Schröder, T., & Richter, E. 2003 The horse chestnut scale insect Pulvinaria regalis Canard, 1968 (Homoptera, Coccidae): A new pest on urban trees in Braunschweig, Lower Saxony, Germany.. Braunschweiger Naturkundliche Schriften 6(4): 803-812.

Notes: Since its first observation in England in the 1960s the introduced horse chestnut scale insect Pulvinaria regalis has spread over Europe. Until now, it was observed in the United Kingdom, France, Belgium, the Netherlands, Switzerland and at least in Ireland. In Germany P. regalis appeared first in the north Rhine region in 1989. Since that time it spread to the south and north of Germany and was observed in Braunschweig in 2002 on single lime trees (Tilia sp.). During a first survey in July 2003 in the urban center of Braunschweig P. regalis was found on trees of Tilia, Acer, and Aesculus hippocastanum. P. regalis is univoltine with an enormous reproductive capacity. The first larval stage spreads with the wind to new host trees. The host spectrum of this polyphagus species covers trees of 24 families. These facts explain its tremendous rate of spreading. Until now, there is not enough information about long-term effects of infestation and the necessity of control measures. But since the female adults pollute the trunks and main branches with the white waxy wool of their egg sacks they at least reduce the ornamental value. Control methods with native antagonists are under investigation at the moment.