Mating Disruption with Biodegradable Dispensers Complemented with Insecticide Sprays Allows an Effective Management of Tuta absoluta in Greenhouse Tomatoes

Developing effective tools for the sustainable management of Tuta absoluta (Lepidoptera: Gelechiidae) remains a challenge. Pheromone-based control is attracting growing attention for managing this moth pest. In the present study, we assessed the efficacy of a mating disruption approach relying on biodegradable pheromone dispensers, tested at 300 and 500 dispensers/ha, for the control of T. absoluta on greenhouse tomato. The mating disruption strategy was coupled with a reference base treatment that alternates the most commonly used insecticides for the pest (the insecticide-based grower's standard). Mating disruption with biodegradable dispensers achieved a significant reduction in T. absoluta male catches and leaf and fruit damages when compared to those obtained with the grower's standard treatment alone, and performed better than commercial non-biodegradable dispensers. Overall, our study sheds light on the intriguing potential of biodegradable dispensers for T. absoluta management on greenhouse tomato.Abstract IPM approaches based on pheromone-based techniques for the management of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), are of great interest. We evaluated the effectiveness of mating disruption (MD) experiments against T. absoluta using a biodegradable pheromone dispenser (Isonet-T TT BIOX234) in greenhouse-grown tomatoes over two years in southern Italy. A base treatment alternating the most used insecticides for the pest, i.e., the farmer treatment schedule (FTS), was assigned as a reference, and two MD dispenser densities (i.e., 300 and 500 dispensers/ha) were compared with the MD commercial product Isonet T at 1000 units/ha. We conducted two trials on crops at a density of 37,000 plants/ha. Pest flights were monitored in summer-autumn 2023 and 2024 with pheromone-baited Delta traps. The FTS ensured a generally low level of T. absoluta attacks (about 1 leaflet/leaf and 1/300 fruits). Even so, mating disruption resulted in further appreciable reductions in the presence and attacks of the target pest: 89%, 76% and 52% fewer catches; 61%, 45% and 37% fewer mined leaflets; and 76%, 59% and 54% fewer attacked fruits, for Isonet-T TT 500, Isonet-T TT 300 and Isonet T 1000, respectively. Overall, MD biodegradable dispensers could be a valuable tool for controlling T. absoluta in greenhouse-grown tomatoes, while also reducing plastic waste in the agricultural setting.