Olive lace bug (Froggattia olivina): how to identify it and when to spray
Olive lace bug (Froggattia olivina) is a native Australian sap-sucking insect that attacks olive trees. Left unchecked it can strip a grove of leaves in a single season. This guide explains how to identify it, why the underside of the leaf matters, how its life cycle drives spray timing, and what growers must check before reaching for any product.
How to identify olive lace bug
- Adults are about 3 mm long with clear, lacy, net-veined wings held flat over the body.
- Nymphs are smaller, wingless, dark and spiny, and cluster on the leaf underside.
- Damage shows on the upper leaf surface as pale yellow or bronzed mottling and stippling.
- Turn the leaf over: you will see the insects plus dark, varnish-like specks of excrement.
- Heavy infestations cause leaf drop, dieback, reduced fruit set and weakened trees.
Why underside feeding changes everything
Olive lace bug feeds and breeds almost exclusively on the underside of the leaf. Contact insecticides only work on what they physically touch, so a spray that wets only the top of the canopy will miss the pest entirely. Aim for thorough coverage of the leaf underside, spraying from below and from both sides of the tree, and use enough water to wet the canopy to the point of run-off.
Life cycle and what a contact spray can reach
| Stage | Where it is | Killed by a contact spray? |
|---|---|---|
| Eggs | Inserted into the leaf tissue on the underside | No – eggs are protected inside the leaf and are NOT killed by contact insecticides |
| Nymphs | Clustered on the leaf underside | Yes – but only if the spray physically contacts the underside |
| Adults | Leaf underside, mobile within the canopy | Yes – but only if the spray physically contacts the underside |
The 12–14 day follow-up spray
Because eggs sitting inside the leaf survive the first application, a single spray never gives control. Eggs keep hatching after you spray, so plan a follow-up application about 12–14 days after the first to kill the newly emerged nymphs before they mature and lay again. Keep monitoring leaf undersides after the second spray; in a bad season further rounds may be needed.
Important: read the label
The information on this page is general horticultural information about olive lace bug and its biology. The Py-Bo label covers three situations (fruit and vegetable crops, cut flowers and ornamentals; buildings including agricultural sheds; outdoors for flying insects). Always read the label on the pack and follow the rate and directions for your situation. If you are unsure, ask your agronomist or state department of agriculture.
Py-Bo product information
- Py-Bo is a pyrethrin-based contact insecticide used at 1 mL per litre of water.
- Withholding period (WHP): 1 day.
- Pyrethrins break down quickly and have no residual activity, which is why coverage and follow-up timing matter so much.
- Always read and follow the current registered label before use.
Protecting bees
Pyrethrins are toxic to bees. Spray after dark, once bees have stopped foraging, and avoid spraying flowering trees or flowering ground cover during the day. Notify nearby beekeepers before you spray. Spraying after dark also reduces drift and slows evaporation, which improves coverage on the leaf underside.
Quick reference
| Pest | Olive lace bug (Froggattia olivina) |
| Host | Olive trees |
| Key symptom | Yellow or bronze stippling on upper leaf surface; insects and dark specks underneath |
| Spray target | Leaf underside, to run-off |
| Follow-up | 12–14 days after the first spray |
| Py-Bo rate | 1 mL/L |
| Withholding period | 1 day |
| Bee safety | Spray after dark |
| Label | See label; contact only. Follow the rate and directions for your situation |
Frequently asked questions
Why did my trees look worse after one spray?
Existing leaf damage does not repair itself, and eggs inside the leaf keep hatching after the first application. Judge success by whether you are finding live nymphs on leaf undersides, not by the appearance of already-damaged leaves.
Do I really need a second spray?
Yes. A contact spray does not kill the eggs, so a follow-up at 12–14 days is what breaks the cycle.
Can I use Py-Bo on olive lace bug?
Py-Bo is a contact spray, so it has to reach the nymphs and adults on the leaf undersides. The Py-Bo label covers three situations (fruit and vegetable crops, cut flowers and ornamentals; buildings including agricultural sheds; outdoors for flying insects). Always read the label on the pack and follow the rate and directions for your situation.
When is the best time of day to spray?
After dark, to protect foraging bees and to get better coverage in cooler, calmer conditions.
How soon can I harvest?
The Py-Bo withholding period is 1 day, but always confirm the WHP on the current label for your situation.