Cutworms are caterpillars of night-flying moths that lay their eggs in the soil. After the caterpillars emerge they chew young plants and seedlings at ground level, sometimes eating right through the stem, which falls over (hence the name cutworm). The caterpillars grow up to 40mm long and range in colour from light grey or pinkish brown through to almost black. If disturbed they curl up into a flat coil. They eat at night and take shelter in the soil during the day. They usually attack seedlings but can also affect soft fruits like strawberries. Cutworms are more likely to be active after periods of rain.
Prevent cutworm attack by placing small, open-ended plastic cups around plants or by wrapping plant bases with aluminium foil. Cutworms are only active at night, so go out after dark with a torch and check for caterpillars at work.