Effect of four host plants on nutritional performance of cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae)

Effects of four vegetable host plants, artichoke, cabbage, potato and tomato on nutritional indices of the cotton leafworm Spodoptera littoralis (Boisduval) (Lep.: Noctuidae), were studied under laboratory conditions (۲۵ ± ۱ °C, ۶۵ ± ۵% RH, with a ۱۶: ۸ L: D photoperiod). Fourth instar reared on tomato showed the highest approximate digestibility (AD) (۹۰.۴۰۶ ± ۱.۱۲۵%) and efficiency of conversion of ingested food (ECI) (۳۰.۲۴۹ ± ۴.۱۲۸%). The highest values of efficiency of conversion of digested food (ECD) and ECI of fifth instars (۳۸.۶۶۳ ± ۴.۳۴ and ۲۰.۰۸۳ ± ۱.۵۸۱%, respectively) were on artichoke and the lowest of both values on cabbage (ECD: ۶.۳۱۴ ± ۱.۱۲۸ and ECI: ۵.۴۴۸ ± ۱.۰۵۲%).The ۳rd to ۶th instars as a whole showed the highest ECD and ECI values on tomato (۲۳.۴۱۲ ± ۲.۲۵۲ and ۱۹.۸۴۵ ± ۱.۷۹۸%, respectively). However, the highest and lowest values of consumption index (CI) were on cabbage (۳۳.۹۴۳ ± ۲.۶۶۹) and tomato (۶.۱۴۵ ± ۰.۵۷۸). The highest values of relative consumption rate (RCR) and (AD) were obtained on cabbage (۱.۴۹ ± ۰.۱۰۹ mg/mg/day and ۸۶.۴۳۱ ± ۱.۱۴۱%, respectively). The results of nutritional indices and the cluster analysis indicate that tomato was nutritionally the most suitable food for S. littoralis.

Keywords:

Host plants , Lepidoptera , Noctuidae , Nutritional indices , Spodoptera littoralis