Oak slug sawfly (Caliroa annulipes). This 7 mm wasp belongs to the temperate regions of the Northern Hemisphere. The larvae grow 1 cm long and look somewhat like slugs.
The wasps are active from May through September. The 1.5-cm-long caterpillars look alikes eat away the mesophyll on the underside of the leaf. The leaves turn brown and fall off.
The sawfly overwinters in the soil.
A true pest can lead to growth reduction due to leaf drop. Young plantings, lime trees and trees in containers are vulnerable.
Parasitoid wasps are among the natural enemies of leaf wasps: parasitoid wasps lay eggs in the larvae.
Control
Damage from the lime leaf wasp is generally limited; damage occurs mainly in arboriculture and in parks and streets with many trees.
Prevention
Does not apply.
