Effect of elevated temperature on the population dynamics of fall armyworm, Spodoptera frugiperda
K. R. Ashok, V. Balasubramani, John Kennedy, V. Geethalakshmi, P. Jeyakumar, N. Sathiah
Abstract
Aim: The present study was conducted to determine the growth, survival, fecundity and mortality rate of Spodoptera frugiperda in maize at elevated temperature. Methodology: Biology and life table experiments were carried out in custom made Open Top Chambers (4m x 4m x 4m size) fitted with SCADA under increasing temperature regimes viz., 32˚C, 33˚C, 34˚C, 35˚C and 36˚C. Each stage of the insects was examined daily and the fertility and life-table parameters were calculated by using TWOSEX-MS chart. Results: The overall developmental time for egg, larva, pupa and adult stages (total lifespan) at different elevated temperatures were in the order of 32˚C > 33˚C > 34˚C > 35˚C > 36˚C. The fecundity rate of S. frugiperda at different elevated temperatures were in the order of 34˚C > 33˚C > 32˚C > 35˚C > 36˚C. Interpretation: The current study confirms that the elevated temperature regimes had a positive correlation with fecundity rate upto 34˚C and negative correlation with the survival rate of S. frugiperda.