, and H. Y. Forsythe, Jr., Professor of Entomology, in cooperation with David Yarborough, Extension Blueberry Specialist, The University of Maine , Orono, ME 04469. February 1994.