Grasshopper (Orthoptera: Acridoidea) species diversity in the Pampas, Argentina

A study was conducted to describe the major features of geographical and temporal variation in the diversity of grassland grasshopper species (Orthoptera: Acridoidea) in different sites of the Pampas, Argentina. Species richness and relative abundance were assessed at 12 sites in eastern La Pampa and western Buenos Aires provinces, from 1994 through 1999. Mean species richness at the regional level was 10, and 34 grasshopper species were collected throughout of the study. Comparison with grasshopper species diversity from the Great Plains of North America is discussed. An evaluation of the proportions of species in each of the three distribution groups (broad, intermediate and narrow) revealed that, over all sites, broadly distributed species made up 14.7% of species composition and intermediately and narrowly distributed species made up 26.5% and 58.8%, respectively. The three top-ranked species in the studied sites were Dichroplus elongatus, D. pratensis and Staurorhectus longicornis. Results showed that, contrary to what was expected, one of the widely distributed species in the region (i.e. Baeacris punctulatus) does not always constitute one of the most abundant species. Finally, the loss of one of the historically most common species in the Pampas, D. maculipennis, is also discussed.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore

The high-Andean Jivarus Giglio-Tos (Orthoptera, Acridoidea, Melanoplinae): Systematics, phylogenetic and biogeographic considerations

The high-Andean genus Jivarus Giglio-Tos from Ecuador, Colombia and Peru is revised. Morphological cladistic analysis indicated that Jivarus montanus and the new species digiticercus. sp.n. and rugosus. sp.n. must be treated as a separate genus, Maylasacris gen.n. The remaining species included in the analysis are assigned to the genus Jivarus, for which the following six species groups are identified: americanus group, antisanae group, carbonelli group, cohni group, pictifrons group and jagoi group. Twenty-nine species are recognized for Jivarus, with ten described as new: J. rectus. sp.n., J. megacercus sp.n., J. spatulus. sp.n., J. auriculus. sp.n., J. riveti. sp.n., J. sphaericus. sp.n., J. discoloris. sp.n., J. profundus. sp.n., J. ronderosi. sp.n. and J. guarandaensis. sp.n. The following new synonymies are proposed: Jivarus albolineatus Ronderos with J. antisanae (Bolivar) syn.n., J. cerdai Ronderos and J. osunai Ronderos with J. alienus (Walker) syn.n., and J. rubriventris Ronderos with J. ecuadorica (Hebard) syn.n.; the new combinations Jivarus ecuadorica (Ronderos) comb.n. and Maylasacris montanus (Ronderos) comb.n. are proposed. Keys to the species of the genera and a review of the morphological characters defining the taxa are provided. Patterns of distribution of the clades coincide with the geography of the northern Andes of Colombia and Ecuador. Areas of endemism of the Jivarus species groups and Maylasacris are delimited by both the high-altitude curves, including transverse zones, and the drier climates of the intra-Andean valleys, clearly indicating recent, post-glacial palaeogeography, as shown also in vegetation distributions. This paper has been formatted with many embedded links to images of type and paratype specimens, maps based on geo-referenced specimen data and species keys available on the Orthoptera Species file online (http://orthoptera.speciesfile.org).Facultad de Ciencias Naturales y Muse

Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina

A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species.Centro de Estudios Parasitológicos y de VectoresLaboratorio de Investigación de Sistemas Ecológicos y AmbientalesFacultad de Ciencias Naturales y Muse

Patterns of diversification in the high Andean Ponderacris grasshoppers (Orthoptera: Acrididae: Melanoplinae)

Fil: Pocco, Martina E.. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Posadas, Paula. Laboratorio de Sistemática y Biología Evolutiva (LASBE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Lange, Carlos Ernesto. Centro de Estudios en Parasitología y Vectores (CEPAVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Cigliano, María Marta. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Locusts and grasshoppers: behavior, ecology, and biogeography

Presentación del número especial de la revista sobre langostas y saltamontes.Facultad de Ciencias Naturales y Muse

Unraveling the diversification history of grasshoppers belonging to the <i>"Trimerotropis pallidipennis"</i> (Oedipodinae: Acrididae) species group : A hotspot of biodiversity in the Central Andes

The Andean Mountain range has been recognized as one of the biodiversity hotspotsof the world. The proposed mechanisms for such species diversification, among others, are due to the elevation processes occurring during the Miocene and the intensiveglacial action during the Pleistocene. In this study we investigated the diversificationhistory of the grasshopper Trimerotropis pallidipennis species complex which showsa particularly wide latitudinal and altitudinal distribution range across the northern, central and southern Andes in South America. Many genetic lineages of this complexhave been so far discovered, making it an excellent model to investigate the role of thecentral Andes Mountains together with climatic fluctuations as drivers of speciation. Phylogenetics, biogeographic and molecular clock analyses using a multi-locus datasetrevealed that in Peru there are at least two, and possibly four genetic lineages. Twodifferent stocks originated from a common ancestor from North/Central Americawould have dispersed toward southern latitudes favored by the closure of the PanamaIsthmus giving rise to two lineages, the coastal and mountain lineages, which still coexistin Peru (i.e., T. pallidipennis and T. andeana). Subsequent vicariant and dispersalevents continued the differentiation process, giving rise to three to six genetic lineages(i.e., clades) detected in this study, which were geographically restricted to locationsdispersed over the central Andes Mountains in South America. Our results provideanother interesting example of ``island diversification" motored by the topographyplus unstable climatic conditions during the Pleistocene, pointing out the presence ofa hotspot of diversification in the Andean region of Peru.Centro de Estudios Parasitológicos y de Vectore

Technological advances and its applications in cybertaxonomy

Los rápidos avances en la ciber-infraestructura, la bioinformática, la fotografía digital y las tecnologías de la información contribuyen a acceder fácilmente al conocimiento taxonómico y permiten generar información a una escala acorde con las necesidades de la crisis de la biodiversidad. El conocimiento taxonómico básico, como literatura taxonómica, catálogos de nombres científicos, registros de ejemplares, localización de ejemplares tipo en colecciones biológicas, y claves interactivas de varios grupos de organismos ya están disponibles a través de Internet. En este artículo, se analiza cómo la información taxonómica, principalmente la entomológica, es presentada a la comunidad en Internet; se discuten las diferentes formas en que la taxonomía ya ha hecho uso de este medio o podrá hacerlo en un futuro cercano, y cómo los actuales medios de compartir datos, especialmente a través de Internet, están siendo utilizados para hacer más eficientes las tareas taxonómicas, realzar las publicaciones y mejorar los vínculos con los usuarios.The rapid advances in cyber-infrastructure, bioinformatics, digital imaging and related information technologies facilitate the access to taxonomic data and allow generating new information on a scale appropriate to meet the decline in biodiversity. Basic taxonomic information, such as taxonomic literature, catalogues, specimen-level data, location of types, and interactive keys are already available, at least for some groups, on the Web. In this article we explore the modern means of disseminating taxonomic information, mostly entomological information, in the Internet; we review some of the different ways taxonomists have so far made use of the Web or will be able to do so in the near future, and how modern means of sharing data, especially via the Internet, are being used to streamline taxonomic work and improve links with end users.Centro de Estudios Parasitológicos y de Vectore

Technological advances and its applications in cybertaxonomy

Los rápidos avances en la ciber-infraestructura, la bioinformática, la fotografía digital y las tecnologías de la información contribuyen a acceder fácilmente al conocimiento taxonómico y permiten generar información a una escala acorde con las necesidades de la crisis de la biodiversidad. El conocimiento taxonómico básico, como literatura taxonómica, catálogos de nombres científicos, registros de ejemplares, localización de ejemplares tipo en colecciones biológicas, y claves interactivas de varios grupos de organismos ya están disponibles a través de Internet. En este artículo, se analiza cómo la información taxonómica, principalmente la entomológica, es presentada a la comunidad en Internet; se discuten las diferentes formas en que la taxonomía ya ha hecho uso de este medio o podrá hacerlo en un futuro cercano, y cómo los actuales medios de compartir datos, especialmente a través de Internet, están siendo utilizados para hacer más eficientes las tareas taxonómicas, realzar las publicaciones y mejorar los vínculos con los usuarios.The rapid advances in cyber-infrastructure, bioinformatics, digital imaging and related information technologies facilitate the access to taxonomic data and allow generating new information on a scale appropriate to meet the decline in biodiversity. Basic taxonomic information, such as taxonomic literature, catalogues, specimen-level data, location of types, and interactive keys are already available, at least for some groups, on the Web. In this article we explore the modern means of disseminating taxonomic information, mostly entomological information, in the Internet; we review some of the different ways taxonomists have so far made use of the Web or will be able to do so in the near future, and how modern means of sharing data, especially via the Internet, are being used to streamline taxonomic work and improve links with end users.Centro de Estudios Parasitológicos y de Vectore