All olive growers are being told to check their trees for damage caused by the olive lace bug (Froggattia olivinia) which can defoliate entire trees.
Immediate action is required if the bug is found on leaves.
So far the species has been found in olive groves in the Strathbogie Shire and near Seymour and Rushworth.
The indigenous bug lives in native forests but has taken the opportunity of recent high winds to reach olive plantations.
The olive is the species’ preferred host tree.
Australian Olive Association Victorian representative Tina Knight said growers needed to act fast.
“Some people who don’t know what it is and then don’t act immediately find that it defoliates the trees very rapidly,” Ms Knight said.
“They either haven’t known what is was or they haven’t dealt with it once they find out.”
“When these little bugs get airborne and you have it arrive in the grove and it lays lots of eggs, its population will grow exponentially throughout the grove.
“They are sucking food out of the leaf so you see small holes on the leaf that looks like but is not peacock spot.”
(Peacock spot, Spilocaea oleaginea, is a widespread fungal disease that affects leaves and fruit of olive trees.)
One Ovens Valley farmer returned from a holiday in March to find about three quarters of his trees completely defoliated by olive lace bug attack.
Ms Knight said growers throughout Victoria were ‘very good’ with biosecurity, but there was still need to get the word out to fulfil obligations to other growers.
“Be vigilant with continually monitoring the growth — know what you are looking for,” she said.
“There will be a mottled leaf, and on the underside there will be eggs and crawlers.
“Then you have to deal with it: two sprays at two weeks apart.
“As soon as you see it, you need to undertake the first spray.
“That very day.”
