The objective of this study was to evaluate the effect of temperature on survival, development, and reproduction of Copitarsia decolora. Both linear and nonlinear models were used to model temperature-dependent development and population growth for C. decolora reared on asparagus and artificial diet. We used @Risk Software to bootstrap model parameters so that variability in observations could be incorporated into model predictions. C. decolora eggs required ≈69 DD to complete development with a base temperature of 7.8°C. C. decolora developed through four to six instars depending on temperature and food source. Development of larvae from neonate through prepupa required 341.4 DD above a base of 7.3°C on asparagus, whereas 254.5 DD were needed on artificial diet, where the base temperature was 7.7°C. Pupae required ≈236 DD (base temperature 8.2–8.4°C) to develop when reared on asparagus or artificial diet. Female moths laid significantly more eggs at 14.6 and 20.1°C than at higher or lower temperatures. Survival of individuals to the adult stage increased from 71% at 9.7°C to 93% at 24.9°C. Survival fell off rapidly to 25% at 29.5°C. The generation time was the shortest at 29.5°C; however, only 25% of females survived to the adult stage, fecundity was low, and only 53% of the eggs hatched. The capacity for increase, r_c, was low at 9.7°C, peaked at 25.7°C, and declined as temperature increased. We estimated that populations on asparagus would not develop at temperatures >31.3°C or <6.9°C. We show the importance of estimating a range of values for base temperature and degree-days by conducting a preliminary pathway analysis that incorporates the effect of temperature on egg hatch.