Bryobia mites active in the Victorian Mallee

With warmer autumn temperatures, Bryobia mite activity has increased in the Victorian Mallee

Where have they been reported?

Significant populations of Bryobia mites (Bryobia spp.), sometimes called clover mites, have been reported within crops across the Victorian Mallee. They have been recorded on early dry-sown lentils, lupins, vetch, and self-sown medic.

A less dense population of Bryobia mites has also been reported north and east of Murrayville in the Victorian Mallee. These mites were observed in lentils at the 3^rd node growth stage, sown into barley stubble.

About Bryobia mites

Bryobia mites have dark grey, pale orange or olive coloured flattened bodies and eight pale red/orange legs. A distinguishing feature of Bryobia mites is their long front pair of legs, which are 1.5 times their body length. They are smaller than most pest mites, reaching no more than 0.75 mm in size. 

Adult Bryobia mite with distinguishing long front legs and flattened body (left) and their distinctive feeding trails of white-grey spots (right) (Source: cesar)

 

Bryobia mites feed on the upper surfaces of leaves and cotyledons, leaving a distinctive trail of white-grey spots. Unlike most other earth mite species, Bryobia mites are most active in the warmer conditions of autumn, spring and summer, while in winter their populations decline substantially.

There are several species of Bryobia mite in Australia; this might help explain some apparent inconsistencies in their behaviour.

Our advice

Success using chemicals to control Bryobia mites can be inconsistent. Generally, organophosphate insecticides provide better control against Bryobia mites than synthetic pyrethroids. Recommended chemical rates used against other mites have sometimes been found to be ineffective against Bryobia spp.

Chemical control of heavy Bryobia infestations may not always be warranted going into winter because these mites are most active in warm conditions. Nonetheless, there are occasions (such as in 2015) where the mites persisted well into winter.

For more detailed information on Bryobia mites, including their occurrence, lifecycle, behaviour, damage symptoms and management strategies, go to Bryobia mite within the PestNote series. 

 

Sources of field reports of Bryobia mites

Matt Bissett – Agronomy consultant, AGRIvision (Victorian Mallee)

Rick Rundell-Gordon – Senior consultant, all-AG Consulting and Tech Services (Victorian Mallee)