María Marta Cigliano

300 million years of diversification: elucidating the patterns of orthopteran evolution based on comprehensive taxon and gene sampling

Orthoptera is the most diverse order among the polyneopteran groups and includes familiar insects, such as grasshoppers, crickets, katydids, and their kin. Due to a long history of conflicting classification schemes based on different interpretations of morphological characters, the phylogenetic relationships within Orthoptera are poorly understood and its higher classification has remained unstable. In this study, we establish a robust phylogeny of Orthoptera including 36 of 40 families representing all 15 currently recognized superfamilies and based on complete mitochondrial genomes and four nuclear loci, in order to test previous phylogenetic hypotheses and to provide a framework for a natural classification and a reference for studying the pattern of divergence and diversification. We find strong support for monophyletic suborders (Ensifera and Caelifera) as well as major superfamilies. Our results corroborate most of the higher‐level relationships previously proposed for Caelifera, but suggest some novel relationships for Ensifera. Using fossil calibrations, we provide divergence time estimates for major orthopteran lineages and show that the current diversity has been shaped by dynamic shifts of diversification rates at different geological times across different lineages. We also show that mitochondrial tRNA gene orders have been relatively stable throughout the evolutionary history of Orthoptera, but a major tRNA gene rearrangement occurred in the common ancestor of Tetrigoidea and Acridomorpha, thereby representing a robust molecular synapomorphy, which has persisted for 250 Myr.

Ronderosia, a New Genus of South American Melanoplinae (Orthoptera: Acrididae)

-The new genus Ronderosia is proposed for the South American melanoplinae Dichroplus bergi species group. Ronderosia presently includes nine species distributed in Southern Brazil, Paraguay, Uruguay, and north-central Argentina. Dichroplus distinguendus Giglio-Tos, Dichroplus brasiliensis Bruner, and Dichroplus bicolor Giglio-Tos are synonymized under Ronderosia bergi (Stal). The cladistic analysis performed to analyze the relationships of Ronderosia with its closest genera, yielded one most parsimonious tree that showed Ronderosia related to Atrachelacris, Scotussa, and Leiotettix.

Phylogenetic relationships in Dichroplus Stål (Orthoptera: Acrididae: Melanoplinae) inferred from molecular and morphological data: testing karyotype diversification

The neotropical genus Dichroplus and related genera are characterized by a relatively uniform external morphology and a remarkably divergent male genitalia and hence its taxonomy is controversial. It also shows an extreme karyotypic diversification. In this study we used molecular and morphological characters to test the monophyly of the genus and to evaluate chromosome evolution. Twenty‐seven species from Dichroplus and related genera were included in the analysis. Morphological characters refer to the general morphology, male genitalia and female structures. Molecular studies were performed, sequencing part of two mitochondrial genes, cytochrome oxidase I and II. Independent and combined phylogenetic analyses of the data were performed under maximum parsimony. The karyotypic characters (rearrangements) were either mapped onto the combined topology or combined with the other data sets. While the molecular analysis confirms some results attained with morphology, some others do not. All point towards the paraphyly of the genus. Our results show the relevance of morphological data in phylogenetic studies because morphology and molecules supply complementary evidence. The mapping of chromosome characters on the combined tree shows that the most extreme karyotype, in D. silveiraguidoi, is a derived condition, probably reached through several centric fusions, and that X‐autosome centric fusions were recurrently fixed during the evolution of the group.

Phylogenetic analysis of bovine pestiviruses: testing the evolution of clinical symptoms

This study presents a phylogenetic analysis of 115 bovine pestiviruses. A sequence data set from the 5′ untranslated genomic region was analyzed with maximum parsimony, bootstrapping and parsimony jackknifing. We tested for the proposed classifications of the group and analyzed the evolution of the symptoms associated with Pestivirus infections in bovines. Based on the historical framework provided by our phylogenetic trees, we also characterized the extent and importance of contamination caused in biologicals by the virus. Our phylogenetic analyses showed that the previously defined genotypes are monophyletic, except for genotype 1a. Based on our cladograms, we propose the existence of more than 12 monophyletic groups within the species BVDV 1. The mapping of clinical symptoms suggests that the emergence of some genotypes could have been driven by a change in the pathogenic process. Enteric Problems appear to be ancestral, while Reproductive and Respiratory Problems arise with the emergence of genotypes 1b, 1d and the herein‐proposed genotype Arg 1. The distribution of contaminant strains on the cladograms shows that pestiviral contamination is a common process, and also suggests that a contaminated product might be a vehicle for virus dispersion. Implications for virus evolution, virus taxonomy, veterinary medicine and biotechnology are discussed.

Grasshopper (Orthoptera: Acrididae) community composition and temporal variation in the Pampas, Argentina

Abstract To evaluate temporal changes in grasshopper communities over a 5-y period (1997–2001), density and species relative abundance were estimated at 27 sites in Benito Juárez county, Southern Pampas, Argentina, established across vegetation associations with different disturbance histories. A total of 22 grasshopper species were collected, Melanoplinae being the most abundant and diverse subfamily, followed by Gomphocerinae, Acridinae, Copiocerinae and Leptysminae. Results allowed us to categorize years into nonoutbreak (1997, 1998, 1999), transitional (2000) and outbreak (2001) based on the spatiotemporal characteristics of grasshopper density trends. On average, grasshopper density was over 7 times greater in 2001 than in nonoutbreak years. During nonoutbreak years, grasshopper densities showed no significant variation across disturbance categories. During the outbreak year, densities were significantly higher in pastures and halophilous steppes, with highly disturbed pastures being the most affected sites of all. Species richness changed significantly in outbreak versus nonoutbreak years: nearly twice as many species were collected during the outbreak year. Although 22 species were collected, results showed that a small number influence overall abundance from nonoutbreak to outbreak conditions. Although Dichroplus elongatus, Covasacris albitarsis, and Scotussa lemniscata were the three topranked species throughoutthe studied period, D. elongatus contributed most to overall shifts in grasshopper density.

PHYLOGENETIC RELATIONSHIPS OF SCOTUSSA AND LEIOTETTIX (ORTHOPTERA: ACRIDIDAE)

Abstract— A cladistic analysis of the South American grasshopper generaScotussaandLeiotettixwas performed in order to test the monophyly of these genera.Eurotettix, Chlorusand theDichroplus bergispecies group were included as terminal taxa. The genusAtrachelacriswas used to root the tree. Twenty‐nine characters from external morphology, male genitalia and female ovipositor were used in the analysis. In order to test for association between the structural change that occurred in the ovipositor valves ofScotussaand the functional change of the oviposition habits, the data matrix was partitioned and two analyses were performed. Characters from the female ovipositor were excluded from the data set used in the first analysis and another analysis was performed where all the characters were included in the analysis. Information on oviposition habits was then mapped on the cladogram, to determine the transformation for performance. Both analyses yielded only one most parsimonious tree and produced congruent results, confirming the monophyly ofLeiotettixandScotussaand corroborating their close relationship. Characters from the female ovipositor valves were informative not only at the species level but also at higher levels in the cladogram. The results also support the hypothesis of association between the structural change that occurred in the ovipositor valves ofScotussawith the functional change in the oviposition habits. However, this association did not seem to be correlated with the adaptive radiation in the genus.

Locusts and grasshoppers: Behavior, ecology, and biogeography

1Department of Renewable Resources, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA 2School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia 3Department of Entomology, Faculty of Ecology and Evolutionary Biology, Heep Building, Texas A&M University, College Station, TX 77842-2475, USA 4Department of General Biology and Ecology, Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090, Russia 5Laboratory of Insect Ecology, Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, 11 Frunze Street, Novosibirsk 630091, Russia 6Division Entomologia, Museo de La Plata, Universidad Nacional de la Plata, Paseo del Bosque S/N,1900 La Plata, Argentina 7CIRAD Bioagresseurs, TA A-106/D, Campus International de Baillarguet, 34398 Montpellier cedex 5, France

Field‐scale Variations in Plant and Grasshopper Communities: A GIS‐based Assessment

GIS technology allowed us to examine species-specific occurrence and abundance patterns of important grassland herbivore species through the use of appropriate statistical methods and the superior spatial representation commonly available in existing GIS packages. The study was conducted on a 254 ha grassland area located 10 km south of Three Forks, Gallatin County, Montana, in the Agropyron spicatum province of the western steppe region of the U.S.A. From an ecological perspective, grasshopper species distribution and abundance patterns observed on a local, non-uniform landscape (2.6 km 2) were consistent with results found in other studies at the valley (≈1,400 km 2) and state-level (≈237,000 km 2) scales. Our observations at the local scale further demonstrate the importance of vegetation type and specific local stand physiognomies in structuring grasshopper populations. The application of results from studies conducted at various scales to the development of decision support tools for resource managers is also discussed.

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 digiticercussp.n. and rugosussp.n. must be treated as a separate genus, Maylasacrisgen.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. rectussp.n., J. megacercussp.n., J. spatulussp.n., J. auriculussp.n., J. rivetisp.n., J. sphaericussp.n., J. discolorissp.n., J. profundussp.n., J. ronderosisp.n. and J. guarandaensissp.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).

Systematic revision and phylogenetic analysis of the South American genus Chlorus (Orthoptera, Acridoidea, Melanoplinae)

The South American grasshopper genus Chlorus (Melanoplinae, Dichroplini) from Bolivia, southern Brazil and Paraguay is revised. Cladistic analysis of morphological characters indicates that Chlorus constitutes a monophyletic group whose generic relationships remain unsolved. If the external morphology is considered, Chlorus showed to be related to Dichromatos, while characters from the male genitalia support the relationship between Chlorus and Eurotettix. Seven species are recognised for Chlorus with three of them described as new: Chlorus spatulus, Ch. chiquitensis and Ch. attenuatus. Keys to the species of the genus and a review of the morphological characters defining the taxa are provided.