Bertha armyworm

Description:

The moth has a wing span of about 4 cm and is active only at night. The forewing is predominantly grey and flecked with patches of black, brown, olive and white scales. Near the middle of the forewing, towards the leading wing margin (front), there is a prominent, white, kidney-shaped marking defined with a ring of whitish scales. Near the tip of the forewing, there is a conspicuous white and olive-coloured, irregular transverse marking. At maturity, the larvae are about 4 cm long, with a light brown head and a broad, yellowish-orange stripe along each side. The velvety black larvae have three narrow, broken white lines on their backs.

Notes:

Larvae are the only development stage of the bertha armyworm to cause crop damage. They feed on a variety of crops and weeds. Canola, mustard, alfalfa, lamb’s quarters and related plants are preferred host plants. Bertha armyworm will also feed on a range of secondary hosts including flax, peas and potato.