antibiotic resistance of canola cultivars affecting demography of spodoptera exigua (lepidoptera: noctuidae)

spodoptera exigua (hübner) was studied in laboratory (25±1ºc, 60±5% rh, and 16:8 l:d h) exploring the antibiotic effects of 10 canola cultivars (sarigol, slm046, hayula420, rgs003, opera, okapi, licord, modena, zarfam and talaye) on its demographic parameters. the age-stage, two-sex and the traditional female age-specific life tables were constructed by using the demographic data. the larval period was longest on modena (17.53 days) and pupal period was longest on opera (8.96 days). the longest and shortest development time of immature stages lasted 29.96 and 25.82 days on talaye and okapi, respectively. male adult longevity was longest on okapi (14.93 days) and shortest on hayula420 (9.14 days), and female adult longevity was longest on zarfam (18.04 days) and shortest on hayula420 (8.07 days). based on the two-sex life table, the net reproductive rate (r0), intrinsic rate of increase (r), and finite rate of increase (λ) were highest on okapi (352.96 offspring per individual, 0.201 and 1.223 day-1, respectively). the lowest of r0 was recorded on opera (152.73 offspring per individual) and lowest of r and λ on talaye (0.142 and 1.153 day-1, respectively). the mean generation time (t) took longest time on modena (36.41 days) and shortest on okapi (29.06 days). the results of this study showed that ‘okapi’ was the most suitable canola cultivar for reproduction and population growth of s. exigua, which revealed higher susceptibility of ‘okapi’ to this pest.