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
Ali Niazee, M. T. 1976. Thermal unit requirements for determining adult emergence of the Western cherry fruit fly (Diptera: Tephritidae) in the Willamette Valley of Oregon. Environ. Ent. 5: 397-402.
- Location of study: Albany, Oregon (field studies)
- Lower developmental threshold: 41.0°F (5.0°C)
- Method of calculation: Max-min method (UC IPM recommends Single Sine)
Degree-day accumulations required for each stage of development
Start date: March 1
Air Temperatures
- First adult spring emergence: 842.4 (°F) 468.0 (°C)
- Peak adult spring emergence: 1142.1 (°F) 634.5 (°C)
- Last adult spring emergence: 1755.0 (°F) 975.0 (°C)
Soil Temperatures at 5 centimeters
- First adult spring emergence: 1296.0 (°F) 720.0 (°C)
- Peak adult spring emergence: 1710.0 (°F) 950.0 (°C)
- Last adult spring emergence: 2034.0 (°F) 1130.0 (°C)
Soil Temperatures at 10 centimeters
- First adult spring emergence: 1182.6 (°F) 657.0 (°C)
- Peak adult spring emergence: 1571.4 (°F) 873.0 (°C)
- Last adult spring emergence: 1900.8 (°F) 1056.0 (°C)
Model 2
Ali Niazee, M. T. 1979. A computerized phenology model for predicting biological events of Rhagoletis indifferens (Diptera: Tephritidae). Can. Ent. 111: 1101-1109.
- Location of study: Albany, Oregon (field studies)
- Lower developmental threshold: 41.0°F (5.0°C)
- Method of calculation: Max-min method (UC IPM recommends Single Sine)
Degree-day accumulations required for each stage of development
Start date: March 1
- First adult spring emergence: 831.6 (°F) 462.0 (°C)
- Beginning of egg-laying: 973.8 (°F) 541.0 (°C)
- Egg hatch: 1069.2 (°F) 594.0 (°C)
- 50% adult spring emergence: 1135.8 (°F) 631.0 (°C)
- Peak Egg-laying: 1233.0 (°F) 685.0 (°C)
- Pupation: 1431.0 (°F) 795.0 (°C)
Model 3
Van Kirk, J. R., Ali Niazee., and M. T. 1981. Determining low-temperature threshold for pupal development of the Western cherry fruit fly for use in phenology models. Environ. Ent. 10: 968-971.
- Location of study: Albany, Oregon (field studies)
- Lower developmental threshold: 47.0°F (8.3°C) (soil temperatures at 2 inches (5.1cm))
- Method of calculation: Max-min method (UC IPM recommends Single Sine)
Degree-day accumulations required for each stage of development
Start date: March 1
- First adult spring emergence: 104.0 (°F) 57.8 (°C)
- 50% adult spring emergence: 198.0 (°F) 110.0 (°C)
Model 4
Jones, V. P., D. G. Alston, J. F. Brunner, D. W. Davis, and M. D. Shelton. 1991. Phenology of the Western cherry fruit fly (Diptera: Tephritidae) in Utah and Washington. Ann. Entomol. Soc. Am. 84: 488-492.
- Location of study: Utah and Washington (field studies)
- Lower developmental threshold: 41°F (5°C)
- Method of calculation: Single Sine
Degree-day accumulations required for each stage of development
Host: Sweet and sour cherries
- Flies first detected (Utah): 1031 (°F) 573 (°C)
- Flies first detected (Washington): 1066 (°F) 592 (°C)
Model 5
Stark, S. B., and M. T. AliNiazee. 1982. Model of Postdiapause development in the Western Cherry Fruit Fly. Environ. Ent. 11: 471-474.
- Location of study: Albany, Oregon (laboratory studies)
- Lower developmental threshold: 48.2°F ( 9.0°C)
- Upper developmental threshold: 90.0°F (32.2°C)
- Method of calculation: 1/(development rate) (UC IPM recommends Single Sine)
- Cutoff method: Vertical
Degree-day accumulations required for each stage of development
Start date: March 1
- Mean adult spring emergence: 860.8 (°F) 478.2 (°C)
