Native budworm

Native budworm (Helicoverpa punctigera) is a major pest of many crops and pastures over spring. The larvae are up to 40 mm long with substantial colour variation, 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.

Consultant, Glen Shepard (IMAG Consulting), says native budworm remain a threat to crops around Dubbo, in the Central West Slopes and Plains of NSW. Glen says some crops have been sprayed twice, however, this is more a function of high commodity prices (i.e. worth protecting crops at lower thresholds) rather than a high number of caterpillars. Agronomist, Phil Stoddart (Landmark), reported that there are relatively high numbers of budworm in irrigated lucerne paddocks, near Mudgee, in the Central Tablelands of NSW. Phil says chemical control was being considered. Consultants, Sandy Biddulph (Biddulph Rural Consulting) and Sarah Giblin (Giblin Agronomy Services), report some native budworm near Cootamundra (South West Slopes, NSW) and Walgett (North West Slopes and Plains, NSW), respectively. Native budworm have been found on peas, canola and cereals, however, the present numbers are not at worrying levels.

The following native budworm pheromone trapping information in Victoria for October 16^th – 23^rd has been provided by the Victorian Department of Primary Industries. For further information, contact Michelle Pardy (Victoria DPI) on 03 5871 0600 or by email: michelle.pardy@dpi.vic.gov.au. Many thanks to Michelle and all the trap operators for their continuing efforts in collating and providing this information.

Region	Trap Sites	Moth 7 day count	Crop & Growth Stage	Comments
Mallee	Walpeup	0	Peas - harvested	No rain
Wimmera	Warracknabeal	56	Vetch - cut for hay	Dry
North Central	Kerang	115	Faba Beans - late podding	Dry
South West	Hamilton	182	Peas - filling	Dry

Many of the pheromone traps throughout Victoria have been taken down as most stressed crops are being harvested or cut for hay. Budworm numbers also appear to be declining. The North Central and South West regions recorded relatively high numbers of moths from October 16^th – 23^rd; however, this is unlikely to be of concern as emerging grubs will have difficulty burrowing into hardening/ripening pods.

Michelle says native budworm numbers this season were relatively high compared with last year. This season, activity peaked in late September/early October. Given the lack of rain during this period, thresholds were increased as growers evaluated the cost of spraying with lower than average yield potentials in mind. Although numbers of native budworm were high this year, there were no significant incursions of the lesser budworm (Heliothis punctifera), which required chemical control to protect many crops in the Mallee and Wimmera districts of Victoria in 2005.