Freilij, D. | Search bioRxiv

bioRxiv2026

Potential range shifts of the Anastrepha fraterculus complex (Diptera:Tephritidae) morphotypes: implications under climate change scenarios

The South American fruit fly Anastrepha fraterculus is a cryptic species complex that comprises at least eight morphotypes and endangers part of the fruit production across the Americas. In this study, we modeled the current and future potential distributions of the whole complex and each morphotype. Filtered occurrence data (n = 339) were analyzed against six previously selected non-collinear bioclimatic predictors. Ensemble models created with statistical and machine learning algorithms identified [~]6 million km{superscript 2} of environmentally suitable area for the complex, mainly in Brazil and Argentina. Morphotype-level analyses revealed contrasting range extension and suitable areas: Brazilian-1 exhibited the broadest distribution and environmental breadth, whereas Brazilian-2 and -3 were restricted to coastal regions. High-elevation morphotypes (Andean, Ecuadorian, Peruvian, Venezuelan) were strongly constrained by temperature, while the Mexican morphotype distribution was more related with precipitation and displayed a significant potential for expansion into Central and North America. Future projections indicated overall contractions (18-40%) of the areas presenting high-suitability for the presence of the species, along with southward range shifts and increased morphotype overlap in temperate regions; nevertheless, the remaining high-suitable area include the current zones of high production of fruits. These results provide a morphotype-explicit reference for anticipating invasion risk and support area-wide integrated pest management strategies under climate change.

ecology↗

bioRxiv2026

Southern South American Maize Landraces: A Source of Phenotypic Diversity

Maize (Zea mays L.) is a globally important crop for food, feed, and industrial uses. Modern breeding increasingly targets traits beyond yield, including stress tolerance, nutritional quality, and pest resistance. Progress toward these goals is constrained by the narrow genetic diversity of commercial varieties, a consequence of the repeated use of a limited number of inbred lines. Maize landraces therefore represent valuable reservoirs of genetic and phenotypic diversity. Northern Argentina is one of the southernmost regions of maize landrace cultivation and comprises two main centers of diversity: Northeastern Argentina (NEA; <2000 m.a.s.l.) and Northwestern Argentina (NWA; >2000 m.a.s.l.). Despite their potential relevance, phenotypic characterization of these landraces remains limited, particularly for biochemical traits, which, although less visible, play key roles in biomass accumulation, defense against pathogens and herbivores, tolerance to environmental stress, and quality attributes such as flavor. Here, we evaluated 17 phenotypic traits, including morphological traits, leaf biochemical compounds (such as pigments, carbohydrates, and phenolics), and salt stress tolerance, in 19 maize landrace accessions from Northern Argentina. Substantial variation was detected across all traits, both within and among accessions, indicating that each accession harbors a distinct phenotypic profile. While no significant differences were observed between regions, redundancy analysis revealed associations between phenotypic variation and collection-site altitude. These findings highlight the value of Argentine maize landraces as sources of biochemical and stress-related traits and support their conservation and use in breeding programs aimed at broadening the genetic base of cultivated maize. Main ConclusionMaize landraces from Southern South America show high within and between accession phenotypic variability, while differences between regions of origin are associated with altitude.

plant biology↗