The occurrence, ecology and control of Buddleja davidii in the UK

摘要

Buddleja davidii (butterfly-bush) was introduced to England from China in the 1890's and spread slowly in southern England as a garden escape. It increased greatly on bomb-damage sites in urban areas after the 1939-1945 war and is now widely distributed throughout the British Isles. As a successful colonist of disturbed and compacted sites it occurs particularly on railway sidings and tracksides, unused industrial areas, hard-rock quarries, beside waterways and on old walls and buildings. Reasons forthe success of B. davidii in these situations are reviewed. Because of the attraction of its nectar it is visited by many species of insects, particularly Lepidoptera. As one of the few woody species able to colonise compacted land it may therefore be regarded, ecologically and aesthetically, as an asset. In certain situations however it causes problems and requires control. The dense infestations that develop on railway and industrial sites restrict access and visibility; presence on walls can lead tostructural damage. Control may be mechanical or chemical. Glyphosate and triclopyr are moderately effective as foliar sprays on established plants; regrowth often requires further treatment after 2 years. Triclopyr ester as a foliar spray or cut-stump treatment is the preferred herbicide for specific control. Results of trials comparing triclopyr amine + fluroxypyr and glyphosate formulations applied to B. davidii in summer are presented.