Citrus Leaf Miner

2020 has been a  particularly bad year for Citrus Leaf Miner

This season has been remarkably bad for citrus leaf miner - with a likely reason being an infestation brought into the region with changing weather conditions.

Citrus leaf miner is a pest that attacks all varieties of citrus, including some Australian native species. The adult is a tiny, night flying moth with a wingspan of only five millimetres. But it's not the moth that actually does the damage, it's their larvae. Eggs are laid on new leaves where they hatch and tunnel or mine their way through the leaves leaving a squiggly, silver trail in their path.

• Symptoms: Squiggly lines on the leaves are the first sign and the leaves then become distorted, which inhibits their photosynthesising ability. This won't kill trees, but they will be stunted and unhealthy, reducing yield. When fully grown, the larvae will curl the leaf around for protection while they pupate. The cycle only takes two to three weeks, so it's quite possible for numerous generations to occur in a season.
• Control: Natural predators such as parasitic wasps and lacewings are useful with helping to control them but unfortunately they're not always around. A simple organic solution is possible if action is taken when the pest is first noticed. Cut off any damaged, curled or rolled leaves that might be hiding the pupae. Spray with horticultural oil to deter the moth from laying new eggs. The oil won't kill the larvae which is why it's important to remove any infested growth. Spray first thing in the morning to avoid spraying beneficial insects which are less active at this time. This also reduces the chance of burning foliage. 
• Response: Neem oil remains the best remedy for this bug and you are always best to use a certified variety rather than a synthetic option. 

​It is critical to note that the full benefits of neem are only realised when the active ingredient from the oil is extracted, processed and bottled correctly. Otherwise you risk buying and using a product that will not be as effective as needed. At The Garden Shed Nursery, we have developed a concentrate called Neem Active - that contains only the constituent ingredient that actually kills bugs. A 250ml bottle (used with our directions) should last you months.