RESPONSE OF MULTIPLE GENERATIONS OF TOBACCO CATERPILLAR SPODOPTERA LITURA FAB, FEEDING ON PEANUT, TO ELEVATED CO2

Changes in quality of host plants under elevated CO 2 (eCO 2 ) conditions likely in future can affect the survival, growth and development, and population dynamics of insect herbivores.The present study aimed to examine the effects of eCO 2 on leaf quality of peanut (Arachis hypogaea L.) and consequent effects on growth characteristics of leaf feeding tobacco caterpillar, Spodoptera litura (Fabricius) over four successive generations.The feeding trials were conducted using peanut foliage grown in open top chambers (OTCs) under two eCO 2 (550 ppm and 700 ppm) concentrations and one ambient CO 2 concentration.Significantly lower leaf nitrogen, higher carbon, higher relative proportion of carbon to nitrogen (C: N) and higher polyphenols content were observed in eCO 2 foliage.Larvae fed with eCO 2 foliage exhibited longer larval duration, higher larval weights and increased consumption in all four generations.Increased Approximate Digestibility (AD) (about 9%) and Relative Consumption Rate (RCR) (7%), decreased levels of efficiency of conversion of ingested food (ECI) (13%), efficiency of conversion of digested food (ECD) (19%), and relative growth rate (RGR) (9%) were noticed in larvae fed eCO 2 foliage.Significant and cumulative effect of CO 2 on S.litura was observed over four successive generations.