Blue oat mites

Blue oat mites have also hatched following good autumn rains in many parts of Victoria and NSW. In Victoria, reports have come from the Western District, Northern Country, North Central and the North East. It is likely that blue oat mites have hatched in the Gippsland region which has received good early rainfall. It is wise to be on the lookout for blue oat mites in the Southern Tablelands and South West Slopes of NSW. Lynda Crosby (farmer) has reported blue oat mites attacking oats in southern QLD. On advice, it was decided to spray with Dimethoate to protect the growing seedlings.

Blue oat mites are often mistaken for redlegged earth mites due to their similar appearance and sympatric life-cycle. However, blue oat mites and the redlegged earth mite differ markedly in their biology and tolerance to pesticides, and require separate management strategies. Blue oat mites are the most abundant earth mites in many cropping and pastoral areas of Victoria, Tasmania and NSW.

Reports of blue oat mite outbreaks have been in pastures and newly sown crops, particularly canola and cereals. Chemical spraying of paddocks during the spring prior to the cropping year (as for redlegged earth mite control), is not an effective strategy for controlling blue oat mites; instead, target these within two to three weeks of emergence. This approach should protect newly germinated seedlings, which are most prone to mite attack. Be aware, continual monitoring of mite populations is needed and some damage to emerging pasture and crop plants may already have occurred by the time sprays are applied.

Non-chemical options are available for blue oat mites. For instance, pasture and crop rotations can limit the need for any pesticide spraying in a given year. Crops such as chickpeas and some lentil varieties are generally poor hosts of earth mites. As with redlegged earth mites, weed control can suppress the build up of blue oat mites during the growing season.