Agronomist, John Robertson (Agwise Services P/L), has found native budworm (Helicoverpa punctigera) larvae in several newly established pasture paddocks near Stawell, in the Wimmera district of Victoria. Part of one paddock has been completely bared off, whereas other paddocks have lighter infestations. John says the caterpillars are 30-40 mm long, and all paddocks have been sprayed with alpha-cypermethrin which has provided good control at this stage.
Native budworm larvae are a major pest of a variety of crops during spring to early summer. They feed on buds, flowers, fruiting parts and seeds. They attack field pea, faba bean, lentil, chickpea, lupin and canola crops as well as pasture seed crops of lucerne, annual medic and clover. Native budworm larvae can be up to 40 mm long with substantial colour variation (shades of brown, green and orange), usually with darkish strips along the body and bumpy skin with sparse stiff black hairs. Newly hatched larvae are light in colour with dark brown heads and spots, and as they develop they become darker in colour.
Native budworm moths migrate into agricultural areas in eastern Australia in late winter and early spring, when over-wintering pupae in the soil emerge. The numbers and timing of these migratory flights are mostly unpredictable as the moths often travel hundreds of kilometres, carried on high altitude wind currents from pastoral regions. When moths arrive their eggs are likely to be laid onto crops and the resulting caterpillars can cause serious damage if left uncontrolled. Adult moths are approximately 30-35 mm long, light brown to red-brown, with numerous dark spots and blotches.
Click here for images of native budworm.