Tomato Leaf Miner
On Crops: Tomato
Throughout the UK and Europe. A notifiable pest in Northern Ireland
The adult tomato leaf miner is a small dark-coloured fly with a yellow dot on its back, approximately 4mm in length. The female flies make small puncture marks usually around the edges of tomato leaves in order to feed and lay eggs. Eggs hatch into maggots that burrow under the leaf surface creating tunnels as they feed and grow. At the end of their mining, the maggots usually exit the leaf and turn into small brown-black pupae on the leaf surface or fall to the ground.
Tomato leaf miner larvae feed on the cells within tomato leaves and create silvery lines across the infested leaves. In low numbers, tomato leaf miner damage is usually cosmetic, however severe infestations will reduce the photosynthetic capabilities of the plant and reduce its vigour and yields.
Yellow sticky traps placed near plants can capture many adults before they lay eggs on plants. Leaves that display the small white dots around their edges can be removed and destroyed.
Leaves displaying the larval mines can be removed and destroyed. Pupae that have formed on the leaves can also be removed and destroyed. Parasitic wasps can be purchased and released around affected plants when they are grown in greenhouses.
Tomato leaf miners are rarely a problem on outdoor grown tomatoes and therefore do not require controlling on outdoor crops.