Caracterização dos danos de Spodoptera eridania (Cramer) e Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) a estruturas de algodoeiro / Characterization of the damage of Spodoptera eridania (Cramer) and Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) to structures of cotton plants

ABSTRACT

The cotton plant, Gossypium hirsutum, hosts various pests that damage different structures. Among these pests, Spodoptera cosmioides (Walker) and Spodoptera eridania (Cramer) (Lepidoptera Noctuidae) are considered important. The objectives of this study were to characterize and to quantify the potential damage of S. eridania and S. cosmioides feeding on different structures of cotton plants. For this purpose, newly-hatched larvae were reared on the following plant parts leaf and flower bud; leaf and boll; flower bud or boll; and leaf, flower bud and boll. The survival of S. cosmioides and S. eridania was greater than 80 percent and 70 percent for larvae fed on cotton plant parts offered separately or together, respectively. One larva of S. eridania damaged 1.7 flower buds, but did not damage bolls, while one larva of S. cosmioides damaged 5.2 flower buds and 3.0 cotton bolls. Spodoptera eridania and S. cosmioides can be considered species with potential to cause economic damage to cotton plants because they can occur throughout cotton developmental stages causing defoliation and losses of reproductive structures. Therefore, the results validate field observations that these two species of Spodoptera are potential pests for cotton.