Brassica – Diamondback Moth

Crop:        Brassica
Insect(s): Diamondback Moth


  1. To help prevent the development of resistance to any one specific active ingredient (see table below), observe the following instructions:
    * Use in accordance with the current IRMS for your region. For growers in the Lockyer Valley region, please refer to the Lockyer Valley Diamondback Moth Insecticide Resistance Management Strategy. For growers in Western Australia, please refer to the Western Australian Department of Primary Industries and Regional Development two-window strategy.
    * Apply a specific active ingredient using a “window” approach to avoid exposure of consecutive insect pest generations to the same mode of action. Multiple successive applications of a specific active ingredient are acceptable if they are used to treat a single pest generation.
    * Following a “window” of a specific mode of action product, rotate to a “window” of applications of effective insecticides with a different mode of action.
    * The total exposure period of any one mode of action “active window” applied throughout the crop cycle (from seedling to harvest) should not exceed 50% of the crop cycle.
    * Incorporate IPM techniques into the overall pest management program and
    * Monitor insect populations for loss of field efficacy.
  2. Always read and follow product labels. Some products place a limit on the number of times they can be applied per crop (see table below) and when they can be applied.
  3. Monitor crops regularly and only apply insecticide when the pest threshold is reached.
  4. Be aware of insecticide mode of actions used in the nursery phase of the crop and ensure a one generation break exists before re-use of that same mode of action in the field phase of the crop.
  5. Ensure spray rig is properly calibrated and achieving good coverage with appropriate sized spray droplets.
  6. Time the application to the most susceptible life stage of the target pest.
  7. To encourage beneficial insects, use Bacillus thuringiensis (Bt) sprays and avoid broad spectrum insecticides, particularly early to mid-crop cycle.
  8. Be cautious of using insecticide tank-mixes where both active ingredients control DBM as this strategy is generally not considered best practice for resistance management. Refer to document IRAC International Insecticide Mixture Statement for more information on this subject.
  9. DO NOT re-treat a spray failure with a product from the same chemical group.
  10. Practice good crop hygiene to reduce DBM pressure- plant clean seedlings and incorporate crop residue as soon as practical after harvest.
Mode of Action Group as specified on the product labeled on product labelActive ingredientNumber applications permitted per crop per season from product label
1Amethomyl, thiodicarbNot specified
2Bfipronil4 per year within 8 week period
3Asynthetic pyrethroids (various)Not specified
6emamectin benzoate4 per any one crop
11ABacillus thuringiensisnot specified
13chlorfenapyr2 but 4 in brussel sprouts
23spirotetramat2 but 3 in brassica leafy vegetables
28chlorantraniliprole, flubendiamide3 but 1 for mixtures of chlorantraniliprole and thiamethoxam

Content last updated: July 1, 2019

CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmers’ adoption of resistance management. All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.

These Resistance Management Strategies do not replace product labels. They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance. It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through

The information given in this strategy is provided in good faith and without any liability for loss or damage suffered as a result of its application and use. Advice given in this strategy is valid as at 27 June 2019. All previous versions of this strategy are now invalid.