Horse-chestnut leafminer

It won’t surprise you that the horse chestnut leaf miner Cameraria ohridella causes extensive damage in horse chestnut trees (Aesculus spp.). However, also maple trees (Acer spp.) can be seriously damaged by this pest. The horse chestnut leaf miner is a micro-moth that originates in Macedonia and has spread all over Europe. Time for action and a close follow-up!

What damage can the horse chestnut leaf miner cause?

• The larvae make mines causing clear damage. The mines can even overlap, due to which the leaves discolour and start to fall off.
• Damaged trees will develop fewer leaves in the following year as they have built up less reserves during the summer.
• Affected trees are more vulnerable for other pests and diseases.

How to control the horse chestnut leaf miner?

For monitoring and catching adult males, you can rely on the pheromone Cameraria ohhridella combined with traps such as the Funnel Trap^®.

What are the characteristics of the horse chestnut leaf miner?

• The larvae are 2 to 5 mm with remarkable deep indented segments.
• Full-grown larvae pupate in a silken cocoon inside the mine.
• The moths are 5 mm and have shiny, bright brown forewings with thin, silvery-white stripes.

What about the horse chestnut leaf miner’s life cycle?

• Females lay about 20 to 30 eggs on top of the leaf. The eggs hatch 2 to 3 weeks later.
• The horse chestnut leaf miners have 5 mobile larval stages and 2 pre-pupal stages.
• Cameraria ohridella hibernate as pupae inside the leaves that have fallen onto the ground.
• Pupae appear 4 weeks after hatching and adults emerge 2 weeks later.
• The number of generations depends on the climate as there are for example 5 generations in Southern Europe, 3 in Central Europe and 2 in Northern Europe.