age-stage, two-sex life table of helicoverpa armigera (lepidoptera: noctuidae) on different bean cultivars

the cotton bollworm, helicoverpa armigera (hübner), is one of the important polyphagous pests causing serious loss to many economically important crops in iran. the goal of this experiment was to study the age-stage, two-sex life table of h. armigera on different bean cultivars including white kidney bean (cultivars daneshkadeh, pak, and shokufa), red kidney bean (cultivars akhtar, naz, and sayyad) and common bean (cultivar talash) under laboratory conditions (25±1ºc, 65±5% rh, a 16:8 h light-dark photoperiod). the longest and shortest larval period and development time of total pre-adult h. armigera were 19.83±3.83 and 37.58±0.90 days on red kidney bean akhtar, respectively, and 14.13±0.32 and 31.82±0.42 days on white kidney bean pak, respectively. the lowest intrinsic rate of increase (r) was on red kidney bean akhtar (0.115±0.009 day-1) and the highest on white kidney bean pak and common bean talash (0.142±0.001 day-1). the lowest and highest values of the net reproductive rate (r0) were on red kidney bean akhtar (177.3±6.7 offspring) and white kidney bean shokufa (270.1±6.7 offspring), respectively. the mean generation time (t) on different bean cultivars ranged from 37.03±0.05 to 44.64±0.07 days, which was shortest on white kidney bean pak and longest on red kidney bean akhtar. the results revealed that the cultivar akhtar was the most unsuitable host for population growth of h. armigera.