Elucidating the role of Nesidiocoris tenuis in Italy: a contemporary perspective

Abstract: Nesidiocoris tenuis is a valuable generalist predator of several key pests in
Mediterranean protected crops. However, its actual role in crop protection has been questioned for decades. Upon the first introduction of Tuta absoluta in Italy, few natural enemy species were identified as potential biological control agents, and N. tenuis has rapidly gained importance due to its high efficacy against the new pest. In this scenario, various studies have been carried out with the aim to evaluate new sustainable strategies exploiting the role of this predator, while managing its potential negative impacts own to its herbivory. Biotic interactions influencing N. tenuis populations in Italian tomato crops have been studied with reference to the model of the invasive pest T. absoluta. The zoo-phytophagous mirid has been extensively investigated for its pest biocontrol services and its ability to induce direct and indirect plant defenses in tomato. Our studies showed the ecological success of N. tenuis over indigenous parasitoids by competitive interactions. A multi-prey system trials combining N. tenuis and Macrolophus pygmaeus in presence of Bemisia tabaci and T. absoluta demonstrated that using both mirid predators together reduces N. tenuis density, maintains biocontrol efficiency reducing plant feeding activity. Augmentative and conservation biological control strategies based on N. tenuis have proven effective in managing T. absoluta. Sesame and verbena have been evaluated, as companion plants to mitigaGaetano Siscaro, Michele Ricupero, Antonio Biondi, Antonio Gugliuzzo,
Giovanna Tropea Garzia, Lucia Zappalàte tomato damage caused by N. tenuis, with promising results. The toxicity of synthetic and naturally derived pesticides currently used in various protected crops was tested for the compatibility with N. tenuis. Sustainable control tools and new attractive compounds were also identified to incorporate the mirid into Integrated Pest Management programmes. Continued research and implementation efforts are crucial to promote the use of this effective biocontrol agent in Italy.