They’re affectionally known as ‘Doreens’ and growers within the Greater NSW/ACT wine regions are hoping they’ll munch their way to controlling unwanted pests in the vineyard.
In an innovative Wine Australia Regional Program initiative, millions of native Australian mites (Typhlodromus doreenae) – or ‘Doreens’ – have been released via Unmanned Aerial Vehicle (UAV) drone technology across 12 vineyards in Orange and Mudgee.
It is hoped the mites will combat pests such as bud, blister and rust mite that can have a devastating effect on vines by stunting growth, reducing yield and impacting leaf photosynthesis.
Photo: Parabug Australia UAV releasing beneficial predatory mites (Darren Fahey, NSW DPI)
The initiative came about when NSW Department of Primary Industries viticulture development officer Darren Fahey noticed significant damage from pest mites across numerous vineyards in both Mudgee and Orange after the drought ended in 2020.
“Because mites are microscopic in size, many growers tend to only see the damage when it’s all too late,” Darren said.
“Similar to symptoms caused by restricted spring growth and cold injury, bud mites move up the growing shoot tip after budburst and bury themselves into next year’s buds where they feed – causing malformation of leaves, aborted or damaged bunch structures, tip death and even bud death.”
Photo: Bud mite tracks and small bunch structure are visible signs of bud mite damage (Darren Fahey, NSW DPI)
Darren said growers had only a very short window to manage bud mite as they migrated between old and new buds from the woolly bud stage. “Within a three-week period, bud mites bury themselves again in the developing buds, so timing of control measures is critical.”
Chemical applications and high rates of sulfur can also reduce beneficial predatory mites that can assist in managing population dynamics between pest mites and beneficials.
The initiative has been carried out with the help of commerical insectorary Biological Services, who were approached to breed up large numbers of Doreens for release; while UAV drone flights were contracted out to Parabug Australia, who conduct biological control releases of beneficial predatory insects across horticulture and agriculture industries.
Darren said releasing a large volume of predatory mites when the canopy was at its maximum growth stage in summer helped to guarantee survival of Doreen.
“Because Dorreen feeds on blister and rust mite that are present at that time of the season, populations should remain viable over winter to be there to feed on the bud mite as it comes to migrate during bud burst period.”
The project team will collect leaves to assess mite populations and identification of species found across several sites covered in the trial. They hope that by increasing the numbers of predators, they should see less damage into proceeding seasons.
Darren said growers should keep vigilant for symptoms of blister mite on leaves throughout the season. “Leaf bronzing is an indicator of rust mite during the grape harvest period and assessments for overwintering bud mite in pruned shoots can be made when viewing bud dissections under a stereo microscope.”