Many species, including variegated cutworm (Peridroma saucia)
Pest description and crop damage Larvae can be brown, gray, or greenish and range from 0.25 to 1.25 inches long. They are most damaging to trees that have high weeds around their bases. Feeding is nocturnal. Leaves and buds may be heavily damaged. Generally controlled with dormant or delayed-dormant sprays.
Biology and life history Weeds are the preferred source of food for these larvae, and eggs typically are laid on weeds around the trees. Depending on species, they may overwinter as pupae or larvae in the soil. The larvae spend the day in the soil, then climb up the tree during the night to feed.
Control weeds, grasses, and debris in the orchard that provide cover. Encourage natural enemies of cutworms like spiders. Hand-pick cutworm larvae, using a flashlight to find them, if practical. Scratch the soil at the base of plants to find larvae in the daytime. Tanglefoot or a similar sticky material applied as a band to the trunk will stop movement of larvae up the trunk. Wrap the trunk tightly with plastic wrap to ensure the insects can't crawl beneath the wrap. Apply the Tanglefoot to the plastic wrap, not the tree, as it can soften bark. Note: Young trees may be harmed by banding Tanglefoot directly on thin bark.
Management-chemical control: HOME USE
Climbing cutworms can be difficult to control.
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- Bacillus thuringiensis kurstaki-Some formulations are OMRI-listed for organic use.
- Beauveria bassiana-Some formulations are OMRI-listed for organic use.
- imidacloprid-Soil drenches may have residual activity in woody plants lasting for 12 or more months. If short-term management is the goal, consider other approaches.
- kaolin clay (Surround at Home)-Repels some insect pests when applied as a spray to leaves, stems, and fruit. OMRI-listed for organic use.
- pyrethrins-Some formulations are OMRI-listed for organic use.
- spinosad-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
Insecticides applied as a full dilute spray to the tree trunks and bases will control most cutworm species. If other cutworms are involved, spray the whole tree and the ground around the tree. Treat in spring when buds swell or when cutworms become active. Control weeds under trees to keep cutworms from climbing up into the trees.
Dormant-season and delayed-dormant sprays
- chlorpyrifos (Lorsban 4E) at 1.5 to 4 pint/a plus horticultural mineral oil (rates vary; see label). REI 4 days. Do not exceed one application of chlorpyrifos as a dormant or delayed-dormant per season. Avoid contact with foliage in sweet cherries as premature leaf drop may result. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.