Beet armyworms, Spodoptera exigua, have been anecdotally reported to lay more eggs on drought stressed cotton plants than on non-stressed cotton plants. This study demonstrates that, using potted cotton plants grown in water saturated conditions, and on water deficit regimes of 1,500, 1,000, and 750 ml water per week, beet armyworms deposited 3.3, 4.6, and 2.3 times more (P < 0.05) eggs on plants in the three respective water deficit regimes than on the three respective water deficit regimes. Third instar beet armyworms raised on the water saturated cotton plants were 1.5, 2.3, and 2.6 times heavier than third instars raised on cotton plants grown in the 1,500, 1,000, and 750 ml water per week regimes (P < 0.05). Pupal weights followed the same trend (P < 0.05). Although beet armyworms preferred to oviposit on water deficit stressed cotton plants, the larvae fared poorly. Physiochemical analyses of soluble protein, free amino acids, and carbohydrates (relevant to nutritional value) and leaf water potentials of the differently stressed cotton leaves were used to explain results.
Species 1: Lepidoptera Noctuidae Spodoptera exigua (beet armyworm)
Keywords: drought, beet armyworm
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