Constraint - Armyworm


  • Pupae of all three species are soil dwelling,  around 20 mm long and shiny brown

  • Caterpillars of all three species are similar, and 30 - 40 mm long

  • Moths are medium-sized, with a wingspan of 30 - 40 mm


  • Mostly cause damage by feeding on leaves

  • Occasionally feed on stems when leaves dry out, resulting in head loss and yield loss


  • If in sufficient numbers, yield loss due to head damage can be up to 20%


There are a number of chemicals registered for control of armyworms. Armyworms are active at night, therefore, spraying should be carried out in late afternoon or early evening for maximum effect.



Links and Resources

DEPI VIC - Armyworm

Importance, description, biology, seasonal activity, damage caused, stubble retention, sampling and detection, and control. Published 1995.

I Spy Manual - Armyworm

Page 50. Information on 4 species of armyworm, distinguishing characteristics/ description, confused with/similar to, distribution, pest status and risk period, host range, symptoms, monitoring/sampling, and management. Published 2012.

Insectopedia - Armyworm

Page contains information on 3 species of armyworm, factors contributing to outbreaks, feeding habits, description,  biology, lifecycle, damage, and control. Published 2000.

SARDI - Armyworm

3 page PDF. Information on three species of armyworm, monitoring, economic threshold, and control. Last updated 1999.