Dryocosmus kuriphilus, or the Chestnut Gall Wasp, is a tiny, fly-like wasp. Chestnut Gall Wasps are highly specialised, they're sometimes referred to as parasitic wasps or parasitoids. They require a plant host to reproduce successfully. The female gall wasp lays eggs in the leaves of Sweet Chestnut trees, resulting in the production of pink and green fleshy galls that protrude from the veins of leaves. Invasive species can be problematic because native species are not used to their effects. Unfortunately, the presence of this wasp can weaken Sweet Chestnut trees, making them vulnerable diseases like sweet chestnut blight. Luckily this wasp isn't found in South Africa.