Bryobia mites

Consultant, Glen Smith (3D-Ag), has reported bryobia mites (Bryobia spp.) in an emerging canola crop south of Lockhart, in the South West Slopes of New South Wales. The mites have caused significant damage to a large part of the paddock, which was sown to cereals last year. Glen says in the worst affected areas, 1-2 mites can be seen per cotyledon and there is an obvious difference in plant development compared with plants in other parts of the paddock where no or few mites are present. The paddock was treated with endosulfan several weeks ago but mites are still being found. Similar situations have been reported in previous years where paddocks have been treated with endosulfan as a post-sowing, pre-emergent spray to control bryobia mites.

Agronomist, Craig Drum (Tatyoon Rural), has also reported bryobia mites in two canola paddocks and a clover/pasture paddock near Tatyoon, in the Western district of Victoria. Although high numbers have been observed, Craig says there has been limited damage. Given bryobia mite numbers are likely to decline significantly as conditions become cooler and wetter, these paddocks will not be sprayed but monitored over the next few weeks.

Bryobia mites are an important pest of clovers, canola, wheat and lupins. Often called the ‘clover mite’, bryobia mites are less than 1 mm long with a fawn-orange coloured body and orange legs. In the field they are often misidentified as the redlegged earth mite. Bryobia mites can be distinguished by their long forelegs, which are about 1.5 times their body length. Unlike most other earth mite species, bryobia mites are most active in warm conditions in autumn, spring and summer. These mites are generally found in low numbers and are unlikely to be problematic over the winter period. Click here for images of bryobia mites.

Bryobia mites can be difficult to control with pesticides, and they are often reported to persist in the field following chemical applications aimed at other mite species. Recent findings by cesar have found that organophosphates may provide better control of bryobia mites than synthetic pyrethroids.