Dryocosmus kuriphilus

When it was first discovered, the wasp was considered to be a species of Biorhiza. It was given its current name in 1951, when it was formally described. By this time it had invaded Japan and was attacking chestnuts there. It is now in Korea, Nepal, Italy, Slovenia, France, Switzerland and other parts of Europe including Flanders, Belgium, and the southeastern United States. ==Life history and ecology==

The adult female wasp is 2.5 to 3 millimeters long and shiny black in color with brown legs. It produces stalked white eggs, each about 0.2 millimeters long, and the larva is white and about 2.5 millimeters long. The adult male of the species has never been observed. The galls are green or pinkish and up to 2 centimeters wide. Chestnut species affected by the gall wasp include Japanese chestnut (Castanea crenata), American chestnut (C. dentata), Chinese chestnut (C. mollissima), European chestnut (C. sativa), Seguin chestnut (C. seguinii), Henry's chinquapin (C. henryi), and hybrids. So far it has not been observed on the Allegheny chinquapin (C. pumila). Pesticides are generally not effective because the insects take cover inside the galls. A number of other parasitoids have been noted with the gall wasp, including the torymids Torymus beneficus, T. geranii, and Megastigmus nipponicus, the ormyrid wasps Ormyris punctiger and O. flavitibialis, and the eurytomid wasps Eurytoma brunniventris and E. setigera. These species do not make effective control agents, as their rates of parasitism are not high. ==References==