Redlegged earth mites

There have been several reports of redlegged earth mites (Halotydeus destructor) emerging from over-summering eggs in various regions of Victoria and New South Wales. Consultant, Josh Andrews (Josh Andrews Agronomy & Rural Consulting), has reported high numbers of redlegged earth mites in a ryegrass paddock south-west of Tumbarumba, in the South West Slopes district of New South Wales. The ryegrass is currently at the 3-4 leaf stage and some damage was evident, so the paddock has been sprayed with bifenthrin.

Agronomist, James O’Brien (Landmark), reports finding high numbers of redlegged earth mites in several pasture paddocks south of Camperdown, in the Western district of Victoria. Two paddocks had very high numbers, whilst other paddocks had lower numbers, across a total area of approximately 100 ha. The affected paddocks were established pastures which had recently been over-sown with ryegrass. James says some damage is visible and chemical control is being considered. Redlegged earth mites have also been observed in other parts of the Western district this week, in paddocks around Colac, Winchelsea and Skipton.

The redlegged earth mite is up to 1 mm in length with a globular shaped black body and red legs. They are one of the most important crop establishment pests. They attack a variety of crops and pastures, including cereals, oilseeds, legumes and fodder crops. Redlegged earth mites can also survive on a variety of weeds, particularly broad-leaved weeds. For this reason, management of weeds can play an important role in reducing the build-up of mite populations within crops.

Click here to view images of redlegged earth mites.

It is important to monitor mite numbers at this time of the year because emerging seedlings are particularly vulnerable to attack. Examine plants for damage and search for mites on leaves and on the soil surface. Before deciding on the most appropriate control measure, ensure the correct mite species has been identified. Problems can occur when growers use targeted rates of pesticide to control a particular mite pest and have then found another unexpected mite is present that is not controlled by the sprays. For example, pesticide rates of many products used against redlegged earth mites are not effective against bryobia mites and balaustium mites.