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

Abstract

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