The Effect of Constant Temperatures on the Development Time of Eggs of Heliothis Armiger (Hübner) (Lepidoptera: Noctuidae)

The development times of Heliothis armiger eggs were determined over a range of constant temperatures from 8.0°C to 39.4°C, and ranged from 443.5 h at 13.3°C to 48.8 h at 35.0°C. Using thermal summation, a development threshold temperature of 11.7°C and a thermal constant of 1039.4 deg h were calculated. The data were also fitted to Davidson's and Pradhan's formulae.