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Sempervivum leaf miner was first recorded in southern England during 2008. It has spread slowly but can cause serious damage to house leeks. It originates from mainland Europe.
Common name: Sempervivum leaf minerScientific name Cheilosia caerulescensPlants affected House leeks (Sempervivum tectorum, S. arachnoides and S. montanum)Main symptoms Outer leaves wilt and discolour;.may contain maggots Most active May to June and August to September
Sempervivum leaf miner is a hoverfly that as a larva mines the leaves of Sempervivum species.
You may see the following symptoms:
Over-watering or poor drainage can cause similar symptoms to sempervivum leaf miner, however closer examination should reveal the presence of plump whitish maggots, up to 8-10mm (about 3/8in) long, inside some of the damaged leaves.
Remove damaged leaves and larvae when you see them.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
The adult fly is 8-10mm (approx. 3/8in) long and is black with short whitish hairs on the thorax and abdomen. Eggs are laid on the foliage of house leeks in late spring to early summer, with a second generation in late summer.
After hatching, the larvae bore into the outer leaves and eat out the internal tissues. Each larva will mine several leaves before it is fully fed and ready to pupate in the soil.
Adults of the second generation emerge in July to August and further larval feeding occurs in August to September. This pest overwinters as pupae in the soil.
Allium leaf minerApple leaf miner Astrantia leaf minerBeet leaf mining fly Celery leaf mining fly Chrysanthemum leaf minerEchinops leafminer Hellebore leaf minerHolly leaf minerHolm oak leaf-mining mothsHorse chestnut leaf-mining mothGreen roofsLaburnum leaf mining moth Lilac leaf mining moth Pyracantha leaf-mining moth
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