Trierweiler, P., & Balder, H. 2005 Spread of horse chestnut scale (Pulvinaria regalis) in Germany.. Plant Protection and Plant Health in Europe: Introduction and Spread of Invasive Species, held at Humboldt University, Berlin, Germany, 9-11 June 200 British Crop Protection Council Alton, UK

Notes: [Symposium Proceedings NO. 81.] Results are presented of a nationwide survey conducted by the Plant Protection Service in 2004 on the current status of knowledge regarding the spread, infestation and management of horse chestnut scale (Pulvinaria regalis) in some cities and nurseries in Germany. In recent years, the pest has increased its geographical range and infestations have also become more severe. The pest is no longer restricted to the major cities, but has also spread to smaller ones. The pest occurs mainly in urban locations, rather than in nurseries, where it is an aesthetic problems in green areas such as city parks. Nevertheless, infestations in nurseries appear to be increasing, so commercial problems are to be expected. Pest control on parkland and roadside trees is rarely practiced, even following infestations of horse chestnut scale. Usually, control measures are taken only on high quality trees. In general, recommendations and advice for the adoption of chemical and biological control measures are wanting. Future spread and infestations can be controlled with the adaption of beneficial organisms (parasitoids and predators) and strict monitoring and inspection of traded plants.