Redlegged earth mites

Redlegged earth mites have hatched widely across many parts of southern Victoria and southern New South Wales, and are now building up in numbers.

In New South Wales, young redlegged earth mites have been reported from a pasture paddock near Lockhart, in the Riverina district of New South Wales. Farm consultant, Tim Condon (Delta Agribusiness), has reported that redlegged earth mites are now present around Harden, in the South West Slopes district of New South Wales. Redlegged earth mites have also been observed at Cootamundra, in the South West Slopes district.

In Victoria, Garry McDonald (cesar) has confirmed extensive hatchings of redlegged earth mites at Werribee, Geelong and Ballarat, in the Western district, near Horsham in the Wimmera district, and south of Bendigo, in the Northern Country district. Agronomist, Brad Jackson (Tyler's Hardware & Rural Supplies), has reported seeing the first hatchings of redlegged earth mites around Rupanyup, in the Wimmera district of Victoria. Until now, conditions have remained too dry in most parts of northern Victoria for substantial hatchings. It is predicted mites will hatch over the coming two weeks in these areas.

Redlegged earth mites (Halotydeus destructor) generally hatch from over-summering diapause eggs in April and early May. This year, the widespread emergence of mites has been delayed due to the dry and mild conditions experienced throughout autumn. This means that many early-sown crops are likely to be at an advantage because they will have grown beyond the most vulnerable growth stage. Redlegged earth mites are most damaging to newly establishing pastures and crops, greatly reducing seedling survival and development.

Closely inspect susceptible crops that have been recently sown. Check for the presence of mites and evidence of feeding damage, which is characterised by ‘silvering’ of the attacked foliage. It is especially important to inspect crops regularly in the first three to five weeks after sowing. Cold weather conditions will slow plant growth, leaving seedlings susceptible to mite attack for longer.

Chemicals are the most commonly used control option against mites. While a number of chemicals are registered for control of active redlegged earth mites, there are no currently registered insecticides that are effective against mite eggs. Before deciding on the most appropriate control measure, ensure the correct mite species has been identified. For assistance with identification download the GRDC Back Pocket Guide - Crop Mites.