Invasive flower thrips threaten Australian berry crops
An invasive pest detected in Australia has caused millions of dollars in damage to berry crops in Queensland and could spread to other fruit and vegetable produce, raising concerns about supermarket prices if it is not contained.
Invasive flower thrips, formally identified as the intonsa variant, were first detected in Australia three years ago but only recently confirmed by authorities. The insects are currently attacking berry farms across southeast Queensland, where standard insecticides have proven ineffective.
What damage are the thrips causing?
Farmers have been forced to discard tonnes of fruit rendered unusable by the pest. Adrian Schultz, President of the Queensland Strawberry Growers Association, described the impact to ABC Radio National.
“This is a rasping insect; it creates damage to the structure of the [fruit's] skin from a really early stage, in the flowering stage. That damage stays with the fruit; it results in what we call a bit of a bronzing colour. It breaks down the structural integrity of the skin, so every time we get a bit of rain... the fruit basically falls apart.”
Experts fear the pest could extend beyond berries to other fruit and vegetable crops, potentially adding further pressure to the national produce supply.
How can farmers control the pest?
While authorities investigate how the thrips breached Australia's biosecurity measures, growers are exploring control methods. Schultz noted that predator bugs have been used effectively in other parts of the world, particularly in protected cropping environments such as tunnel-grown strawberries and raspberries.
However, the predator insects are fragile and can be harmed by temperature fluctuations or the application of other chemical sprays. Trial work is underway on farms to find a viable solution for the next growing season.
All of Australia's winter strawberry production comes from Queensland. As the season transitions to summer, production shifts to Victoria, Western Australia and Tasmania, giving growers limited time to prepare.
How did the intonsa flower thrips arrive in Australia?
Schultz explained that the insect remained unidentified because various thrips species are present in Australia at all times. The recent surge in numbers, likely driven by weather conditions, allowed scientists to identify the intonsa variant.
“That's probably coming from New Zealand,” Schultz said, though the exact pathway of introduction remains under investigation.
The case has highlighted the importance of biosecurity declarations for travellers who have visited farms overseas. Schultz noted that the pest can survive on clothing for three to four days, making it extremely difficult to detect at the border.
What is the outlook for Australian produce?
Biosecurity authorities are working to determine how the pest entered the country and to assess the risk of spread. For growers, the immediate priority is finding an effective control method before the summer production season begins.
The situation underscores the ongoing challenges facing Australian agriculture from invasive species and the importance of robust biosecurity measures to protect domestic food production.