Thermal indices of Spodoptera frugiperda (J. E. Smith) on maize in northern India

The growth and development of Spodoptera frugiperda (J.E. Smith) was studied on maize hybrid PMH 10 under laboratory conditions at five alternating temperature viz., 18:07, 24:12, 28:17, 32:22 and 36:27°C during 2021-22. The duration of different developmental stages viz., incubation, larva, pupa, and adults reduced significantly with increase in temperature combinations of 18:7, 24:12, 28:17, 32:22 and 36:27 °C. The thermal constant for egg, larval, pupal and adult stages was 45.45, 333.33, 166.67 and 125.00 Degree Days (DD), respectively totalling to 670.45 DD while, the lower developmental threshold was 12.59, 12.33, 12.67 and 10.50 °C for the respective stages.Such study can be utilized in development of prediction models, aiding in the early prediction of an insect attack and enabling prompt pest control.