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
Guppy, J. C., and M. K. Mukerji. 1974. Effects of temperature on developmental rate of the immature stages of the alfalfa weevil, Hypera postica (Coleoptera: Curculionidae). Can. Ent. 106: 93-100.
- Location of study: Ottawa, Ontario (laboratory & field studies)
- Lower developmental threshold: 50.0°F (10.0°C)
- Upper developmental threshold: 87.8°F (31.0°C)
- Method of calculation: not specified (UC IPM recommends Single Sine)
- Cutoff method: not specified (UC IPM recommends Horizontal)
Degree-day accumulations required for each stage of development
Biofix: First occurrence or peak of an earlier stage.
Host: Alfalfa
- Eggs: 196.2 (°F) 109.0 (°C)
- Larvae: 307.8 (°F) 171.0 (°C)
- Prepupae: 61.2 (°F) 34.0 (°C)
- Pupae: 135.0 (°F) 75.0 (°C)
- Generation time (egg to adult): 700.2 (°F) 389.0 (°C)
Model 2
Whiteford, F., and S. S. Quisenberry.1990.Population dynamics and seasonal biology of the alfalfa weevil (Coleoptera: Curculionidae) on alfalfa in Louisiana.Environ. Entomol. 19: 1443-1451.
- Location of study: Baton Rouge, Louisiana (field studies)
- Lower developmental threshold: 48.0°F (8.9°C)
- Method of calculation: Max-min (UC IPM recommends Single Sine)
Host: Alfalfa
- Egg eclosion: 540.0 (°F) 300.0 (°C)
- Scout for larvae: 450-720 (°F) 250-400 (°C)
