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 of 5
Codling Moth. IN: Integrated Pest Management for Apples and Pears. University of California Statewide Integrated Pest Management Project. Div. Agr. Sci. Publ. #3340.
- Location of study: California
- Lower developmental threshold: 50.0°F (10.0°C)
- Upper developmental threshold: 88.0°F (31.1°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: When traps catch moths on two successive nights AND when sunset temperatures are above 62°F (16.7°C).
Host: Apple and pear
- Eggs: 158.0 (°F) 87.8 (°C)
- Larvae: 471.0 (°F) 261.7 (°C)
- Pupae: 431.0 (°F) 239.4 (°C)
- Generation time (egg to adult): 1060.0 (°F) 588.9 (°C)
- Pre-egglaying adults: 58.0 (°F) 32.2 (°C)
- Generation time (egg to egg): 1118.0 (°F) 621.1 (°C)
Set out traps: Bud break
- Pre-egglaying adults: 58.0 (°F) 32.2 (°C)
- Eggs: 158.0 (°F) 87.8 (°C)
- Average egg hatch: 216.0 (°F) 120.0 (°C)
Model 2 of 5
Pickel, C.P., R. S. Bethell, W. W. Coates. 1986. Codling Moth Management Using Degree-days. University of California Statewide IPM Project. Publication #4.
- Location of study: California
- Lower developmental threshold: 52.0°F (11.1°C)
- Upper developmental threshold: 94.0°F (34.4°C)
- Method of calculation: Sine-wave (UC IPM recommends Single Sine)
- Cutoff method: not specified (UC IPM recommends Horizontal)
Degree-day accumulations required for each stage of development
Biofix: When traps catch moths on two successive nights AND when sunset temperatures are above 62F (16.7°C).
Host: Apple, pear, walnut: Set out traps: Bud break
- Preoviposition + eggs: 160.0 (°F) 88.9 (°C)
- Larvae: 475.0 (°F) 263.9 (°C)
- Pupae: 400.0 (°F) 222.2 (°C)
- Generation time (egg to egg): 1035.0 (°F) 575.0 (°C)
Model 3 of 5
Bethell, R. S. 1978. Pear pest management. U.C. Div. Agr. Sci. Publ. #4086. pp. 22-41.
- Location of study: California
- Lower developmental threshold: 52.0°F (11.1°C)
- Upper developmental threshold: 82.0°F (27.8°C)
- Method of calculation: Max-min (UC IPM recommends Single Sine)
- Cutoff method: not specified (UC IPM recommends Horizontal)
Degree-day accumulations required for each stage of development
Start date: When twilight temperatures are > 60°F (15.6°C)
Host: Pear
- Eggs: 160.0 (°F) 88.9 (°C)
- Larvae: 475.0 (°F) 263.9 (°C)
- Pupae: 400.0 (°F) 222.2 (°C)
- Generation time (egg to adult): 1035.0 (°F) 575.0 (°C)
- Pre-egglaying adults: 50.0 (°F) 27.8 (°C)
- Generation time (egg to egg): 1085.0 (°F) 602.8 (°C)
Emmergence of Adults
- Start of adult emergence: 725.0 (°F) 402.8 (°C)
- First hatch of their eggs: 775.0 (°F) 430.6 (°C)
Model 4 of 5
Pitcairn, M. J., F. G. Zalom, and R. E. Rice. 1992. Degree-day forecasting of generation time of Cydia pomonella (Lepidoptera: Tortricidae) populations in California. Environ. Entomol. 21: 441-446.
- Location of study: California
- Lower developmental threshold: 50.0°F (10.0°C)
- Upper developmental threshold: 88.3°F (31.1°C)
- Method of calculation: not specified (UC IPM recommends Single Sine)
- Cutoff method: Horizontal Cutoff
Degree-day accumulations required for each stage of development
Biofix: First moth capture from overwintering generation
Host: Walnut, Apples, and Pears
- First generation: 1058.4 (°F) 588.0 (°C)
- Second generation: 1182.6 (°F) 657.0 (°C)
- Third generation: 1182.6 (°F) 657.0 (°C)
- Mean generation time: 1114.2 (°F) 619.0 (°C)
Model 5 of 5
Integrated Pest Management for Walnuts. University of California Statewide Integrated Pest Management Project. Div. Agr. Sci. Publ. #3270. pp. 36-41.
- Location of study: California
- Lower developmental threshold: 50.0°F (10.0°C)
- Upper developmental threshold: 90.0°F (32.2°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
Host: Walnut
- Generation time (egg to egg): 1000.0 (°F) 555.6 (°C)
