Oak apple gall wasp

Biorhiza pallida

  • Where it lives:

  • Non native species

About

The oak apple gall wasp, Biorhiza pallida, is a tiny wasp that causes growths, or 'galls', on oak twigs. These galls can be found between May and June where the female has laid her eggs in the leaf bud. Inside the gall, there are a number of chambers, each housing a larva which eats its way out. Adults emerge in June and July.

How to identify

The oak apple gall wasp produces a large, rough, buffish-brown, apple-like gall that can be found on oak twigs.

Did you know?

The oak apple gall wasp has a second generation: the females that emerge in spring mate and drop to the ground to lay eggs in oak roots, producing further galls.

How people can help

Our gardens are a vital resource for wildlife, providing corridors of green space between open countryside, allowing species to move about. In fact, the UK's gardens provide more space for nature than all the National Nature Reserves put together. So why not try leaving wilder areas in your garden, such as patches of buttercups in your lawn or nettles near your compost heap, to see who comes to visit? To find out more about encouraging wildlife into your garden, visit our Wild About Gardens website: a joint initiative with the RHS, there's plenty of facts and tips to get you started.