Scientific name Phytomyza astrantiae
Plants affected Astrantia
Main cause Larvae of a leaf-mining fly tunnelling in the foliage
Timing April-May and July-August
What is astrantia leaf miner?
Astrantia leaf miner is a small fly which develops as larvae that feed within the foliage of astrantia plants.
The adult flies are 2mm long and greyish brown in colour. They feed by rasping the leaf surface, leaving small pale spots on the upper leaf surface.
More significant markings are caused by the creamy white larvae. They eat the internal tissues of the leaves and cause whitish brown discoloured blotches. The mines typically have a pale edge around the darker brownish centre.
There are two generations during the summer and by August each leaf can be affected by several mines.
Astrantia plants will survive and produce flowers, even when there is extensive leaf mining, so control measures are not necessary.
Affected leaves can be removed or the larvae squashed within the mines.
Leaf miners can be part of a healthy balanced garden, most species will have natural enemies including parasitoid wasps. Birds such as blue tits can sometimes open mines to consume the larvae within.
Pesticide controlNone of the pesticides available to home gardeners is likely to give good control of leaf miners.
Astrantia leaf miner has two generations during the summer. The females deposit their eggs on the foliage during April and July. The eggs hatch into legless larvae that tunnel into the foliage where they eat the internal tissues. The mines are initially linear but later broaden to form a whitish brown blotch mine. When fully fed, the larvae pupate within the mines.
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