Pasture / Winter Crops – Redlegged Earth Mite; RLEM (๐˜๐˜ข๐˜ญ๐˜ฐ๐˜ต๐˜บ๐˜ฅ๐˜ฆ๐˜ถ๐˜ด ๐˜ฅ๐˜ฆ๐˜ด๐˜ต๐˜ณ๐˜ถ๐˜ค๐˜ต๐˜ฐ๐˜ณ)

Crop(s) Pasture/Winter crops
Insect(s) Redlegged earth mite (RLEM) (Halotydeus destructor)

 

Guidelines

  1. Determine the risk of RLEM for each paddock before making management decisions.1
  2. Rotate insecticide Groups.
  3. Do not apply consecutive sprays of products from any one insecticide Group.
  4. Avoid prophylactic pre-emergence/bare-earth sprays in autumn.
Crop stage Group* Chemical subgroup Example chemical
Seed treatment (or in-furrow) 4A

1B

2B

30

neonicotinoids or

organophosphates or

phenylpyrazoles or isoxazolines

Imidacloprid

Chlorpyrifos

fipronil isocycloseram (Canola only)

Bare Earth (Pre-emergent) 1B

3A

organophosphates or synthetic pyrethroids omethoate

bifenthrin

Early post-emergence 1B

3A

12A

organophosphates or synthetic pyrethroids or diafenthiuron s Chlorpyrifos

alpha-cypermethrin

diafenthiuron (Canola only)

Spring 1B

3A

12A

organophosphates or
synthetic pyrethroids or
diafenthiuron
omethoate

gamma-cyhalothrin

diafenthiuron

(Canola only)

* Refer: CropLife Expert Committee on Insecticide Resistance Mode of Action Classification for Insecticides.

Further detailed information about registered products and chemical windowing strategies for RLEM is available at: https://ipmguidelinesforgrains.com.au/important/uploads/Science-behind-the-RLEM-IRMS-in-Australian-grains-and-pastures_October-2024.pdf

  1. Monitoring and timing of sprays:
    1. Monitor RLEM activity carefully, particularly in the first 3-5 weeks after sowing.
    2. Only apply chemical if damage has reached economic threshold levels and/or the risk of RLEM is elevated.
    3. Use the hatch timing tool to estimate RLEM hatching in autumn.2
    4. Optimal timing of spring sprays can be calculated using the TIMERITEยฎ tool.3 Follow the recommended best spray date and ensure RLEM is the dominant mite species.
  2. Placement of sprays:
    1. Apply perimeter sprays where infestations are concentrated on the edge of paddocks.
    2. Spray the entire paddock when RLEM numbers exceed thresholds or risk is elevated. However, with pyrethroid products, recent research has shown that the risk of Group 3Aresistance can be minimised through the application of foliar pyrethroids in a 50 m strip with 10 m spacing.4
  3. Cultural practices:
    1. Decrease pasture foliage through grazing or cutting hay/silage to reduce RLEM numbers.
    2. Keep paddocks and fence-lines free of host weeds, such as capeweed.
    3. Sow crops and pastures that are more tolerant to RLEM, such as chickpeas.
    4. Encourage predator survival by judicious use of insecticides.
    5. Burn stubble prior to sowing to directly kill RLEM and its eggs.

 

Notes regarding the application of insecticides:

  1. There is known RLEM resistance to Group 3A and Group 1B insecticides in Western Australia, South Australia, and Victoria. Resistance is expected to expand across these regions.
  2. To ensure the most effective control of RLEM:
    1. Follow the recommendations in the RLEM Best Management Practice Guide https://ipmguidelinesforgrains.com.au/important/uploads/Redlegged-Earth-Mite-GRDC-24111322.pdf
    2. Product labels should at all times be carefully read and adhered to;
    3. Full recommended rates of registered insecticides should always be used; and
    4. Ensure good coverage of the target area to maximise contact.

References

  1. The online RLEM seasonal risk tool developed by Cesar Australia considers multiple risks and management tactics https://cesaraustralia.shinyapps.io/rlemseasonalrisk/
  2. The Hatch timing tool developed by Cesar Australia to aids early season monitoring and prediction of RLEM risk at crop establishment https://cesaraustralia.shinyapps.io/RLEM-hatch/

3 TIMERITEยฎ predicts the best spray window and ideal spray date in spring to control RLEM https://www.wool.com/timerite/

  1. Strip spraying delays pyrethroid resistance in the redlegged earth mite, Halotydeus destructor: a novel refuge strategy – Maino – 2021 – Pest Management Science – Wiley Online Library

URL: https://croplife.org.au/resources/programs/resistance-management/pasture-winter-crops-redlegged-earth-mite/
Content last updated: June 26, 2025

CropLife Australiaโ€™s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmersโ€™ 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 regulatorโ€™s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through www.apvma.gov.au

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 26 June 2025. All previous versions of this strategy are now invalid.