Schaub, L.P., Bloesch, B., Hippe, C., Keimer, C., Schmid, A., & Brunetti, R. 1999 Validation d'un modele de la phenologie du pou de San Jose. [Validation of a phenology model for San Jose scale.]. Revue Suisse de Viticulture, d'Arboriculture et d'Horticulture 31(5): 253-257.

Notes: Simulations of San Jose scale (Quadraspidiotus perniciosus) [Diaspidiotus perniciosus] phenology are compared to field observations of larval emergence and trap catches of males in flight. In the region of Lake Geneva, Switzerland, heat unit accumulation starting at the beginning of male flight is an excellent tool to describe Q. perniciosus development. In other regions of Switzerland the model is less precise. For the start of heat unit accumulation, 2 simple alternatives to the beginning of male flight are the end of apple tree blooming and the beginning of the year.