Etapa larval y comportamiento minador de Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) en tomate (Solanum lycopersicum L.) bajo condiciones de cultivo comercial

Abstract

This study aimed to evaluate the dynamics of the larval stage of Tuta absoluta in a commercial tomato crop. The study sought to identify the onset of mining activity and estimate the approximate duration of this stage. This was achieved by integrating observational records with the detection of adults and the sampling of infested leaves. The study contributes to the establishment of useful biological parameters for optimising monitoring and decision-making in pest management. The study employed an observational approach involving weekly monitoring of adults using pheromone traps placed at various locations within the crop bed, alongside periodic sampling of infested leaves. The collected material was analysed in the laboratory using a stereomicroscope to allow photographic recording of the pest's different life stages and documentation of egg hatching, leaf penetration and frass presence. The results revealed a consistent presence of T. absoluta adults throughout the monitoring period, with variations in catch rates observed between traps. Mining activity was observed to begin immediately after egg hatching, during the first larval instar (L1), confirming early penetration of leaf tissue and formation of internal galleries. The four larval instars, the pupal stage and the adult stage were also documented, as was the damage caused by larval activity to tomato leaves and fruits, including newly set fruits and those in the process of formation. However, it was not possible to accurately estimate the duration of the larval mining phase due to the absence of chronological monitoring of individual cohorts under controlled conditions, which was a methodological limitation of the study. In conclusion, this study provided a descriptive characterisation of the larval stage dynamics of T. absoluta under commercial growing conditions. It identified the onset of mining activity and documented the early behaviour of the pest and its manifestations of damage.