A native bug has been destroying Victorian olive crops, with some growers losing almost their entire annual harvest.
Michael Freudenstein, who farms between the north-east Victorian towns of Myrtleford and Bright, said he had never seen his 1,000-tree olive grove so bare.
“This is the first year we’ve had an attack of this lace bug, and it’s been quick and extensive,” he said.
Mr Freudenstein is one of several Victorian farmers battling the olive lace bug, a sap-sucking native insect which targets olive trees.
“Between 70 and 75 per cent of our trees have been badly damaged,” he said.
“We should save the rest, but we won’t get a crop this year.”
Spreading ‘far and wide’
Mr Freudenstein came back from his Christmas break to find his grove infested.
“There was some deterioration of some of the leaves before we left in November, but I didn’t know whether it was a nutrient issue or something else,” he said.
“So I left it, but when we came back the trees were totally denuded of leaf.”
Australian Olive Association Victorian representative Tina Knight said Mr Freudenstein’s experience was far from isolated.
She said she had been fielding calls from distressed farmers across north-central Victoria affected by the bug “and asking what they can do about it”.
“Once they hatch and grow wings, they’re spreading far and wide … especially with some of the strong winds we’ve had,” Ms Knight said.
She said she was managing an infestation at her own 27,000-tree grove at Rushworth in central Victoria.
“We thought better have a look in our own grove, and when we did, we found about four patches of trees infested with lace bugs,” she said.
Pest paradise
Agriculture Victoria plant pests and diseases manager Chris Pittock said the spike in infestations was likely due to recent favourable weather conditions for the bug.
He said last year’s mild winter and spring and “a not-too-hot summer” had led to the infestation.
“So what we’re seeing at the moment is insects are quite comfortable, because they’ve got a lush environment to feed off and live in,” he said.
Some growers have been applying chemical sprays to curb the problem pest, but Mr Freudenstein said it wasn’t a silver bullet.
“We sprayed the grove once, but it didn’t knock everything out because there were some sort of eggs still on the leaves,” he said.
“You turn the leaves over, you could see up to 10 or 15 on the back of each leaf.
“Once they take hold, they just multiply.”
Damage bill
Battling lace bug infestations is proving costly for affected olive growers.
Mr Freudenstein said chemicals and labour had become major expenses.
“The pesticide costs more than $400 for 20 litres, and it’s another $3,000 a day to get the arborist in to trim all the trees back so they can regrow,” he said.
“So that’s a serious amount of money, and you’ve got to sell a lot of product to recoup that sort of investment.”
Mr Freudenstein, who sells his own olive oil, said with only 25 per cent of his usual crop available, some of his customers could be disappointed.
“It’ll impact us greatly because we’ve only got 1,000 trees, so this season our oil production will be way down and we’ll probably get a smaller crop next year as well,” he said.
But Ms Knight said a global undersupply of olive oil could spare growers from more pain.
“Spain is the biggest producer of oil in the world, but it’s had two bad years in a row so the global price of olive oil has gone up quite markedly in the last 12 months,” she said.
“So while we might get a reduced crop, hopefully we can get a higher percentage of oil from our crop to then sell it at a good price.”
Boosting biosecurity
Mr Freudenstein was also concerned poor biosecurity practices could be increasing the spread of pests like the lace bug.
“In the grape industry, biosecurity is really tight because whenever a harvester comes into a grove, it has been in a heat room and is totally clean,” he said.
“Whereas with the olive industry, the harvesters just travel around from grove to grove and if someone has an infestation, then it’s quite likely that they will carry eggs and bugs into the next grove.”
An Agriculture Victoria spokesperson said machinery hygiene was critical.
“Cleaning the vehicle from the top down, including floors and tyres of soil, plant material and pests, especially after visiting other properties, is important,” the spokesperson said.
“Growers can also let contractors know of any declared or notifiable pests are already present in the property.”
According to Ms Knight, more attention must be paid to untended groves.
“Perhaps the government can look at groves that have been abandoned, because they then become a real pool for the diseases and bugs that affect olive growers,” she said.
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