Pampas fox (Lycalopex gymnocercus) of the Argentine Pampas as intermediate host for Neospora caninum

The Pampas fox (Lycalopex gymnocercus) is the most abundant wild canid from South America. This wild canid inhabits grasslands, open woodlands, and areas highly modified by extensive ranching and agricultural activities. We aimed to evaluate Neospora caninum infection in tissues from the Pampas fox from Argentina. A total of 41 free-living Pampas foxes were sampled in rural areas located in the Humid Pampas region, Argentina. Brain tissue and different muscles were assessed by histologic and molecular methods. No N. caninum cysts were observed in brain and muscle tissue samples analyzed by histology and immunohistochemistry. Molecular N. caninum identification from brain tissue was based on amplification by PCR of Nc-5 gene and ITS1 rRNA fragments and subsequent sequencing. The presence of N. caninum DNA was 74% (23/31) for the Nc-5 gene and was confirmed by a second ITS1 PCR in 55% (17/31) of the brain tested. Thirteen ITS1 consensus sequences were obtained, and all have a 99.58–100% similarity with N. caninum reference sequences. Only 4% (1/23) of muscles samples analyzed were positive for the Nc-5 gene of N. caninum. This study demonstrated a high prevalence of N. caninum DNA in brain from free-ranging Pampas fox of the Pampa Argentine, thus confirming that this wild canid is a wide distributed intermediate host.     

Status of the alien pathogen Paranosema locustae (Microsporidia) in grasshoppers (Orthoptera: Acridoidea) of the Argentine Pampas

After experimental introductions from North America in 1978–1982, the biocontrol agent Paranosema locustae became established in grasshopper communities of the western Pampas region of Argentina. The use and establishment of P. locustae in Argentina constitute both a case of neoclassical or new association biological control (use of an alien species against native pests) and a case of pathogen pollution (anthropogenic introduction–establishment of an infectious disease in populations of native species). Since P. locustae is a multihost pathogen among grasshoppers, its presence in the western Pampas represents an additional factor disrupting grasshopper communities according to the differential susceptibility of each species and possibly threatening some species. Microscopic examination of 504 grasshopper samples (the mean number of individuals per sample = 185) belonging to 43 species from 93 localities throughout the Pampas revealed an establishment area of approximate 90,000 km² from about 35° North to 38° South and from 61° East to 65° West. Field infections by P. locustae have now been detected in 21 grasshopper species in the western Pampas. Susceptible species with geographic distributions mostly restricted to the establishment area and with numerically small populations, like the melanopline Scotussa daguerrei, are predicted to be the ones facing higher risks of negative impacts.     

Records of the land planarian Polycladus gayi (Tricladida,Geoplanidae) preying on black snails Macrocyclis peruvianus (Gastropoda,Macrocyclidae)

Polycladus gayi is a colourful and easily recognizable land planarian native to the temperate to cold rainforests of the west coast of southern South America, in Chile and Argentina; however, its ecology is poorly understood. Here, we describe the first records of P. gayi preying on a black snail Macrocyclis peruvianus in the wild. Two events were recorded, the first in a healthy forest in Llancahue Alto, Panguipulli, Chile, during the austral summer of 2023, and the second in a mature evergreen forest in the coastal range of La Union, Chile. These records expand our knowledge of the feeding habits and behaviour of P. gayi and add M. peruvianus to its prey list.     

Potential distribution of the invasive freshwater dinoflagellate Ceratium furcoides (Levander) Langhans (Dinophyta) in South America

Dinoflagellates of the genus Ceratium are predominantly found in marine environments, with a few species in inland waters. Over the last decades, the freshwater species Ceratium hirundinella and Ceratium furcoides have colonized and invaded several South American basins. The purpose of this study was to create a distribution model for the invasive dinoflagellate C. furcoides in South America in order to further investigate the basins at potential risk, as well as the environmental conditions that influence its expansion. This species is known to develop blooms due to its mobility, resistance to sedimentation, and optimized use of resources. Although nontoxic, blooms of the species cause many problems to both the natural ecosystems and water users. Potential distribution was predicted by using a maximum entropy algorithm (MaxEnt). Model was run with 101 occurrences obtained from the scientific literature, and climatic, hydrological and topographic variables. The developed model had a very good performance for the study area. The most susceptible areas identified were mainly concentrated in the basins between southeastern Brazil and northeastern Argentina. Besides already affected regions, new potentially suitable areas were identified in temperate regions of South America. The information generated here will be useful for authorities responsible for water and watershed management to monitor the spread of this species and address problems related to its establishment in new environments.     

Assessment of the global potential distribution of the predatory land planarian Artioposthia triangulata (Dendy) (Tricladida: Terricola) from ecoclimatic data

Abstract

Artioposthia triangulata was originally described from New Zealand in 1895 but was subsequently found to have spread to Northern Ireland in 1963 and Scotland and England in 1965. It is now widespread in both Ireland and Scotland, where it has been shown to reduce earthworm numbers to below detectable levels. Ecoclimatic data were used in the computer program CLIMEX to estimate the potential spread of A. triangulata to Europe and the rest of the world. Results indicated it could establish in agricultural land in most of north‐western Europe, and persist in domestic gardens throughout much of central Europe, east and west North America, Australia, southern South America, and South Africa. It is difficult to assess either the extent to which earthworm numbers and diversity would be decreased or how far the effect of their loss to soil structure, nutrient cycling, or wildlife would be detrimental in these areas.     

北美刺龙葵在中国的适生区预测

【背景】北美刺龙葵是一种全球广泛分布的恶性杂草,已被列入我国进境检疫性有害生物名单。近年来北美刺龙葵不断随进口货物传入我国,明确其传入途径和适生区对控制其入侵具有重要意义。【方法】采用GIS、空间统计学、Maxent生态位模型等方法分析了北美刺龙葵的传入途径与潜在分布区,并通过ROC分析法对模型进行检验。【结果】跨区域农产品贸易是北美刺龙葵全球扩散的驱动力与传入我国的主要途径。生态模型预测结果表明,北美刺龙葵在我国具有广阔的适生区,除黑龙江、吉林、内蒙古、青海、甘肃、西藏、四川西北部以外的区域都是其在我国的适生区,其中高风险区主要集中在东部和南部沿海、西南边境和新疆的部分地区。AUC值为0.789,表明本研究建立的Maxent模型的预测能力较强,能够很好地拟合物种已知分布的环境生态位。【结论与意义】北美刺龙葵在我国的传入风险极高。基于北美刺龙葵在我国的主要传入途径与潜在扩散媒介的时空分布,划定了重点监测的区域,建议对适生区内极易传入的高风险区如港口、机场、物流中转站、加工厂等开展早期监测预警,以预防其再次入侵与进一步扩散蔓延。     

Multilocus molecular systematics and evolution in time and space of Calligrapha (Coleoptera: Chrysomelidae,Chrysomelinae)

Calligrapha (Coleoptera: Chrysomelidae) is a genus with species present in most of the American continent, from the Arctic polar circle to the Pampas in Argentina. In its current concept, the genus comprises some 80 species, but the diagnosis of the genus is problematic, based on a combination of potentially symplesiomorphic character states. In this study, we investigate the largest taxonomic sample of Calligrapha diversity to date (43 species) using a phylogenetic perspective based on more than 6000 molecular characters from eight genes (four mitochondrial and four nuclear) for a systematic evaluation of the genus. The analyses also include thirteen species in the closely related Zygospila (currently a subgenus of Zygogramma) to assist the systematic delimitation of Calligrapha. Partitioned and total evidence phylogenetic trees were additionally used for molecular clock analyses and dating based on standard mtDNA evolutionary rates, and for likelihood‐based inference of ancestral areas. Calligrapha and Zygospila are reciprocally paraphyletic, and our interpretation of taxonomic stability merges both taxa into a larger genus Calligrapha which plausibly originated in the dry steppes of southern North America in the Late Miocene. The genus includes a minimum of five strongly supported lineages which initially diversified in the Pliocene, fully congruent with expectations from morphology, but of uncertain mutual relationships. Only two of these lineages dispersed to South America: the group of C. polyspila right at the time of the final closure of the Isthmus of Panama in the Early Pliocene and the group of C. argus only in recent times, well in the Pleistocene. The most species‐rich lineage of Calligrapha, associated to trees and shrubs typical of riverine and lacustrine environments (as opposed to herbaceous steppe plants, generally Malvaceae and Asteraceae, for most other groups) diversified and spread in North America in the Late Pliocene. The ecological shift to a stable habitat spreading in the continent due to climate change is hypothesized as one possible explanation for the evolutionary success of this group.     

Ethnobotany of the genusCyphomandra (Solanaceae)

Plants of the genusCyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo,Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South America and is now dispersed worldwide in subtropical areas. Its origin and wild relatives are still unknown, but there are tentative reports of wild populations ofC. betacea in southern Bolivia and northwestern Argentina. Wild species ofCyphomandra such asC. hartwegii, C. sibundoyensis, andC. cajanumensis also produce edible fruits. Other species ofCyphomandra are used in medicinal preparations and as dyes. This group of plants is of increasing economic importance and may have considerable potential for future exploitation.     

The Known Distribution and Ecological Preferences of the Tick Subgenus Boophilus (Acari: Ixodidae) in Africa and Latin America

A compilation of the known distribution of Boophilus ticks in Africa and Latin America is presented, together with details on climate preferences. B. annulatus is recorded mainly in the western part of a strip from the equator to parallel 20° N. It associates with woodlands and forests (lowland rain forest and secondary grassland). This species is also present in the Mediterranean region, associated to woodland and open areas. B. decoloratus extends southern to parallel 20° N, in woodland with montane vegetation and Zambezian miombo; some records have been collected in the highveld grassland. B. geigyi is mainly collected in the western range of a stripe extending between parallels 5° N and 18° N, associated with Sudanian woodland, lowland rain forest with secondary grassland and woodland. Confirmed records of microplus in Africa are restricted to Malagasy region and south and eastern Africa, being predominant in the Zambezian miombo, deciduous forest with secondary grassland, and woodland. In Latin America, microplus is abundant in the Mesoamerican corridor to Venezuela and Colombia, and southern in Brazil and Argentina. The tick is mainly associated to the biomes of Chaco and Pampas in Argentina, the North-central moist Andes, the Atlantic forest (southern range) and the moist Meso-American vegetation (northern range). Most collections of B. annulatus and B. geigyi came from areas where winter minimum temperature is above 15 °C, maximum temperatures remain between 33 and 36 °C and maximum rainfall is recorded between June and September. B. decoloratus and African B. microplus are recorded in sites with low temperatures in May–September. Minimum temperature requirements are similar for both B. decoloratus and African B. microplus, and both are around 4 °C less than the value recorded for collections of Latin-American B. microplus. The rainfall pattern observed for decoloratus shows a minimum in May and June. The requirements of total rainfall are highest for B. microplus in Latin America, while records of African B. microplus are concentrated in areas of low rainfall between May and October, and high rainfall between November and March (low rainfall in the same period for B. decoloratus). Statistical analysis revealed the existence of populations (demes) with ecologically different requirements within each tick species. Both B. annulatus and B. decoloratus showed many different demes clearly associated to defined areas. The collections of Latin American B. microplus are very homogeneous according climate preferences and well separated from the African counterpart.     

Araucnephia iberaensis n. sp., a neotropical black fly with a peculiar distribution (Diptera-Simuliidae)

Araucnephia Wygodzinsky & Coscarón is a Neotropical black fly genus in which only one species from Central Chile is known. Another species has now been found in Corrientes province on the eastern side of the Iberá tropical swamps of Argentina, on the western border of the mountainous region of southern Brazil. This new species, A. iberaensis, is herein described and illustrated and information on its bionomics is recorded. It is an interesting species because previous to its discovery no black fly genus or subgenus from Central Chile region has been found in tropical areas, because these two regions are separated by the Monte and Pampas realms. Similarly, no Brazilian genus or subgenus has crossed the Andes mountains to Chile. A comparison with other Neotropical, Nearctic, Ethiopian (Afrotropical) and Australian Prosimuliini (sensu Crosskey & Howard) showed Araucnephia to be a valid taxon most closely related to Araucnephioides (sympatric in Chile). Araucnephia also shows great affinities with Lutzsimulium from Southeast Brazil and Argentina and Paracnephia from South Africa.     

The last stronghold of Muñoa’s Pampas cat (Leopardus munoai) in Argentina?

The Muñoa’s Pampas cat (Leopardus munoai) is a relatively understudied species restricted to open savannas and grasslands of Southern Brazil, Uruguay and NE Argentina, that has been recently split from the broader “Pampas cat” species complex. Only three documented records of the species have been published since the year 2000 for the Argentine portion of its distribution, a situation that led to speculations regarding its conservation status in Argentina. We conducted an intensive camera-trap survey (2,067 camera-trapping stations and 15,560 camera-trapping days) to assess the presence of the Muñoa’s Pampas cat in an area of 275.3 km² within the Iberá National Park and the adjacent Iberá National Reserve, Corrientes province, Argentina. Four records of Muñoa’s Pampas cat were obtained, representing at least two adults and one young individual. Only one camera-trapping record of this species had been previously obtained in Argentina, during a survey carried out in 2009 in the same study area, despite an important camera-trapping effort in the Corrientes province. All camera-trap records of Muñoa’s Pampas cat in Argentina are concentrated in areas of temporally flooded grasslands locally known as “Malezales”, suggesting that this habitat type is critically important for the conservation of this rare felid. The Iberá National Park and the adjacent Iberá National Reserve provide the adequate framework for the conservation of an important piece of habitat for Muñoa’s Pampas cat and constitute a stronghold for the species in Argentina.     

Multiple introductions and gene flow in subtropical South American populations of the fireweed,Senecio madagascariensis(Asteraceae)

Non-indigenous plants exhibit different attributes that make them aggressive competitors with indigenous plants and serious threats to biodiversity.Senecio madagascariensis (fireweed, Asteraceae), a native from southern Africa, is a strong competitor in agricultural activities and has toxic alkaloids that may result in high cattle mortality. In Brazil, this weed was collected for the first time in 1995 and has since spread quickly throughout the Pampas region. To better understand the invasion of the fireweed in South America, we used a genetic characterization with internal transcribed spacer (ITS) and microsatellite markers. Based on the ITS data, the southern Brazil populations of S. madagascariensis shared genetic homology with samples taken from the Hawaiian Islands and South Africa. Microsatellite analysis showed the genetic diversity split in two clusters, perhaps intimating the independent introduction of each species into South America. Although fireweed was introduced recently in southern Brazil, the considerable levels of genetic diversity, gene flow, and inbreeding may indicate success in the species establishment in this environment.     

Diversity and paleoenviromental significance of Brazilian fossil Galictis (Carnivora: Mustelidae)

The evolutionary history of the genus Galictis in South America probably begins after the Great American Biotic Interchange. Two species are recognised: Galictis vittata and Galictis cuja. The latter are more frequently found in open areas in southern South America and the first occurs in humid forests from northern South America to Central America. Apparently, they do not occur in sympatry. Both are differentiate by the presence of a metaconid in the first inferior molar of G. vittata and for its bigger size when compared to G. cuja. The fossil record of Galictis is scarce, G. cuja is known by few specimens from Argentina, Chile and Brazil; G. vittata have only one record from Southern Brazil. The specimens related to this record were collected by Peter Lund and are housed at the Statens Naturhistoriske Museum. However, the specimens published by Lund are not fossils. Thus, it is presented here other unpublished specimens collected by Lund and housed at the same museum that we recognise as the first G. vittata fossils. Additionally, it is described here the first fossil record for G. cuja from the late Pleistocene of Brazil – an almost complete mandible recovered from sedimentary deposits from Central Brazil.     

Parachoerus carlesi (Mammalia,Tayassuidae) in the Late Pleistocene (northern Argentina,South America): paleoecological and palaeobiogeographic considerations

Abstract

The Tayassuidae is one of the first families of North American immigrant mammals that arrived into South America during the ‘Great American Biotic Interchange’. They have been found associated with Late Cenozoic deposits mainly in Argentina and Brazil, but also in Uruguay, Bolivia, Colombia, Peru and Venezuela. Theirs records within Argentina come from the Pampean Region, Mesopotamia and north-central region. Here, we report the first record of P. carlesi with precise stratigraphic (26.630 ± 370 14C years BP, Late Pleistocene) data in Argentina, precisely from the Chacoan region. This specimen represents the most complete fossil material of this extinct species, increasing its morphological and morphometrical knowledge, and it provides relevant ecological and climatic information. From a palaeoenvironmental point of view, the fauna registered in this paleontological site, includes taxa mainly adapted to open or semi-open and arid or semi-arid environments. The bearing sediments and the peculiarities of the faunal assemblages, as well as the chronological data, allow confirming that arid and semiarid conditions, with scarce or absent vegetation cover were developed in this area of Argentina during the last part of MIS 3 and beginning of MIS 2. These environmental conditions favored the settlement of megamammals adapted to open environments.     

Contribution to the taxonomy of Gryllus Linnaeus, 1758 in South America: Part I: Redescription of Gryllus argentinus Saussure, 1874 (Orthoptera,Grylloidea, Gryllidae)

The genus Gryllus includes 82 described species that occur in America from Canada to Argentina as well as in several areas of Africa, Europe and Asia. There are 12 species in South America, which were described in the nineteenth century based on a small number of samples and inconsistent characters such as body coloration and external morphology. The aim of this article is to redescribe Gryllus argentinus Saussure, 1874 collected in the urban areas of Pelotas, Capão do Leão and Rio Grande, in the state of Rio Grande do Sul, southern Brazil, highlighting phallic sclerites, calling song and body morphometry. We designate the lectotype male, provide a combination of diagnostic characteristics and discuss the taxonomic situation of South American Gryllus species.     

The phylogeny and geography of Myrceugenia (Myrtaceae)

Myrceugenia is a mainly temperate South American genus with two species on the Juan Fernández Islands, 12 in central and southern Chile and adjacent Argentina, and 25 in the highlands of southeastern Brazil and adjacent regions. The continental populations are separated by about 1000 km. Numerical cladistic procedures based on the criteria of parsimony, compatible characters and a combination of compatible characters and character correlation are used to deduce hypothetical phylogenetic undirected trees. These indicate that 3–8 groups of species bridge the continent of South America. An explanation of how the distribution of the genus could have come about is given based on: 1) the above mentioned numerical analyses, 2) the ecology of the species, 3) the distribution of other plant genera, and 4) theories of the geologic and climatic history of southern South America. Myrceugenia is hypothesized to have grown continuously across South America during the early Tertiary and to have become divided into eastern and western populations probably during the Miocene.     

Probable origin and toxin profile of Alexandrium tamarense (Lebour) Balech from southern Brazil

The distribution of the toxic dinoflagellate Alexandrium tamarense Lebour has apparently expanded within the southern hemisphere during the last 2 decades. Toxic blooms of A. tamarense were recorded in Argentinean coastal waters since 1980; however, the first documented bloom in southern Brazil was in 1996. In this study, 13 strains of A. tamarense from southern Brazil were isolated and kept in culture. Phylogenetic analysis using RFLP and DNA sequences of the D1–D2 region of large subunit ribosomal DNA (rDNA) clearly indicates that Brazilian strains are most closely related to other South American strains. The strains from South America are placed firmly within a phylogenetic clade which contains strains from North America, northern Europe and northern Asia, previously called the North American clade. Possible dispersal hypotheses are discussed. The cultures were also analyzed for saxitoxin and its derivatives by high performance liquid chromatography (HPLC). The main saxitoxin groups found were the low toxicity N-sulfocarbamoyl group, C1, 2 (30–84%), followed by the high potency carbamate toxins, gonyautoxins 1, 4 (6.6–55%), gonyautoxins 2, 3 (0.3–29%), neosaxitoxin (1.4–24%) and saxitoxin (0–4.4%). The toxin composition is similar to that of other strains from South America, supporting a close relationship between A. tamarense from southern Brazil and other areas of South America. Toxicity values were variable (7.07–65.92 pg STX cell⁻¹), with the higher range falling among the most toxic values recorded for cultures of A. tamarense, indicating the significant risk for shellfish contamination and human intoxication during blooms of this species along the southern Brazilian coast.     

The biogeography of Hoffmannseggia (Leguminosae, Caesalpinioideae, Caesalpinieae): a tale of many travels

Aim The flowering plant genus Hoffmannseggia consists of 21 species distributed amphitropically between the arid regions of the south‐western United States and adjacent Mexico, and west‐central South America. This pattern of geographical disjunction is shared by numerous other angiosperm genera and has been the subject of discussions for more than a century with various authors advocating a northern origin for particular taxa and others advocating a southern origin. This study uses a well‐supported phylogeny of a genus with numerous species in each area to address the issues of a northern or southern origin and the facility with which organisms move between the two continents. Location South‐western United States and northern Mexico, northern Chile and Argentina, southern Bolivia, and western Peru. Methods Using DNA sequence data from the nuclear and chloroplast genomes, we generated a phylogenetic hypothesis for all species of Hoffmannseggia rooted with Zuccagnia and Balsamocarpon. Geographical data were optimized on the resultant tree to assess the probable continent of origin for the genus, the pattern of disjunctions between North and South America, and species radiations within the genus. Main conclusions Hoffmannseggia arose in South America and initially split into a suffrutescent (somewhat woody) and an herbaceous clade. Within each of these major clades, there have been at least two exchanges between North and South America. There are no data to support an ancestral pan‐American range for Hoffmannseggia and we therefore ascribe the amphitropical disjunctions to long‐distance dispersal. The phylogeny clearly shows that all dispersals were from South to North America and they occurred at different times and thus the pattern is not the result of a single simultaneous set of dispersals.     

Baccharis spicata (Asteraceae), a new potentially invasive species to Europe

Baccharis spicata, a species native to South America (southern Brazil, Paraguay, Uruguay, and northeastern and central Argentina) is reported for the first time from Europe. In September 2015, two naturalized populations were detected in the surroundings of Porto (Matosinhos and Vila do Conde) in Portugal. Based on literature data, the species’ taxonomy and nomenclature are analyzed and it is described and illustrated. Furthermore, its ecology, habitat, biology, and possible vector of introduction are discussed. Finally, its invasive potential for the European Union is assessed, based on climatic variables and two different risk assessment methods.