Entomologist Dr David Logan’s love of nature sprouted while growing up in New Guinea where his parents were missionaries.
Born in Wudinna, South Australia, but raised in New Guinea, Dr Logan’s career has taken him from the Northern Territory to Queensland and then New Zealand before returning to Australia last year to take up a position as Senior Research Fellow in Pest Management, funded jointly by the University of Adelaide and the South Australian Research & Development Institute (SARDI).
After completing his schooling in New Guinea, Dr Logan returned to Australia for his tertiary studies, first at Queensland Agricultural College and then Queensland University where he studied entomology. With both his parents hailing from farming families – his mum’s from Western Australia and his dad’s from Queensland – a future career in agriculture was in his blood.
But Dr Logan’s first scientific role saw him involved with entomology of a medical nature while based in Darwin. He would return to Queensland, specifically Bundaberg, to complete a PhD on canegrubs – the larvae of cane beetles – which are a significant economic pest of sugarcane. Remaining in the sugar industry, he subsequently moved to northern Queensland to work for Sugar Research Australia, an industry-owned research and development company for the Australian sugarcane industry.
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| David Logan and fellow entomologist Hieu Bui |
After nine years working in the industry, Dr Logan and his family moved to Te Puke, in the Bay of Plenty on the north island of New Zealand where around 80% of the nation’s kiwifruit is grown. Working for the Horticulture and Food Research Institute of New Zealand, now known as the New Zealand Institute for Plant and Food Research (NZPFR), he spent much of his time focussing on Integrated Pest Management predominantly in kiwifruit but also avocados, the other major crop produced in the Bay of Plenty region.
Much of Dr Logan’s role during this time involved working with growers to solve industry problems – a collaboration he continues to value and foster to this day.
After 21 years in New Zealand, evident by a faint hint of Kiwi accent, Dr Logan returned to Adelaide to assume his joint position with SARDI and the University of Adelaide in February 2023.
His newly-created role “supports research links between the two organisations” with a focus on entomology. Based on his New Zealand experience, Dr Logan is keen to continue supporting the horticulture industries, including winegrapes.
He is now the lead researcher in a three-year collaborative project on grapevine scale biology and monitoring in Australian vineyards, jointly funded by SARDI and Wine Australia. Assisted by fellow entomologist Hieu Bui, the aim of the project is to help the sector manage and mitigate scale-related issues in Australian vineyards.
“There was thought to be two species of scale in Australia until surveys were done, including by the AWRI, that suggested a third species was in the mix,” Dr Logan explains. “We want to confirm the presence of this third species, determine how widespread it is and whether it’s causing the scale issue currently affecting vineyards.
“Knowing what species of scale are prevalent is important as this affects their management.
“We need to compare the biology of each species to see whether they differ at all. That information will have an impact on when you can spray because there’s a period when scale are very young that they are most easily controlled. We need to identify when that period is for each of the species found in different regions.”
Dr Logan said scale had been found in Western Australia, the Riverina, theRiverland, Langhorne Creek, Barossa Valley, McLaren Vale, the Adelaide Hills, and the Hunter Valley. “Scale does seem to be fairly widespread throughout Australia. Most of our site visits are taking place in the Riverland, McLaren Vale, Langhorne Creek and the Adelaide Hills. For other regions, photos and samples of scale supplied by growers during the recent spring season are being used to further build on the knowledge of the prevalence of scale species in those areas.
“Where you have heavy scale infestations you get reduced vine growth. Some species of scale have also been confirmed as transmitting viruses, such as leafroll viruses that will cause long-term decline in vines. Honeydew and sooty mould caused by scale can also be a visual blight on winegrapes and lead to rejection by wineries.” Dr Logan said.
“Understanding the phenology of the scale species present in Australia is also a goal of the project. Having a clearer understanding of their lifecycles will also better inform how to manage them.
“Although the current understanding is that scale have a one-year lifecycle, there have been suggestions that a second generation exists, which would also have implications for management.”
The project is also aiming to establish when each scale species reaches the crawler stage, when the insects are most susceptible to control, and how this relates to growth stages of grapevines, which will help guide applications of chemical control agents, particularly with respect to withholding limits.