Predicting global establishment for biological control: Climatic suitability of three promising larval parasitoids against the invasive tomato leafminer <i>Tuta absoluta</i>

Abstract Background: The invasive tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), poses a significant threat to global tomato production, and the limitations of chemical control necessitate the development of sustainable alternatives, such as biological control through classical or augmentative releases. The success of such programs is contingent on the climatic match between the pest and its natural enemies. Methods: This study conducted a global bioclimatic evaluation of T. absoluta and three promising larval parasitoids – Necremnus tutae , Neochrysocharis formosa , and Dolichogenidea gelechiidivoris – using the CLIMEX model to guide their strategic deployment. We predicted their climatic suitability based on an integrated scenario that accounts for both rainfed and irrigated agriculture. These predictions were then overlaid with global tomato cultivation areas to assess high-risk areas (pest Ecological Index (EI) ≥ 30) and quantify biocontrol potential (parasitoid EI ≥ 30). Results: The three parasitoids possess largely distinct climatic niches, with regions highly suitable for all three covering only approximately 5% of the pest’s high-suitability habitat. Critically, overlaying predictions with tomato cultivation areas revealed that T. absoluta presents a high climatic risk to approximately 53% of these areas. Approximately 50% of this high-risk area was climatically suitable for at least one highly suitable parasitoid species, while the biocontrol potential varies starkly by region. Conclusions: These findings provide a proactive, yet conservative and realistic, assessment that underscores the necessity of regionally tailored biocontrol strategies. By identifying areas of high climatic suitability, this study offers a scientific basis for developing targeted biological control programs against T. absoluta .