Gall wasps are tiny gall-forming insects that belong to a highly specialised group of wasps. In 2015, an oriental chestnut gall wasp was seen in Kent. Females lay eggs in 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. Suspected infestations should be reported via TreeAlert so that we can learn more about this wasps distribution. Luckily this wasp isn't found in South Africa.