Home and Landscape

Egyptian Alfalfa Weevil

  • Hypera brunnipennis
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

Integrated Pest Management for Alfalfa Hay. University of California Statewide IPM Project. Div. Agr. Sci. Publ. #4104. pp. 47-50.

  • Location of study: California
  • Lower developmental threshold: 45.0°F (7.2°C)
  • Method of calculation: not specified (UC IPM recommends Single Sine)

Degree-day accumulations required for each stage of development

Host: Alfalfa Hay

  • Eggs: 211.0 (°F) 117.2 (°C)
  • Larvae: 372.6 (°F) 207.0 (°C)
  • Pupae: 284.2 (°F) 157.9 (°C)
  • Generation time (egg to adult): 867.8 (°F) 482.1 (°C)
  • Pre-egglaying adults (after aestivation): 279.0 (°F) 155.0 (°C)
Adults on bark of tree. Credit: Jack Kelly Clark, UC IPM. Credit: Jack Kelly Clark, UC IPM
Adult alfalfa weevil or Egyptian alfalfa weevil. Credit: Jack Kelly Clark, UC IPM