Determination of levels of damage caused by different densities of Tuta absoluta populations (Lepidoptera: Gelechiidae) under greenhouse conditions

In order to determine the effect of infestations with Tuta absoluta on the growth and development of tomato plants under greenhouse conditions, six densities of the pest were evaluated (0, 2, 4, 6, 8, and 10 females/plant). A completely random design with three replicates per treatment was employed. The percentage of leaf area and number of fruits damaged were estimated and those variables were used to construct a damage curve. The plants exposed at infestation levels between 6 and 10 females presented the highest percentages of leaf area consumed (between 27 and 43%), damage on fruits (between 45 and 100%), and loss of apical leaves in comparison with the treatments with two and four females/plants. The height, number of internodes, number of leaves and leaflets, number and biomass of fruits were differentially affected by the densities of T. absoluta infestation (P≤0.05). The leaf area and the biomass of stems and leaves did not vary with the infestation levels evaluated. On the damage curve, we observed that with more than two females per plant, the variables biomass, quality and number of fruits, result affected in an important way.