Effect of different host plants on nutritional indices of the pod borer, Helicoverpa armigera.

Nutritional indices of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on different host plants including chickpea (cultivars Arman, Hashem, Azad, and Binivich), common bean (cultivar Khomein), white kidney bean (cultivar Dehghan), red kidney bean (cultivar Goli), cowpea (cultivar Mashhad), tomato (cultivar Meshkin) and potato (cultivars Agria and Satina) were studied under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, 16:8 L:D). Third instar larvae reared on potato Agria showed the highest efficiency of conversion of digested food (ECD) and efficiency of conversion of ingested food (ECI) (50.800 ± 0.104% and 13.630 ± 0.016%, respectively). Approximate digestibility (AD) values of the fourth instar larvae were highest (92.651 ± 0.004%) and lowest (57.140 - 0.049%) on chickpea Azad and potato Agria, respectively. The fifth instar larvae fed on tomato Meshkin and white kidney bean Dehghan had the highest consumption index (CI) (3.717 ± 0.091) and relative consumption rate (RCR) (1.620 ± 0.074), respectively. Whole larval instars showed the highest ECI and ECD values on potatoes Satina (14.640 ± 0.014%) and Agria (21.380 ± 0.015%), respectively, and the lowest of both values on tomato Meshkin (ECI: 5.748 ± 0.002% and ECD: 7.341 ± 0.002%). The results of nutritional indices and the cluster analysis indicated that tomato Meshkin was an unsuitable host for feeding of H. armigera.

Digestive proteolytic and amylolytic activities and feeding responses of Helicoverpa armigera (Lepidoptera: Noctuidae) on different host plants.

Digestive proteolytic and amylolytic activities and feeding responses of fifth instar larvae of Helicoverpa armigera (Hübner) on different host plants including chickpea (cultivars Arman, Hashem, Azad, and Binivich), common bean (cultivar Khomein), white kidney bean (cultivar Dehghan), red kidney bean (cultivar Goli), cowpea (cultivar Mashhad), tomato (cultivar Meshkin), and potato (cultivars Agria and Satina) were studied under laboratory conditions (25 +/- 1 degrees C, 65 +/- 5% RH and a photoperiod of 16:8 [L:D] h). Our results showed that the highest protease activity in optimal pH was on cultivar Dehghan (8.717 U/mg) and lowest one was on Meshkin (3.338 U/mg). In addition, the highest amylase activity in optimal pH was on cultivar Dehghan (0.340 mU/mg) and lowest was on Meshkin (0.088 mU/mg). The larval weight of fifth instar H. armigera showed significant difference, being heaviest on Binivich (125.290 +/- 5.050 mg) and lightest on Meshkin (22.773 +/- 0.575 mg). Furthermore, the highest and lowest values of food consumed were on Goli (362.800 +/- 27.500 mg) and Satina (51.280 +/- 4.500 mg), respectively. In addition, the lowest values of prepupal and pupal weight were on Meshkin (32.413 +/- 0.980 and 41.820 +/- 1.270 mg, respectively). The results indicated that tomato (Meshkin) was unsuitable host for feeding fifth instar larvae of H. armigera.