Genetic demography at the leading edge of the distribution of a rabies virus vector

The common vampire bat, Desmodus rotundus, ranges from South America into northern Mexico in North America. This sanguivorous species of bat feeds primarily on medium to large‐sized mammals and is known to rely on livestock as primary prey. Each year, there are hotspot areas of D. rotundus‐specific rabies virus outbreaks that lead to the deaths of livestock and economic losses. Based on incidental captures in our study area, which is an area of high cattle mortality from D. rotundus transmitted rabies, it appears that D. rotundus are being caught regularly in areas and elevations where they previously were thought to be uncommon. Our goal was to investigate demographic processes and genetic diversity at the north eastern edge of the range of D. rotundus in Mexico. We generated control region sequences (441 bp) and 12‐locus microsatellite genotypes for 602 individuals of D. rotundus. These data were analyzed using network analyses, Bayesian clustering approaches, and standard population genetic statistical analyses. Our results demonstrate panmixia across our sampling area with low genetic diversity, low population differentiation, loss of intermediate frequency alleles at microsatellite loci, and very low mtDNA haplotype diversity with all haplotypes being very closely related. Our study also revealed strong signals of population expansion. These results follow predictions from the leading‐edge model of expanding populations and supports conclusions from another study that climate change may allow this species to find suitable habitat within the U.S. border.     

Mitochondrial DNA phylogeography reveals marked population structure in the common vampire bat, Desmodus rotundus (Phyllostomidae)

Desmodus rotundus (Chiroptera: Phyllostomidae; Desmodontinae) is the most common vampire bat and has a broad distribution, ranging from southern Mexico to central Chile in the west, and Paraguay and northern Argentina in the east of South America ( Koopman 1988 ). Because of its feeding habit, this bat is considered the main source of rabies transmission to cattle. Although this species has a large spectrum of morphological variability throughout its range, thus far no study has examined the distribution of genetic lineages over its geographic range. Four geographically circumscribed clades of D. rotundus were described in the Brazilian territory on the basis of mitochondrial sequence analyses: southern Atlantic forest (SAF), northern Atlantic forest (NAF), Pantanal (PAN) and Amazon plus Cerrado (AMC) clade. The differentiation among these clades is strongly supported statistically, although the phylogenetic relationship between them remains uncertain. The extremely high levels of sequence divergence that were found between clades (ranging from 6% to 11%) are the highest ever described for a Neotropical bat species and cannot be explained by female philopatry alone. This indicates that D. rotundus comprises two or more distinct, possibly cryptic species. The biogeographic pattern described for this bat is similar to those described for other bats and terrestrial mammals, suggesting geographical congruence between historical vicariant processes, including likely vicariant events between north and south Atlantic Forest and between the Atlantic Forest and the Amazon.     

Predicting the distribution of a novel bark beetle and its pine hosts under future climate conditions

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警惕外来危险性害虫椰蛀梗象入侵为害

椰蛀梗象Homalinotus coriaceusGyllenhal主要分布于南美洲的巴西、圭亚那、巴拉圭、阿根廷北部、厄瓜多尔、秘鲁、委内瑞拉,严重危害棕榈科植物。为警惕该虫的传入,对椰蛀梗象的分类地位、形态特征、分布、寄主、危害、生物学特性等作了简要介绍,并提出预防建议。     

Species richness,endemism, and conservation of American tree ferns (Cyatheales)

Analyses of richness and endemism of Cyatheales (tree ferns) in tropical America were performed and evidence of a diversity gradient is presented. For this, the occurrence ranges of 239 species were plotted into a 5° × 5° grid-cell map and then analyzed using species richness and endemism indices. Here we show that species richness and endemism are not distributed randomly over the landscape, but do aggregate into defined regions of high diversity in tropical America: the northern Andes, lower Central America, upper Central America and Mexico, the Guyana Highlands, southeastern Brazil, and the Antilles. These distributional patterns are congruent with the geographical distribution of cloud forest, which in turn is determined by topography, high humidity, and persistent cloud immersion. The mountain regions of tropical America, especially the cloud forests, harbour most of the species of American Cyatheales and have high levels of habitat loss and climatic fragility. Conservation policies for Cyatheales are centred on the local use and trade of many tree fern species, but none such policies focus on cloud forest habitat loss. This makes tree ferns a critically endangered group of plants. In the face of the current environmental crisis and global climate change, the presence of Cyatheales in these regions sounds the alarm on their conservation priorities.     

Potential geographical distribution of the red palm mite in South America

Among pests that have recently been introduced into the Americas, the red palm mite, Raoiella indica Hirst (Prostigmata: Tenuipalpidae), is the most invasive. This mite has spread rapidly to several Caribbean countries, United States of America, Mexico, Venezuela, Colombia and Brazil. The potential dispersion of R. indica to other regions of South America could seriously impact the cultivation of coconuts, bananas, exotic and native palms and tropical flowers such as the Heliconiaceae. To facilitate the development of efficacious R. indica management techniques such as the adoption of phytosanitary measures to prevent or delay the dispersion of this pest, the objective of this paper was to estimate the potential geographical distribution of R. indica in South America using a maximum entropy model. The R. indica occurrence data used in this model were obtained from extant literature, online databases and field sampling data. The model predicted potential suitable areas for R. indica in northern Colombia, central and northern Venezuela, Guyana, Suriname, east French Guiana and many parts of Brazil, including Roraima, the eastern Amazonas, northern Pará, Amapá and the coastal zones, from Pará to north of Rio de Janeiro. These results indicate the potential for significant R. indica related economic and social impacts in all of these countries, particularly in Brazil, because the suitable habitat regions overlap with agricultural areas for R. indica host plants such as coconuts and bananas.     

Projected bioclimatic distributions in Nearctic Bovidae signal the potential for reduced overlap with protected areas

Assumptions about factors such as climate in shaping species'' realized and potential distributions underlie much of conservation planning and wildlife management. Climate and climatic change lead to shifts in species distributions through both direct and indirect ecological pressures. Distributional shifts may be particularly important if range overlap is altered between interacting species, or between species and protected areas. The cattle family (Bovidae) represents a culturally, economically, and ecologically important taxon that occupies many of the world''s rangelands. In contemporary North America, five wild bovid species inhabit deserts, prairies, mountains, and tundra from Mexico to Greenland. Here, we aim to understand how future climate change will modify environmental characteristics associated with North American bovid species relative to the distribution of extant protected areas. We fit species distribution models for each species to climate, topography, and land cover data using observations from a citizen science dataset. We then projected modeled distributions to the end of the 21st century for each bovid species under two scenarios of anticipated climate change. Modeling results suggest that suitable habitat will shift inconsistently across species and that such shifts will lead to species‐specific variation in overlap between potential habitat and existing protected areas. Furthermore, projected overlap with protected areas was sensitive to the warming scenario under consideration, with diminished realized protected area under greater warming. Conservation priorities and designation of new protected areas should account for ecological consequences of climate change.     

The emergent macrophyte Montrichardia linifera (Arruda) Schott (Alismatales: Araceae), a rekindled old friend from the Pacific Slope of lower Central America and western Colombia

The genus Montrichardia are among the most remarkable emergent macrophytes in tropical wetlands. It occurs exclusively in the Neotropics and contains two living species, M. linifera (Arruda) Schott and M. arborescens (L.) Schott. Montrichardia linifera has been reported mainly in the Amazon basin (southern Venezuela to Guyana, Brazil, Ecuador and Peru), whereas M. arborescens occurs in Central America (Mexico to Panama), the Lesser Antilles and northern South America. Based on our review of herbarium specimens from Central America and Colombia, as well as field documentation in Panama, we hereby provide the first report of the occurrence of M. linifera in Panama, Central America and western Colombia. Furthermore, this finding represents the first record on the Pacific Slope for this species in the Neotropics. The habitat, ecology, life-form, taxonomic remarks and morphological characteristics of the species are presented, discussed and illustrated. Additionally, a key for the species of the genus Montrichardia is included; we also provide a discussion about the helophyte concept for the genus Montrichardia.     

PERMANENT GENETIC RESOURCES: Development of polymorphic microsatellite loci for the common vampire bat, Desmodus rotundus (Chiroptera: Phylostomidae)

The common vampire bat (Desmodus rotundus) is one of three haematophagous species of bats and the only species in this genus. These New World bats prey on mammals and create significant economic impacts through transmission of rabies in areas where livestock are prevalent. Furthermore, in some portions of their range, it is not uncommon for them to prey upon humans. It is critical to the management of this species and for understanding the spread of bat rabies that detailed studies of D. rotundus population structure be conducted. To further such studies, we have characterized 12 microsatellite loci for this species.     

Revisions of Pterogastra and Schwackaea (Melastomataceae: Melastomeae)

The closely related neotropical melastomean genera Pterogastra and Schwackaea are revised, the species illustrated, and their distribution mapped. Schwackaea is maintained as a monotypic genus because it is readily distinguished from all other melastomes by its 8-winged capsule. This weedy little plant occurs from Mexico throughout Central America, chiefly on the Pacific slope, to northern Colombia and on Cocos Island and grows in natural or man-made savannas from sealevel to 2000 m altitude. Two species are recognized in Pterogastra and one new combination, P. divaricata spp. glabra , is made. Pterogastra is characterized by distinctly 4- or 5-winged capsules, unlike those of Schwackaea or any other New World melastome. The more widespread species occurs in Colombia, Venezuela, Guyana, Ecuador, and Peru at altitudes between sealevel and 2600 m in natural or disturbed grasslands. The second species is endemic in southwestern Venezuela and is confined to natural savannas at low altitudes.     

Survey of bat populations from Mexico and Paraguay for rabies

A mammalian survey was conducted in Mexico (October 1994-January 1996) and in Paraguay (August 1996-March 1997); a complete specimen was collected for each bat in the survey, including primary voucher specimen, ectoparasites, karyotype, and various frozen tissues. The surveys combined provided 937 brain samples (65 bat species) for rabies diagnosis. One male Lasiurus ega, collected in Paraguay, tested positive for the rabies virus (overall prevalence rate of 0.1%). Nucleotide sequence from a 300 bp region of the rabies nucleoprotein gene was compared with sequence obtained from representative rabies virus samples in the repository at the Centers for Disease Control and Prevention (Atlanta, Georgia, USA). Rabies virus extracted from the brain material of L. ega differed by only one nucleotide from a 300 bp consensus sequence (>99% homology) derived from samples for the variant of rabies virus transmitted by Lasiurus cinereus. Lasiurus ego differed by approximately 15% for the variant transmitted by Desmodus rotundus. Phylogenetic analysis found no evidence to suggest L. ego is a reservoir for rabies antigenic variant 6. The most likely explanation for rabies in L. ega was infection following contact with a rabid L. cinereus.     

Ticks (Ixodidae) on humans in South America

Twenty eight species of Ixodidae have been found on man in South America (21 Amblyomma, 1 Boophilus, 2 Dermacentor, 2 Haemaphysalis, 1 Ixodes and 1 Rhipicephalus species). Most of them are rarely found on man. However, three species frequently parasitize humans in restricted areas of Argentina (A. neumanni reported from 46 localities), Uruguay (A. triste from 21 sites) and Argentina–Brazil (A. parvum from 27 localities). The most widespread ticks are A. cajennense (134 localities in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Suriname and Venezuela), A. ovale (37 localities in Argentina, Brazil, Ecuador, French Guiana, Guyana, Paraguay, Suriname and Venezuela) and A. oblongoguttatum (28 sites in Brazil, Colombia, French Guiana, Guyana, Suriname and Venezuela). Amblyomma aureolatum (18 localities in Argentina, Brazil, French Guiana and Paraguay), A. cajennense, and A. triste are vectors of rickettsioses to man in South America. A better understanding of the respective roles of these and other tick species in transmitting pathogens to humans will require further local investigations. Amblyomma ticks should be the main subjects of these studies followed by species of Boophilus, Dermacentor, Haemaphysalis and Rhipicephalus species. In contrast with North America, Europe and Asia, ticks of the genus Ixodes do not appear to be major players in transmitting diseases to human. Indeed, there is only one record of an Ixodes collected while feeding on man for all South America.     

Revision of the Neotropical genus Nyttum (Hemiptera: Coreidae)

Abstract The Neotropical genus Nyttum, belonging to the wholly New World tribe Acanthocephalini of the plant-feeding heteropterous family Coreidae, is redescribed. Its distribution is shown to extend from Mexico to Uruguay. Nyttum limbatum Spinola, from Brazil, and N.punctatum (Dallas), widespread in South and Central America, are redescribed; Anasa perfusa Distant is synonymized with N.punctatum. Seven new species are described: Nyttum amaralae, from Uruguay; N.beckeri, from Brazil and 'West Indies' N.nigrum, from Venezuela; N.pallens, from Mexico; N.pulchrum, from Peru; N.rubrum, from Brazil; and N.spinolai from Brazil and Guyana. A key to the species is included. Placoscelis is regarded as the genus most closely related to Nyttum and it is shown that the same two types of paramere and the same two types of aedaegus occur in both genera.  

Resumen

. Se redescribe el género neotropical Nyttum, perteneciente a la tribu Acanthocephalini que se encuentra exclusivamente en el Nuevo Mundo, dentro de la familia Coreidae (Hemiptera-Heteroptera) que se alimenta exclusivamente de vegetales. Se indica que la distribución de este género se extiende desde Mexico al Uruguay. Se redescriben Nyttum limbatum Spinola del Brasil y N.punctatum (Dallas), de amplia distribución en América del Sur y Central. Anasa perfusa Distant es sinonimizada con N.punctatum. Se describen siete neuvas especies: Nyttum amaralae, del Uruguay; N.beckeri, del Brasil e 'Indias Occindentales' N.nigrum, de Venezuela; N.pallens, de Mexico; N.pulchrum, de Perú; N.rubrum, de Brasil; y N.spinolai, de Brasil y Guyana. Se incluye una clava para la separation de las especies. Se considera que Placoscelis es el género mas cercano a Nyttum, y se indica que los mismos dos tipos de parameros y los mismos dos tipos de aedeagus se encuentran en ambos.     

Climate Change Impacts on the Future Distribution of Date Palms: A Modeling Exercise Using CLIMEX

Climate is changing and, as a consequence, some areas that are climatically suitable for date palm (Phoenix dactylifera L.) cultivation at the present time will become unsuitable in the future. In contrast, some areas that are unsuitable under the current climate will become suitable in the future. Consequently, countries that are dependent on date fruit export will experience economic decline, while other countries’ economies could improve. Knowledge of the likely potential distribution of this economically important crop under current and future climate scenarios will be useful in planning better strategies to manage such issues. This study used CLIMEX to estimate potential date palm distribution under current and future climate models by using one emission scenario (A2) with two different global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR). The results indicate that in North Africa, many areas with a suitable climate for this species are projected to become climatically unsuitable by 2100. In North and South America, locations such as south-eastern Bolivia and northern Venezuela will become climatically more suitable. By 2070, Saudi Arabia, Iraq and western Iran are projected to have a reduction in climate suitability. The results indicate that cold and dry stresses will play an important role in date palm distribution in the future. These results can inform strategic planning by government and agricultural organizations by identifying new areas in which to cultivate this economically important crop in the future and those areas that will need greater attention due to becoming marginal regions for continued date palm cultivation.     

Downscaling Pest Risk Analyses: Identifying Current and Future Potentially Suitable Habitats for Parthenium hysterophorus with Particular Reference to Europe and North Africa

Pest Risk Assessments (PRAs) routinely employ climatic niche models to identify endangered areas. Typically, these models consider only climatic factors, ignoring the ‘Swiss Cheese’ nature of species ranges due to the interplay of climatic and habitat factors. As part of a PRA conducted for the European and Mediterranean Plant Protection Organization, we developed a climatic niche model for Parthenium hysterophorus, explicitly including the effects of irrigation where it was known to be practiced. We then downscaled the climatic risk model using two different methods to identify the suitable habitat types: expert opinion (following the EPPO PRA guidelines) and inferred from the global spatial distribution. The PRA revealed a substantial risk to the EPPO region and Central and Western Africa, highlighting the desirability of avoiding an invasion by P. hysterophorus. We also consider the effects of climate change on the modelled risks. The climate change scenario indicated the risk of substantial further spread of P. hysterophorus in temperate northern hemisphere regions (North America, Europe and the northern Middle East), and also high elevation equatorial regions (Western Brazil, Central Africa, and South East Asia) if minimum temperatures increase substantially. Downscaling the climate model using habitat factors resulted in substantial (approximately 22–53%) reductions in the areas estimated to be endangered. Applying expert assessments as to suitable habitat classes resulted in the greatest reduction in the estimated endangered area, whereas inferring suitable habitats factors from distribution data identified more land use classes and a larger endangered area. Despite some scaling issues with using a globally conformal Land Use Systems dataset, the inferential downscaling method shows promise as a routine addition to the PRA toolkit, as either a direct model component, or simply as a means of better informing an expert assessment of the suitable habitat types.     

基于MaxEnt模型不同气候变化情景下的豆梨潜在地理分布

针对豆梨的原生境保护和资源利用问题,本研究基于豆梨全球236个分布点和19个环境因子,利用最大熵模型(MaxEnt)和地理信息系统(GIS)预测了豆梨在不同气候条件下的全球生态适宜区.结果表明: 豆梨的生态适宜区主要集中在北美洲、亚洲等地区,面积共约1.6×10⁷ km².其中,中国生态适宜度较高的地区主要分布在湖南省、湖北省、安徽省、江西省、江苏省、浙江省、福建省等地.影响豆梨地理分布的主要气候因子是年平均气温和年降水量,气温季节性变化次之.由模型预测可知,在不同的气候背景下,豆梨适宜生境和低适宜生境的面积有所不同.在空间分布上,豆梨适宜生境和低适宜生境的范围和几何中心都由东部向西部地区扩散,北美洲的适宜生境增长较快,而欧洲地区的低适宜生境增长较快.     

A comprehensive description and evolutionary analysis of 9 Loliginidae mitochondrial genomes

Forty South American aquatic plant species were selected and categorised in four a priori status classes (alien naturalised, alien invasive, native and absent) according to expert opinion, for 16 South American regions (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falklands Islands, French Guiana, Galapagos, Guyana, Paraguay, Peru, South Georgia and South Sandwich Islands, Suriname, Uruguay and Venezuela). The 40 aquatic plant species were assessed using the US Aquatic Weed Risk Assessment (USAqWRA) scheme for each of the 16 South American regions, for a total number of 644 assessments and for South America (153 assessments). The method was benchmarked against expert opinion (invasive, non-invasive). We ranked 17 of them as naturalised, and 15 as invasive species in at least one South American region. The USAqWRA distinguished between non-invaders and invaders with an overall accuracy of 84.9% in South America and 54.1% in the 16 regions, with areas under the curves equal to 0.893 and 0.853, at a threshold score of 51.5 and 43.5, respectively. The study highlights that the USAqWRA could represent a suitable screening protocol to prioritise aquatic species that have the potential to cause negative impacts, prevent attempts of introduction and to manage risky aquatic plants in South America.     

Historical and present distribution of coyote (Canis latrans) in Mexico and Central America

Aim Coyote (Canis latrans) distribution in Mexico and Central America has expanded recently reaching the Yucatan peninsula, Belize and Panama, probably promoted by deforestation of tropical areas. Historically, the southern distribution of coyotes prior to European settlement in America was described as reaching only as far south as central Mexico and that introduction of livestock favoured migration of coyotes to southern Mexico and Central America. However, coyote fossil records in Central America and Yucatan, as well as observational records of travellers during the sixteenth century suggest that the coyote's arrival to the region was earlier. Because of the uncertainty of past coyote distribution and the possible economic and ecological impacts due to recent range expansion, the objectives of this study were to confirm if paleontological and historical evidence support the hypothesis that the southernmost limit of coyote distribution before the arrival of European settlers was the centre of Mexico, to discuss the possible factors that have influenced historical shifts in coyote distribution, and to model the present distribution of the coyote in Mexico and Central America, determining the areas where they could invade in the near future. Location The research area comprises continental Mexico and the Central American Isthmus countries: Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. Methods The historical distribution (Pleistocene–Early Holocene, Pre‐Columbian, sixteenth to nineteenth centuries and twentieth century) was established from coyote records obtained from museum collections and specialized literature. Present coyote distribution for Mexico and Central America was modelled using the Genetic Algorithms for Rule‐set Prediction (GARP). Results Historical coyote records show that this species was distributed in southern Mexico and Central America during the Pleistocene–Early Holocene, the Pre‐Columbian period, and during the arrival of Europeans in the sixteenth century. Coyote records indicate a continuous range expansion during the twentieth century. Historical advance and regression of tropical forests in southern Mexico and Central America produced by natural and human events such as climatic changes and variation in human densities could help us understand the historical coyote distribution. The modelled present‐day coyote distribution included the north of Belize, the north of Panama, the north of the Yucatan Peninsula and a corridor on the Gulf costal plain of Campeche in Mexico. Also, the model predicted a region north of the Darien in southern Panama as appropriate for the presence of coyotes, although they have not been detected there so far. Main conclusion Coyote records in southern Mexico and Central America during the Pleistocene–Early Holocene, the Pre‐Columbian period, and early arrival of European settlers to the area indicated that coyotes were probably already present there and did not recently disperse from the north of Mexico to the south due to livestock introduction.     

Dispersal limitations increase vulnerability under climate change for reptiles and amphibians in the southwestern United States

Species conservation plans frequently rely on information that spans political and administrative boundaries, especially when predictions are needed of future habitat under climate change; however, most species conservation plans and their requisite predictions of future habitat are often limited in geographical scope. Moreover, dispersal constraints for species of concern are not often incorporated into distribution models, which can result in overly optimistic predictions of future habitat. We used a standard modeling approach across a suite of 23 taxa of amphibians and reptiles in the North American deserts (560,024 km² across 13 ecoregions) to assess impacts of climate change on habitat and combined landscape population dispersal simulations with species distribution modeling to reduce the risk of predicting future habitat in areas that are not available to species given their dispersal abilities. We used 3 general circulation models and 2 representative concentration pathways (RCPs) to represent multiple scenarios of future habitat potential and assess which study species may be most vulnerable to changes forecasted under each climate scenario. Amphibians were the most vulnerable taxa, but the most vulnerable species tended to be those with the lowest dispersal ability rather than those with the most specialized niches. Under the most optimistic climate scenario considered (RCP 2.6; a stringent scenario requiring declining emissions from 2020 to near zero emissions by 2100), 76% of the study area may experience a loss of >20% of the species examined, while up to 87% of the species currently present may be lost in some areas under the most pessimistic climate scenario (RCP 8.5; a scenario wherein greenhouse gases continue to increase through 2100 based on trajectories from the mid-century). Most areas with high losses were concentrated in the Arizona and New Mexico Plateau ecoregion, the Edwards Plateau in Texas, and the Southwestern Tablelands in New Mexico and Texas, USA. Under the most pessimistic climate scenario, all species are predicted to lose some existing habitat, with an average of 34% loss of extant habitat across all species. Even under the most optimistic scenario, we detected an average loss of 24% of extant habitat across all species, suggesting that changing climates may influence the ranges of reptiles and amphibians in the Southwest.     

Habitat area and climate stability determine geographical variation in plant species range sizes

Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~ 85 000 plant species across the New World. We assess prominent hypothesised range‐size controls, finding that plant range sizes are codetermined by habitat area and long‐ and short‐term climate stability. Strong short‐ and long‐term climate instability in large parts of North America, including past glaciations, are associated with broad‐ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small‐ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen concerns over the potential effects of future climate change and habitat loss on biodiversity.