An alpine grasshopper radiation older than the mountains, on Ka Tiritiri o te Moana (Southern Alps) of Aotearoa (New Zealand).

In New Zealand, 13 flightless species of endemic grasshopper are associated with alpine habitats and freeze tolerance. We examined the phylogenetic relationships of the New Zealand species and a subset of Australian alpine grasshoppers using DNA sequences from the entire mitochondrial genome, nuclear 45S rRNA and Histone H3 and H4 loci. Within our sampling, the New Zealand alpine taxa are monophyletic and sister to a pair of alpine Tasmanian grasshoppers. We used six Orthopteran fossils to calibrate a molecular clock analysis to infer that the most recent common ancestor of New Zealand and Tasmanian grasshoppers existed about 20 million years ago, before alpine habitat was available in New Zealand. We inferred a radiation of New Zealand grasshoppers ~13-15 Mya, suggesting alpine species diversification occurred in New Zealand well before the Southern Alps were formed by the mountain building events of the Kaikoura Orogeny 2-5 Mya. This would suggest that either the ancestors of today's New Zealand grasshoppers were not dependent on living in the alpine zone, or they diversified outside of New Zealand.

Integrating genomic and phenotypic data to evaluate alternative phylogenetic and species delimitation hypotheses in a recent evolutionary radiation of grasshoppers.

Although resolving phylogenetic relationships and establishing species limits are primary goals of systematics, these tasks remain challenging at both conceptual and analytical levels. Here, we integrated genomic and phenotypic data and employed a comprehensive suite of coalescent-based analyses to develop and evaluate competing phylogenetic and species delimitation hypotheses in a recent evolutionary radiation of grasshoppers (Chorthippus binotatus group) composed of two species and eight putative subspecies. To resolve the evolutionary relationships within this complex, we first evaluated alternative phylogenetic hypotheses arising from multiple schemes of genomic data processing and contrasted genetic-based inferences with different sources of phenotypic information. Second, we examined the importance of number of loci, demographic priors, number and kind of phenotypic characters and sex-based trait variation for developing alternative species delimitation hypotheses. The best-supported topology was largely compatible with phenotypic data and showed the presence of two clades corresponding to the nominative species groups, one including three well-resolved lineages and the other comprising a four-lineage polytomy and a well-differentiated sister taxon. Integrative species delimitation analyses indicated that the number of employed loci had little impact on the obtained inferences but revealed the higher power provided by an increasing number of phenotypic characters and the usefulness of assessing their phylogenetic information content and differences between sexes in among-taxa trait variation. Overall, our study highlights the importance of integrating multiple sources of information to test competing phylogenetic hypotheses and elucidate the evolutionary history of species complexes representing early stages of divergence where conflicting inferences are more prone to appear.

Phylogeny of locusts and grasshoppers reveals complex evolution of density-dependent phenotypic plasticity.

Locusts are grasshoppers that can form dense migrating swarms through an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. We present a comprehensive phylogeny of the genus Schistocerca, which contains both non-swarming grasshoppers and swarming locusts. We find that the desert locust, S. gregaria, which is the only Old World representative of the genus, is the earliest diverging lineage. This suggests that the common ancestor of Schistocerca must have been a swarming locust that crossed the Atlantic Ocean from Africa to America approximately 6 million years ago, giving rise to the current diversity in the New World. This also implies that density-dependent phenotypic plasticity is an ancestral trait for the genus. Through ancestral character reconstruction of reaction norms, we show that colour plasticity has been largely retained in most species in the genus, but behavioural plasticity was lost and regained at least twice. Furthermore, we show that swarming species do not form a monophyletic group and non-swarming species that are closely related to locusts often express locust-like plastic reaction norms. Thus, we conclude that individual reaction norms have followed different evolutionary trajectories, which have led to the evolutionary transition between grasshoppers and locusts - and vice versa.

Climate-driven geographic distribution of the desert locust during recession periods: Subspecies' niche differentiation and relative risks under scenarios of climate change.

The desert locust is an agricultural pest that is able to switch from a harmless solitarious stage, during recession periods, to swarms of gregarious individuals that disperse long distances and affect areas from western Africa to India during outbreak periods. Large outbreaks have been recorded through centuries, and the Food and Agriculture Organization keeps a long-term, large-scale monitoring survey database in the area. However, there is also a much less known subspecies that occupies a limited area in Southern Africa. We used large-scale climatic and occurrence data of the solitarious phase of each subspecies during recession periods to understand whether both subspecies climatic niches differ from each other, what is the current potential geographical distribution of each subspecies, and how climate change is likely to shift their potential distribution with respect to current conditions. We evaluated whether subspecies are significantly specialized along available climate gradients by using null models of background climatic differences within and between southern and northern ranges and applying niche similarity and niche equivalency tests. The results point to climatic niche conservatism between the two clades. We complemented this analysis with species distribution modeling to characterize current solitarious distributions and forecast potential recession range shifts under two extreme climate change scenarios at the 2050 and 2090 time horizon. Projections suggest that, at a global scale, the northern clade could contract its solitarious recession range, while the southern clade is likely to expand its recession range. However, local expansions were also predicted in the northern clade, in particular in southern and northern margins of the current geographical distribution. In conclusion, monitoring and management practices should remain in place in northern Africa, while in Southern Africa the potential for the subspecies to pose a threat in the future should be investigated more closely.

Two types of albino mutants in desert and migratory locusts are caused by gene defects in the same signaling pathway.

Albinism is caused by mutations in the genes involved in melanin production. Albino nymphs of Locusta migratoria and Schistocerca gregaria reared under crowded conditions are uniformly creamy-white in color. However, nothing is known about the molecular mechanisms underlying this phenomenon in locusts. The albino strain of L. migratoria is known to lack the dark-color-inducing neuropeptide corazonin (Crz). In this study, we report that this albino strain has a 10-base-pair deletion in the gene LmCRZ, which encodes Crz. This mutation was found to cause a frame-shift, resulting in a null mutation in Crz. On the other hand, the albino strain of S. gregaria is known to have an intact Crz. This strain was found to possess a single-nucleotide substitution in the middle of the Crz receptor-encoding gene, SgCRZR, which caused a nonsense mutation, resulting in a truncated receptor. Silencing of SgCRZR in wild-type S. gregaria nymphs greatly reduced the area and intensity of their black patterning, suggesting that the functional defect of SgCRZR likely causes the albinism. The expression level of SgCRZR in the albino S. gregaria was comparable to that in the wild type. Unlike the wild type, the albino strain of this locust did not show a phase-dependent shift in a morphometric trait controlled by Crz. From these results, we conclude that the mutations in LmCRZ and SgCRZR are responsible for the albinism in L. migratoria and S. gregaria, respectively, indicating that the two types of albinism are caused by different genetic defects in the same Crz signaling pathway.

The comparative mitogenomics and phylogenetics of the two grouse-grasshoppers (Insecta, Orthoptera, Tetrigoidea)

OBJECTIVE: This study aimed to reveal the mitochondrial genomes (mtgenomes) of Tetrix japonica and Alulatettix yunnanensis, and the phylogenetics of Orthoptera species. METHODS: The mtgenomes of A. yunnanensis and T. japonica were firstly sequenced and assembled through partial sequences amplification, and then the genome organization and gene arrangement were analyzed. Based on nucleotide/amino acid sequences of 13 protein-coding genes and whole mtgenomes, phylogenetic trees were established on 37 Orthoptera species and 5 outgroups, respectively. RESULTS: Except for a regulation region (A+T rich region), a total of 37 genes were found in mtgenomes of T. japonicaand A. yunnanensis, including 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, which exhibited similar characters with other Orthoptera species. Phylogenetic tree based on 13 concatenated protein-coding nucleotide sequences were considered to be more suitable for phylogenetic reconstruction of Orthoptera species than amino acid sequences and mtgenomes. The phylogenetic relationships of Caelifera species were Acridoidea and Pamphagoidea > Pyrgomorphoidea > Pneumoroidea > Eumastacoidea > Tetrigoidea > Tridactyloidea. Besides, a sister-group relationship between Tettigonioidea and Rhaphidophoroidea was revealed in Ensifera. CONCLUSION: Concatenated protein-coding nucleotide sequences of 13 genes were suitable for reconstruction of phylogenetic relationship in orthopteroid species. Tridactyloidea was a sister group of Tetrigoidea in Caelifera, and Rhaphidophoroidea was a sister group of Tettigonioidea in Ensifera.

Biomasa de Cornops aquaticum (Orthoptera: Acrididae) en humedales del nordeste de Argentina / Biomass of Cornops aquaticum (Orthoptera: Acrididae) in wetlands of Northeast Argentina

The estimation of biomass in insect populations is a key factor to quantify the available resources and energy fluxes in ecosystems food webs. Cornops aquaticum is a common herbivore in Eichhornia plants in wetlands of Northeast Argentina. We aimed to analyse its biomass variation, related to the different grasshopper age categories populations in two host-plants: Eichhornia azurea and Eichhornia crassipes. For this, standard samplings of C. aquaticum populations were carried out with an entomological net of 70cm diameter in two wetlands with E. azurea and E. crassipes, in Corrientes and Chaco Provinces; besides, dry weight was also obtained (directly and indirectly), and a regression model to indirectly estimate the biomass from a linear dimension measure (hind femur length) is proposed. A total of 2 307 individuals were collected and separated in different age categories; their abundance and linear dimension data were obtained. The model proposed was lnDM=lna+b*lnH (where DM=dry mass, a and b are constants and H=hind femur length) (R²=0.97). The population biomass variations of C. aquaticum were due to the relative abundance of each age category and the grasshopper individual dry weight. No significant differences were found between populations biomasses obtained by direct and indirect methods in E. azurea and E. crassipes floating meadows. This model made easier the C. aquaticum biomass calculation for both individuals and the population, and accelerated the processing of high number of samples. Finally, high biomass values of populations and individual age category (especially in adults) emphasize the importance of C. aquaticum as a consumer and a resource for predators on Eichhornia floating meadows food webs. Rev. Biol. Trop. 63 (1): 127-138. Epub 2015 March 01.

La estimación de la biomasa en las poblaciones de insectos, es un factor clave para cuantificar los recursos disponibles y los flujos de energía en las redes tróficas de los ecosistemas. Cornops aquaticum es un herbívoro común en las plantas de Eichhornia en los humedales del nordeste de Argentina. Nuestro objetivo fue analizar la variación de su biomasa en relación a las distintas categorías de edades de la población de este acridio, en dos plantas huésped: Eichhornia azurea y Eichhornia crassipes. Para ello, se realizaron muestreos estándar de las poblaciones de C. aquaticum con una red entomológica de 70cm de diámetro, en dos humedales con E. azurea y E. crassipes en las provincias de Corrientes y Chaco; además, se obtuvo el peso seco de los individuos (de manera directa e indirecta) y, se propuso un modelo de regresión para estimar la biomasa de C. aquaticum de manera indirecta a partir de una medida de dimensión lineal (longitud del fémur posterior). Un total de 2 307 individuos fueron recolectados y separados en distintas categorías de edades; se obtuvo su abundancia y distintas medidas de dimensión lineal. El modelo propuesto fue lnPS=lna+b*lnH (donde PS=peso seco, a y b son constantes y H=longitud del fémur posterior) (R²=0.97). Las variaciones en la biomasa de las poblaciones de C. aquaticum se debieron a la abundancia relativa de cada categoría de edad y al peso seco individual de estos acridios. No hubo diferencias significativas entre la biomasa de las poblaciones de C. aquaticum obtenida por los métodos directo e indirecto en las praderas flotantes de E. azurea y E. crassipes. Este modelo facilita el cálculo de la biomasa individual y poblacional de C. aquaticum y acelera el procesamiento de un gran número de muestras. Finalmente, los valores altos de biomasa poblacional e individual de las categorías de edades (especialmente en adultos) enfatizan la importancia de C. aquaticum como consumidor y como recurso para los depredadores en las redes alimenticias de las praderas flotantes de Eichhornia.

On cockroaches of the subfamily Epilamprinae (Dictyoptera: Blaberidae) from South India and Sri Lanka, with descriptions of new taxa.

The new genus Indoapterolampra, gen. nov. and two new species (I. rugosiuscula sp. nov. and Morphna lucida sp. nov.) are described. Rhabdoblatta praecipua (Walker, 1868) is removed from the synonymy with 'Polyzosteria' terranea Walker, 1868. The latter species is considered Epilamprinae gen. sp. The lectotype of Phoraspis (Thorax) porcellana Saussure, 1862 is designated. A key for the genera of Epilamprinae from South India and Sri Lanka is provided. Detailed morphological descriptions of the studied taxa are given. The structure of the male genitalia of I. rugosiuscula sp. nov., M. lucida sp. nov., M. plana (Brunner von Wattenwyl, 1865), M. decolyi (Bolivar, 1897) and R. praecipua and that of the female genital complex of M. decolyi, P. (T.) porcellana and Phlebonotus anomalus (Saussure, 1863) are described for the first time. Some aspects of the cockroach evolution are briefly discussed. 

Morphometry of Cornops aquaticum (Orthoptera: Acrididae: Leptysminae) in the Pantanal of Mato Grosso, Brazil / Morfometria de Cornops aquaticum (Orthoptera: Acrididae: Leptysminae) no Pantanal de Mato Grosso, Brasil

Insects show morphometric variations associated with the environment that may be the result of phenotypic response or genetic inheritance, or both. Thereby, studies that emphasise the variability in body size are very useful for understanding the dynamics and the stability of ecological systems. Cornops aquaticum (Bruner, 1906) (Acrididae) is a semi-aquatic grasshopper, distributed from the southeast of Mexico to the south of Buenos Aires Province, Argentina, and is intimately associated with the aquatic macrophytes Eichhornia spp. and Pontederia spp. In its wide habitat distribution, C. aquaticum shows variations in its life cycle and morphometric differences that were observed suggesting geographic and host plant influence. Considering these findings, this study aimed to find out the morphometric characteristics of this species at the Pantanal of Poconé – MT, using the protocol of the project “HICWA – Host-Insect Coevolution on Waterhyacinth”, as well as to assess possible differences in each stage of development between the sexes and among seasonal periods (flood, high water, low water and dry). During 12 months a total of 600 individuals were collected in monthly collections of 50 grasshoppers, and of this total, 261 were adults and 339 nymphs. The following measurements were taken: total length (A); body length (B); wing length (I) and measurement of the hind femur (H). The results showed that both male and female have different measurements but not correlated with seasonal periods. The average obtained for each character and the seasonality showed the highest values during the flood period. In nymphs, the measurement of the posterior femur presented the lower variation between individuals and characters.

Insetos apresentam variações morfométricas associadas ao ambiente que podem ser resultado tanto de respostas fenotípicas, quanto da herança genética, ou de ambos. Assim, estudos que enfatizam a variabilidade no tamanho do corpo do inseto são de grande utilidade para o entendimento da dinâmica e da estabilidade dos sistemas ecológicos. Cornops aquaticum (Bruner, 1906) (Acrididae) é um gafanhoto semi-aquático, distribuído desde o sudeste do México até o sul da província de Buenos Aires, Argentina, demonstrando íntima associação com macrófitas aquáticas dos gêneros Eichhornia e Pontederia. Em sua ampla distribuição de habitats, C. aquaticum apresenta variações em seu ciclo biológico e diferenças morfométricas que sugerem uma influência tanto geográfica, quanto da planta hospedeira. Diante disto, esse estudo objetivou conhecer as características morfométricas dessa espécie no Pantanal de Poconé (MT), empregando o protocolo do projeto “HICWA – Host-Insect Coevolution on Waterhyacinth”, bem como avaliar possíveis diferenças em cada estádio de desenvolvimento entre os sexos e entre os períodos sazonais dessa região (enchente, cheia, vazante e seca). Durante 12 meses foram coletados, mensalmente, 50 gafanhotos, totalizando 600 indivíduos, sendo 261 adultos e 339 ninfas, nos quais foram tomadas as medidas do comprimento total (A); comprimento do corpo (B); comprimento da asa (I) e medida do fêmur posterior (H). Os resultados indicam indivíduos adultos, tanto machos quanto fêmeas, de tamanho variado em todos os períodos sazonais, entretanto, essas variações não estão correlacionadas à sazonalidade. As médias obtidas para cada caracter entre os períodos sazonais demonstraram que houve diferenciação entre as medidas, revelando os maiores valores médios durante a enchente. Em ninfas, a menor variação entre os indivíduos em relação aos outros caracteres avaliados foi encontrada na medida do fêmur posterior.

Diversidad y distribución de acridios (Orthoptera: Acridoidea) en pastizales del sur de la región pampeana, Argentina / Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina

In Argentina, the grasslands of Pampas region comprise approximately 15% of the country. As in other grasslands of the world, grasshoppers are among the most important native herbivores. Their economic importance has been recognized in Argentina since the mid to late nineteenth century, since outbreaks of different species have become recurrent phenomena. Therefore, the main objective of this work was to study their diversity and distribution in grasslands of the Southern Pampas region (Laprida county, Buenos Aires province), as one of the most affected areas. The study was conducted during five seasons (2005-10). Sampling sites were represented by the most common plant communities in this area, classified in four categories: native grasslands, disturbed grasslands, implanted pastures and halophilous grasslands. The samplings were conducted from mid-spring to early autumn, with five or six samples per season. We estimated the following population descriptors: species richness (S), eveness (E), dominance (J), and diversity index (H´). In order to evaluate the similitude of the grasshopper communities present in the different plant communities, we used qualitative and quantitative coefficients of similitude. A total of 22 species of grasshoppers were collected, of which 21 belong to the family Acrididae. The subfamily Melanoplinae was the most diverse with eight species. The largest species richness was recorded in native grasslands (18). The different communities of grasshoppers had similar indices of evenness and dominance (p>0.05). Considering all plant communities, the average value of Shannon-Wiener index was 1.58±0.075. There was a positive correlation between evenness index and species richness (p<0.05). The diversity index H’ was different between plants communities (p<0.05), and it was higher in the disturbed grassland (1.75±0.096, p<0.05) than in the halophilous grasslands (1.34±0.12). Native and disturbed grasslands had a higher plant richness than halophilous grasslands and implanted pastures (p<0.05). There was a positive relationship between plant richness and grasshoppers species richness, and diversity of grasshoppers. According to the qualitative indices applied, the similitude between different grasshopper communities was higher than 60%. In general, the species that had a higher frequency of occurrence showed greater abundance and distribution. Covasacris pallidinota, Dichroplus elongatus, D. maculipennis, Borellia bruneri and B. pallid were the most widely distributed species, most of them (12) showed a restricted distribution and few (five) an intermediate distribution.

Los acridios son componentes nativos de los pastizales, dichos sistemas han sido modificados debido a la intensificación de las actividades agrícola-ganaderas y por lo tanto se considera importante estudiar las comunidades de acridios asociadas. Se estudió la diversidad y distribución de acridios en el Sur de la región pampeana a través de muestreos realizados en las comunidades vegetales más representativas del partido de Laprida, provincia de Buenos Aires, durante cinco temporadas (2005-2010). Se recolectaron 22 especies. La subfamilia Melanoplinae fue la más diversa (ocho especies). La mayor cantidad de especies se observó en los pastizales nativos (18). La diversidad en los pastizales alterados (1.75±0.096) fue superior (p<0.05) a la de los pastizales halófilos (1.34±0.12). La riqueza de plantas en los pastizales nativos y los pastizales alterados fue superior (p<0.05) a la de las demás comunidades. Se registro una relación positiva entre la riqueza de plantas y las variables riqueza y diversidad de acridios. La similitud entre las comunidades de acridios estimada por los índices cualitativos fue superior al 60%. En general, las especies que tuvieron una mayor frecuencia de aparición, mostraron una mayor abundancia y distribución. Covasacris pallidinota, Dichroplus elongatus, D. maculipennis, Borellia bruneri y B. pallida fueron las de mayor distribución, cinco especies tuvieron una distribución intermedia y la mayoría (12) una distribución restringida.

Desarrollo post-embrionario, fecundidad y consumo de alimento de Dichroplus exilis (Orthoptera: Acrididae) bajo condiciones controladas

Postembryonic development, fecundity and food consumption of Dichroplus exilis (Orthoptera: Acrididae) under controlled conditions. Dichroplus exilis is a widely distributed species in Southern South America. Although there have been reports of D. exilis as an agricultural pest, some recent observations suggest that the damage attributed to D. elongatus may actually have been caused by D. exilis. This study was conducted to determine the postembryonic life cycle stages, fertility and food consumption of this species under controlled conditions (30°C, 14L-10D, 40% RH).Individuals employed belong to the laboratory-hatched first generation (F1), from adults (n=64, ♀=28, ♂=36) collected in natural grasslands near Rafaela, Santa Fe province in North- Eastern Argentina. Three cohorts of 16, 17 and 20 individuals were monitored independently in acetate tubes on a daily basis, until death of the last insect. Average fecundity was 381.84, 38.54 eggs per female. Egg-pod incubation time was 14.4, 1.08 days and six nymphal instars were recorded. Nymphal development time was 41.38, 0.71 days (I=8.73, 0.20; II=6.38, 0.24; III=5.64, 0.33; IV=7.15; 0.43; V=9.76, 0.54; IV=7.85, 0.95). The recorded food consumption was 9.89, 1.08 (mg/ind/day) for nymphs IV, 18.04, 0.73 (mg/ind/day) for nymphs V-IV, 16.76, 1.06 (mg/ind/day) for pre-reproductive males, 28.09, 1.81 (mg/ind/day) for pre-reproductive females, 7.71, 0.91 (mg/ind/day) for reproductive males and 13.06, 0.71 (mg/ind/day) for reproductive females, while the average adult food consumption, regardless of sex and reproductive status, was 16.41, 4.32mg/day. Average food consumption of adult females was 17.47, 1.15mg, and was significantly higher than that of males (10.83, 0.91mg). Data obtained in this study showed that D. exilis exhibits at least some of the biological attributes needed to configure an actual or potential agricultural pest, albeit not yet recognized as such. Field monitoring ...

La Subfamilia Melanoplinae tiene una relevancia central dentro de la acridiofauna Argentina. Varias especies suelen ser numéricamente dominantes en las comunidades de acridios del país y algunas constituyen serias plagas. El objetivo de este trabajo fue conocer el ciclo de vida postembrionario, la fecundidad y supervivencia de las hembras y el consumo de alimento de Dichruplus exilis bajo condiciones controladas (30°C; 40%HR y 14L-10O). Para ello se realizó el seguimiento de tres cohortes de 16, 17 y 20 individuos. El tiempo de incubación fue de 14.4±1.08 días. La duración del desarrollo ninfal fue 41.38; 0.71 días (I 8.73; 0.20, II 6.38; 0.24, III 5.64; 0.33, IV 7.15; 0.43, V 9.76; 0.54; IV 7.85; 0.95); la fecundidad promedio fue de 381.84, 38.54huevos/hembra. El consumo registrado fue de 9.89; 1.08 (mg/ind./día) para las ninfas de IV, 18.04; 0.73 (mg/ind./día) para las de V y IV, mientras que el consumo promedio de los adultos, sin diferenciar sexo y estado reproductivo, fue de 16.41; 4.32mg/día. Estos parámetros, al ser comparados con los de otras especies afines, indican que D. exilis exhibe atributos biológicos que condicen con los de otros melanoplinos considerados plaga.

Evolutionary history and taxonomy of a short-horned grasshopper subfamily: the Melanoplinae (Orthoptera: Acrididae).

The Melanoplinae is one of the largest subfamilies of the Acrididae grasshoppers, with a Holarctic-Neotropical distribution. To investigate its controversial taxonomy and evolutionary history, we studied 19 species representative of its main tribes, and 7 Acridoidea outgroup species. More than 1650 base pairs of three regions of nuclear rDNA (18S, ITS1, 28S) and one mitochondrial rDNA (12S) were combined and used to construct parsimony, maximum likelihood and Bayesian phylogenies. Our results correspond with the present geographical distribution of the taxa rather than the existing taxonomy based on morphological characters. The morphologically unclassified and atypical taxa group with the Neotropical Melanoplinae. The currently recognized Melanoplinae appear to be polyphyletic due to inclusion of the Mexican genus Netrosoma. The distribution of the American and Eurasiatic Melanoplinae fauna can be explained by climatic and geological events, such as the Andean uplift, that would have affected the diversification and migration of Neotropical taxa.

Why certain male grasshoppers have clubbed antennae?

The significance of clubbed antennae in grasshoppers was assessed by investigating the sensilla repertoire of 15 gomphocerine species. The influence of the diet type (graminivorous or polyphagous) and the apical thickening of antenna on the number of sensilla were tested. It appears that the antennal thickening has a stronger impact on the number of sensilla than the food mode. The species bearing clubbed antennae are globally low in olfactive and contact sensilla, maybe in relation with a more complex courtship, but are richer in mechanoreceptors, probably involved in the control of antenna movements. The food mode change from oligophagy to polyphagy is not associated to an increase in the number of olfactive or contact sensilla. In contrast, the high number of these sensilla in a monophagous grasshopper feeding on Ulex bushes is interpreted in the context of alkaloid detection.

The locust foraging gene.

Our knowledge of how genes act on the nervous system in response to the environment to generate behavioral plasticity is limited. A number of recent advancements in this area concern food-related behaviors and a specific gene family called foraging (for), which encodes a cGMP-dependent protein kinase (PKG). The desert locust (Schistocerca gregaria) is notorious for its destructive feeding and long-term migratory behavior. Locust phase polyphenism is an extreme example of environmentally induced behavioral plasticity. In response to changes in population density, locusts dramatically alter their behavior, from solitary and relatively sedentary behavior to active aggregation and swarming. Very little is known about the molecular and genetic basis of this striking behavioral phenomenon. Here we initiated studies into the locust for gene by identifying, cloning, and studying expression of the gene in the locust brain. We determined the phylogenetic relationships between the locust PKG and other known PKG proteins in insects. FOR expression was found to be confined to neurons of the anterior midline of the brain, the pars intercerebralis. Our results suggest that differences in PKG enzyme activity are correlated to well-established phase-related behavioral differences. These results lay the groundwork for functional studies of the locust for gene and its possible relations to locust phase polyphenism.

Molecular taxonomy and species delimitation in Andean Schistocerca (Orthoptera: Acrididae).

The acridian genus Schistocerca comprises about 50 species which are endemic to the New World, except the Old World locust S. gregaria. Their morphological identification is rendered difficult by phase polyphenism, geographical overlap due to migrations or swarming, the difficulty to easily differentiate genitalia and the occurrence of interspecific hybrids. The three species reported from Peru include the swarming species S. interrita, a pest that can be recognized only by taxonomists. We show that it can be unambiguously identified using a mitochondrial DNA fragment known to have barcoding properties in this genus. We used several methods to delimitate Peruvian species. While S. interrita and S. pallens were well characterized, S. piceifrons peruviana was split into several taxa by a phylogeny-based method, whereas a combination of population genetics methods led one to identify only the three nominal species. A tentative reconstruction of the species history shows that several populations of S. piceifrons peruviana have recently increased in number, while exchanging some migrants, whereas an isolated population at the northern margin of the species range is substantially differentiated while exchanging no migrants with the others. This complex history has resulted in an atypical lineage pattern that appears to have confounded the standard assumptions underlying available species delimitation methods. Because of its behavioral property which tends to keep it panmictic, the identification of the swarming S. interrita remained unaffected.

Distribution of grasshoppers (Othoptera: Acridoidea) in the Tapacurá ecological station (São Lourenço da Mata, PE/Brazil)

Over the last five years, collection and periodic observation in the Tapacurá Ecological Station, São Lourenço da Mata, Pernambuco, Brazil, have been carried out to produce a systematic ecological inventory of grasshopper distribution within the station based on the classifying criteria for Acridoidea, providing new data on families, subfamilies, tribes, genera and species related to the various types of vegetation and environments the station affords.

Através de procedimento de coletas e observações periódicas, ao longo de cinco anos, na Estação Ecológica do Tapacurá, São Lourenço da Mata, PE, procedeu-se a um inventário sistemático-ecológico da distribuição dos gafanhotos da estação, adotando-se critérios classificatórios de Acridoidea com novos assinalamentos de famílias, subfamílias, tribos, gêneros e espécies, relacionados aos diversos tipos de vegetação e ambientes da estação.

Ronderosia ommexechoides: a new species of Brazilian Dichroplini (Orthoptera: Acrididae, Melanoplinae)

A new species of the genus Ronderosia Cigliano 1997 is described. Color illustrations of the female and male, drawings of female and male external genitalia as well as drawings of its phallic structures and photographs of the chromosomes are included.

Uma nova espécie do gênero Ronderosia Cigliano, 1997 é descrita. Ilustrações em cor de fêmea e macho, desenhos de fêmea e genitália externa do macho, assim como desenhos da estrutura fálica e fotografias de seus cromossomos são incluídos.

Revisão dos gêneros Sitalces, Eusitalces e Parasitalces (Orthoptera, Acrididae, Abracrini) e descrição de três novos gêneros / Revision of the genera Sitalces, Eusitalces and Parasitalces (Orthoptera, Acrididae, Abracrini) and description of three new genera

Revisão dos gêneros Sitalces, Eusitalces e Parasitalces (Orthoptera, Acrididae, Abracrini) e descrição de três novos gêneros. Os gêneros sulamericanos de Abracrini Sitalces Stål, 1878, Eusitalces Bruner, 1911, Parasitalces Bruner, 1911, Liebermannacris gen. nov., Robustusacris gen. nov., e Arimacris gen. nov. são revisados, descritos, redescritos e redefinidos. Quatro espécies são novas combinações: Liebermannacris dorsualis (Giglio-Tos, 1898) comb. nov., Liebermannacris punctifrons (Stål,1878) comb. nov., Robustusacris balzapambae (Rehn, 1913) comb. nov., e Arimacris trinitatis (Bruner, 1906) comb. nov., todas removidas de Sitalces Stål, 1878. Nove espécies são novos sinônimos: Sitalces robustus Bruner, 1908 (de S. volxemi Stål, 1878); S. infuscatus Bruner, 1908, S. nudus Bruner, 1908, S. ovatipennis Bruner, 1908, S. madeirensis Rehn, 1916 (de Liebermannacris dorsualis (Giglio-Tos, 1898); S. rubripes Hebard, 1924 (de Robustusacris balzapambae (Rehn, 1913); E. amazonicus Günther, 1940 e S. apolinari Hebard, 1923 (de Eusitalces vittatus Bruner, 1911); E. rubripes Günther, 1940 (de P. vulneratus (Bruner,1919)). Lectótipos e paralectótipos são designados. São fornecidas chaves para identificação, medidas, mapa de distribuição geográfica e ilustrações dos gêneros e espécies.

Revision of the genera Sitalces, Eusitalces and Parasitalces (Orthoptera, Acrididae, Abracrini) and description of three new genera. The South American Abracrini genera Sitalces Stål, 1878, Eusitalces Bruner, 1911, Parasitalces Bruner, 1911, Liebermannacris gen. nov., Robustusacris gen. nov., and Arimacris gen. nov. are reviewed, described, redescribed and redefined. Four species are new combinations: Liebermannacris dorsualis (Giglio-Tos, 1898) comb. nov., Liebermannacris punctifrons (Stål,1878) comb. nov., Arimacris trinitatis (Bruner, 1906) comb. nov., and Robustusacris balzapambae (Rehn, 1913) comb. nov., all removed of Sitalces Stål, 1878. Nine species are new synonymous: Sitalces robustus Bruner, 1908 (of S. volxemi Stål, 1878); S. infuscatus Bruner, 1908; S. nudus Bruner, 1908; S. ovatipennis Bruner, 1908; S. madeirensis Rehn, 1916 (of Liebermannacris dorsualis (Giglio-Tos, 1898); S. rubripes Hebard, 1924 (of Robustusacris balzapambae (Rehn, 1913); E. amazonicus Günther, 1940 and S. apolinari Hebard, 1923 (of Eusitalces vittatus Bruner, 1911); E. rubripes Günther, 1940 (of P. vulneratus (Bruner, 1919)). Lectotypes and paralectotypes are designated. Keys to identification of the genera and species, measurements, map of the geographical distribution and illustrations are added.

A molecular phylogeny of Oxya (Orthoptera: Acridoidea) in China inferred from partial cytochrome b gene sequences.

The grasshoppers of the genus Oxya are well known to damage rice, sugar cane, and other crops, yet their phylogenetic relationships have not been examined with molecular data. In this study, we obtained the 432 bp DNA sequences of the mitochondrial cytochrome b gene from 91 individuals of nine Oxya species and two outgroups (Gesonula punctifrons and Acrida cinerea). Phylogenetic analyses for the molecular data set were then carried out using the maximum parsimony and neighbor-joining methods. The results showed that the nine Oxya species form four well-supported clades, which include (1) O. intricata and O. flavefemura; (2) O. japonica and O. bicingula; (3) O. agavisa; and (4) O. chinensis, O. brachyptera, O. adentata, and O. hainanensis, respectively. In particular, the monophyly of O. hainanensis and O. agavisa is strongly supported, respectively. However, O. flavefemura and O. intricata, O. bicingula, and O. japonica form paraphyletic groups, respectively, and O. chinensis, O. adentata, and O. brachyptera form a polyphyletic group, suggesting that they should be merged as few as three species.

To be or not to be a locust? A comparative analysis of behavioral phase change in nymphs of Schistocerca americana and S. gregaria.

Phenotypic plasticity in behavior induced by high rearing density is often part of a migratory syndrome in insects called phase polyphenism. Among locust species, swarming and the expression of phase polyphenism are highly correlated. The american grasshopper, Schistocerca americana, rarely swarms even though it is closely related to the swarming Old World desert locust, S. gregaria, as well as two swarming New World locusts. Anecdotal field observations of locust-like behavior in S. americana indicate that it may express behavioral phase polyphenism, but empirical investigations are lacking. In this study, I tested the hypothesis that S. americana expresses locust-like density-dependent changes in behavior during both the first and final nymphal instars. I then compared the expression of behavioral phase change between S. americana and S. gregaria. First instar S. americana exhibited significant geographic variation in behavior with grasshoppers from a North Carolina population expressing more pronounced density-dependent changes relative to grasshoppers from a Texas population. The behavior of final instar S. americana was only slightly affected by rearing density and there was no evidence for a difference between populations. Comparison with S. gregaria revealed that the magnitude of density-dependent behavioral change, particularly among final instar nymphs, was much reduced in S. americana.