Tuta absoluta (Lepidoptera: Gelechiidae) rearing in artificial diet

The tomato pinworm, Tuta absoluta is a key pest of tomato and other solanaceous crops in South America. Since 2006, this pest has caused a serious damage in tomato crops in Europe and Africa. One important tool to study and develop strategies to control T. absoluta is the rearing in laboratory artificial diets without the natural host. In this study, we evaluate nine artificial diets based on three basic ones: Greene et al. (1976), Hensley and Hammond (1968) and Berger (1963) and variations of them with the addition of sucrose and tomato powder. 100 vials were prepared for each diet and three newly hatched larvae were inoculated. It was evaluated: larval survival seven days after inoculation, larval and pupal viability and development time, pupal weight, sex ratio, longevity, fertility and fecundity. With the obtained data, fertility lifetables were calculated. No significant differences were obtained with the addition of tomato powder or sugar. Cluster analysis show that the less adequate diets were those based on Greene et al. (1976). The highest total viability (70%), shortest development time (32 d), highest pupal weight (4,11 mg) were obtained for Berger (1963) diet. Net reproductive rate per generation (Ro) and increase finite rate (λ) were 45,01 and 1,12 respectively. Although these values are lower than those obtained on natural diet, they are better than previous diets selected for the tomato pinworm. Insects were maintained on the best diet for eight generations without deleterious effects on the insect development.