Seeking a solution for light brown apple moth

Seeking a solution for light brown apple moth

The Clare Valley is renowned for its world-class wine, but among its beautiful vineyards, light brown apple moth (LBAM) - a small, native insect - is causing some issues, and it has grape growers looking for a solution.

LBAM has the potential to decrease grape yields and increase susceptibility of vines to disease, particularly during a cooler summer, as was experienced in 2022-2023.

On the back of this, the region’s grape growers were successful in gaining Northern and Yorke Landscape Board Grassroots Grants funding to leverage trials being undertaken in two local test sites.

Clare Valley Wine & Grape Association (CVWGA) engagement and education officer Rachel Trengove said the funding had directly enabled the group to engage an expert entomologist to assist in monitoring the insects.

“Light brown apple moth caterpillars feed on leaves, flowers and bunches, but the significant cost is seen in the reduction of both yield and quality of winegrapes by increasing the susceptibility of grapes to diseases such as botrytis,” she said.

Seeking a solution for light brown apple moth

The Grassroots Grants funding has built on an already-established project, with CVWGA working on demonstrating best-practice integrated pest management for the control of LBAM by increasing biodiversity. Two demonstration sites have been established as part of the EcoVineyards program and have put the moth firmly in the sights of the local industry.

Clare Valley grape grower Ben Castine has a shiraz vineyard hosting native species under vine plantings. Meanwhile, Skillogallee Estate has planted a permanent sward of Wallaby grass in the mid-row of one of its Riesling blocks. Both have the capacity to provide habitat for natural predatory insects, with the potential for biocontrol of LBAM.

“What we are really asking is, do we see more beneficial insects in the EcoVineyards demonstration sites with greater plant diversity providing habitat,” Rachel said. “And if so, does it have a beneficial effect on reducing LBAM numbers in comparison to conventionally-managed blocks?”

While the study is ongoing, the localised results are expected to be shared with CVWGA’s 150 members after the 2024 vintage.

Seeking a solution for light brown apple moth

It is already known that damage caused by LBAM is often worse in seasons where cool conditions extend into summer, and as a result, the 2022-2023 grape growing season in the Clare Valley was particularly challenging with vines more susceptible to disease. It was a timely boost for the CVWGA to receive the Grassroots Grants funding to further its field research.

The funding meant that experienced entomologist Dr Michael Nash was able to be engaged to help the CVWGA leverage its existing EcoVineyards trials, assisting with insect counts and eventually the delivery of results to growers.

“It is important to find solutions targeting successful control of the moth and other determinantal insects,” Rachel said. “One solution is integrated pest management – a technique using a combination of biological, cultural and chemical control to holistically reduce the incidence of problematic pests.”

It is hoped the study will provide some answers to the problem and give growers a greater insight into how to manage LBAM in their vineyards. Rachel said the Grassroots Grants funding had partnered perfectly with the group’s already-established programs and growers’ thirst for information.

“Biocontrol of pests and diseases has gained increasing interest from Clare Valley grape growers and winemakers due to growing concerns about environmental impact and sustainability, so the Grassroots Grant has been a timely investment,” she said.