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Multidisciplinary taxonomic studies have enhanced the delimitation of species within complex taxonomic groups. In the cycad genus Ceratozamia, the taxonomy is still not fully resolved for the several species complexes that have been proposed. Five Ceratozamia species occur in geographic proximity in the Soconusco region of southwestern Mexico. Because of similarity and variable morphology across these species, their taxonomy is a source of confusion. Based on integrative taxonomy, including morphological (qualitative and quantitative), ecological, and molecular data, we aimed to diagnose the species from the Soconusco region. We carried out extensive field sampling, collecting 225 individuals from a total of 12 populations, and reviewed one hundred herbarium specimens to evaluate whether the species are diagnosable. We carried out morphometric analyses at the population level on vegetative and reproductive characters and present the first analyses of phenotypic variability of pollen and ovulate strobili in neotropical cycads. Additionally, we evaluated the influence of climatic factors on morphological variation. Morphological characters of ovulate strobili were correlated with climatic conditions. In contrast, there was no significant correlation between the morphology of pollen strobili and the environment. In the pollen strobili, we found fixed characters that allow for the identification of the species. The haplotype networks displayed several groups of related haplotypes, which in some species corresponded to mixed population clusters. We detected a discordance between phenotypic and genetic evidence. The integration of evidence offers grounded views for clarifying species boundaries and outlining the differences among species, which we incorporated into a taxonomic key. In general, the mixed relations within this group of species may be due to historical hybridization events favored by common phenology and sharing of biotic pollination vectors. Finally, based on our results, we discuss the use of morphology for species delimitation and inference of evolutionary relationships in cycads. [ABSTRACT FROM AUTHOR]

There is extensive knowledge about the visual system and the implications of the evolution of trichromatic color vision in howler monkeys (genus Alouatta) related to food selection; however, information about the other sensory systems is limited. In this study we assessed the use of touch, sniffing, and taste in fruit evaluation by 20 adult mantled howler monkeys (Alouatta palliata) on Agaltepec Island, Mexico. During 9 months of observation, we recorded the frequency that each monkey used touch, sniffing, and taste in evaluating cryptic fruits (that remain green during their ripening process) and conspicuous fruits (with red, yellow, or orange colorations when they are ripe). Sucrose content and hardness measurements were made to establish the degree of ripeness of the fruits. We found that mantled howler monkeys used long behavioral sequences during conspicuous fruit investigations. Sniffing was used infrequently, but significantly more often in the evaluation of conspicuous-ripe and unripe fruits compared to cryptic-ripe and unripe fruits. During the evaluation of cryptic-ripe fruits, mantled howler monkeys increased the use of touch compared to evaluating cryptic-unripe fruits. We did not find significant differences in the use of taste in the evaluation of cryptic and conspicuous fruits (both ripe and unripe). Our results suggest that the non-visual senses play an essential role in fruit selection by howler monkeys, with differences in the behavioral strategy according to the fruit's conspicuity. The multimodal signals of ripe and unripe fruits allow the howler monkeys to assess their palatability before being consumed. [ABSTRACT FROM AUTHOR]

Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields. [ABSTRACT FROM AUTHOR]

Traditionally, most studies have described the organization of host–parasite interaction networks by considering only few host groups at limited geographical extents. However, host–parasite relationships are merged within different taxonomic groups and factors shaping these interactions likely differ between host and parasite groups, making group‐level differences important to better understand the ecological and evolutionary dynamics of these interactive communities.Here we used a dataset of 629 ectoparasite species and 251 species of terrestrial mammals, comprising 10 orders distributed across the Nearctic and Neotropical regions of Mexico to assess the species‐level drivers of mammalian ectoparasite faunas. Specifically, we evaluated whether body weight, geographical range size and within‐range mammal species richness (i.e. diversity field) predict mammal ectoparasite species richness (i.e. degree centrality) and their closeness centrality within the mammal–ectoparasite network. In addition, we also tested if the observed patterns differ among mammal orders and if taxonomic closely related host mammals could more likely share the same set of ectoparasites.We found that ectoparasite species richness of small mammals (mainly rodents) with large proportional range sizes was high compared to large‐bodied mammals, whereas the diversity field of mammals had no predictive value (except for bats). We also observed that taxonomic proximity was a main determinant of the probability to share ectoparasite species. Specifically, the probability to share ectoparasites in congeneric species reached up to 90% and decreased exponentially as the taxonomic distance increased.Further, we also detected that some ectoparasites are generalists and capable to infect mammalian species across different orders and that rodents have a remarkable role in the network structure, being closely connected to many other taxa.Hence, because many rodent species have synanthropic habits they could act as undesired reservoirs of disease agents for humans and urban animals. Considering the reported worldwide phenomenon of the proliferation of rodents accompanying the demographic decrease or even local extinction of large‐bodied mammal species, these organisms may already be an increasing health threat in many regions of the world. [ABSTRACT FROM AUTHOR]

A team of 79 scientists from more than 50 institutions partnered to gather all available information regarding Mexican ants since 1894, the year in which the first geographical record of an ant is known for the country. Photo credit: Diana Ahuatzin. gl GLO:69VH/01apr20:bes21666-fig-0002.jpg PHOTO (COLOR): Turtle ant Cephalotes scutulatus (Formicidae: Myrmicinae), a tree-dwelling myrmicine ant species native to Mexico and distributed in the Neotropical and Transition zone of the country occurring from sea level to an elevation of ~1200 m. [Extracted from the article]

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Gradient analysis is rarely used in studies of fungal communities. Data on macromycetes from eight sites along an elevation gradient in central Veracruz, Mexico, were used to demonstrate methods for gradient analysis that can be applied to studies of communities of fungi. Selected sites from 100 to 3,500 m altitude represent tropical dry forest, tropical montane cloud forest, conifer forest, and their ecotones. From May to October 2010, macromycetes were collected monthly within ten 10 × 10 m permanent plots per site. In total, 672 individuals of 213 species of macromycetes were recorded. Models for richness and diversity for all macromycete and ectomycorrhizal communities displayed peaks in the mid-part of the gradient, and a tendency to increase with elevation, whereas xylophagous fungi displayed a peak in the mid-lower part but tended to decrease with elevation. Cluster and Maximum Likelihood analyses distinguished four communities for both macromycetes and trees, but plant and fungal communities were only partly concordant. Canonical correspondence analysis indicated that macromycete distribution along the gradient is related to slope, relative humidity, soil temperature, soil water content, canopy openness, and litter depth. Spearman's correlation and regression trees suggested that air and soil temperature, relative humidity, soil water content, canopy openness, vegetation structure and tree species richness were most strongly related to macrofungal functional groups, but these environmental variables were often correlated to the forest type and may not be causal. Variation in the environment along the elevation gradient differentially affected macromycete functional groups. Results from the different methods used in this work were concordant and showed significant patterns. [ABSTRACT FROM AUTHOR]

The consequences of tropical forest fragmentation on herbivory are poorly understood. The limited evidence suggests that forest fragmentation can have positive, negative or neutral effects on herbivory. Inconsistencies may be partly explained by plant interspecific variation and differential responses related to plant life history. In this study we examined the effects of forest fragmentation and plant regeneration mode (shade-tolerant and light-demanding species) on sapling herbivory using a large sample of the community (97 species, representing 25% of the woody flora of the study site), and a subset of species shared by forest fragments and continuous forest. For the latter, we also analyzed the effects of species identity on variation in herbivory. Also, for the shared species we used two techniques to measure herbivory: standing herbivory (i.e. instantaneous, actual damage) and cumulative herbivory (i.e. damage, accumulated over time, on initially intact leaves). Insect herbivory was the predominant type of damage in the two forest types, and standing herbivory at both the community and the shared species level was significantly higher in continuous forest than in fragments. Considering shared species, both standing and cumulative herbivory were significantly higher in light-demanding than in shade-tolerant species. Cumulative herbivory also showed a significant interaction between forest fragmentation and plant regeneration mode, whereby a significant decline in herbivory in fragments was driven by reduced herbivory in shade-tolerant species, whereas for light-demanding species herbivory did not change significantly, due to contrasting species-specific responses. We conclude that tropical forest fragmentation reduces insect herbivory, but this depends on plant regeneration mode and species identity. These changes could have effects on plant regeneration and diversity in forest fragments via long-term demographic consequences. [ABSTRACT FROM AUTHOR]

Abstract: Mycelial mats in a tropical rainforest in southern Mexico were more abundant under large buttressed trees than small trees of Brosimum alicastrum. P and K, though not N, concentrations were lower in fine roots from mats than in control samples and complex changes in functional groups of arthropods associated with mats were also evident. [Copyright &y& Elsevier]

Mexico is one of the most biodiverse countries in the world, with an important proportion of endemism mainly because of the convergence of the Nearctic and Neotropical biogeographic regions, which generate great diversity and species turnover at different spatial scales. However, most of our knowledge of the Mexican ant biota is limited to a few well‐studied taxa, and we lack a comprehensive synthesis of ant biodiversity information. For instance, most of the knowledge available in the literature on Mexican ant fauna refers only to species lists by states, or is focused on only a few regions of the country, which prevents the study of several basic and applied aspects of ants, from diversity and distribution to conservation. Our aims in this data paper are therefore (1) to compile all the information available regarding ants across the Mexican territory, and (2) to identify major patterns in the gathered data set and geographic gaps in order to direct future sampling efforts. All records were obtained from raw data, including both unpublished and published information. After exhaustive filtering and updating information and synonyms, we compiled a total of 21,731 records for 887 ant species distributed throughout Mexico from 1894 to 2018. These records were concentrated mainly in the states of Chiapas (n = 6,902, 32.76%) and Veracruz de Ignacio de la Llave (n = 4,329, 19.92%), which together comprise half the records. The subfamily with the highest number of records was Myrmicinae (n = 10,458 records, 48.12%), followed by Formicinae (n = 3,284, 15.11%) and Ponerinae (n = 1,914, 8.8%). Most ant records were collected in the Neotropical region of the country (n = 12,646, 58.19%), followed by the Mexican transition zone (n = 5,237, 24.09%) and the Nearctic region (n = 3,848, 17.72%). Native species comprised 95.46% of the records (n = 20,745). To the best of our knowledge, this is the most complete data set available to date in the literature for the country. We hope that this compilation will encourage researchers to explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events. [ABSTRACT FROM AUTHOR]

• Here, we investigated the spatial and temporal abundance of mycelial mats in a tropical rain forest to determine their effects on the concentration of mineral nutrients in soils and fine roots. • Mats were marked and followed over three seasons. Fine-root mass and the concentration of mineral nutrients in both soils and roots were determined for mat-associated soils and for a control group. • Mats were more abundant in the dry season than in the wet season. The concentration of mineral nutrients in soils and fine roots increased from the rainy season to the end of the dry season. Mats appeared to affect the concentration of phosphorus, potassium and calcium, and the carbon : nitrogen and nitrogen : phosphorus ratios in soils and roots during all seasons. • Mats appeared to compete with plants for certain minerals. This could be part of ‘bottom up’ effects that may influence underground herbivory, as well as the above-ground concentrations of mineral nutrients in plants. Mats are relevant to understanding soil biodiversity and the potential feedback paths between the soil and above-ground subsystems. © New Phytologist (2004) doi: 10.1111/j.1469-8137.2004.01099.x [ABSTRACT FROM AUTHOR]

Insect-aroid interaction studies have focused largely on pollination systems; however, few report trophic interactions with other herbivores. This study features the endophagous insect community in reproductive aroid structures of a tropical rainforest of Mexico, and the shifting that occurs along an altitudinal gradient and among different hosts. In three sites of the Los Tuxtlas Biosphere Reserve in Mexico, we surveyed eight aroid species over a yearly cycle. The insects found were reared in the laboratory, quantified and identified. Data were analyzed through species interaction networks. We recorded 34 endophagous species from 21 families belonging to four insect orders. The community was highly specialized at both network and species levels. Along the altitudinal gradient, there was a reduction in richness and a high turnover of species, while the assemblage among hosts was also highly specific, with different dominant species. Our findings suggest that intrinsic plant factors could influence their occupation, and that the coexistence of distinct insect species in the assemblage could exert a direct or indirect influence on their ability to colonize such resources. [ABSTRACT FROM AUTHOR]

Wildfires are significant disruptors of established communities, but natural fire regimens are essential to sustaining biodiversity in fire-prone ecosystems. Besides plants, soil arthropods are highly affected by wildfires, but their communities are also highly resilient to such catastrophic events. It is known that both stochastic (local extinction, dispersion, and colonization probabilities) and deterministic (environmental and biotic filters) processes take part in the reassembly of biotic communities after wildfires. However, the contribution of stochastic and deterministic processes in reassembling soil arthropod communities after wildfires remains unclear, and it is largely unknown how this is affected by fire severity. This study reports on the trophic guilds, taxa composition, and alpha and beta diversity partitioning of a soil arthropod community over one year, considering unburnt forest and two levels of fire severity in a pine forest in the eastern mountainous region of Mexico. The wildfire had a positive effect on the abundance of saprophagous species, especially in moderate-fire severity sites. Overall, the diversity of the community of soil arthropods has increased over time since the fire. Taxa turnover contributed beyond random expectations to the observed beta diversity, suggesting that stochastic processes predominated in the reassemblage of the soil arthropod community. We conclude that the changes in the alpha and beta diversity of the postfire soil arthropod community were affected by the severity of the wildfire and by the time that had passed since the fire event, showing a capacity for recovery to this type of disturbance. • Moderate-fire severity positively affected the abundance of saprophagous species. • Taxa richness, abundance, and diversity were low in burnt areas compared to the unburnt forest one year after the fire. • The contribution of taxa turnover to beta diversity increased with wildfire severity. • Taxa turnover was higher than expected by null models. • Stochastic processes prevailed in the recovery of the soil arthropod community after a wildfire. [ABSTRACT FROM AUTHOR]

• Clustering of functional traits in tropical woody plant species shed light on the ecology and evolution of plant herbivore interactions. • Suites of functional traits define three defense syndromes: low nutrition, defense and tolerance to herbivory. • The low nutritional quality syndrome seems to be the ancestral antiherbivore defense syndrome in woody tropical rain forest species. • Tolerance and defense syndromes cluster closely phylogenetically related species. A set of species, not linked by close ancestry, with similar functional responses to selective pressures, is known as a functional group or response syndrome. Some studies have investigated antiherbivore plant defenses in the context of defense syndromes, with contrasting results. We analyze how the assembly of leaf-functional traits and wood density can explain insect herbivory in 69 woody species in a tropical rain forest in southern Mexico. In addition, we used a phylogenetic hypothesis to address whether the observed syndromes were at least in part driven by ancestry. Three functional groups of woody plants were detected and related to 1) low nutritional quality, 2) resistance, and 3) tolerance to herbivory. Herbivory tolerant species presented the highest damage by herbivores, which is concordant with theoretical expectations and other empirical observations. In contrast, herbivory in the defensive resistance and low nutrition syndromes were 35 % and 55 % lower than in herbivory tolerant species, respectively. Taxa in the defensive resistance syndrome were significantly clustered based on the net relatedness index (NRI) and the nearest taxon index (NTI). In contrast, in the other two syndromes, the NRI showed a random structure but opposed deviations from random expectations in the NTI. Taxa in the low nutritional quality syndrome were over-dispersed in the phylogeny, while tolerant species appeared clustered. This evidence suggests that the low nutritional quality syndrome may represent the ancestral antiherbivore defense of woody plants in the tropical rain forest. In contrast, the tolerance and defensive resistance syndromes included clades of recent diversification. [ABSTRACT FROM AUTHOR]

Evolution and radiation between insects and flowering plants are both opportunistic and obligatory when the former feeds on the reproductive structures of the latter, whereas direct and indirect effects can influence the fitness of individuals, populations, and plant communities. The Araceae family constitutes an important element of the tropical rainforest of the Neotropics, and its morphology and floral biology provide a remarkable system for studying trophic interactions with insects, including the Richardiidae flies (Diptera). We studied the trophic interactions of the aroid-fly system, assessing infestation rates under natural conditions over an annual cycle. In the Neotropical region, we discovered for the first time that seven aroid species became infested by four richardiid species: Beebeomyia tuxtlaensis Hernández-Ortiz and Aguirre with Dieffenbachia oerstedii Schott and D. wendlandii Schott; B. palposa (Cresson) with Xanthosoma robustum Schott; Beebeomyia sp.3. in association with Philodendron radiatum Schott, P. tripartitum (Jacq.) Schott, and P. sagittifolium Liebm.; while Sepsisoma sp. only infested Rhodospatha wendlandii Schott. Infestation rates differed significantly among hosts, but comparisons with morphological traits did not provide evidence of a causal factor of the infestation. In contrast, larval density and time of development both exhibited significant differences between hosts. The findings suggest the high specialization of the flies, and that intrinsic factors of the plants, such as the presence of secondary metabolites and their maturation periods, may influence their infestation rates., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America.)

It has been suggested that tropical defaunation may unleash community-wide cascading effects, leading to reductions in plant diversity. However, experimental evidence establishing cause-effect relationships thereof is poor. Through a 5 year exclosure experiment, we tested the hypothesis that mammalian defaunation affects tree seedling/sapling community dynamics leading to reductions in understorey plant diversity. We established plot triplets (n = 25) representing three defaunation contexts: terrestrial-mammal exclosure (TE), medium/large mammal exclosure (PE) and open access controls (C). Seedlings/saplings 30-100 cm tall were marked and identified within each of these plots and re-censused three times to record survival and recruitment. In the periods 2010-2011 and 2011-2013, survival was greater in PE than in C plots and recruitment was higher in TE plots than in C plots. Overall, seedling density increased by 61% in TE plots and 23% in PE plots, whereas it decreased by 5% in C plots. Common species highly consumed by mammals (e.g. Brosimum alicastrum and Ampelocera hottlei) increased in their abundance in TE plots. Rarefaction curves showed that species diversity decreased in TE plots from 2008 to 2013, whereas it remained similar for C plots. Given the prevalence of tropical defaunation, we posit this is an anthropogenic effect threatening the maintenance of tropical forest diversity., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)

Objective: To evaluate risk factors facilitating the colonization of dwellings by Triatoma dimidiata in the central region of the state of Veracruz., Materials and Methods: We applied socioeconomic questionnaires and entomologic surveys in three localities (Chavarrillo, Soyacuautla and Arroyo Agrio) in central Veracruz involving 115 households., Results: We found that the main risk factors were the predominance of unplastered walls and particularly those made of light weight aggregate concrete blocks and wood. At Chavarrillo, houses usually have unplastered walls, whereas in Soyocuautla walls are commonly manufactured with wood. In Arroyo Agrio, the phenomenon was seasonal, and bugs were commonly found in the dry season, particularly in relatively new houses, less than 20 years old., Conclusions: These results help to improve the surveillance capacity for this vector and the control strategies to reduce the transmission of Chagas disease in the state of Veracruz and other sites where this species is present.

The hypothesis that plant species are more responsive to mycorrhiza in late than in early successional stages was assessed in grasses from a successional process occurring in two-phase mosaics from the Mexican Chihuahuan Desert. We estimated the density of spores of arbuscular mycorrhizal (AM) fungi and the AM colonization of pioneer and late-successional grasses in the field. In growth chamber experiments, we tested the effect of the native AM fungal community on grasses growing in soils from different successional stages. Spore density was higher in late than in early successional stages. Late-successional species were more responsive to AM (positive AM responsiveness) whereas pioneer species were nondependent on mycorrhiza or if associated to AM fungi, the interaction showed a negative AM responsiveness for the seedling stage. Our findings showed that late successional species fitted the proposed models of mycorrhizal performance, but the two pioneer species differed in their AM condition and responsiveness. This further supports the idea that AM interactions are more complex along the successional processes than the predictions of the more widely cited hypotheses.