Earth mites

There have been continued reports of various earth mite species attacking crops in several regions of Victoria. Agronomist, Ben Cordes (Tylers Hardware and Rural Supplies), has reported blue oat mites (Penthaleus spp.) causing feeding damage to a canola crop north east of Rupanyup, in the Wimmera district of Victoria. The mites have severely attacked about 15-20 ha of the paddock. There is extensive silvering of the leaves, and many seedlings have been completely lost. Ben said omethoate was applied to part of the paddock at crop emergence, but failed to provide much protection. Omethoate does not have soil residual properties and is not the best defense against mites at establishment time. Ben also reported the presence of predatory snout mites. Snout mites are widely distributed across Victoria and New South Wales, and are effective predators of earth mites and lucerne flea.

Agronomist, Doug Perryman (Rodwells), has reported observing high numbers of blue oat mites and Bryobia mites (Bryobia spp.) in various paddocks around Boort, in the Mallee district of Victoria. Blue oat mites have predominantly caused damage to cereals, while Bryobia mites were seen earlier in the season attacking canola seedlings. Senior agronomist, Greg Toomey (Landmark), has also reported high numbers of blue oat mites and redlegged earth mites (Halotydeus destructor) in various crops around Elmore, in the Northern Country district of Victoria. Greg said the numbers of earth mites found across many paddocks this year has been particularly high.

Although the majority of crop and pasture plants are now well established, it is important that monitoring continues due to the presence of high mite populations this season. Growers should keep a close eye on late-sown crops as they can remain susceptible to mite damage long after any seed dressing protection can persist.