Range & Status
Hymenoptera: Cynipidae; both sexual (on catkins) and agamic (on buds) stages are uncommon.
Both stages were recorded in Cornwall pre-1906. In 1989 the sexual stage was recorded on the south bank of the River Camel Trail SW97.
Habitat & Ecology
Associated species: Quercus spp. Galls on catkins (sexual) cause a mass of white cotton wool-like hairs up to 20 mm. long completely concealing the gall chambers; up to 20 chambers, each with a larva.
Oak trees have been affected and died in recent years; this may have been caused by drought brought on by possible global warming and/or the spread of Sudden Oak Death disease, Phytophthora ramorum . The decline of oak trees will cause a major negative environmental effect on all invertebrate species which depend on Quercus , not just those that form galls.
Foresters are planting Quercus robur , but more research on causes of oak deaths and into disease resistant species of oak should be conducted.