Thorax - 10-11 segments. Spiracles on segments 1 to 8. Prolegs on segments 3-6 and 10.
Habits - Herbivorous. Curls up when disturbed. Usually found on sandy soils. Feed at night and bury themselves during the day close to damaged plants.
Moth flies by night and lays several hundred eggs on plants or the soil.. These hatch in 4-7 days. Caterpillars live for around 4 weeks and remain close to where eggs were laid. Pupate in the soil at a depth of 15-75 mm. There may be several generations per year.
Origin and History:
Caterpillar is a major pest of cereals, grasses and lupins that cuts the plant off just above the surface. 2-3 caterpillars can cut off all plants in a square metre. Lupins are most susceptible to damage from emergence to the 4 leaf stage. In lupins, they cut off portions of the leaf or cotyledons or cut through the stem just above ground level. Plants may survive moderate damage to the leaves or cotyledons but will die if the stem is cut.
Management and Control:
Biological control by fungi, wasps and flies often prevent outbreaks.
Insecticides provide reliable control for outbreaks.
Cereals - 4 large larvae per metre of crop row.
Canola - 4 large larvae per metre of crop row.
Lupins - Less than one larva per square metre for young crops. Check for damage to young leaves and cotyledons and for stems being cut just above ground level. They rarely cause economic damage after the crop has reached the 4 leaf stage.
Check the crop early and regularly for any sign of plants being cut off. Larvae can be difficult to find because they are often underground.