Life History Studies of the Beet Armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) on 10 Corn Hybrids

Abstract

The beet armyworm, Spodoptera exigua (Hübner) is a polyphagous insect pest that damages several field crops including corn, cotton, soybean, alfalfa and tomato in many parts of the world. In this study, the effect of 10 corn hybrids (SC700, DC370,SC704, SC260, SC500, Keynes540, Keynes410, KSC260, KSC400and KSC301) on life history of S. exigua was studied under laboratory conditions (25±1 °C, 65±5% RH, and 16:8 (L: D) h). The results showed that the longest larval and pupal period was on SC500 (29.55 and 14.33 days, respectively). The longest and shortest development time was on SC500 and KSC260, respectively (39.50 and 29.47 days, respectively). The lowest percentage of mortality and highest fecundity was observed on Keynes540. Our findings indicated that the lowest growth index in the pupal stage (2.05) and the highest percentage of mortality in larval and pupal stages were on hybrid SC700. Therefore, it was concluded that SC700 was partially resistant to S. exigua in comparison with the other hybrids tested.