Oak Gall Wasp
Oak Gall Wasp
Oak Gall Wasps are tiny gall-forming insects that belong to a highly specialised group of wasps, sometimes referred to as parasitoids. Gall wasps need a plant host to survive. However, the damage they cause is never detrimental to the plant. A gall can take many forms and looks like an abnormal growth. Gall Wasp eggs are laid in the shoot tips of new leaves in Oak. Plants begin to rapidly-produce cells, and growth becomes malformed. This particular genus is well-known for its Oak apple galls, which look a lot like apples! Each Apple Gall contains numerous chambers concealing the wasp larvae.
Wasps cause host plant to produce abnormal growths, known as galls.
Galling activity doesn't permanently damage hosts.
Adults: Adult wasps are sometimes compared to ants due to their small size and black-brown colouration; some are even wingless! They're tiny so it's unlikely you'd see them. Wasps are normally identified by the galls produced on the infested plant. The gall wasp eggs and larvae remain inside the plant and gall. Galls: This genus of gall wasp is best recognised from the 'apple galls' produced by some species when in oak. These look like apples, are typically attached to the underside of oak leaves and are spongy in texture. They begin looking pinky-green but will eventually dry out once larvae emerge, turning brown. Dried out galls are often found covered in numerous emergence holes where matured larvae have left the gall.
Squidgey, apple-like tumours may be evident underneath oak leaves or in areas of new growth. Some years tree crops can be low.
This wasp will not impact the longterm yield of trees, but the galls it produces may be unsightly. Gall wasps seem to be more frequent in some years than others, so trees typically have quieter periods in which they recover.
Insecticides are unlikely to work on this wasp.