Nutritional indices of Helicoverpa armigera (Lep.: Noctuidae) on seeds of five host plants

In this study, the nutritional indices of Helicoverpa. armigera larvae on five different host plants including cowpea, chickpea, soybean, navy bean and corn were determined in the laboratory. The lowest relative consumption rate (RCR) of the third instar larvae was on cowpea (3.21±0.512). The efficiency of conversion of ingested food (ECI) and the relative growth rate (RGR) were the highest on cowpea (6.8±0.004 and 0.243±0.007, respectively). The lowest values of efficiency of conversion of ingested food (ECI) and Efficiency of conversion of digested food (ECD) (2.4±0.002 and 6.9 ±0.005, respectively) of the fourth instar larvae were observed on corn.The highest ECI and ECD of the fifth instar larvae (23.2±0.010 and 84.5±0.10, respectively) and the sixth instar larvae (26.7±0.017 and 40.5±0.011, respectively) were obtained on cowpea. The Approximate digestibility (AD) of whole larval instars (the third to sixth instars) on different host plants ranged from 28.9±0.024 to 55±0.015, which was the lowest on corn and highest on cowpea. The larvae fed on cowpea showed the highest values of ECI and ECD (20.1±0.002 and 83.4±0.080, respectively) and RGR (7.59±0.15).