Daryl David Cruz

Cryptic speciation in triatomine bugs challenges taxonomic delimitation and vector surveillance. Triatoma pallidipennis Stål (Hemiptera: Reduviidae), a primary vector of Trypanosoma cruzi in Mexico, was recently proposed as a complex of five putative cryptic lineages (haplogroups H-I to H-V) on molecular and morphometric grounds, and differentiation in their current climatic niches has been reported. However, how this differentiation is structured along genealogy, and how climatic disparity accumulated through time, remain untested. We characterized the climatic space sampled by each haplogroup by integrating a time-calibrated phylogeny with six bioclimatic variables from WorldClim 2.1, combining ancestral reconstructions under Brownian motion, disparity-through-time (DTT) analyses, evolutionary model comparison, and probabilistic niche estimation (NicheROVER). Reconstructions placed the common ancestor at intermediate thermal and hydric conditions, from which terminal haplogroups diverged toward non-equivalent portions of climatic space. All disparity index (MDI) values were positive (range: 0.252-0.388), indicating greater within-subclade climatic disparity than expected under the Brownian reference. Five of the six combinations were nominally significant under both one- and two-tailed criteria, and four remained significant under both criteria after Holm correction. No variable supported a non-zero early-burst rate-deceleration parameter. Niche overlap was strongly directional: probabilities that other haplogroups fall within the niche of H-V remained below 10%, whereas the reverse reached 58.9%. This asymmetry reflects niche volume, since H-V occupies a volume 9.2-14.4-fold lower than the other three analyzed haplogroups. These results identify H-V as occupying a markedly narrower realized climatic niche and provide independent ecological evidence consistent with differentiation among lineages that diverged during the Pleistocene.

Frugivorous bats of the genus Vampyrodes (Phyllostomidae) play a vital ecological role through seed dispersal and habitat maintenance in Neotropical forests. However, they are increasingly threatened by habitat loss and climate change. This study examined the current and potential future distributions of V. major and V. caraccioli to assess their ecological requirements and evaluate conservation challenges. We compiled occurrence records from literature and databases, selecting relevant climatic variables to develop environmental niche models using the Maxent algorithm. Model performance was optimized by comparing multiple parameter combinations and validated through established statistical criteria. V. major shows relatively stable climatic suitability areas under both low-emission (SSP1-2.6) and high-emission (SSP5-8.5) scenarios, suggesting broader climatic niche breadth. By contrast, V. caraccioli faces substantial losses of climatically suitable areas – up to 50 % in the most extreme emission scenario – especially in the Amazon basin. The projected reduction of climatic suitability within protected areas further highlights the vulnerability of V. caraccioli , raising concerns about their long-term viability and the potential disruptions to seed dispersal networks. Conversely, while V. major retains climatically suitable areas in protected zones, ongoing deforestation and fragmentation remain significant threats. These findings underscore the importance of formulating differentiated conservation strategies for each species. Specifically, bolstering corridor networks, preserving intact forest patches, and developing climate change mitigation policies are critical to safeguarding these bats' ecological functions. By providing a clearer understanding of present and future distributional patterns, this study aims to guide more effective, science-based management of Vampyrodes species across their geographic range.

The Barranca del Amatzinac is the principal hydrological system in northeastern Morelos, crossing several municipalities, including the recently established Indigenous municipality of Hueyapan. Despite its ecological importance, reliable information on the diversity of medium- to large-bodied mammals—and other taxonomic groups—is lacking. Here, we present the first report on the diversity of medium- to large- bodied mammals and describe the activity patterns of species recorded in the upper basin of the Barranca del Amatzinac. We deployed 15 camera traps strategically across the upper basin and conducted 12 monthly sampling sessions from May 2023 to April 2024, each lasting one week. In parallel, we performed transect-based sign surveys (track and sign identification) with two walks per month over the same period. Species richness was estimated using Hill numbers. We also calculated proportional capture rates for each species recorded by camera trapping and encounter rates for each species recorded from signs and inferred activity patterns using the Diel.Niche package in R. In total, we documented 15 species of medium- to large-bodied mammals. With 1,183 trap-days, camera traps recorded 12 species, and nearly 264 km of transect walks yielded 11 species. Alpha diversity (α, using Hill numbers) was 6.57 for camera-trap records and 6.52 for sign surveys. The most common species were Dasypus mexicanus, Didelphis virginiana, and Bassariscus astutus. Consistent activity patterns were obtained for most of the photographed species, as well as seasonal changes in some taxa (Canis latrans and Nasua narica), suggesting temporal partitioning and responses to seasonal environmental variation. This study provides the first formal data on medium- to large-bodied mammals for the Indigenous municipality of Hueyapan and northeastern Morelos, establishing a baseline for future biological research in the area.

Las cucarachas de arena se encuentran entre los grupos menos estudiados de Blattodea. En América del Norte, esta familia comprende ocho géneros, de los cuales la subfamilia Corydiinae está representada únicamente por tres: Homoeogamia, Arenivaga y Eremoblatta. Homoeogamia es el único género monoespecífico y estrictamente mexicano, aunque su especie está ampliamente distribuida en el centro de México. El objetivo de este estudio es actualizar la distribución conocida de la especie mediante la revisión de registros publicados, especímenes verificados en colecciones, y observaciones fotográficas provenientes de la plataforma de ciencia ciudadana iNaturalist. Adicionalmente, complementamos los datos con la recolección de ejemplares nuevos. La distribución actualizada incluye 36 nuevos registros de localidad en cinco estados previamente no documentados, lo que amplía el rango de distribución conocido de H. mexicana a 19 estados mexicanos.

Aquí presentamos, a través de colectas de campo mediante trampas tipo Sherman y de análisis filogenéticos del gen mitocondrial del citocromo b obtenido mediante secuenciación Sanger, registros relevantes de especies de roedores de la Estación Científica Las Joyas (LJSS) dentro de la Reserva de la Biosfera Sierra de Manantlán. Reportamos por primera vez la presencia de Nyctomys sumichrasti colimensis en esta localidad. Además, presentamos nuevos registros de Reithrodontomys wagneri y especímenes pertenecientes al clado IV de Reithrodontomys sumichrasti, clado reconocido como especie no descrita dentro del complejo de especies de R. sumichrasti; este último amplía la distribución geográfica de esta nueva especie. Finalmente, incluimos registros de especímenes de Microtus formando un clado hermano con M. mexicanus/M. mogollonensis, aunque con valores de distancia genética superiores al 9%. Nuestros hallazgos subrayan la importancia evolutiva del aparente aislamiento de la Sierra de Manantlán, Jalisco, particularmente al influir en el proceso de especiación de varias especies de roedores. Estos hallazgos subrayan la importancia de continuar con los inventarios biológicos en áreas poco exploradas de México.

Background: Spots and coloring patterns evaluated quantitatively can be used to discriminate and identify possible cryptic species. Species included in the Triatoma dimidiata (Reduviidae: Triatominae) complex are major disease vectors of Chagas disease. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. We report here our evaluation of the possibility of correctly discriminating these three T. dimidiata haplogroups using the pattern of the dorsal spots. Methods: Digital images of the dorsal region of individuals from the three haplogroups were used. Image processing was used to extract primary and secondary variables characterizing the dorsal spot pattern. Statistical analysis of the variables included descriptive statistics, non-parametric Kruskal–Wallis tests, discriminant function analysis (DFA) and a neural classification network. Results: A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, which was characterized by its notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all of the variables analyzed, with the largest differences seen for relative spot area, mean relative area of central spots, central spots Feret diameter and lateral spots Feret diameter and aspect ratio. Both the DFA and the neural network had correct discrimination values of > 90%. Conclusions: Based on the results of this analysis, we conclude that the spot pattern can be reliably used to discriminate among the three haplogroups of T. dimidiata in Mexico, and possibly among triatomine species. Graphical

Background: Spots and coloring patterns evaluated quantitatively can be used to discrimination and identify possible cryptic species. Triatoma dimidiata (Reduviidae: Triatominae) is one of the main complexes of Chagas disease vector species. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. In this work, we evaluate the possibility of correctly discriminating among these T. dimidiata haplogroups using the pattern of dorsal spots.Methods: Digital images of the dorsal region of individuals from the three haplogroups were used. We used image processing to extract primary and secondary variables characterizing the dorsal spot pattern. The statistical analysis of the variables included descriptive statistics, non-parametric Kruskal-Wallis tests, Discriminant Function Analysis (DFA), and a neural classification network.Results: A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, mainly apparent in the notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all the variables analyzed, these differences being greater in relative spot area, mean relative area of central spots, central spots Feret diameters, lateral spots Feret diameters and aspect ratio. Both the DFA and the neural network had correct discrimination values above 90%. Conclusions: We conclude that the spot pattern can be reliably used to discriminate among haplogroups, and possibly among triatomine species.

Background: Spots and coloring patterns evaluated quantitatively can be used to discrimination and identify possible cryptic species. Triatoma dimidiata (Reduviidae: Triatominae) is one of the main complexes of Chagas disease vector species. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. In this work, we evaluate the possibility of correctly discriminating among these T. dimidiata haplogroups using the pattern of dorsal spots.Results: A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, mainly apparent in the notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all the variables analyzed, these differences being greater in relative spot area, mean relative area of central spots, central spots Feret diameters, lateral spots Feret diameters and aspect ratio. Both the DFA and the neural network had correct discrimination values above 90%. Conclusions: We conclude that the spot pattern can be reliably used to discriminate among haplogroups, and possibly among triatomine species.