Bryobia mites

Agronomist, James Murray (IK Caldwell), has reported finding bryobia mites (Bryobia spp.) in several emerging canola crops around Numurkah and Cobram, in the Northern Country district of Victoria. The mites have been found in several paddocks which have all been long-term pasture paddocks prior to this season. James says numbers of mites varied between paddocks, but they have caused significant damage in some areas, necessitating chemical control.  

Agronomist, Neil Durning (AGnVET Services), also reports finding bryobia mites in several canola crops sown into old pasture paddocks near Wagga Wagga, in the South West Slopes district of New South Wales. Some of the affected paddocks were treated with endosulfan as a post-sowing, pre-emergent spray, however bryobia mites are still being found. Neil and James both say they have observed some ‘cupping’ of canola cotyledons, which is typical of bryobia mite damage in canola.

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.