Development and fecundity ofSpodoptera exigua(Hübner) (Lepidoptera: Noctuidae) on different soybean cultivars

The life history of Spodoptera exigua was studied under laboratory conditions at temperature of 25°C ± 1°C, relative humidity (RH) of 60% ± 5% and a photoperiod of 16:8 h (Light:Dark) on nine soybean (Glycine max L.) cultivars: 032, 033, Hill, M4, M7, M9, M11, TMS and Zan. Larval and pupal development times were longest on M7 cultivar (14.09 ± 0.078 and 7.78 ± 0.090 days) and shortest on 033 cultivar (11.98 ± 0.054 and 7.033 ± 0.090 days). The longest and shortest female and male longevities were observed on Hill and Zan cultivars, respectively. The results showed that the whole life span varied from 32.80 ± 0.89 to 37 ± 0.98 days for females and from 33.3 ± 0.66 to 38.74 ± 0.95 days for males. The highest daily fecundity was obtained on M9 (102. 38 eggs), and the lowest on Hill (75.87 eggs). Mean total fecundity per female during adult life was highest on 033 (1156.20 eggs) and lowest on M7 cultivars (841.68 eggs). Clustering analysis of the biological parameters of S. exigua confirmed that 033 and Hill cultivars were the susceptible and the resistant cultivars, respectively.