Effect of temperature and diet on Plodia interpunctella (Lepidoptera: Pyralidae) development with special reference to Isomegalen diagram and accumulated degree days

Immature development times of the Indian meal moth, Plodia interpunctella were studied in the laboratory at four different constant temperatures (20, 23, 25, 27°C) reared on a standard diet (D1) and chocolate (D2). The minimal duration of development from oviposition to adult emergence was inversely related to temperature, ranging from 2.3±0.36 days to 50.5±0.5 days for D1 and from 36.7±0.53 days to 106.73±1.10 days for D2 for 27°C and 20°C, respectively. The minimum development threshold (tL), obtained from linear regression model of the development rates at the four studied constant temperature regimes, for total immature development is 15.3°C and 17.1°C for D1 and D2, respectively and the accumulated degree days (ADD) for P. interpunctella is 249.51°C for D1 and 358.4°C for D2 above the threshold.