The present paper reports some cytogenetic peculiarities observed in the Ag-NORs of Pamphagus ortolaniae chromosomes, the unusual behaviour of ribosomal sites after silver staining and the intense Ag-positive reaction of centromeric regions at spermatogonial metaphase and spermatocyte metaphase I and II. Moreover, a conclusive identification and localization of all the ribosomal clusters is provided by using heterologous rDNA FISH on spermatocyte chromosomes. 18S-28S rDNA mapped on a single chromosome pair and resulted multiclustered along the chromosomal body in three distinct serial regions, r1, r2 and r3. Surprisingly, these areas were scarcely (r1) or never (r2 and r3) detectable by silver impregnation. As in other Orthoptera and many groups of arthropods, FISH with the pentamer (TTAGG)n as the probe labelled the telomeres of all chromosomes.
In some species of insects, individuals with fully developed wings and capable of flying coexist with flightless individuals that lack functional wings. Their diets may differ if long-winged individuals are more mobile and therefore likely to be better at finding and utilizing high quality food resources, or if they have different food preferences or physiological requirements. Despite its potential importance, differences in the diet of dispersal phenotypes have not been unequivocally demonstrated under natural conditions. To test for dietary divergence, we compared natural abundances of carbon and nitrogen stable isotope ratios (d13C and d15N) in long- and short-winged free ranging Tetrix subulata pygmy grasshoppers collected as adults from two natural populations. Overall, this comparison of stable isotopes indicated long-term differences in the diet of the two wing morphs in both populations, but not between males and females of the same morph. We conclude that it is likely that the dietary niches of the long winged and flightless individuals differ under natural conditions. This may reduce intra-specific competition, offset the expected trade-off between flight capacity and reproduction and promote ecological speciation. Address, Einat Karpestam, Anders Forsman., and Obsahuje seznam literatury
This paper presents biological notes on two species of Orthoptera: Tettigoniidae that emerged from old spongy-woody galls of Dryocosmus kuriphilus Yasumatsu, 1951 collected in Sicily (Italy) in April 2015: Leptophyes sicula Kleukers, Odé et Fontana, 2010 (Phaneropterinae) and Cyrtaspis scutata (Charpentier, 1825) (Meconematinae). Between the end of April and the first few days of May a total of 30 neanids emerged from the galls, were reared and their life-cycle recorded. While L. sicula laid eggs in groups, C. scutata laid single eggs inside the galls; both species in a few years have adapted to exploiting this new shelter for egg laying. No interaction with the gall inducing insect was noted., Giuliano Cerasa, Bruno Massa., and Obsahuje bibliografii
We discuss and criticise the contention of Colombo (2012) that the central-marginal model does not apply to three species of chromosomally polymorphic acridid grasshoppers, and that chromosomal clines in these species are a consequence of temperature gradients. We also discuss Colombo’s interpretation of our own results on the South American melanopline grasshopper, Dichroplus pratensis Bruner., Claudio J. Bidau, Dardo A. Martí., and Obsahuje seznam literatury
Whereas the classification of plant communities has a long tradition that of animal assemblages remains poorly developed. Here we propose a classification scheme for orthopteran communities based on regional "character species", "differential species" and "attendant species" at different levels of habitat complexity, which is also applicable to other insect groups. In this context there are three main points of special importance: (i) the geographical reference area, (ii) the hierarchical spatial level (e.g. habitat complex, habitat and microhabitat) and (iii) precise constancy criteria for the definition of character species and differential species. We develop this new approach using a study on orthopteran communites of central German semi-dry calcareous grasslands. Within this habitat, we describe seven structural types that are characterized by specific orthopteran communities. For the arrangement of the structural types several environmental parameters (e.g. height and density of vegetation) were collected. Orthopteran densities were sampled at 80 sites using a biocoenometer (box quadrat). Regional character species of semi-dry grasslands include Myrmeleotettix maculatus, Metrioptera brachyptera, Stenobothrus lineatus and Tetrix tenuicornis. Within this habitat, Chorthippus parallelus, Metrioptera roeselii, Omocestus viridulus, Pholidoptera griseoaptera and Tettigonia viridissima were designated as differential species for particular structural types. Furthermore, Tettigonia cantans and Tettigonia viridissima act as altitudinal differential species. Chorthippus biguttulus is the only attendant species with high constancy values in all structural types. This classification is a powerful tool for arthropod conservation, since it allows one to determine community completeness of very important and threatened habitats, like semi-dry calcareous grasslands.
In summer 2008, the Orthopteran species Chorthippus biguttulus, Myrmeleotettix maculatus (Caelifera), Decticus verrucivorus and Platycleis albopunctata (Ensifera) were sampled in coastal heathland on the German Baltic Sea island of Hiddensee. The aim of this study was to assess differences in abundance of Orthoptera in three different habitats and determine the importance of habitat mosaics. Distribution patterns varied among species and total abundance of Orthoptera differed significantly among the three habitats. Due to species-specific habitat preferences the Caelifera were most abundant in grey dunes and the Ensifera in dwarf-shrub heath adjoining grey dunes. In conclusion, grey dunes are a suitable habitat for the Caelifera studied, while the Ensifera require a heathland mosaic consisting of both grey dunes and dwarf shrub vegetation.
A short-winged morph, whose occurrence is controlled by a simple recessive Mendelian unit, was recently discovered in Locusta migratoria. The existence of trade-offs between flight capability associated with wing length and other fitness-related traits are often documented for insects. The present study investigated the evolutionary significance of the short-winged and long-winged morphs of this locust using two laboratory strains showing wing dimorphism. The life-history traits examined included nymphal development, adult body weight, percentage adult survival, age at first reproduction, egg production and hatchling body weight. The results indicate that there are no consistent morph-specific differences in any of these traits. Of the several possibilities considered, the most likely is that the short-winged morph of this locust is an aberration or represents an initial stage in the evolution of this species., Yudai Nishide, Seiji Tanaka., and Obsahuje seznam literatury
Although there is a considerable amount of information on the ecology, genetics and physiology of life-history traits there is little information on the morphological variations associated with flight ability within species. In this paper, the morphology and ultrastructure of certain organelles in the flight muscles of Gryllus firmus are recorded using transmission electron microscopy. The ultrastructure of the flight muscles of 7-day-old female adults reveals that the ratio of thick to thin filaments is 1 : 3. Each thick filament is surrounded by 6 thin filaments in a hexagonal arrangement. The length of the sarcomere of each myofibril is significantly shorter and diameter of the myofibrils significantly smaller in long-winged than in short-winged morphs. However, the thick filaments in the long-winged morph are denser than those in the short-winged morph. Furthermore, in the long winged morph there are a greater number of mitochondria than in the short-winged morph. These differences correspond with the fact that long-winged crickets are stronger fliers than short-winged crickets., Cheng-Ji Jiang ... [et al.]., and Obsahuje seznam literatury