Liothrips tractabilis sp.n. (Thysanoptera: Phlaeothripinae) from Argentina, a potential biocontrol agent of Weedy Campuloclinium macrocephalum (Asteraceae) in South Africa

A new species, Liothrips tractabilis, is described from northern Argentina. Feeding by this thrips causes severe damage to the leaves of Campuloclinium macrocephalum, a plant that has been introduced to South Africa where it is a serious weed of grasslands. A key is provided to the four species of the genus Liothrips recorded from Argentina.     

Pseudochakura (Hymenoptera: Eucharitidae), a New World genus of chalcidoids parasitic on ants

Abstract. The genus Pseudochakura Ashmead (Eucharitidae: Eucharitinae) is revised to include thirteen species which all share the complete fusion of the genae behind the mandibles and a loss of functional mouthparts. Eight Neotropical and one Nearctic species of Pseudochakura are described as new: atra (Mexico), condylus (lesser Antilles), excruciata (Brazil), frustrata (Argentina), liburna (Florida, U.S.A.), pauca (Argentina), prolata (Argentina), sculpturata (Brazil; Florida, U.S.A.), septuosa (Mexico). P. chilensis Kieffer is redescribed. The known distribution of P.nigrocyanea Ashmead is extended to Uruguay and Venezuela. The known distribution of P. americana (Howard) [comb.n.] is extended to Panama, Columbia, Ecuador, Argentina and northward into the southern tip of Florida. All three previously described Nearctic species are synonomized under the name P.gibbosa (Provancher) with P.arizonensis (Crawford) and P.californica (Ashmead) as junior synonyms. Biological information is summarized providing new information on both plant and ant hosts. A phylogenetic hypothesis for the genus is nresenteri.     

Phomopsidone, a novel depsidone from an endophyte of the medicinal plant Eupatorium arnottianum

The medicinal plant Eupatorium arnottianum can be found in the Northeast and center of Argentina and the South of Bolivia. From plant material collected in Argentina an endophytic Phomopsis was isolated. The fungus was identified by microscopic features and analysis of its ITS sequence. Cultures yielded, besides mellein and nectriapyrone, a novel depsidone derivative for which we propose the name phomopsidone (1). The structure of 1 was determined from its spectroscopic data.     

Alien plants in southern South America. A framework for evaluation and management of mutual risk of invasion between Chile and Argentina

Most of the Chilean traffic exchange takes place along the border with Argentina. The road network between both countries facilitates the transport of alien plant species, raising the chance of new introductions of plant species and increasing the propagule pressure of already introduced plants. We used a modified version of the Australian Weed Risk Assessment method (AWRA) to analyze if alien plant species already present either exclusively in Chile or Argentina can be a potential source of risk for new alien species introduction and, specifically, which of the two countries poses a higher risk for its counterpart. We recorded 875 alien species of which 288 are exclusive to Chile, 283 are exclusive to Argentina, and 304 are shared by both countries. Considering the risk of new alien plants introductions, Chile presents a higher threat to Argentina than vice versa. Specifically, twenty-two alien species are exclusive to Chile, and are present on roadsides connecting both countries, hence they are regarded as a top risk for Argentina; a comparable top risk of alien species is absent from Argentinean roadsides. Both countries have a similar number of alien species being exclusive to one country, but are not present along roadsides (Chile 162; Argentina 186), which could represent a potential risk to the other country. The methodological approach proposed here may be a useful tool not only for screening potential new alien plant introductions, but also for the prioritization of eradication or control measures of those species already introduced.     

Increasing the Understanding of Plant Invasions in Southern South America: First Symposium on Alien Plant Invasions in Chile

The first symposium on Alien Plant Invasions in Chile was held in southern Chile in November of 2002. Chile represents an interesting setting to study biological invasions because of its long history of introductions, and its high rate of endemisms that makes it more prone to invasions. However, little is known about plant invasions in Chile and the country lacks a clear policy on alien species. The speakers at the symposium discussed their research on several aspects of alien plant invasions in southern Chile and Argentina. They also elaborated a list of future challenges of plant invasion ecology for the area. The package of recommendations may be useful for other developing countries with similar state of knowledge of their flora and similar environmental and economic issues. We expect that this type of meeting will help to stimulate the scientific debate about invasion ecology and the development of coordinated research to answer local questions, while contributing to find generalities in plant invasion patterns and processes.     

High infraspecific diversity of wild sunflowers (Helianthus annuus L.) naturally developed in central Argentina

The sunflower's wild relative Helianthus annuus L. is a non-native invader in several regions of the world. It was introduced as an experimental forage plant in central Argentina six decades ago where it probably escaped and developed extended populations coexisting with the sunflower crop. If the invasive taxon was diffused without modifications, it would be expected to have phenotypic similarities with its parental sources. Nine populations representative of different geographic regions of central Argentina were compared with 17 populations from the USA (center of origin) in a common garden study at Bahía Blanca, Argentina using 47 phenotypic traits. The nine invasive wild populations were differentiated among themselves and from the native populations by plant form and life cycle traits, oil composition, inflorescence, and achene morphology. Populations from both continents shared traits related to domesticated sunflower, such as bract width over 0.8 cm, but the frequency of this trait was higher in populations from Argentina. The high variability of wild H. annuus populations from Argentina did not reveal any founder effects. The diversity found in the invasive populations reflected about three-fourths of the phenotypic variability of those from the center of origin, even though the environmental conditions of the Argentine habitats represented only half of the variability present in the North American habitats. The current findings demonstrated that the invasive wild sunflower populations have developed within few decades a high degree of variability, which could be a source of a novel biodiversity useful as a genetic resource for sunflower crop improvement.     

Algerian ivy dermatitis; a California disease

A hitherto unrecognized cause of contact dermatitis in California is the widely cultivated plant known as Algerian ivy. This plant, which grows in California (and its close relative, English ivy) causes a dermatitis which is similar to although milder than that caused by poison oak. Dermatitis from this cause occurs most frequently when persons who have become sensitive to it by previous contact trim the plant back in the spring after its seasonal spurt of growth. For persons whose occupations require repeated contact with the plant, dermatitis from this cause is an occupational hazard. Dermatitis from this plant is easily diagnosed by means of a simple patch test. In a series of 12 cases the only effective treatment was with corticosteroid agents.     

ALGERIAN IVY DERMATITIS—A California Disease

A hitherto unrecognized cause of contact dermatitis in California is the widely cultivated plant known as Algerian ivy. This plant, which grows in California (and its close relative, English ivy) causes a dermatitis which is similar to although milder than that caused by poison oak. Dermatitis from this cause occurs most frequently when persons who have become sensitive to it by previous contact trim the plant back in the spring after its seasonal spurt of growth. For persons whose occupations require repeated contact with the plant, dermatitis from this cause is an occupational hazard. Dermatitis from this plant is easily diagnosed by means of a simple patch test.In a series of 12 cases the only effective treatment was with corticosteroid agents.     

New host-plant records for the defoliator Ormiscodes amphimone (Fabricius) (Lepidoptera: Saturniidae)

Ormiscodes amphimone (Fabricius) is a phytophagous moth species known to severely defoliate woody species in Chile and Argentina. Here we document new records of O. amphimonehost associations emphasizing the role of Nothofagus pumilio as its primary host in our study area. This new record for Argentina is highly significant given the economic importance of N. pumilio as a timber resource and the potential of O. amphimone to generate extensive outbreaks.     

The effect of solar UV-B radiation on terpenes and biomass production in Grindelia chiloensis (Asteraceae), a woody perennial of Patagonia,Argentina

UV-B radiation is absorbed effectively by nucleic acids and other sensitive targets, potentially causing harmful photochemical effects. Protection against UV-B radiation may be afforded by flavonoids and other phenolics, which absorb strongly in the UV region, but little is known about the role played by other compounds, such as terpenes. Grindelia chiloensis, native of Patagonia (Argentina), can accumulate as much as 25% resin (terpenes) in its leaves. The present investigation was carried out to test the effect of solar UV-B radiation on the allocation of photoassimilates to biomass and terpenes. Exposure to UV-B radiation reduced whole plant biomass, plant height and leaf area, and increased leaf thickness and resin accumulation in Grindelia chiloensis. Higher absorbance was found for refined resin in the UV-B waveband from plants grown under solar UV-B radiation than plants without UV-B radiation. These chemical and structural changes could protect the plant from UV radiation, and may help elucidate the importance of epicuticular resins for a species as G. chiloensis native to an environment with maximum daily integrated values of solar UV-B irradiance.     

The Arabidopsis BE1 Gene,Encoding a Putative Glycoside Hydrolase Localized in Plastids,Plays Crucial Roles during Embryogenesis and Carbohydrate Metabolism

Carbohydrate metabolism is central to plant growth and development. However, little is known about its role in embryogenesis. Here, we report the characterization of multiple alleles of the BRANCHING ENZYME1 (BE1) gene (also known as EMB2729). The weak allele of be1-3, characterized by positional cloning, carries a single-nucleotide substitution in an exon-intron junction and shows various develop- mental defects during post-germination growth. This mutation causes a reduced level of BE1 mRNA that, likely g...     

Has the bumblebee <Emphasis Type="Italic">Bombus bellicosus</Emphasis> gone extinct in the northern portion of its distribution range in Brazil?

Evidence for the extinction of the bumblebee Bombus bellicosus in Paraná state, in Brazil, is presented. The species is found in areas covered with open grass fields and shrub vegetation, originally ranging from northwestern Argentina to Paraná, where it reached its northeastern limit. Until the early 1980s, B. bellicosus was relatively abundant in Paraná, when the last known specimens were collected. In recent surveys conducted from 2002 to 2005, no specimens were recovered at sites in which the species was previously known to occur. Possible causes for local extinction of this species are discussed, including habitat conversion, pollution and climate change.     

New species of Allorhogas Gahan (Hymenoptera: Braconidae) reared from galls on Lycium cestroides Schltdl. (Solanaceae) in Argentina

Allorhogas cordobensis sp. nov. (Hymenoptera: Braconidae: Doryctinae) is described from the province of Córdoba, Argentina. Its representatives can be distinguished from all other known species of the genus by the unusual morphology of the ovipositor tip and the expanded clypeus apically. Remarkably, this species is also characterized by having a tridentate mandible, a feature known only in exodont braconids, mostly of the subfamily Alysiinae. The new species was reared from stem galls on Lycium cestroides, which constitutes the second record of an Allorhogas species associated with galls on representatives of the plant family Solanaceae.     

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.     

Benzodiazepine-like molecules, as well as other ligands for the brain benzodiazepine receptors, are relatively common constituents of plants

The presence of benzodiazepine (BZD)-like molecules as well as of other substances with affinity for the brain BZD-receptors was explored in eight non-flowering plants known to contain biflavonoids, three flowering plants used as sedatives in folkloric medicine and one plant extensively used in Argentina, Uruguay, Brazil and Paraguay as a tea substitute. All the plants examined contained substances which bound to the central BZD-receptors and the majority of them also had BZD-like compounds detected by their specific interaction with a monoclonal antibody against BZDs. In various cases this last type of compound was present in amounts which exceeded trace levels (0.5-1.0 ng/g). The biological or clinical significance for humans of all these substances should be explored.     

Genetic diversity of Phytophthora capsici isolates from pepper and pumpkin in Argentina

Phytophthora capsici is a soilborne oomycete plant pathogen that limits pepper production worldwide. The population structure varies significantly depending on the location (e.g. Peru vs. USA) and little is known about the diversity of P. capsici in Argentina. Our objective was to assess the diversity of P. capsici in Argentina at key pepper production areas. Forty isolates were recovered 2006-2009 from pepper and one isolate from pumpkin at 11 locations. Isolates were assessed for mating type, mefenoxam sensitivity and multilocus single nucleotide polymorphism (SNP) genotype profiles. Ten isolates with identical SNP profiles also were genotyped with amplified fragment length polymorphism (AFLP) markers. All 41 isolates had the A1 mating type and were sensitive to mefenoxam. Genotypic analysis using eight polymorphic SNP markers indicated 87% of the isolates had the same multilocus genotype, which is fixed for heterozygosity at seven of the eight SNP sites. AFLP analyses confirmed these findings, and overall it appears that clonal reproduction drives the population structure of P. capsici in Argentina. The implications for breeding resistant peppers and overall disease management are discussed.     

Geographic distributions,host plants and biology of species in the genus Huequenia (Coleoptera: Cerambycidae), with new records from Southwestern Argentina

Araucaria trees as host plants of the longhorned beetle Huequenia livida (Coleoptera: Cerambycidae) in Argentina are reviewed. Araucaria araucana is its natural host plant in SW Argentina, but the larvae also developed in dead branches of A. angustifolia and A. bidwillii (new host plant records), when both plants were kept in the same rearing cage with the natural host plant. Pinus contorta var. murrayana, also mentioned from Argentina, may be a recently adopted secondary host. A winter and a summer generation of H. livida was documented for the first time. Huequenia livida exceeds the actual natural distribution of A. araucana following the distribution of cultivated A. araucana and Pinus trees.     

Essential oil chemotypes of Aloysia citrodora (Verbenaceae) in Northwestern Argentina

Chemical biodiversity of essential oils of natural populations of Aloysia citrodora Palau (“lemon verbena”, “cedrón”) in Northwestern Argentina was assessed by collecting in the same sites through different years. A total of 36 samples were collected in the Provinces of Salta (El Maray, La Paya, El Sunchal, El Alisal, Chorrillos), Jujuy (Chilcayo, San Roque), Catamarca (Mutquin, Colana) and Tucumán (Amaicha del Valle) in Argentina.Essential oils were obtained by hydrodistillation (Clevenger) of naturally air-dried plant material. Yields ranged from 0.16% to 1.93% (v/w), being the highest those of the collections of Mutquin. More than 65 compounds were identified by CG-FID-MS. Only 19 of these constituents, accounting from 77.3 to 98.9% of the total oil, present in more than 4.0% in at least one sample, were considered as variables for statistical analysis. Agglomerative Hierarchical Cluster analysis was conducted, showing at 65% of similarity, five groups. This grouping was in direct accordance to the biosynthetic pathways of main compounds (chemotypes).In the two sites of Jujuy, 21 collections evidenced four different chemotypes, named after the dominant component as follows: thujones, citronellal, carvone, and citral (neral + geranial). In the populations of Salta and Catamarca, linalool appeared as a new different chemotype.Though cedron is considered as a citral-bearing plant, curiously, in the 36 samples collected in the NW of Argentina, only two samples contained citral as main constituent. On the other hand, a dominance of citronellal and thujones compositions were found in the bulk of the samples collected, while others had very high content of linalool or carvone and its derivatives. Northwestern Argentina has repeatedly been mentioned as the center of biodiversity of this species.The new evidences found on the chemical biodiversity of essential oils of Aloysia citrodora in natural populations in this region, reinforce firmly this idea.     

Invasive alien plants in the Pampas grasslands: a tri-national cooperation challenge

The challenge of managing biological invasions requires novel approaches and coordinated efforts, especially among countries linked by intense trade routes and sharing common biomes. This is the case in Southern South America, where Argentina, Brazil and Uruguay maintain intense commercial relationships, whilst sharing continuous portions of the Pampas grasslands. Transnational similarities in this case exceed ecological features, including a common colonization history and similar development trends. This study represents a tri-national cooperation effort to describe the alien plant flora invading the Pampas grasslands of Argentina, Brazil and Uruguay and analyses their characteristics in order to detect species and traits that are shared among the three countries and those that have not yet managed to invade the whole region. Furthermore, we highlight the opportunities and needs of a common approach across countries to deal with plant invasions. Information about alien plant species was retrieved from the IABIN Invasives Information Network (I3N) project databases of Argentina, Brazil and Uruguay, complemented with some national herbaria. Three hundred and fifty-six alien plant species were recorded growing in natural or semi-natural habitats of the Pampas. A total of 50 species were found in Pampas grasslands of the three countries. Argentina shared 48 and 36 species with Brazil and Uruguay, respectively, while the Brazilian and the Uruguayan Pampas shared only 20 species. Poaceae, Asteraceae and Fabaceae were the families with the highest number of invasive species, and herbs were the most common life form (75 %). Most invasive plants originated from Europe, Asia and Africa, and almost one-quarter of the species is associated with some human use, especially gardening. We discuss the opportunities and needs for international cooperation, as the prevention of introductions from one country to another through the use of risk analysis tools, definition of priority invasive species, as well as the detection, containment, eradication and control of common invasions. Furthermore, we suggest the establishment of coherent regional legislation and the inclusion of social issues and the public perception in the biological invasion quest.