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
Carey, J. R., and J. W. Bradley. 1982. Developmental rates, vital schedules, sex ratios, and life tables for Tetranychus urticae, T. turkestani and T. pacificus (Acarina: Tetranychidae) on cotton. Acarologia 23: 333-345.
- Location of study: Five Points, California (laboratory studies)
- Lower developmental threshold: 53.6°F (12.0°C)
- Method of calculation: not specified (UC IPM recommends Single Sine)
Degree-day accumulations required for each stage of development
Host: Cotton
- Eggs: 89.5 (°F) 49.7 (°C)
- Larvae: 41.8 (°F) 23.2 (°C)
- Protonymphs: 33.1 (°F) 18.4 (°C)
- Deutonymphs: 37.4 (°F) 20.8 (°C)
- Generation time (egg to adult): 201.8 (°F) 112.1 (°C)
- Pre-egglaying adults: 24.8 (°F) 13.8 (°C)
- Generation time (egg to egg): 226.6 (°F) 125.9 (°C)
