Balaustium mites

Grower, Damien Barri, has reported balaustium mites (Balaustium medicagoense) attacking emerging pasture seedlings in a paddock near Kilmore, in the Northern Country district of Victoria. We have also received reports of balaustium mites in established pasture paddocks near Rokewood and Ararat in the Western district of Victoria. It is likely that balaustium mites are now also present in other cropping regions of Victoria and New South Wales. Researcher, Aston Arthur (cesar), says balaustium mites are typically present in highest numbers in May and June, and tend to decrease after this time (peaking again in spring).

Balaustium mites are often confused with other mite pests. Adults reach about 2 mm long, which is twice the size of redlegged earth mites. They have a rounded red-brown coloured body, densely covered with stout hairs, and eight orange-red legs. Leaf damage symptoms can also help to identify different mite species. Balaustium mites cause cupping and leathering of cotyledons whereas blue oat mites and redlegged earth mites typically cause silvering of plant cotyledons and leaves. Click here for images of balaustium mites

Balaustium mites can be difficult to control with pesticides and they have been reported to persist in the field following chemical applications aimed at other mite species. Recent findings by cesar show balaustium mites are more tolerant to a range of organophosphorus and synthetic pyrethroid chemicals compared with other mites. It is therefore important to correctly identify mite species and seriously consider non-chemical control methods for these mites. Reports indicate that crops sown into paddocks with a pasture history and high levels of broad-leaved weeds, especially capeweed, will be most at risk from mite damage.