EVALUATION OF Spodoptera frugiperda (J. E. SMITH, 1797) (LEPIDOPTERA, NOCTUIDAE) DAMAGES IN THE COTTON PLANT IAC-17 CULTIVAR

Abstract

This work was conducted with the purpose of evaluate the damages provoked by Spodoptera frugiperda (J. E. Smith, 1797) in cotton-plant yield. To evaluate the decrease in the cotton yield four levels of artificial infestation were used at 75 and 95 days from plant germination. The damage was evaluated on cotton seeds per plot. The differences in the yield of infested plants at 75 and 95 days from germination, when compared to the check, were statistically significant for the infestations of 1, 2 and 4 larvae per plant. At 75 days when the plants presented a low number of fruit organs, the yield decrease was due to the attack of larvae cutting partially or totally the shoots and stems. As to the infestation at 95 days the yield decreased linearly in relation to the different levels of infestation; at this time the larvae showed a preference for the fruit structures of the cotton plants.