Wine Industry Newsletter

Entomologist reflects on 47 years in R&D

Stewart Learmonth
Retiring senior entomologist Stewart Learmonth has been witness to the impact of insect pests on the emergence and success of many of Western Australia’s agricultural crops over a career that has spanned nearly half a century and the state.

Retiring Senior Entomologist Stewart Learmonth has been witness to the impact of insect pests on many of Western Australia’s agricultural crops over a career that has spanned nearly half a century and the State.

The University of Queensland graduate started his 47 years as an entomologist with the then Department of Agriculture in Kununurra in 1973, after a short stint at the South Perth office.

Then the Ord River Irrigation Area was in its infancy and cotton was the main crop.

Stewart spent the next three years working alongside his mentor Phil Michael to mitigate the impact of a range of pests on the northern cotton crop.

“Every crop has a suite of pests so it was a great learning curve for a young entomologist,” he said.

“There’s an old adage that goes: you need an agronomist to find the right crop and 10 entomologists to sort out the pest issues – that was certainly the case in Kununurra.”

With help from Dr Mike Carroll, who went on to become Director General, Stewart then took a two year sabbatical to study for his Masters Degree at the Waite Institute in South Australia before returning to Kununurra, to find the landscape had changed dramatically.

“Cotton was no longer king and a wide range of other crops were being grown to try to find replacements,” he said.

In 1986 Stewart moved to the department’s Manjimup office, where he initially worked with the CSIRO seeking alternatives to organochlorine insecticides to control soil pests of potatoes.

“The removal of these insecticides changed the industry overnight,” he said. “One day you had organochlorines and the next day you didn’t.

“It was a frustrating time for industry but exciting times for a scientist.”

Stewart has been based at Manjimup ever since, where he has been involved in entomological research alongside the development of a range of crops.

Stewart was introduced to viticulture through his studies into the life cycle and management of garden weevil in the late 1980's which cumulated into a research partnership with Curtin University titled ‘Sustainable protection of grapevines from garden weevil’ completed in 2011.

From this time Stewart has worked on grapevine pests such as African black beetle, mealy bug, apple looper, six-spotted mite, auger beetles, rust mite and thrips.

Stewart has presented at numerous wine and table grape workshops over the years across many (if not all) regions. He fondly remembers the series of Research to Practice workshops on Integrated Pest Management (IPM) in the early 2000’s when the industry was expanding and engagement with stakeholders was high.

More recently, Stewart has been involved with research to assist the expanding avocado industry by reducing the impact of six-spotted mite through the use of beneficials.

He has also worked with the Australian truffle industry contributing to an IPM manual and a field guide.

Stewart said he feels privileged to have worked alongside innovative farmers and many wonderful colleagues, including mentors and technical officers.

“The department has been a terrific place to work,” he said. “It seems to attract good, hard working people, who are happy to put in the hours and work well with industry.”

Stewart offers his thanks to the many vignerons he has had contact with over the years especially for their generosity of their time, access to vineyards and sharing of information.

His work on avocados, truffles, grapes and a suite of other crops will be continued by his colleague, DPIRD research scientist Alison Mathews.