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
Whalon, M. E., and Z. Smilowitz. 1979. Temperature-dependent model for predicting field populations of green peach aphid, Myzus persicae (Homoptera: Aphididae). Can. Ent. 111: 1025-1032.
- Location of study: Rock Springs, Pennsylvania (laboratory and field studies)
- Lower developmental threshold: 39.2°F ( 4.0°C)
- Upper developmental threshold: 86.0°F (30.0°C)
- Method of calculation: Double Sine
- Cutoff method: Horizontal
Degree-day accumulations required for each stage of development
Host: Potato
- Generation time (nymph to nymph): 233.6 (°F) 129.8 (°C)
Model 2
Weed, A. 1927. Metamorphosis and reproduction in apterous forms of Myzus persicae Sulzer as influenced by temperature and humidity. J. Econ. Entomol. 20: 150-157.
- Location of study: Wisconsin (laboratory studies)
- Lower developmental threshold: 39.2°F ( 4.0°C)
- Upper developmental threshold: 82.4°F (28.0°C)
- Method of calculation: not specified (UC IPM recommends Single Sine)
- Cutoff method: not specified (UC IPM recommends Vertical)
Degree-day accumulations required for each stage of development
Host: Spinach
- Nymphs: 240.1 (°F) 133.4 (°C)
- Pre-larviposition time: 34.4 (°F) 19.1 (°C)
- Generation time (nymph to nymph): 274.5 (°F) 152.5 (°C)
Model 3
El Din, N. S. 1976. Effects of temperature on the aphid Myzus persicae (Sulz.), with special reference to critically low and high temperature. Zeitschrift fur Angewandte Entomologie 80: 7-14.
- Location of study: England (laboratory studies)
- Lower developmental threshold: 37.9°F ( 3.3°C)
- Upper developmental threshold: 77.0°F (25.0°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
Host: Brussels sprouts
- Nymphs: 237.8 (°F) 132.1 (°C)
