Performance Evaluation of Spodoptera exigua (Lepidoptera: Noctuidae) Larvae on ۱۰ Sugar Beet Genotypes Using Nutritional Indices

The aim of this study was to evaluate the effect of ten different sugar beet genotypes on nutritional indices of the beet army worm, Spodoptera exigua (Hübner) (Lep.: Noctuidae) at ۲۵±۱°C, ۶۰±۵% RH and a photoperiod of ۱۶:۸ (L: D) hour. The sugar beets evaluated in this study included two sugar beet cultivars (HM ۱۳۳۹ RZ and SBSI۰۰۶), five populations (SB۲۶, SB۲۷, SB۲۹, SB۳۳, SB۳۴), one hybrid (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵ and two lines (FC ۳۰۱ and FC ۲۲۰). Fourth instar larvae reared on (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵ showed the highest Relative Growth Rate (RGR) of ۰.۳۱ mg mg-۱ day-۱, Relative Consumption Rate (RCR) of ۴.۷۹ mg mg-۱ day-۱ and Approximate Digestibility (AD) value of ۹۴.۳۵% compared with the other host plants. The lowest value of RCR (۰.۸۱ mg mg-۱ day-۱) was on SBSI۰۰۶. The Efficiency of Conversion of Ingested food (ECI) was varied from ۱.۸۰% on FC ۲۲۰ to ۹.۱۴% on SB۳۴. The highest AD value of fifth instar (۹۲.۶۳%) wason (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵ and the lowest value of this index was recorded on SB۲۷ (۸۳.۷۱%). The highest AD value of whole larval instars was noted in (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵ (۹۳.۷۳%). The lowest value of RCR (۱.۷۸ mg mg-۱ day-۱) was found on SB۲۷. The heaviest pre-pupa (۸۱.۰۱ mg), pupa (۷۲.۵۵ mg) and wet adults (۱۹.۱۴ mg) of beet armyworm were recorded on (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵. The results indicated that (۷۱۱۲*SB۳۶)*Sh-۱-HSF-۵ was the most suitable host for S. exigua that should be considered in cultivation or breeding programs.