Habitats In Mexico Research Articles

Ladybird predators in natural and agricultural landscapes in Mexico: diversity and parasitism

Ladybirds (Coleoptera: Coccinellidae) are a significant predator group that plays a role in agricultural contexts. They serve as important biocontrol agents against several agricultural pests. However, there is limited information available about how ladybirds’ populations are regulated by their natural enemies and habitat perturbation. In this study, we evaluated ladybird communities associated with natural and managed areas during the agricultural cycle of 2018 (June–September). We identified seven ladybird species; the most abundant species were Hippodamia convergens (70% individuals) and Cycloneda sanguinea (20% individuals), followed by the exotic species Harmonia axyridis (3.33% individuals), while Paranaemia vittigera, Coleomegilla maculata, Brachiacantha sp., and Olla v-nigrum represented less than 3% each. Ladybirds were more abundant in agricultural fields than in natural habitats. We identified several natural enemies associated with the collected ladybirds, including parasitoids (Dinocampus coccinellae, Hymenoptera: Braconidae), ectoparasitic Acari (Coccipolipus sp., Podapolipidae), and nematodes (Mermithidae). However, none of the natural enemies affected more than 10% of the ladybirds, so natural enemies do not appear to be exerting substantial control over their populations. Our results corroborated that ladybirds can efficiently thrive in anthropogenic habitats in Mexico and therefore may represent good biocontrol agents for agriculture. It is important to consider the ecology of agriculturally important ladybirds in programs for integrated pest management. This includes factors contributing to the mortality of ladybirds, including their natural enemies.

Changes in Growth and Heavy Metal and Phenolic Compound Accumulation in Buddleja cordata Cell Suspension Culture under Cu, Fe, Mn, and Zn Enrichment.

Buddleja cordata cell suspension cultures could be used as a tool for investigating the capabilities of this species to tolerate heavy metals (HMs) and for assessing the effects of HMs on the accumulation of phenolic compounds in this species. It grows in a wide range of habitats in Mexico, including ultramafic soils, and mobilizes some HMs in the soil. The mobilization of these HMs has been associated with phenolic substances. In addition, this species is used in Mexican traditional medicine. In the present study, a B. cordata cell suspension culture was grown for 18 days in a culture medium enriched with Cu (0.03-0.25 mM), Fe (0.25-1.5 mM), Mn (0.5-3.0 mM), or Zn (0.5-2.0 mM) to determine the effects of these HMs on growth and HM accumulation. We also assessed the effects of the HMs on phenolic compound accumulation after 1 and 18 days of HM exposure. Cells were able to grow at almost all tested HM concentrations and accumulated significant amounts of each HM. The highest accumulation levels were as follows: 1160 mg Cu kg-1, 6845 mg Fe kg-1, 3770 mg Mn kg-1, and 6581 mg Zn kg-1. Phenolic compound accumulation was affected by the HM exposure time and corresponded to each HM and its concentration. Future research should analyze whole plants to determine the capabilities of Buddleja cordata to accumulate abnormally high amounts of HM and to evaluate the physiological impact of changes in the accumulation of phenolic compounds.

Changes in landscape and climate in Mexico and Texas reveal small effects on migratory habitat of monarch butterflies (Danaus plexippus)

The decline of the iconic monarch butterfly (Danaus plexippus) in North America has motivated research on the impacts of land use and land cover (LULC) change and climate variability on monarch habitat and population dynamics. We investigated spring and fall trends in LULC, milkweed and nectar resources over a 20-year period, and ~ 30 years of climate variables in Mexico and Texas, U.S. This region supports spring breeding, and spring and fall migration during the annual life cycle of the monarch. We estimated a − 2.9% decline in milkweed in Texas, but little to no change in Mexico. Fall and spring nectar resources declined < 1% in both study extents. Vegetation greenness increased in the fall and spring in Mexico while the other climate variables did not change in both Mexico and Texas. Monarch habitat in Mexico and Texas appears relatively more intact than in the midwestern, agricultural landscapes of the U.S. Given the relatively modest observed changes in nectar and milkweed, the relatively stable climate conditions, and increased vegetation greenness in Mexico, it seems unlikely that habitat loss (quantity or quality) in Mexico and Texas has caused large declines in population size or survival during migration.

Evolutionary and ecological trends in the Neotropical cycad genus Dioon (Zamiaceae): An example of success of evolutionary stasis

AbstractCycads represent an example of the success of evolutionary stasis. Despite their early origin, they survived multiple events of mass extinction and diversified in modern tropical ecosystems during the Cenozoic without major changes in their morphology. What factors have allowed their persistence and diversification despite their conservative nature? We reviewed documentation on the micro‐ and macro‐evolutionary processes involved in the diversification of the Neotropical genus Dioon. Dioon comprises 18 species from varied habitats in Mexico and Honduras, and serves as a model to understand the patterns of cycad diversification. Here, we synthesize evidence reached from different fields, especially biogeography, phylogenetics, population ecology, and speciation, to propose a mechanism that can explain the current patterns of biodiversity in Dioon. At the macroevolutionary scale, a Paleogene origin for Dioon is more likely than an alternative hypothesis of a Neogene origin. Dioon lineages have dispersed along with the expansion of tropical forests throughout main mountain chains. Subsequently, climate change, and particularly aridification, promoted the fragmentation of the tropical forests, allowing the main Dioon clades to evolve in isolation at distinct biogeographic regimes. At the microevolutionary scale, low seed dispersal capability, stochastic demographic processes, and niche conservatism restrict the lineages to isolate themselves at narrow habitats, promoting local adaptation in populations. Local adaptation seems to be a process achieved through many generations under stabilizing selection. Altogether, these processes shaped the diversification in Dioon. This review attempts to stimulate further research on cycads and other biological groups that have diversified despite their apparent evolutionary stasis.

Description of one new genus and two new species of Apomecynini (Cerambycidae: Lamiinae) from Mexico

The knowledge of the diversity of leaf litter cerambycid fauna is limited, particularly in the Neotropics, where several species likely remain unreported. Most of these small and apterous beetles commonly belong to the tribe Apomecynini (Cerambycidae: Lamiinae). Herein, one new genus and two new species of Apomecynini are described and illustrated from material collected in leaf litter and subcortical habitats in Mexico: Enochlisi tlaloque sp. nov., from Cofre de Perote mountain, Veracruz, and Folilectia muye gen. &amp; sp. nov., from Xochicoatlán, Hidalgo. The new genus differs from related taxa in divided eyes, antennomere IV longer than scape, and elytra not vermiculated or tuberculated, elongate in the apical third. Enochlisi tlaloque differs from E. micri Santos-Silva 2022 mainly in size of antennae, pronotum coarsely punctate, and elytra weakly vermiculate, with distinctive pubescent color pattern.

A review of the entomofauna associated with decaying cacti in New World deserts

Abstract Cactus species are well represented in arid and semiarid environments, where they sometimes even dominate the landscape, forming true cactus forests. In this review, we summarize for the first time the importance of cactus species as a wood resource for a neglected saproxylic (dead wood-dependent) entomofauna associated with decomposing and decomposed tissues in arid and semiarid environments. The complex decomposition process of cactus species is discussed in depth. We provide a checklist of the entomofauna living in decaying and decayed cacti, in which insects represented 93% of the species recorded. In particular, Coleoptera (41.5%) and Diptera (43.8%) orders together represented 85% of the insect species recorded. The family Drosophilidae made up 50% of studied Diptera species because the drosophilid–cactus–yeast complex has been widely studied during recent decades. However, we found that during the last 2 decades, there has been increasing interest in investigating the diversity of arthropods in this saproxylic habitat in Mexico, with a special focus on Syrphidae (Diptera) and Coleoptera, the former for their role in the decomposition process. Disentangling the role of the insects associated with decaying cactus is a challenge when it comes to understanding the function of xeric saprophagous insects in this environment. One frontier in this research area is to find whether decomposed stems in xeric soils would act as “islands” of fertility due to the amount of nitrogen which could be recuperated from these microecosystems. Further research is needed to understand the ecological succession of the entomofauna playing a role in the decomposition process of cactus species in semiarid environments.

Integrating local ecological knowledge, ecological monitoring, and computer simulation to evaluate conservation outcomes

AbstractSuccessful conservation of long‐lived species requires reliable understanding of long‐term trends and historical baselines. We present a framework for evaluating abundance trends and conservation outcomes for long‐lived marine species by integrating local ecological knowledge (LEK), ecological monitoring, and computer simulation, tested on a case‐study of long‐lived and heavily exploited green turtles (Chelonia mydas) in the Eastern Pacific. Models fit to LEK and monitoring data indicate that turtle abundance is increasing, but only after ∼40 years of safeguarding the species’ nesting and foraging habitats in Mexico. However, current abundance is at ∼60% of baseline levels and historic population structure has not been reestablished, indicating the need for sustained, long‐term conservation actions. We demonstrate the potential of linking LEK and ecological science to provide critical information for conservation, by establishing reference baselines and gauging population status with a long‐term historical perspective, while promoting equitable and sustainable futures.

기후소설로 본 바바라 킹솔버의 『비상』

The purpose of this study is to examine Barbara Kingsolver’s Flight Behavior focused on the function of literature. Climate fiction(Cli-fi) deals with environmental threats such as climate change or global warming. Cli-fi effectively delivers literary imagination based on scientific facts. In Flight Behavior, Dellarobia Turnbow, who is a main character, is an accidentally early-married young woman. She experiences a process of development through Professor Ovid Byron and Monarch Butterflies. As a Cli-fi, Flight Behavior deals with environmental crisis using Monarch butterflies’ unusual migration to Appalachian Mountains because their habitat in Mexico was destroyed by unprecedented flooding. Dellarobia including readers have learned ‘an entirely new form of panic’ caused by scientific knowledge generated from Dr. Byron and rare butterfly events. As a good listener and beginner assistant to Dr. Byron, Dellarobia finally finds her own inner possibilities and recognizes an impending climate crisis. Like Monarch butterflies, she who is defined as a ‘Perfect Female’ is ready to stand up on her feet and discover her new colony through persistent flight behavior.

SPECIES DIVERSITY OF MAMMALS AND BIRDS USING CAMERA-TRAPS IN A CLOUD FOREST IN A MEXICAN HOTSPOT

The cloud forests comprise high levels of species richness and endemism, and are the most threatened habitat in Mexico. They are listed as priority regions for conservation nationwide. Here, we estimated species richness and relative abundance of birds and mammals using camera-traps in a cloud forest located in a biodiversity hotspot of Mexico. From December 2013 to December 2014, we sampled 538 independent records from 27 species, including 11 species listed with some level of threat. Expected species richness, using first-order Jackknife estimator, was 37.08 species DE ± 2.86. We reported the greatest number of birds and mammals observed in cloud forests using camera-traps, and a high relative abundance index for some species. We found a significant difference between species composition observed in our study and other studies using camera-traps in Mexico. We observed a similar species composition in a nearby tropical rainforest habitat, suggesting that the recorded species are not restricted to cloud forests and move between different habitats. This highlights the importance of this region as a connector with “Los Chimalapas,” the largest and northernmost rain forest patch in Mexico.

Asymbiotic Germination, Effect of Plant Growth Regulators, and Chitosan on the Mass Propagation of Stanhopea hernandezii (Orchidaceae)

Background: Stanhopea hernandezii was collected from natural habitat in Mexico for its beautiful fragrant flowers. Biotechnological strategies of propagation may satisfy the market demand and are useful for conservation programs.&#x0D; Hypothesis: Vigorous seedlings of S. hernandezii can be produced in vitro by asymbiotic seed germination techniques and the addition of chitosan to the culture medium in the temporary immersion system (RITA®) and in semi-solid medium systems.&#x0D; Methods: The first step was the in vitro germination of seeds obtained from a mature capsule of wild plants, followed by multiplication via adventitious protocorm induction known as protocorm-like bodies, using plant growth regulators. For this purpose, we utilized Murashige and Skoog (MS) basal medium amended with 0.5 mg/L ?-Naphthaleneacetic acid, combined with different concentrations of 6-Benzylaminepurine (1, 3, and 5 mg/L). The following step comprised the growth and development of protocorms to obtain plantlets in RITA® flasks containing 250 mL of liquid MS medium combined or not with different chitosan concentrations (5, 10, 15, 20, and 25 mg/L).&#x0D; Results: The results showed that media supplemented with 5, 10, and 15 mg/L chitosan concentrations enabled the obtaining of a larger biomass with a range of 40-48 seedlings/RITA® and an average height of 13 mm. The last step was the development from seedlings into plantlets, the latter being, vigorous and achieving up to 100 % survival after 12 weeks of ex vitro cultivation.&#x0D; Conclusion: This paper describes an efficient process of asymbiotic germination and mass propagation of S. hernandezii , a vulnerable orchid species endemic to Mexico.

Emesis planeca n. comb. (Lepidoptera: Riodinidae): a new combination revealed by molecular evidence with a description of its morphological variation.

We transfer Apodemia planeca R. de la Maza E. J. de la Maza E. 2017 to Emesis as Emesis planeca (R. de la Maza E. J. de la Maza E.) n. comb. based on phylogenetic hypotheses estimated with one mtDNA and two nDNA markers. This is a rare and poorly known metalmark, endemic to the central region of Balsas Basin in Michoacán, Mexico, originally described from material collected 23 years ago. Here we analyze new specimens from the type locality not included in the original description. With this new material, we describe the morphological variation of adults, including male and female genitalia. This variation is then discussed and compared with the original description. Emesis planeca n. comb. is restricted to the Tropical Deciduous Forest and the adults fly only in the dry season. Due to the spatial, temporal, and ecological rareness of Emesis planeca n. comb., considering it has not been collected in more than two decades and that the Tropical Deciduous Forest is one of the most threatened habitats in Mexico; we propose assigning a protection status to this species.

Rediscovering the Axolotl as a Model for Thyroid Hormone Dependent Development.

The Mexican axolotl (Ambystoma mexicanum) is an important model organism in biomedical research. Much current attention is focused on the axolotl's amazing ability to regenerate tissues and whole organs after injury. However, not forgotten is the axolotl's equally amazing ability to thwart aspects of tissue maturation and retain juvenile morphology into the adult phase of life. Unlike close tiger salamander relatives that undergo a thyroid hormone regulated metamorphosis, the axolotl does not typically undergo a metamorphosis. Instead, the axolotl exhibits a paedomorphic mode of development that enables a completely aquatic life cycle. The evolution of paedomorphosis allowed axolotls to exploit relatively permanent habitats in Mexico, and preadapted axolotls for domestication and laboratory study. In this perspective, we first introduce the axolotl and the various meanings of paedomorphosis, and then stress the need to move beyond endocrinology-guided approaches to understand the axolotl's hypothyroid state. With the recent completion of the axolotl genome assembly and established methods to manipulate gene functions, the axolotl is poised to provide new insights about paedomorphosis and the role of thyroid hormone in development and evolution.

Marine Threats Overlap Key Foraging Habitat for Two Imperiled Sea Turtle Species in the Gulf of Mexico

Effective management of human activities affecting listed species requires understanding both threats and animal habitat-use patterns. However, the extent of spatial overlap between high-use foraging areas (where multiple marine species congregate) and anthropogenic threats is not well known. Our modeling approach incorporates data on sea turtle spatial ecology and a suite of threats in the Gulf of Mexico to identify and map “hot spots” of threats to two imperiled turtle species. Of all 820 “high” threats grid cells, our tracked turtles foraged at least one day in 77% of them. Although threat data were not available outside the U.S. Exclusive Economic Zone, our map of turtle and threat “hotspots” can be incorporated in future more comprehensive threat analyses for the region. Knowledge of these shared foraging- and threat-areas can assist managers charged with designing effective conservation and population recovery strategies, in future habitat modeling efforts, and in designations of Gulf of Mexico habitat with high conservation value.

Assessing Role of Major Drivers in Recent Decline of Monarch Butterfly Population in North America

Monarch (Danaus plexippus L.) is a long distance migratory species of butterfly in North America that has experienced population declines in recent years. Several interacting factors have been postulated to contribute to this decline. For example, reduced overwintering habitat in Mexico as a result of logging leading to deforestation and reduced breeding habitats in the United States. Decreased spring breeding populations and inclement weather patterns have also been proposed. Herbicides are commonly used in many agricultural production systems planted with genetically modified (GM) cultivars that are resistant to these chemicals. However, the non-target effects of these commonly used herbicides to the monarch host-plant, milkweed (Asclepias spp. L.), which commonly grows within GM planted agricultural fields has also been hypothesized to explain reduced breeding habitats in the Midwestern United States. Currently, significant uncertainty regarding the dynamics of these multiple hypotheses and how their interaction may impact the eastern monarch butterfly population remains. Meanwhile, several efforts to help monarchs have been launched; for example, milkweed plantings and campaigns to minimize deforestation in overwintering habitats. In this context, this mini-review highlights different population decline hypotheses and conservation initiatives and discusses knowledge gaps in awareness and research efforts to mitigate the eastern monarch butterfly population decline.

Willingness to Pay for Conservation of Transborder Migratory Species: A Case Study of the Mexican Free-Tailed Bat in the United States and Mexico.

We estimated U.S. and Mexican citizens' willingness to pay (WTP) for protecting habitat for a transborder migratory species, the Mexican free-tailed bat (Tadarida brasiliensis mexicana), using the contingent valuation method. Few contingent valuation surveys have evaluated whether households in one country would pay to protect habitat in another country. This study addresses that gap. In our study, Mexican respondents were asked about their WTP for conservation of Mexican free-tailed bat habitat in Mexico and in the United States. Similarly, U.S. respondents were asked about their WTP for conservation in the United States and in Mexico. U.S. households would pay $30 annually to protect habitat in the United States and $24 annually to protect habitat in Mexico. Mexican households would pay $8 annually to protect habitat in Mexico and $5 annually to protect habitat in the United States. In both countries, these WTP amounts rose significantly for increasing the size of the bat population rather than simply stabilizing the current bat population. The ratio of Mexican household WTP relative to U.S. household WTP is nearly identical to that of Mexican household income relative to U.S. household income. This suggests that the perceived economic benefits received from the bats is similar in Mexico and the United States, and that scaling WTP by relative income in international benefit transfer may be plausible.

Quantifying ecosystem service flows at multiple scales across the range of a long-distance migratory species

Migratory species provide ecosystem goods and services throughout their annual cycles, often over long distances. Designing effective conservation solutions for migratory species requires knowledge of both species ecology and the socioeconomic context of their migrations. We present a framework built around the concept that migratory species act as carriers, delivering benefit flows to people throughout their annual cycle that are supported by the network of ecosystems upon which the species depend. We apply this framework to the monarch butterfly (Danaus plexippus) migration of eastern North America by calculating their spatial subsidies. Spatial subsidies are the net ecosystem service flows throughout a species’ range and a quantitative measure of the spatial mismatch between the locations where people receive most benefits and the locations of habitats that most support the species. Results indicate cultural benefits provided by monarchs in the U.S. and Canada are subsidized by migration and overwintering habitat in Mexico. At a finer scale, throughout the monarch range, habitat in rural landscapes subsidizes urban residents. Understanding the spatial distribution of benefits derived from and ecological support provided to monarchs and other migratory species offers a promising means of understanding the costs and benefits associated with conservation across jurisdictional borders.

Seasonal variation in non-structural carbohydrates, sucrolytic activity and secondary metabolites in deciduous and perennial Diospyros species sampled in Western Mexico.

This study was performed to test the working hypothesis that the primary determinants influencing seasonal driven modifications in carbon mobilization and other key biochemical parameters in leaves of poorly known Diospyros digyna (Ddg; semi-domesticated; perennial) and D. rekoi (Dre; undomesticated; deciduous) trees are determined by environmental growing conditions, agronomic management and physiological plasticity. Thus, biochemical changes in leaves of both trees were recorded seasonally during two successive fruiting years. Trees were randomly sampled in Western Mexico habitats with differing soil quality, climatic conditions, luminosity, and cultivation practices. Leaves of Ddg had consistently higher total chlorophyll contents (CT) that, unexpectedly, peaked in the winter of 2015. In Dre, the highest leaf CT values recorded in the summer of 2015 inversely correlated with low average luminosity and high Chl a/ Chlb ratios. The seasonal CT variations in Dre were congruent with varying luminosity, whereas those in Ddg were probably affected by other factors, such as fluctuating leaf protein contents and the funneling of light energy to foliar non-structural carbohydrates (NSCs) accumulation, which were consistently higher than those detected in Dre leaves. Seasonal foliar NSC fluctuations in both species were in agreement with the carbon (C) demands of flowering, fruiting and/ or leaf regrowth. Seasonal changes in foliar hexose to sucrose (Hex/ Suc) ratios coincided with cell wall invertase activity in both species. In Dre, high Hex/ Suc ratios in spring leaves possibly allowed an accumulation of phenolic acids, not observed in Ddg. The above results supported the hypothesis proposed by showing that leaf responses to changing environmental conditions differ in perennial and deciduous Diospyros trees, including a dynamic adjustment of NSCs to supply the C demands imposed by reproduction, leaf regrowth and, possibly, stress.

Revisiting revising Mexican wolf historical range: A reply to Hendricks et al.

Hendricks et al. () questioned our clarification of Mexican wolf historical range and our criticism of their expansion proposals far to the north and west. A recent habitat suitability analysis identifies large areas of high quality habitat in Mexico and the latest population viability analysis shows Mexican wolves can be recovered in their historical range. Expanding historical range descriptions based on poorly understood distribution of molecular markers is unnecessary and serves only to impede the recent successful progress to recover the Mexican wolf.

Human Management of a Wild Plant Modulates the Evolutionary Dynamics of a Gene Determining Recessive Resistance to Virus Infection.

This work analyses the genetic variation and evolutionary patterns of recessive resistance loci involved in matching-allele (MA) host-pathogen interactions, focusing on the pvr2 resistance gene to potyviruses of the wild pepper Capsicum annuum glabriusculum (chiltepin). Chiltepin grows in a variety of wild habitats in Mexico, and its cultivation in home gardens started about 25 years ago. Potyvirus infection of Capsicum plants requires the physical interaction of the viral VPg with the pvr2 product, the translation initiation factor eIF4E1. Mutations impairing this interaction result in resistance, according to the MA model. The diversity of pvr2/eIF4E1 in wild and cultivated chiltepin populations from six biogeographical provinces in Mexico was analysed in 109 full-length coding sequences from 97 plants. Eleven alleles were found, and their interaction with potyvirus VPg in yeast-two-hybrid assays, plus infection assays of plants, identified six resistance alleles. Mapping resistance mutations on a pvr2/eIF4E1 model structure showed that most were around the cap-binding pocket and strongly altered its surface electrostatic potential, suggesting resistance-associated costs due to functional constraints. The pvr2/eIF4E1 phylogeny established that susceptibility was ancestral and resistance was derived. The spatial structure of pvr2/eIF4E1 diversity differed from that of neutral markers, but no evidence of selection for resistance was found in wild populations. In contrast, the resistance alleles were much more frequent, and positive selection stronger, in cultivated chiltepin populations, where diversification of pvr2/eIF4E1 was higher. This analysis of the genetic variation of a recessive resistance gene involved in MA host-pathogen interactions in populations of a wild plant show that evolutionary patterns differ according to the plant habitat, wild or cultivated. It also demonstrates that human management of the plant population has profound effects on the diversity and the evolution of the resistance gene, resulting in the selection of resistance alleles.

Assessment of non-cultured aquatic fungal diversity from different habitats in Mexico

With the aim to explore the diversity of aquatic fungi in Mexico we present an investigation using a fragment of the 18S ribosomal DNA as a molecular marker obtained from different water bodies (marine, brackish and fresh water). Ribosomal gene fragments were obtained by DNA amplification, the resulting sequences were compared using multiple alignments against a collection of classified reference fungal sequences and then subjected to phylogenetic clustering allowing the identification and classification of DNA sequences from environmental isolates as fungal down to the family level, provided enough reference sequence were available. From our ensemble of 2,020 sequences identified as fungal, 23.8% were classified at the family level, 48.5% at the order level, 13% at the class/subphylum level and 14.7% of the sequences (all from the same site) could not be unambiguously positioned in any of our reference fungal groups but were closely related to uncultivated marine fungi. The most frequently recovered phylum was Ascomycota (89.1%), followed by Chytridiomycota (8.1%), Basidiomycota (2.8%) and Mucoromycotina (1.3%).