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 17 / 22 The H. (Feropsyche) has 36 valid species, and H. (Cochliopsyche) present ten valid species with adult females depos- ited (in material examined), but not formally described in published studies (Table 1). Both subgenera have specimens of immature stages deposited in museums and collections that have not yet been associated with adult males (Table 1). These data demonstrate the enormous potential of the material to be described and fulfil the biodiversity shortfalls. The description of these semaphoronts can contribute to a better circumscription of the species, the correction of possible taxonomic errors, and the formation of a complementary database for studies related to the understanding of relationships and biogeographic history [9]. To our knowledge, this is one of first inference describing environmental gradients for Trichoptera species [preceded by the work of [25,26], which investigating the influence of elevation on Trichoptera]. Here are addresses Hutchinsonian deficits by empirically defining species’ abiotic limits and identifying areas with a higher probability of distribution in regions of high suitability, focusing on the niches of H. (Feropsyche) and H. (Cochliopsyche). This also provides evidence of niche differentiation between the two living lineages of Helicopsychidae in the New World. Additionally, these data help identify species more vulnerable to extinction due to their narrow distribution gradients in biogeoclimatic variables. However, we

acknowledge that our data are limited by current knowledge of species distribution, and future research may expand the distribution range of species. Distribution patterns and potential distribution in New World The initial step in addressing the challenges posed by BKS is the compilation of inventories, checklists, descriptions of new species, and new distribution records [36]. However, it is equally important to consider other aspects, such as ecology, biology, phenology, and ethology, which can inform biodiversity conservation policies and the consequences of anthropogenic interventions (e.g., climate change, suppression of riparian vegetation) [23,25,26,71]. This study estab- lishes the environmental gradients for the H. (Feropsyche) and H. (Cochliopsyche) species. Despite the considerable range of elevation, temperature, and precipitation observed across both subgenera, the data indicated a higher prev- alence of H. (Feropsyche) species in coastal areas of tropical and temperate environments, across a wide elevation gradient (0–5042 m a.s.l.), in low order streams and in areas with high rainfall (Figs 3 and 4). On the other hand, the H. (Cochliopsyche) species are restricted to tropical environments, with prevalence in rainforests and lowland areas. Of the distributional records, 55% are in higher order streams (>4th order) (Figs 3 and 4). The results presented here concur with previous hypotheses proposed by Monson et al. [72], Flint [62,63], and Johan-

son [41,45]. However, this study provides a comprehensive overview of the distribution and analyzes the differences in environmental space between the subgenera. In addition to the morphological differences, these factors contribute to the accumulation of divergence between the NW Helicopsychidae lineages. Currently, there is still no clear resolution regard- ing their phylogenetic relationship. Some hypotheses suggest that they are sister groups [73], while others posit that they are distant clades [30], further complicating their taxonomic placement. Despite its wide distribution in tropical regions, H. (Cochliopsyche) is largely restricted to the type locality or adjacent localities (S1 Table). Distribution records are scarce and generally consist of single collections with a small number of specimens (S1 Table). This is primarily due to the greater concentration of collection and research efforts on Trichoptera in small, oxygenated freshwater environments, where most of the group’s diversity is concentrated [34]. It is therefore rec- ommended that research efforts be directed towards the at inventorying of South America’s large rivers, with priority areas for H. (Cochliopsyche) studies (areas of high suitability and low research effort) including all South America’s large river basins (e.g., Amazon, Orinoco, Paraná, and São Francisco River basins), with a particular focus on the large size rivers (Fig 1C). The species of H. (Feropsyche) are distributed across a wide range of habitats, from the temperate areas of the

Nearctic Region to the Andean areas of Chile (Fig 1E). However, the areas with the highest environmental suitability are throughout Central America (including the Antilles), the Florida Keys, areas east of the Andes between Argentina and