Upper and Lower Threshold Temperatures and Degree-Day Estimates for Development of the Frit Fly (Diptera: Chloropidae) at Eight Constant Temperatures

Abstract

Development of the frit fly (FF), Oscinella frit (L.), on Lolium perenne L. was studied at several constant temperatures ranging from 15 to 35°C. The lower developmental thresholds for eggs, larvae, and pupae were extrapolated from the linear relationship between temperature and rate of development. Lower developmental thresholds were estimated to be 10.32 ± 3.03 (95% CL) (eggs), 10.36 ± 2.52 (larvae), and 10.78 ± 4.79°C (pupae). FF developmental rates for all life stages increased with temperature up through 27.5°C; thereafter, the rates decreased. Biophysical model predictions estimated developmental upper and lethal thresholds to be 29 and 34 °C respectively, for all three life stages. Degree-day (DD) accumulations of 48.73 ± 2.41 (x ± SEM), 292.63 ± 12.56, and 109.95 ± 6.02 were required for completion of the egg, larval, and pupal stages, respectively. A total of 451.31 ± 52.91 (95% CL) DD was required for development from egg to adult in the laboratory.