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
Grout, T.G., J.G. Morse, N.V. O'Connell, D.L. Flaherty, P.B. Goodell, M.W. Freeman, and R.L. Coviello. 1986. Citrus thrips (Thysanoptera: Thripidae) phenology and sampling in the San Joaquin Valley. J. Econ. Entomol. 79:1516-1523.
- Location of study: Fresno, Kern, and Tulare Counties, California (field studies)
- Lower developmental threshold: 58.26°F (14.59°C)
- Method of calculation: Single Sine
Degree-day accumulations required for each stage of development
Biofix: January 1
Host: Navel Oranges: Mean intergenerational period
- (1st to 2nd Generation) 281 (°F) 156 (°C)
- Mean time between first-instar emergence of the 2nd generation and the second-instar peaks of the first generation 56 (°F) 31 (°C)
The 2nd generation starts emerging 125 DD after the mean peak of the late second instars of the first generation. This would be the optimal time for an insectide application.
