When will redlegged earth mites hatch?

The hatching of the redlegged earth mite (RLEM, Halotydeus destructor) is tuned to temperature and rainfall events in late autumn and winter when winter crops are establishing.

Research by cesar’s Dr Garry McDonald suggests that the process of egg development in autumn requires at least 5 mm of rain accumulated over five consecutive days or less, followed by 10 days of average daily temperatures remaining below 16°C.

Redlegged earth mite biology and lifecycle. Illustration by Elia Pirtle, Cesar Australia

Autumn predictions

We have used recent rainfall and temperature data to run a prediction model to see if peak redlegged earth mite egg-hatch is imminent in south-eastern Australia.

According the predictive model, April has largely been too warm for egg-hatch in south-eastern Australia. Furthermore, while some areas have satisfied this rainfall requirement for egg-hatch (e.g. Wagga Wagga, Albury), other areas have not (e.g. Victorian Mallee).

Please be aware that the predictive model provides a guide only. Redlegged earth mite may hatch earlier than anticipated.

For example, it is not uncommon to hear of redlegged earth mite sightings before predicted dates in irrigated paddocks.

We will continue to monitor temperature and rainfall data in key locations across south-eastern Australia and provide updates on redlegged earth miteegg hatch.

Other mites could be around

While redlegged earth mite are still expected to be dormant, there are other mite pests that you may find in your surroundings that also have dark bodies and reddish legs.

Recently, Bryobia mites has been found attacking establishing canola in southern NSW.

While redlegged earth mite have a round, velvety black body, Bryobia mites are flattened ‘pie-dish’ shape body with distinctively long front legs.

Unlike redlegged earth mite, Bryobia mites prefer warmer conditions.

For more information on mite identification in broadacre crops and pastures see the GRDC Crop Mites Back Pocket Guide.

Cover image: Photo by Andrew Weeks, Cesar Australia

What is Pestfacts south-eastern?

PestFacts south-eastern keeps growers and advisers informed about invertebrate pests and beneficials in broadacre crops and pastures during the winter-cropping season in Victoria and southern New South Wales.


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Since 2019 PestFacts south-eastern has been running through IPMforGrains: Best Practice Insect Pest Management, a project delivered by the National Pest Information Network (Cesar Australia, DPIRD, QDAF, NSW DPI, and SARDI). This project aims to provide grain growers and advisors with information on invertebrate grain pest occurrence and equip industry with the knowledge needed to implement integrated pest management practices. This initiative is a GRDC investment and includes in-kind contributions from all project partner organisations.

The online PestFacts south-eastern collection also includes a selection of articles published between 2015 – 2018 when the service was run through a previous GRDC investment, The National Pest Information Service.

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