How to Manage Pests

UC Pest Management Guidelines

Cutworm larvae feed at night and come in various colors and patterns but always appear as smooth-skinned caterpillars to the naked eye. They frequently roll into a C-shape when disturbed. The mature variegated curworm larva is yellow to brown, a little over an inch long (3 cm), with a row of 4 to 6 yellow or pink diamond-shaped spots down the back. The mature darksided cutworm is somewhat larger than the variegated cutworm (1.5–2 inches, 4–5 cm) and gray to greenish gray in color with irregular, longitudinal stripes.

Adult cutworm moths are rather nondescript with dark gray or brown front wings that have irregular spots or bands and lighter hind wings.

Larvae feed at night on the tender tips of new asparagus spears where they eat small holes. One-sided feeding may also cause the spears to curl. The variegated cutworm also feeds underground and at the soil surface. Fern damage is generally rare.

Carry out good weed control in and around the field and incorporate field trash and previous crop residues thoroughly to reduce egg and worm overwintering. Look for damage symptoms and confirm cutworm's presence by digging into the soil an inch or so around a damaged spear. Begin applications when insects first appear. If infestations are localized, consider spot treatments.

Organically Acceptable Methods
Good weed management and field cultivation are acceptable to use in an organically certified crop.

PUBLICATION

UC IPM Pest Management Guidelines: Asparagus
UC ANR Publication 3435
Insects
W. E. Chaney, UC Cooperative Extension, Monterey Co.
E. T. Natwick, UC Cooperative Extension, Imperial Co.
C. B. Fouche, UC Cooperative Extension, San Joaquin Co.
Acknowledgment for contributions to the insects section:
R. J. Mullen, UC Cooperative Extension, San Joaquin Co.

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