Cutworms (Noctuidae)

This is the largest family in the order Lepidoptera

Adults:

Noctuid adults are known as "owlet" moths in reference to the owl-like appearance of the head. The adults are robust moths with wings of a trapezoidal shape.

Larvae:

The colouration and size of larvae varies with the different species. Special note should be taken of the black army cutworm Actebia fennica, which is 40 mm long, dark grey and marked with two double white lines on either side of its body.

Damage:

The most important cutworm in B.C.'s forests is the black army cutworm Actebia fennica. The larvae are defoliators, feeding in the daylight hours in the spring, but as the season warms they hide in the soil by day and feed only after sunset. Normally the larvae feed on the first herbaceous weed cover that grows on a site after a fire. Only when the native weed species have been eaten does the larva feed on juniper buds (as above) or on tree foliage (see opposite). The black army cutworm is also a pest of blueberry in the east and burnt over alphalpha fields.

Principal Hosts:

Many species of coniferous seedlings, especially on newly planted sites which have been burned and are devoid of herbaceous vegetation. Black army cutworm caterpillars prefer weed species over conifer seedlings.

Economic Importance:

The Prince George Forest Region has reported outbreaks since 1973 and the Prince Rupert Forest Region reported severe defoliation of seedlings in 1974. Infestations have decreased considerably since the cessation of slash burning for site preparation. Adult females are able to locate recently burnt over areas and broadcast their eggs over them. Other cutworms, such as Peridroma saucia can be important pests in greenhouses. Adults are attracted by bright lights. Caterpillars can eat several germinants in an evening. They hide in the soil during the day. Faecal pellets around eaten seedlings indicate cutworm activity.

References and Links:

EAG: 549, 551-553; FC: 230-232.

See Diseases and Insects in British Columbia Forest Seedling Nurseries and JP17.

Additional Images:

	Life Cycle Diagram