Tansy Beetles at Red House
The Tansy beetle, which is about the size of your small finger nail, is a very rare insect in Britain with its main, and almost last, habitat on a 40km stretch of banks of the River Ouse around York. Red House manages about 1km of the bank in this zone so we have quite an important role in the beetle's survival. This beautiful, metallic green creature survives only on the tansy plant which grows in small clumps along the river. It does not fly so, to expand its breeding area, it must crawl between the clumps where it lays its eggs. The larva, after feeding on the tansy, overwinter in the roots. Unfortunately the tansy plant finds it difficult to compete against grazing animals, willow trees and modern invasive species like himalayan balsam. By converting our far ings fields to woodland we have eliminated the grazing problem but now have to be active in weed control along that section of the river bank. Our new management regime seems to have worked in the beetle's favour as this is the first time we have seen the beetles. It is also, apparently, very unusual to see them so late in the year.