Remember to sweep net crops for native budworm caterpillars
Native budworm caterpillar activity
- Narra Tarra
Joanne Walker (DPIRD) reports finding one budworm caterpillar (5mm) per 10 sweeps in a lupin crop near Narra Tarra.
An agronomist has reported finding two budworm caterpillars (5-10mm) per 10 sweeps in a canola crop west of Dalwallinu.
A farmer near Doodlakine has found five budworm grubs per ten sweeps in a lupin crop.
A farmer south of Kellerberrin reports finding two grubs (5-15mm) per 10 sweeps in a lupin crop, but found no caterpillars in a nearby canola crop.
A budworm trapper near Maya reports finding 1 budworm caterpillar per 10 sweeps in a field pea crop. The size of the caterpillars captured during the sweep netting varied between 10 and 30mm. He also commented that he had noticed a few of pods that had been damaged by budworm caterpillar feeding.
Field pea, chickpea, lentil and faba bean crops are very susceptible to all sizes of caterpillars during the formation and development of pods. Tiny caterpillars can enter developing pods and damage seed or devour the entire contents of the pod.
Narrow-leafed lupin pods and seeds are not usually damaged by native budworm until they are close to maturity and the pods are losing their green colouration, although there has been one report this year of budworm caterpillars damaging young lupin pods.
Canola is similar to narrow-leafed lupin in that pods only become attractive to caterpillars as the crop nears maturity and begins to hay-off. Caterpillars of all sizes will enter pods at this stage, with larger caterpillars doing the most damage.
Native budworm moth trapping surveillance
- Usual automated and manual trapping locations
Budworm moth numbers reported by volunteer farmers, agronomists and DPIRD staff have again remained low for most of WA’s wheatbelt over the past week. The higher numbers reported this week include: Merredin (45 moths), Southern Cross (23), Mount Ridley (20), Doodlakine (14), Dowerin (9), Kellerberrin (9) and Kirwan (7).
A mapped view of the native budworm trap captures is available at cesar’s MothTrapVisWA page. For recent native budworm field reports refer to DPIRD’s PestFax map.
The economic spray threshold levels will vary with crop type, grain price and control cost; these can be calculated for each grower’s particular situation using a simple formula outlined in DPIRD’s Management and economic thresholds for Native Budworm page.
More information on native budworm can be found at DPIRD’s;
- 2020 PestFax Issue 7 article Native budworm and other moths are active
- PestFax Issue 10 article Native budworm update. Caterpillars are being found in cereals
- PestFax Issue 13 article Native budworm caterpillars are damaging cereal crops.
For more information contact Alan Lord, Technical Officer, South Perth +61 (0)8 9368 3758 or +61 (0)409 689 468.
Article author: Alan Lord (DPIRD South Perth).