Bryobia mites

Agronomist, Greg Condon (Grassroots Agronomy), has reported further Bryobia mite activity across many paddocks around Lockhart, in the Riverina district of New South Wales. Greg says the mites are very active on emerging canola crops, with highest numbers being found in paddocks sown after legume crops such as lupins and brown manure peas. Lower numbers have been found in areas that had cereal crops in 2012. Bryobia mites have also been reported attacking an emergining canola crop near Junee, in the South West Slopes district of New South Wales. Very high numbers of mites are being found; up to 3-4 mites per leaf.

Bryobia mites are an important pest of clovers, canola, wheat and lupins. It is recommended that growers across NSW and northern Victoria monitor paddocks closely, especially if moisture remains sub-optimal and emerging crops remain stressed. Look for mites and evidence of feeding damage on newly established crops and pastures. Unlike many other species of mites, which spend a lot of time on the soil surface, Bryobia mites are mostly found on the lower and upper leaf surfaces of plants.

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 are most active in warm conditions in autumn, spring and summer. They are generally found in low numbers and are unlikely to be problematic over the winter period. It is likely that Bryobia numbers will naturally decline in most areas with the onset of cooler winter conditions.

It is important to distinguish Bryobia mites from other mite species before deciding on control options. If chemicals are required, application rates need to be higher than for other pest mites. This is because Bryobia mites have a higher natural tolerance to some chemicals.

Click here for further information on Bryobia mites or refer to PestFacts Issue No. 1.