PestChewing insects
Sawfly larvae
Caterpillar-like larvae of sawflies that can strip gooseberries, currants and roses of their leaves in days.
Also known as: Gooseberry sawfly, Rose sawfly
Symptoms and identification
Leaves are eaten from the edges inward, often starting in the centre of the bush, until only the veins remain. Groups of small green, often spotted larvae feed together.
Causes
Adult sawflies lay eggs on leaves in spring, with several generations through summer.
Organic treatment
Pick off larvae by hand or shake them onto a sheet. Unlike caterpillars, sawfly larvae are not affected by Bt.
Prevention
Inspect the centre of bushes and leaf undersides from mid-spring.
Chemical treatment (use with care)
Use an insecticide labelled for sawfly larvae on that plant, following the label.