PestFacts WA

Cold temperatures have slowed native budworm moth flights

  • Usual automated and manual trapping locations
An adult native budworm moth.
An adult native budworm moth. Photo courtesy of: Alan Lord (DPIRD).

Budworm moth numbers reported by volunteer farmers, agronomists and DPIRD staff have remained relatively low for most of WA’s wheatbelt over the past week.  The higher numbers reported this week include Mukinbudin (61 moths), Grass Patch West (35), Maya South East (30), Beacon (18), Maya East (10) and Wyalkatchem (8).

The moth flights have probably been reduced somewhat as a result of the cold fronts that passed through the S.W in the past week. Also eggs and very small larvae can be dislodged and will die after heavy rain or wind.

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.

These numbers give an indication of the movement of native budworm moth flights and can be used to alert growers to regional changes and the necessity to check crops using a sweep net.

Native budworm moth flights are often variable and unpredictable but moths generally prefer to land in flowering crops in preference to nearby crops that are yet to flower. Field pea, faba bean, lentil and chickpea crops are very susceptible to budworm as their pods are attractive to all sizes of caterpillars. Lupin and canola pods are less attractive to native budworm caterpillars which do not commence to feed on these pods until closer to leaf drop and pod maturity. Serradella, lucerne, clover and annual medic seed crops will also be at risk of attack.

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 and PestFax Issue 10 article Native budworm update. Caterpillars are being found in cereals.

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).