Addressing biodiversity knowledge shortfalls in New World Helicopsychidae (Insecta, Trichoptera): Potential distribution, environmental gradients, and identification of conservation and research priority areas

PLOS One | https://doi.org/10.1371/journal.pone.0327580 July 28, 2025 14 / 22 Distribution modelling After conducting correlation testing, nine raster variables were found to be uncorrelated, belonging to five groups (biocli- matic, elevation, precipitation, solar radiation, and wind speed), as listed in Table 3 (for more details, see S3 Table and S1 Fig). Among the four algorithms tested, all yielded AUC values higher than the cut-off value (S2 Fig). These values were subsequently used to generate environmental suitability maps for the subgenera (Fig 1). Distribution modelling indicates high environmental suitability (values > 0.7) for H. (Cochliopsyche) species across broad areas of the Neotropical region, particularly throughout the Brazilian and Chacoan subregions. Areas of notable suitability include: (i) the Amazon Basin, (ii) the Atlantic Forest dominion, and (iii) high-altitude regions in the eastern por- tions of the Caatinga and Cerrado dominions (Fig 1A and C). In contrast, areas of low suitability are primarily found in the (i) Mexican and South American transition zones; (ii) the Mesoamerican dominion, and (iii) the Antillean subregion. Within the Brazilian subregion, low suitability is also observed in the (iv) Pará, Xingu-Tapajos, Cerrado, Chacoan, and Pampean provinces, as well as across the entire (v) Patagonian region (Fig 1A and C). For H. (Feropsyche) species, the model predicts high environmental suitability (> 0.7) primarily in the Nearctic region,

especially: (i) in South Florida (Florida Keys), where no species records currently exist. In the Mexican transition zone, (ii) southern portions of the Chihuahuan Desert, Sierra Madre Occidental and Oriental, and the Trans-Mexican Volcanic Belt also show high suitability. In the Neotropical region, four major areas exhibit high suitability: (iii) the entire Antillean subregion; in the Brazilian subregion (iv) most part of the Mesoamerican dominion, excluding the coastal areas of the Veracruzan province and nearly all of the Yucatán Peninsula; (v) in the Pacific dominion, the Guatuso–Talamanca, Puntar- enas–Chiriquí, and Chocó–Darién provinces, as well as high-altitude (Andean Cordillera) and coastal regions of Colombia and Venezuela—except much of the Guajira and Magdalena provinces; (vi) in the Boreal Brazilian dominion, the western portions of the Guiana Lowlands and Yungas provinces; and Chacoan subregion (vii) the entire Paraná domain and areas east of Caatinga Cerrado and Chacoan provinces where they are bordered by the Atlantic Forest and Paraná provinces (Fig 1D and F). Conversely, areas of low environmental suitability for H. (Feropsyche) species are primarily located in: (i) most of the South American transition zone; (ii) nearly all the Boreal Brazilian, South Brazilian, and Southeastern Amazo- nian dominions; and (iii) most of the Chacoan dominion, except for eastern portions of Caatinga, Cerrado and Chacoan provinces (Fig 1D and F). Discussion Biodiversity knowledge shortfalls and challenges

Our results demonstrate the clear increment of species descriptions and cataloguing of distributional records, mainly in under-explored areas of Neotropical region. This increase can be related with the development of trichopterology in the Neotropical, Nearctic and Patagonian regions [as indicated in 33,67], cooperation among researchers of NT with other researchers’ groups [e.g., 24,36], and the establishment of research groups in different countries of the Neotropical and Patagonian regions [e.g., 23,38,68]. After Johanson [30,35,41,45,69], who established the modern panorama of Helico- psychidae taxonomy in the Neotropical, Nearctic and Patagonian regions, several contributions have been made by local researchers [e.g., 32,37,40,62,70], but no one with a broad perspective. However, our results indicate more dramatic scenarios for Helicopsyche, with up to 75% of the fauna still unknown and numerous unexplored areas, when compared with previous estimates for Trichoptera in the NT [23,24], both with around 50% unknown species] (Table 2). These results are consistent when looking at the number of known species and the vast Fig 3. Boxplot of biogeoclimatic variables of New World Helicopsyche species. A. Elevation range of Helicopsyche (Cochliopsyche) species; B. Elevation range of Helicopsyche (Feropsyche) species; C. Freshwater Stahler order range of Helicopsyche (Cochliopsyche) species; D. Freshwater Stahler order range of Helicopsyche (Feropsyche) species. https://doi.org/10.1371/journal.pone.0327580.g003