Native budworm activity update
- Grass Patch
Technical officer Joanne Walker (DPIRD) reports finding 10 native budworm budworm caterpillars (0-10mm) per 10 sweeps in a lupin crop near Geraldton.
David Cameron (Farmanco) reports that no budworm have been found recently in canola in Watheroo and Coorow areas. However, up to 4 budworm per 10 sweeps could be found in wheat. David said that budworm are noticeably higher in wheat crops which have lupin stubble than those without. Up to 13 budworm per 10 sweeps were found in wheat with lupin stubble.
DPIRD entomologist Dusty Severtson sweep netted several flowering canola crops and a flowering lupin crop between Northam and Goomalling and found less than one caterpillar per 10 sweeps in these crops.
Matt Flint (DKT Rural Agencies) reports finding more than six budworm caterpillars per 10 sweeps in a serradella paddock near Kellerberrin.
Rachel Minett (Primaries CRT) reports finding 3-5 budworm caterpillars per 10 sweeps in flowering faba bean crops near Grass Patch and Beaumont.
Native budworm moth trapping surveillance
- Usual automated and manual trapping locations
High native budworm moth numbers have been recorded in the Wyalkatchem and Doodlakine areas this week, while Dowerin has recorded quite high numbers over the last 3-4 weeks.
Other higher captures this week include; Doodlakine (380 moths), Wyalkatchem (360), Dowerin (242), Binnu (98), Scaddan (81), Cunderdin (78) and Burracoppin (52).
Results of this week's automated and manual trappings are available at the department’s Native budworm moth numbers 2019.
A mapped view of the native budworm trap captures is available at cesar’s MothTrapVisWA page. Viewers need to select the desired trapping date range.
Growers and consultants are urged to keep sweep netting crops
Information provided by the traps on moth flights is very useful in alerting growers to potential native budworm risk but be mindful that the native budworm traps cover only a very small area of the WA cropping zone.
Given the crop damage that has occurred in parts of the northern grain belt and the very high numbers of budworm moths in some locations, there is no substitute for sweep netting crops to check for native budworm grubs. Particularly when vulnerable crops like field pea, faba bean, lentil and chickpea commence flowering. It is important to regularly monitor grub numbers and determine whether control measures are required.
Serradella crops that are intending to be harvested for seed should be regularly checked for native budworm caterpillars. Serradellas are reasonably easy to net (but not if hard grazed) and if seed production is important then spray control is required where grubs are found (1-2 grubs per 10 sweeps) whilst the plants have green immature pods.
Along with serradella, lucerne, clover and annual medic seed crops may also be attacked.
White spherical eggs (0.5mm) are laid singly, mostly near the top of the plant. The eggs darken as they mature and tiny caterpillars hatch after about seven days. The young caterpillars feed on leaf or pod material for about two weeks before they become large enough (5mm long) to be noticed in the crop. It takes a further four weeks until they are fully grown (40 mm) which is about seven weeks from the time of egg laying. These development times are based on average spring temperatures. Later in the season, or in more northerly areas, developmental rates for caterpillars will be faster.
Detailed information on this pest can be found at the department’s Management and economic thresholds for native budworm.
Pesticide options for the control of native budworm can be found in the department’s Winter/Spring Insecticide Spray Chart 2019.
Previous budworm activity and management information is available at DPIRD’s;
- 2019 PestFax Issue 15 article Native budworm and lesser budworm caterpillars are causing damage to crops
- 2019 PestFax Issue 14 article Native budworm moth numbers are high
- 2019 PestFax Issue 12 article Native budworm moth trapping and caterpillar activity .
For more information contact Alan Lord, Technical Officer, South Perth on +61 (0)8 9368 3758 or +61 (0)409 689 468.
Article authors: Alan Lord (DPIRD South Perth) and Dustin Severtson (DPIRD Northam).