New insect pests are disrupting biosecurity and destroying berry crops

A devastating insect pest first discovered in Australia is destroying millions of dollars’ worth of berry crops and could drive up food prices.

South east Queensland growers are on the front line of what could be a wide-ranging battle facing fruit, vegetable, flower, nursery and cotton growers and home gardeners.

It is not known how flower thrips enters. Frankliniella intonsa evaded national biosecurity measures designed to prevent the pest from entering the country.

Overseas, it is a serious pest of crops including green beans, squash, cucumbers, melons, peppers, asparagus, alfalfa, cotton and cut flowers.

Tiny flower thrips, 1.2 to 1.8 millimeters long, are attacking strawberry, raspberry and blackberry crops in the Moreton Bay and Sunshine Coast regions.

Biosecurity Queensland officially confirmed Australia’s first detection of the insect in April in damaged raspberries at Elimba Farm.

Strawberry growers in south-east Queensland say insecticides have failed to control thrips, which is listed as an emergency plant pest, and their numbers have skyrocketed.

Growers throw out tons of damaged fruit during the peak season.

“The Perfect Storm of Insects”

Intons Thrips feed and lay eggs inside inflorescences and on young developing fruits.

Their crude mouthparts rupture and suck fluid from plant cells, causing scarring that can reduce crop yield, productivity and marketability.

Although affected fruits are perfectly safe to eat, they are vulnerable to cracking and rain damage.

Queensland Strawberry Growers President Adrian Schultz said. Frankliniella intonsa Combined with the impact of the varroa mite on honey bees, a “perfect storm of insects” has emerged.

“His [intonsa is] absolutely, it has completely and completely infiltrated all the strawberry growing areas of south-east Queensland.

“We’re looking at millions of dollars…on average, most farms [in south-east Queensland] will lose at least 50 percent of their harvest.”

Farmers under pressure

The new pest adds to the financial burden on producers caused by bird damage and rainfall, increased wage costs, and higher packaging and transportation costs caused by the war in Iran.

Mr. Schultz believes Frankliniella intonsa may have been spreading under the radar for several years, and said the industry is working hard to better understand and manage it.

He said losses in the strawberry crop would likely impact consumers.

“I wouldn’t be surprised if in a couple of weeks prices are significantly higher than they are now.”

“Devastating, scary”

At Glass House Mountain, Brandon Hoyle sends only his best, sweet, ripe, red, certified organic, conventionally grown strawberries to market.

But pickers now compost up to 70 percent of its fruit.

“It was terrible, it was devastating… it’s terrible to see the loss,” Mr Hoyle said.

“Efficiency is everything in agriculture and we rely on high-yield crops, efficient harvesting and packaging to try and keep production costs down.

“It throws everything into disarray because the numbers don’t work anymore, especially when strawberries are relatively cheap in stores.”

Natural predators

Paul Jones raises beneficial insects and helps strawberry growers control pests using natural predators.

He said before Frankliniella intonsaother thrips species found in strawberry crops were “beneficial plant pollinators” and “generally not a problem.”

“But the impact of this season has been very devastating for growers,” Mr Jones said.

The director of Bugs for Bugs said that the natural enemies of flower thrips are the predatory mite and the pirate bug.

But Mr Jones said that by the time they started releasing beneficial insects this year, the population of invasive flower thrips was too large for predators to “knock it down”.

“We think beneficial insects are the solution to this problem, but it’s all about timing.”

At the same time, he said customers can help by buying berries.

The pest is widespread

Frankliniella intonsa was first officially recorded in New Zealand in 2002, and has also been found in Europe, China, Taiwan, Vietnam, Japan, Canada and the United States.

It thrives at temperatures between 18 and 28 degrees Celsius.

Mr Jones said the insect may have survived the flight from New Zealand.

“Look, this is a tiny insect. New Zealand is not far from here – a three to four hour flight. It could have just gotten on someone’s clothes, you know, undetected during quarantine,” he said.

“It could be that simple, we don’t know.”

Children’s problems

Greenlife Industry Australia CEO Sean Cole said: Frankliniella intonsa was a global pest of nurseries and garden plants, and rotating three or four different pesticides was important to reduce the risk of chemical resistance.

Mr Cole called for increased vigilance at Australia’s borders.

“Although we do have surveillance of passengers and cargo coming into the country, it is much lower than we would probably like, meaning that a lot of things do end up in the custody of the custodian.”

Impact assessment

In a statement, Biosecurity Queensland said the department “conducted surveillance, diagnostics and technical assessment” of Frankliniella intonsa.

“Government and industry stakeholders will continue to work together to better understand the spread, impact and future management of this pest,” the statement said.