Redlegged earth mites

Philip Jobling (cesar) reports redlegged earth mite (Halotydeus destructor) hatchings around Colac, Inverleigh and Geelong, in the Western district of Victoria. Philip says only low mite numbers are presently being found, and the majority of these are at the nymphal stage. This indicates that mite hatchings have occurred within the last 2-3 weeks. There is little evidence of feeding damage to favoured plant hosts such as capeweed, plantain and clovers. Researcher, Aston Arthur (University of Melbourne), has observed moderate numbers of redlegged earth mites across numerous paddocks near Shepparton, in the Northern country district of Victoria. The majority of mites are small nymphs. Agronomist, Jim Zwar (Greenleaf Crop and Pasture), has also reported finding redlegged earth mites around Lake Bolac, in the Western district of Victoria. Jim says the mites have hatched later than usual this season, and they are not presently causing any noticeable damage.  

Redlegged earth mites attack a wide variety of plant types including cereals, oilseeds, pastures and broad-leaved weeds. They feed by piercing plant cells and sucking out the contents, which results in silver or white patches. High mite populations can kill plants at emergence, when crops are most vulnerable to attack. Philip advises that if pest pressure continues to remain low, a 'preventative spray' strategy may be a waste of time and money, however, mites could easily revert to high numbers under favourable conditions, putting later sown crops under pressure.

Before deciding on the most appropriate control measure, ensure the correct mite species has been identified. Redlegged earth mites are easily confused with other mites, such as blue oat mites and Balaustium mites. The incorrect and over-use of insecticides is likely to be the main factor for the evolution of resistance to synthetic pyrethroid chemicals in the redlegged earth mite.