Symptoms of Damage Damage is caused by the larvae boring and feeding in the crown of the plant. The crown may be hollowed out and stained a reddish-brown colour. The adult crown borers may eat small holes in the leaves and feed off the crowns, creating cavities where eggs are deposited. Weakened plants may be attached by other insects or by disease. Economic injury results from larvae feeding in the crowns of the plants.
Affected plants show abnormal red pigmentation in the leaves.
Monitoring Inspect strawberry plants along the field borders for the presence of wilted or dead plants, beginning when blossoming starts. Check inside the crowns of these plants for the presence of one or two borer larvae in the hollowed-out area. No economic thresholds have been developed for this pest. Comments Crop rotation helps reduce populations of this pest because the flightless beetles can only migrate by crawling. Avoid placing new plantings closer than 300 m to old plantings or to fields containing wild strawberries or cinquefoil.