The most effective LBAM programs typically combine several management strategies.
| Management approach | Key consideration |
|---|
| Monitoring | Supports informed decisions and improves spray timing |
| Biological control | Products such as Bacillus thuringiensis (Bt) are most effective against young larvae |
| Beneficial insects | Natural predators and parasitoids can suppress populations below damaging levels |
| Mating disruption | Suitable for larger vineyard blocks where pest pressure is predictable |
| Weed and host plant management | Reduces alternative hosts and edge effects |
| Selective insecticides | Can provide control while minimising impacts on beneficial species when used appropriately |
Monitoring
LBAM pressure can change between sites and seasons. Use a systematic monitoring program and keep records so you can compare results over time.
Start by checking likely hot spots, including:
- susceptible varieties
- vineyard edges near weeds, trees or other vegetation
- blocks with a history of Botrytis or LBAM damage.
Hot-spot monitoring can help you find LBAM, but it does not represent the whole block. Sample across the block before deciding whether treatment is needed.
What to look for
Monitor for:
- egg masses on the upper surfaces of grapevine leaves
- young caterpillars along leaf veins, around shoot tips and within bunches
- larger caterpillars in rolled leaves, flowers and bunches
- webbing and feeding damage
- beneficial insects and signs of parasitism.
Monitoring is particularly important during flowering, when caterpillars and their webbing can be easier to find in bunches and more management options may be available.
Preliminary action thresholds
Action thresholds should be refined for your region, block, variety and production system. The following preliminary thresholds were developed for cooler regions with higher Botrytis pressure:
- more than 3 viable egg masses per 1,000 leaves
- more than 10 caterpillars per 100 shoots
- more than 10 caterpillars per 100 bunches.
Do not use these figures in isolation. Consider your monitoring results alongside the block’s Botrytis history, variety, beneficial insect activity and damage recorded at harvest.
Consistent monitoring and harvest assessments over several seasons will help you develop thresholds that are appropriate for your vineyard.
Using traps
Pheromone or lure traps can show when adult moths are active. However, trap catches do not reliably indicate the number of caterpillars or whether treatment is needed.
Use trap catches as a prompt to inspect vines for egg masses and caterpillars.
Protect beneficial insects
Predators and parasitoids can help keep LBAM below damaging levels. These include:
- lacewings
- spiders
- predatory shield bugs
- parasitoid wasps, including Dolichogenidea tasmanica and Trichogramma species.
Consider the number and activity of beneficial insects when assessing your vineyard’s risk. Where possible, choose management options that minimise harm to these natural enemies.
Manage weeds and other host plants
LBAM can survive on many plants, including clovers, capeweed, docks and other broadleaf weeds. Caterpillars may overwinter in vineyard-floor vegetation, bunch remnants or nearby vegetation.
Managing broadleaf weeds and other host plants before budburst may reduce overwintering sites and LBAM pressure. However, diverse groundcovers can also provide food and shelter for beneficial insects.
Balance host-plant management with the need to protect beneficial insect habitat. Monitor vineyard-floor plants to understand whether they are contributing to LBAM pressure in your vineyard.
Decide whether control is needed
Base control decisions on:
- monitoring results
- the grape variety
- the block’s history of Botrytis and LBAM damage
- beneficial insect activity
- the likely cost of crop loss or reduced quality
- the cost and potential impact of treatment.
Where treatment is justified, target eggs as they hatch and small caterpillars before they establish protected feeding sites.
Controls targeting caterpillars are generally most effective:
- soon after egg hatch
- before caterpillars reach 3–5 mm long
- before caterpillars build shelters or webbing.
Monitor again after treatment to check its effectiveness. Allow for the period stated on the product label before assessing the result.
Before using an agrochemical, check:
- that the product is currently registered or permitted for the intended use
- the product label and application requirements
- withholding periods and maximum residue limits
- state or territory requirements
- any winery restrictions.
