Home and Landscape

European Elm Scale

  • Gossyparia spuria
Updated: 04/2026

Phenology models predict timing of events in an organism's development. For many organisms which cannot internally regulate their own temperature, development is dependent on temperatures to which they are exposed in the environment.

Information in this database comes from published articles. It may be used in conjunction with field monitoring and a degree-day calculator.

Note: Before using a model that was not field tested in your location, you should test the model for one or more seasons under your conditions to verify that it will work for you.

Model 1

Dreistadt, S. H. and K.S. Hagen. 1994. European elm scale (Homoptera: Eriococcidae) abundance and parasitism in northern California. Pan-Pacific Entomologist 70:240-252.

  • Location of study: Northern California (field studies)
  • Lower developmental threshold: 51.8°F (11°C)
  • Method of calculation: Single Sine

Degree-day accumulations required for each stage of development

Biofix: March 1

Host: English Elm and Siberian Elm

  • Female scale peak 541.8 (°F) 301 (°C)

Note: The lower threshold was taken from the average lower temperature for several other studies. No laboratory developmental rates were developed in this study.