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 2 / 22 vast areas such as the Amazon lowlands, northeast and southwest Atlantic Forest, and transition areas of Atlantic Forest and Dry Diagonal remain underexplored. To the best of our knowledge, this study represents one of first empirical analysis of envi- ronmental gradients for Trichoptera species. It establishes a foundation for under- standing biogeographic patterns, environmental gradients, and the identification of biodiversity hotspots and potential distribution areas for Helicopsychidae in the New World. This work will guide future research and conservation efforts for Helicopsychi- dae and other Trichoptera groups in the region. Introduction The distributional patterns generally used the distribution of known species as a proxy [1], and, consequently, they are strongly related to biased collection efforts [2]. There are huge gaps in biodiversity knowledge related to areas neglected in terms of collection effort, fauna inventories, taxonomists, and investment in research, espe- cially in developing countries [3,4]. These factors cause collection bias and directly affect biodiversity knowledge [5–7]. In this context, some authors have defined the different knowledge gaps, or the Biodiversity Knowledge Shortfalls (BKS), in various categories such as gap of species knowledge is the Linnaean shortfall, the unknown species geographic distribution is the Wallacean shortfall, the gap of knowledge about semaphoronts of

species Haeckelian shortfall, the gap of knowledge about abiotic tolerance of species Hutchinsonian shortfall and unknown of evolution of groups is the Darwinian shortfall [8,9]. Among the tools available to face the biodiversity knowledge shortfalls, dis- tribution modelling can identify areas with a high probability of potential distribution (environmental suitability) [10]. The generated models can help to prioritize resources and efforts in areas with the probability of potential distribution of species [11]. On the other hand, anthropogenic actions have caused planetary-scale changes, which have caused the sixth mass extinction [12] with critical loss of biodiversity faster than our ability to catalogue it [13]. Among the ecosystems, freshwater environ- ments cover only 1% of Earth’s land surface but comprise around 10% of all species [14]. Levels of endemism in these environments are remarkably high, and about 20% of the New World (NW – here composed for West and East Nearctic, Neotropical and Patagonian region sensu de Moor & Ivanov) species are threatened sensu IUCN [15]. Due to these characteristics, freshwater environments have the most acute bio- diversity crisis among ecosystems [16]. The formulation of strategies based on large datasets is urgent to protect species, as well as the priority areas [17], and conse- quently reduce (or reverse) the decline of freshwater biota as much as possible [16]. Several insect orders have species with life stages occurring in freshwater ecosys-

tems, but some orders stand out as having primarily aquatic origins (e.g., Trichoptera) [18]. Among these amphibiotic orders, the caddisflies stand out as having the great- est richness and diversity of functional trophic groups [19]. Despite recent advances in caddisfly taxonomy and phylogeny, the order is underexplored and poorly known and reproduction in any medium, provided the original author and source are credited. Data availability statement: All relevant data are within the manuscript and its Supporting Information files. Funding: We thank the Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio) for collecting permits. ARC acknowledge the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (under Grants 303623/2015-2). RP also thanks to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, finance code 001, PDS-CAPES-88882.453922/2019-01, and PRAPG-CAPES-88887.986811/2024-00) for the doctoral and post-doctoral fellow- ship. We thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Programa de Apoio à Pós-Graduação (PROAP-CAPES) for financial support, and this study was financed in part by the CAPES – Finance Code 001 (PPG Biodiversidade e Evolução). We would like to thank Dra. Neusa Hamada, Dra. Ana Pes and Dr. Gleison Desidério for providing us with data from LACIA-INPA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: There is no conflict of interest.