Native budworm

Native budworm (Helicoverpa punctigera) 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.

Adult moths are approximately 30-35 mm long, light brown to red-brown, with numerous dark spots and blotches. The hind wings are pale with a dark band along the lower edge. They can live for approximately 2-4 weeks and within this period females can lay over 1000 eggs. Eggs are approximately 0.5 mm in diameter and white when laid, but darken before hatching. They are most commonly laid on the top third of the plant and growing points.

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 (approximately 1.5 mm in length) 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. The arrival of moths means that their eggs are likely to be laid onto crops and the resulting caterpillars can cause serious damage to pods if left uncontrolled. 

Each year, the Victorian Department of Primary Industries monitors native budworm activity across Victoria. Samples are collected with traps that work by attracting male H. punctigera moths using baits that mimic the female moth sex pheromone. The traps are very specific to native budworm, and as such, provide a good indication of the timing of moth flights from central Australia and how these compare with previous years. This information gives advance notice of incoming flights and when to be on the lookout for early-mid instar larvae.

The following pheromone trapping information for September 3^rd – 9^th has kindly been provided by The Victorian Department of Primary Industries. For further information about the native budworm pheromone trapping project, contact Ashley Wallace (Victoria DPI) on 03 5362 2135 or by email: ashley.wallace@dpi.vic.gov.au.

Region	Trap Sites	Moth count 7 days	Crop & Growth Stage	Comments
Mallee	Walpeup Whycheproof	395 160	Field peas	Very dry
Wimmera	Brim	440	Field peas - 8-9 node	Very dry, crop not yet wilting
North Central	Kerang Elmore	120 0	Faba beans Canola - fully flowering, early podding	Dry conditions
North East	Cobram	401	Canola

Trap operators have recorded high levels of budworm numbers around Victoria. Moth numbers, and the subsequent generation of grubs, will vary between regions and paddocks, so monitoring remains the best way to determine the risk they pose to individual crops. Crops should be monitored using a sweep net from early flowering and throughout podding in pulse crops. Pod inspections are also essential in order to detect small grubs and accurately determine numbers.

Click here for information on native budworm management and click here for images.