Nutritional indices of the cotton bollworm Helicoverpa armigera on four chickpea and one cowpea cultivars

The cotton bollworm، Helicoverpa armigera (Hübner) is one of the most important polyphagous insect pests attacking different crops in many parts of the world. In the present study، nutritional indices of H. armigera larvae (third to sixth instars) were determined on artificial diets based on the seeds of four chickpea cultivars (Arman، Azad، Binivich and Hashem) and one cowpea cultivar (Mashhad). The experiments were performed at 25±1ºC، 65±5% RH and a photoperiod of 16:8 (L: D) h. The results showed that the nutritional indices of H. armigera were significantly influenced by different host plants tested. Accordingly، the highest and lowest values of efficiency of conversion of ingested food (ECI) for total larval stages were on Arman (0. 427) and Azad (0. 027)، respectively. Additionally، the highest value of efficiency of digested food (ECD) was on Binivich (0. 567) and the lowest value of this index on Azad (0. 030). The highest and lowest value of consumption index (CI) was on Hashem (3. 902 mg/mg/d) and Arman (1. 977 mg/mg/d)، respectively. Also، the results showed that the highest value of approximate digestibility (AD) for total larval stages was on Hashem (0. 933). The relative growth rate (RGR) and relative consumption rate (RCR) were maximum on Hashem and Mashhad (0. 599 and 2. 051 mg/mg/d، respectively). The results obtained in the present study could be helpful in integrated management of H. armigera.