Australia: Watch for major olive pest
The olive lace bug is one of those pests that does its damage quietly — a tiny sap-sucker that mottles the leaves, saps the tree’s vigour and dents next season’s crop before many growers notice. Knowing the early signs is half the battle.
Froggattia olivina, the olive lace bug, is a small native Australian insect that has made the cultivated olive its favourite host. It is established across the mainland olive states and, left alone, it can do real harm: heavy infestations cause leaf yellowing, leaf drop, loss of vigour and reduced yield — sometimes for a season or two afterwards, because a weakened tree carries the setback forward. The frustrating part is how easy it is to miss until the damage is done.
What it is and how it feeds
The adult is only about three millimetres long, flat, mottled brown and cream, with lacy transparent wings held flat over the body and long dark-tipped antennae. The wingless nymphs pass through several stages, shifting from pale green or yellow to orange and near-black in the final instar. Both feed the same way — by sucking sap from the underside of the leaf. That feeding is the whole problem: strip enough sap and the leaf can no longer do its job.
Reading the leaf
The tree tells you before the insect does. The first clue is a fine yellow mottling on the upper leaf surface — pinhead spots where sap has been drawn out from below. Turn the leaf over and you find the confirmation: dark, blackish smears of the bugs’ excrement on the underside, often with the insects themselves. Scout for this from spring and through summer; populations build across the warm months and can peak surprisingly late in the season.
Keeping it in check
Control is about timing more than firepower. Because the bug runs several overlapping generations and over-wintering eggs hatch in waves, a single treatment rarely finishes the job — a follow-up a week or two later catches the nymphs that emerge after the first pass. Pruning out badly infested growth both removes bugs and helps a battered tree recover. Chemical options exist and are regulated; growers should check the current label and their local pesticides authority before spraying, and lean on early detection so they can act small rather than late.
| Pest | Olive lace bug (Froggattia olivina) |
|---|---|
| Origin | Native to Australia |
| Adult size | About 3 mm; flat, mottled brown and cream |
| Feeding | Sap-sucking from the leaf underside |
| First sign | Yellow pinhead mottling on upper leaf surface |
| Under the leaf | Dark excrement smears; bugs present |
| Generations | 2–4 per season; can peak late |
| Control | Scout from spring; time treatments; repeat; prune |
A grower’s checklist
- Scout from early spring and through summer — turn leaves over and look underneath.
- Watch for yellow mottling on top and dark smears below; that pairing is the tell.
- Plan for a follow-up treatment 10–14 days after the first — one pass misses the next hatch.
- Prune hard-hit wood to remove bugs and help the tree bounce back.
- Check current label and authority before using any chemical control.
Olive lace bug: common questions
What does olive lace bug do to a tree?
It sucks sap from the leaves, causing yellow mottling, leaf drop and loss of vigour. Heavy infestations can cut yield for a season or two.
How do I know if I have it?
Look for pinhead yellow spotting on the upper leaf surface and dark excrement smears on the underside, often with the small lacy-winged bugs present.
When should I look for it?
From spring and through summer. Populations build over the warm months and can peak late in the season.
Why does one spray not fix it?
The bug runs several overlapping generations and eggs hatch in waves, so a follow-up treatment 10–14 days later is needed to catch newly emerged nymphs.
Can pruning help?
Yes — removing badly infested growth takes out bugs and helps a weakened tree recover its vigour.
The lace bug’s whole trick is being boring to look at and slow to show. By the time a tree looks obviously sick, you have lost ground that takes a season to win back. So the real skill is not the spray, it is the habit: turn a few leaves over every time you walk the grove in spring and summer. Yellow freckling on top, black specks underneath — act on that, small and early, and you never meet the version of this pest that drops half the canopy.
Drawn from Australian olive-industry advisories on olive lace bug identification and management.