Native budworm

Native budworm activity has increased significantly in the last few weeks following warm weather and prevailing north-westerly winds that occurred in many regions in early-mid September. Agronomist, Tim Condon (Delta Agribusiness), reports seeing high levels of native budworm moths around Harden, in the South West Slopes district of New South Wales. Grower, Vince Lenehan, has reported small caterpillars (10 mm in length) in faba bean crops around Lockhart, in the Riverina district of New South Wales. Vince reports finding 2-3 caterpillars per 10 sweeps. Native budworm caterpillars have also been reported attacking many field pea crops around Griffith, in the Riverina district.

Contracts services manager, Stuart McColl (BCG), has reported small-medium sized caterpillars (10-20 mm in length) in several vetch crops around Birchip, in the Mallee district of Victoria. Stuart says about 10 caterpillars per 10 sweeps have been found within crops, but very little feeding damage has been observed. Agronomist, Andrew McMahen (Landmark), reports finding caterpillars in several canola paddocks near Manangatang, in the Mallee district. Further south, native budworm eggs have been found in several crops around Horsham, in the Wimmera district of Victoria. It is likely these eggs will hatch very shortly. 

Native budworm (Helicoverpa punctigera) attack many crops including field peas, faba beans, lentils, chickpeas, lupins and canola. 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. 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. It typically takes about 7 weeks from the time of egg-laying until native budworm caterpillars are fully-grown.

If caterpillars are detected within a crop, it is important to sample representative parts of the entire paddock prior to making a control decision. Taking multiples of 10 sweeps in at least five locations in a paddock is recommended. Late-season hatchings of native budworm are often too late to cause economic damage. However, caterpillars can still cause damage to canola after windrowing if pods are still green.

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