Integrated Pest Management Guide

FALSE ARMYWORM, Xylena nupera (Lintner)

Pest Status: This pest is not common on cranberries in British Columbia.

Life cycle and feeding habits: False armyworm moths emerge in September, overwinter and fly again in spring. Females lay their eggs in late April or early May, and eggs hatch during the second and third week of May. Newly hatched larvae are whitish with many black spots. Young larvae feed freely during the daytime. Larvae have three pairs of front legs and five pairs of hind legs. Larvae feed nocturnally as they mature in late June. They vary in colour from green with whitish lines along the back and sides when young to grass green to dark brown or black when mature. At maturity, they are 5.1 cm (2 inches) long. Mature larvae remain dormant in the ground for 2 - 6 weeks before pupating. There is only one generation of false armyworms per year. They are voracious feeders, consuming all new growth. Other host plants include apple, wild cherry and many weeds.

Monitoring: Young larvae are rarely seen but would be detected during monitoring for fireworms. They feed on terminal buds. As larvae mature, sweeping at night is the most effective monitoring technique. Mature larvae consume new vine growth and flowers.

Control: Chemical control is usually not necessary, but if many larvae are detected feeding on cranberry plants, a registered insecticide for climbing cutworms is recommended. Consider spot-spraying if the infested area can be defined. Damage will be minimized if larvae are detected soon after hatching and if insecticide is applied in the evening. Insecticides are most effective when larvae are small.
 
 

False armyworm larva	False armyworm moth

• Top of page
• Return to IPM Guide Index Page
• Return to BCCGA Home Page

©2000 Minister of Public Works and Government Services Canada