The caterpillar of the Silver Y moth feeds on foliage and pods and can cause a degree of defoliation when infestation levels are high. However, the main problem occurs when the caterpillar becomes a contaminant in vined peas, or when feeding damage to pods of fresh market peas or beans makes them unmarketable.
Adult moths are about 10 - 15 mm in length, have a brownish grey hairy body and greyish coloured wings, with a distinctive silver coloured y marking on each forewing. They can fly during the day or night and may be seen actively flying in crops during warm summer afternoons. They can often be found flying from plant to plant within the main foliage and at rest, often are seen with the wings folded back and rapidly ‘shivering’.