Impact of elevated carbon dioxide on the bionomics of maize fall armyworm Spodoptera frugiperda: an age-stage, two-sex life table approach

Rising atmospheric CO₂ concentrations are more likely to alter the survival and fecundity of insect pests. Fall armyworm, Spodoptera frugiperda (J. E. Smith) is an important insect pest that severely affects Indian agriculture, yet the influence of elevated CO₂ on population dynamics of this species is still unknown. The elevated CO₂ shortened the overall development time and total lifespan of S. frugiperda in a linear fashion with increase in CO₂ from 410 ppm to 550 ppm. Further, the fecundity of S. frugiperda was reduced with increasing CO₂ above 490 ppm, and the mean number of eggs laid per female moth increased as the atmospheric CO₂ increased from 410 ppm to 490 ppm. Therefore, elevated CO₂ had a positive correlation with fecundity at 430, 460, and 490 ppm, but not at 520 and 550 ppm, indicating a threshold level between 490 and 520 ppm. These results signify that future scenario of global climate change will influence the population fitness of S. frugiperda with increasing CO₂ concentrations.