| effects of b chromosomes and supernumerary segments on morphometric traits and adult fitness components in the grasshopper, dichroplus elongatus (acrididae). | the south american species, dichroplus elongatus, is polymorphic for b chromosomes and supernumerary segments in chromosome pairs m6 (ss6), s9 (ss9) and s10 (ss10). both forms of supernumerary heterochromatin shape chiasma frequency and distribution and b chromosomes also affect male fertility. here, we analysed the effects of these polymorphisms on morphometric traits (total, 3rd femur, 3rd tibia, thorax and tegmen lengths) and several adult fitness components, including male and female mating ... | 2007 | 17210018 |
| establishment of liebermannia dichroplusae n. comb. on the basis of molecular characterization of perezia dichroplusae lange, 1987 (microsporidia). | perezia dichroplusae lange, 1987 is a parasite of the malpighian tubules of an argentine grasshopper, dichroplus elongatus (orthoptera, acrididae, melanoplinae). in order to determine relationships of this microsporidium with perezia nelsoni and with other microsporidia, we sequenced its small subunit ribosomal rna gene (ssu rdna) (genbank accession no. ef016249) and performed phylogenetic analysis of the novel sequence against 17 microsporidian ssu rdna sequences from genbank, using neighbor-jo ... | 2007 | 17552977 |
| new case of long-term persistence of paranosema locustae (microsporidia) in melanopline grasshoppers (orthoptera: acrididae: melanoplinae) of argentina. | we report an additional case of long-term persistence of paranosema locustae in grasshoppers of argentina. the pathogen was introduced from north america on rangeland at loncopué, neuquén province. microsporidia were not detected in pre-introduction samples whereas infected grasshoppers were found 11 years after introduction. affected grasshoppers were the melanoplines dichroplus elongatus, dichroplus maculipennis, and scotussa lemniscata, some of them with high spore loads. the case highlights ... | 2008 | 18814843 |
| phylogeny and chromosomal diversification in the dichroplus elongatus species group (orthoptera, melanoplinae). | in an attempt to track the chromosomal differentiation in the dichroplus elongatus species group, we analyzed the karyotypes of four species with classical cytogenetic and mapping several multigene families through fluorescent in situ hybridization (fish). we improved the taxon sampling of the d. elongatus species group adding new molecular data to infer the phylogeny of the genus and reconstruct the karyotype evolution. our molecular analyses recovered a fully resolved tree with no evidence for ... | 2017 | 28245223 |
| nematodes (mermithidae) parasitizing grasshoppers (orthoptera: acrididae) in the pampean region, argentina. | this work provides the results of a survey of entomonematodes parasites of grasshoppers in grasslands of the pampean region, argentina. nymphs of staurorhectus longicornis giglio-tos, laplatacris dispar rhen, 1939, dichroplus elongatus giglio-tos, 1894 and metaleptea brevicornis (l.) (orthoptera: acrididae) were collected. mermithidae was the only family registered with seven species: agamermis decaudata cobb, steiner and christie, 1923, amphimermis bonaerensis miralles and camino, 1983, amphime ... | 2017 | 27383003 |
| phenotypic variation and sexual size dimorphism in dichroplus elongatus (orthoptera: acrididae). | patterns of body size evolution are of particular interest because body size can affect virtually all the physiological and life history traits of an organism. sexual size dimorphism (ssd), a difference in body size between males and females, is a widespread phenomenon in insects. much of the variation in ssd is genetically based and likely due to differential selection acting on males and females. the importance of environmental variables and evolutionary processes affecting phenotypeic variati ... | 2015 | 26314070 |
| [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 ... | 2013 | 23894966 |
| latitudinal clines in the grasshopper dichroplus elongatus: coevolution of the a genome and b chromosomes? | argentine populations of dichroplus elongatus (orthoptera: acrididae) are polymorphic for b chromosomes. previous studies showed that b chromosomes affect body size and some fitness components in northwestern populations. we studied phenotype and b's variation patterns along a latitudinal cline as well as the relationship between karyotype and body size related traits in 17 populations from east. body size related traits showed a 'saw tooth' pattern of variation being small at low and high latit ... | 2013 | 23517446 |
| spatial genetic structure and mitochondrial dna phylogeography of argentinean populations of the grasshopper dichroplus elongatus. | many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. in this study we report on patterns of genetic variation in the south american grasshopper dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in argentina. we use direct amplification of min ... | 2012 | 22859953 |
| 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 si ... | 2011 | 22220572 |
| postembryonic development and food consumption of dichroplus elongatus giglio-tos and dichroplus maculipennis (blanchard) (orhtoptera: acrididae: melanoplinae) under laboratory conditions. | dichroplus maculipennis (blanchard) and d. elongatus giglio-tos are two of the most important melanoplines in argentina, both ecologically and economically. the postembryonic development and forage loss (consumption of bromus brevis ness + fallen material) caused by older nymphs (instars iv, v, vi) and adults of both species were studied under controlled conditions (30ºc, 14l:10d, 40% rh). five nymphal instars were recorded in d. elongatus, and six in d. maculipennis. total nymphal development w ... | 2011 | 21584399 |
| interaction among different heterocromatic variants in the grasshopper dichroplus elongatus. | simultaneous chromosome polymorphisms for supernumerary elements allow us to analyse the relationships among different forms of heterochromatic variation in nature. we report simultaneous variation patterns for supernumerary segments in chromosomes s10 (ss10), s9 (ss9) and s6 (ss6) and b chromosomes in nine populations of the grasshopper dichroplus elongatus from two biogeographic provinces from east argentina. our results show spatial chromosome differentiation for three out of four supernumera ... | 2004 | 15660978 |
| mitotically unstable b chromosome polymorphism in the grasshopper dichroplus elongatus. | dichroplus elongatus, a widespread south american phytophagous grasshopper, exhibits polymorphisms for supernumerary chromosomes and segments (ss) in natural populations in argentina. in this paper we review the available information on b chromosome polymorphism in d. elongatus related to geographic distribution, patterns of chromosome variation and influence on sperm formation. in d. elongatus the different forms of supernumerary variants are not independent. the proportion of b-carrying indivi ... | 2004 | 15292617 |
| ribosomal dna variation in the grasshopper, dichroplus elongatus. | we report an rflp analysis of ribosomal dna variation in natural populations of the grasshopper, dichroplus elongatus, previously analyzed for mitochondrial dna variation. dna samples were digested with five restriction enzymes, bamhi, ecori, hindiii, psti, and xbai. bamhi was the only enzyme that showed no variation. the remaining enzymes showed fragment size variation at both intra- and interpopulation levels. stepwise regression analysis revealed that the average number of length variants per ... | 2002 | 12502258 |
| the life cycle of gregarina ronderosi n. sp. (apicomplexa: gregarinidae) in the argentine grasshopper dichroplus elongatus (orthoptera: acrididae). | gregarina ronderosi n. sp. is described based on life cycle observations conducted on nymphs and adults of its natural host, the grasshopper dichroplus elongatus. following ingestion of oocysts by the host, parasite development occurs between the epithelium and the food mass in the midgut and gastric caeca. gametocysts are liberated in the faeces. natural prevalence in the type locality, girondo, northwestern buenos aires province, was 39.7% (n=131). the earliest trophozoites seen were small (< ... | 2002 | 12054784 |