In this study, we compiled data from various sources and updated the distribution of the Eumorpha genus in Brazil. Publications including members of this group remain incipient, with only two studies dedicated exclusively to the Eumorpha genus (Ponce et al. 2015; Lima et al. 2023). This scarcity of studies focused on the genus reflects gaps both in taxonomic knowledge and in the ecological and biogeographical understanding of the group.

In many cases, studies with species lists appear as appendices to local or regional faunal inventories (Câmara et al. 2018; Valente and Teston 2024), in which the Eumorpha genus, although present, is not the subject of detailed analysis regarding its ecology, distribution, or phylogeny. This often-fragmented approach limits the advancement of systematic and biogeographical knowledge of the group, in addition to restricting the understanding of its ecological roles and its vulnerability to environmental change. Future research should focus on biogeographic, ecological, modeling, and molecular studies to better characterize patterns of diversity, endemism, and distribution that remain largely unexplored within the Eumorpha genus.

Another aspect highlighted by the analysis of data obtained from published studies was the uneven chronology and trajectory. The earliest records of Eumorpha are concentrated in the Atlantic Forest and Amazon, reflecting the predominance of these biomes in early entomological inventories (see Laroca and Mielke 1975; Motta et al.1991, Motta et al.1998; Motta & Andreazze 2002). In contrast, historical gaps persist in Caatinga, Cerrado, Pampa, and Pantanal, where sampling has been considerably more limited. This concentration of records in the Atlantic Forest and Amazon biomes also demonstrates the historical predominance of these environments in entomological inventories, often due to their recognized megadiversity and the presence of nearby research institutions (Lazos-Ruíz et al. 2021). Furthermore, it may also be related to the species richness of these biomes (Duarte et al. 2008; Lima et al. 2023).

The first Eumorpha moths record in the Caatinga biome appeared in a study in 2005, and another study in 2024 was a study documenting the genus in the region. This gap highlights the historical neglect of biomes considered to have “lower diversity.” Santos et al. (2011) emphasize that the Caatinga has the lowest number of studies and dedicated researchers, especially when compared to the amount of research conducted in humid forests such as the Amazon and Atlantic Forest.

The inclusion of the Cerrado in the literature with genus records occurred even later, in 2009, despite this biome being recognized as a biodiversity hotspot with a high endemism rate (Myers et al. 2000). When it comes to studies on moths, the Cerrado remains greatly neglected compared to other insect groups such as beetles (Coleoptera), bees and wasps (Hymenoptera), and flies (Diptera) (Correa et al. 2025). Despite the recent increase in studies, there is still a need for greater investment, particularly in expanding temporal coverage, increasing sampling effort, and identifying priority areas for understanding the Eumorpha fauna in the Caatinga and Cerrado biomes.

These data highlight the overall scarcity of studies on the genus and a historical pattern of unequal research effort among Brazilian biomes, which limits the understanding of the true geographic distribution, ecological requirements, and evolutionary potential of species belonging to the Eumorpha genus. However, in recent years, an increase in the number of available records has been observed, which may be associated with expanded digitization of collections and the strengthening of open data platforms (Hedrick et al. 2020). Nevertheless, the analytical use of these data remains limited as standardized formats for online available data are still lacking (Feng et al. 2022). The high frequency of records for certain species in publications, such as E. anchemolus, E. fasciatus, E. labruscae, and E. vitis, may be related to multiple ecological and methodological factors. These species generally exhibit attributes that increase detectability in faunal surveys, as taxa with wide geographic distribution and high abundance tend to be more easily recorded (Gaston and Lawton 1988).

Evidence suggests that forest corridors intermittently connected the Amazon and Atlantic Forest in the past (Por 1992), facilitating species exchange, especially among highly mobile groups like hawkmoths, which serve as key pollinators and bioindicators in tropical ecosystems (Cerdal et al. 2002). Despite their ecological importance, we showed that the distribution of many hawkmoth species remains poorly understood.

Species geographical distribution of the Eumorpha genus in Brazil exhibits distinct patterns of occurrence across different biomes, including cases of geographically disjunct distributions, and also with consistent indications that some species may represent complexes due to their cryptic nature, as suggested by Eitschberger (2011) and Lima et al. (2023). When these patterns are analyzed alongside historical occurrence data, they reinforce the importance of integrative approaches for delimiting taxonomic and biogeographic groups.

The species E. capronieri, E. phorbas, E. megaeacus, and E. orientis exhibited disjunct distributions. Patterns of disjunct distributions may raise the possibility of population differentiation along environmental gradients or even following historical fragmentation events (Sgarlata et al. 2025). In Lepidoptera, isolated populations may, in some cases, correspond to divergent lineages or even subspecies, especially in groups with strong associations to specific habitats (Sourakov and Zakharov 2011; Jiang et al. 2016; Vargas-Ortiz et al. 2018). However, for the species treated in this study, no formally described subspecies correspond to these isolated population nuclei (Kitching 2025). Moreover, phylogenetic or phylogeographic studies available for Sphingidae remain limited and, when present, lack sufficiently broad geographic sampling to assess whether these populations represent distinct evolutionary units (Kawahara et al. 2009).

Species such as E. labruscae, E. fasciatus, and E. vitis were found to be widely distributed, with occurrence records across multiple biomes, including urban areas (Haxaire and Mielke 2019). Their ubiquity appears to be related to high ecological plasticity and the ability to adapt to anthropized environments. E. adamsi, although recorded in the Amazon and Atlantic Forest, showed its highest concentration in the Cerrado, likely benefiting from the environmental heterogeneity of the biome, which allows the creation of diverse microhabitats and supports complex ecological interactions (Ratter et al. 2010; Pacheco and Vasconcelos 2012; De Brito Freire et al. 2024; Cardoso et al. 2025).

It was also possible to observe the restricted distribution of some species, such as E. tanslineatus, limited to the southern Atlantic Forest (Haxaire and Mielke 2019). This geographic restriction may be related to greater ecological specialization of the species or may reflect under-sampling in other regions. Accurate delineation of these occurrence areas will depend on broader and more systematic surveys, especially in transition zones between biomes. Eumorpha triangulum also had a record for the Atlantic Forest; however, since this is the first time the species has been reported for Brazil and the record comes from a database entry, caution is recommended regarding its actual occurrence in the country.

Several taxa likely represent as species complexes, including E. analis, E. anchemolus, E. obliquus, and E. orientis, based on genitalia morphological variations (Eitschberger 2011; Lima et al. 2023). These complexes highlight the cryptic diversity within the genus, emphasizing the need for a comprehensive taxonomic revision to clarify species boundaries and more precisely define their geographic distributions.

Despite the data compiled here, this study still presents important limitations. The field collections conducted over a relatively short interval may not fully capture temporal variations in species activity, detectability, or local abundance, especially in groups with seasonal dynamics. Likewise, occurrence records extracted from the literature and online repositories often reflect heterogeneous sampling efforts, taxonomic uncertainties, and spatial gaps—factors that can influence the observed distribution patterns. Although these datasets are complementary, the integrated approach may still underrepresent poorly sampled regions or rare species.