Composition and dynamics of communities of orthopteran insects (orthoptera) in southwestern Tajikistan. II. Hillside communities

The formation of orthopteran communities in the mountains of southwestern Tajikistan is described, with their seasonal dynamics characterized on the basis of counts. It is shown that the dominance structure changes with altitude. The valleys and slopes of different altitudinal belts play an important role in the formation of communities of orthopteran insects.     

Seasonal changes of microclimatic conditions in grasslands and its influence on orthopteran assemblages

We examined the microclimate of different grasslands and the relationships between the seasonal changes in the microclimatic conditions and the structural characteristics of orthopteran assemblages in the most typical grassland types of the plain, hilly and submontaneous territories of Central Europe in 2000–2005 years. According to our results: (i) The seasonal changes of humidity were characteristic of the vegetation units; (ii) The microclimate components of grasslands with similar habitat structure could be similar independently from their ecological circumstances; (iii) The microclimatic changes influenced the structure of the orthopteran assemblages.     

Annual dynamics of bacterioplankton assemblages in the Gulf of Trieste (Northern Adriatic Sea)

Bacterioplankton community diversity was investigated monthly in coastal waters of the Gulf of Trieste (NE Adriatic Sea) throughout 2003. Superficial bacterial assemblages of two differently freshwater influenced stations were studied using PCR-DGGE fingerprinting techniques. Bacterial genetic diversity of the sampled area, as estimates of the number of DGGE bands was high (36-64) compared to that reported in other studies employing this fingerprint technique. The similarity index (Sorensen Index) between assemblages showed a defined operational taxonomic units (OTUs) succession pattern in the more typically marine station with stable winter communities and quickly changing summer ones. On the contrary in the station affected by riverine inputs no clear pattern was detected. In both sites, according to cluster analyses performed on the DGGE banding pattern, three seasonal assemblages were identified: winter-spring, summer and fall. Sequence analysis of fifty-six among the brightest gel bands led to the observation of bacteria affiliated to Gram positive, Cyanobacteria, Cytophaga-Flavobacteria-Bacteroides (CFB) lineages and the alpha-, gamma- and delta- subdivisions of the Proteobacteria. Gamma-Proteobacteria constituted the main fraction (60%) of sequences in the more typically marine station, whereas the river-influenced station was characterised by more heterogeneous assemblages (39% alpha-Proteobacteria, 32% Flavobacteria).     

The maltase of the house cricket Acheta domesticus L. (orthoptera: gryllidae)

• 1.1. The optimal pH of maltase of the house cricket was 5.6 and the optimal temperature was 40°C. The apparent activation energy was 5300 cal/mol
• 2.2. The 50% inactivation time for maltase at 50°C was 69 min and the 50% inhibition concentration for mercuric chloride was 163μmole.
• 3.3. Maltase was only produced by the caecal tissues but its highest activity was found in the foregut lumen and after 5 days of starvation, only 44.6% of the total maltase activity remained.

     

Early changes of orthopteran assemblages after grassland restoration: a comparison of space-for-time substitution versus repeated measures monitoring

Although grasslands harbour significant biodiversity and their restoration is common in biodiversity conservation, we know very little about how such interventions influence arthropod groups. Here we compared orthopteran assemblages in croplands, natural grasslands and one to four-year-old grasslands restored in a large-scale programme in Hortobágy National Park (East Hungary). We sampled orthopterans by standardized sweep-netting both in a repeated measures design from Year 0 (croplands) to 4 and in a space-for-time substitution (chronosequence) design in 2009. Species richness, abundance and Shannon diversity of orthopterans decreased in Year 1 following restoration, but increased afterwards. By Year 4, species richness doubled and abundance increased almost ten-fold in restored grasslands compared to croplands. Species composition diversified compared to croplands and progressed towards natural grasslands. Local restoration conditions (last crop, seed mixture) and landscape configuration (proportion of natural grasslands) did not influence the above patterns in either study design, whereas time since restoration affected almost all community variables. We found that ubiquitous generalist species were the first to appear in restored grasslands and that species characteristic to the target natural grasslands colonised gradually in later years. The qualitative and quantitative properties of the orthopteran assemblages in restored fields did not yet reach those of natural grasslands, therefore, our study suggests that the full regeneration of the orthopteran assemblages takes more than four years. We also concluded that the repeated-measures design was more sensitive to subtle changes and was thus more effective than the chronosequence design at detecting post-restoration changes in orthopteran assemblages.     

Karyotype differences in the crenaticeps-group of Atractomorpha (orthoptera,acridoidea, pyrgomorphidae)

The four known species of the crenaticeps-group of the genus Atractomorpha have 2n ()=18+X0. All members of the complement are rod-chromosomes and the smallest autosome (no. 9) is megameric. The four species have similar amounts of euchromatin but differ markedly in the amount of heterochromatin present in their genomes. In A. similis, A. crenaticeps and the unnamed species, Species-1, there are distinct proximal segments of heterochromatin in the eight large autosomes. In A. similis these chromosomes also have prominent distal segments of heterochromatin. The fourth species, A. australis, has no visible heterochromatin in its eight large autosomes except for a small segment at the proximal end of autosome 4. In all four species, the heterochromatic segments influence chiasma frequency and chiasma position. Moreover the overall chiasma frequency is lowest in A. similis with most heterochromatin and highest in A. australis with least heterochromatin.     

Stratification and seasonal dynamics of weevil (Coleoptera,Curculionoidea) assemblages in the North Caspian semi-desert

In 2003–2004, 102 species of five weevil families were found in the steppe and desert associations of the Caspian semi-desert (Dzhanybek Station). Representatives of Curculionidae predominated (87 species). The majority of the commonest weevil species (20) were most abundant in the steppe associations, only 6 species being found in the desert ones. The composition of the weevil community changed abruptly from spring to summer. The greatest species richness (86 species) was observed in spring; only in this period weevils living mostly on the soil surface had high densities. In the herbage, both in the steppe and desert communities, detritophagous steppe species Archaeophloeus inermis and Trachyphloeus amplithorax were abundant; the habitats of the solonetz complex (on microelevations and in the depressions), the desert-steppe and steppe species (Humeromima nitida, Mesagroicus poriventris, Temnorhinus strabus) associated with saline substrates were also present. The spring hortobiont assemblage was dominated by the polyphagous steppe weevils, Euidosomus acuminatus, Phyllobius brevis and Omias spp. In summer, 53 species of weevils were recorded; their numbers on the soil surface sharply dropped, the core of the herbage assemblage consisted of the weevils feeding on alfalfa (Stenopterapion tenue, Sitona spp., Tychius spp.) in the steppe associations, with the maximum abundance in the more humid depressions. The summer assemblage of the desert herbage was poor and consisted of the species associated with wormwoods and chenopods (Ptochus porcellus, Phacephorus argyrostomus, Metadonus anceps). The autumn groupings with only 24 species were poor and had low population densities.     

A new Upper Carboniferous stem‐orthopteran (Insecta) from Ningxia (China)

Abstract During the Upper Carboniferous, orthopteran insects (grasshoppers, katydids, and crickets) were represented by numerous species distantly related to crown‐orthopterans, such as lobeattid and cnemidolestodean insects. The panorthopterans, including total‐orthopterans and their closest relatives, are represented by comparatively rarer species in localities of this period. Here we describe Heterologus duyiwuer sp. nov., an infrequent panorthopteran from the Late Carboniferous locality of Xiaheyan Village (Zhongwei City, Ningxia Hui Autonomous Region, China). The only available specimen is composed of an isolated forewing exhibiting a combination of character states previously unknown, in particular the lack of posterior radius (RP) / anterior Media (MA) connection, late branchings of the media (M) and anterior cubitus (CuA), and a branched posterior branch of the posterior cubitus (CuPb). Based on its unusual branching pattern, the composite stem resulting from the fusion of CuA and CuPaα (second anterior branch of CuP) is assumed to be composed of a branched CuA and a simple CuPaα.     

Long-term production dynamics of aquatic vegetation in the Arakhlei Lake (Eastern Transbaikalia)

Long-term data on aquatic vegetation production in the mesotrophic Arakhlei Lake was comparatively analyzed. The results demonstrated that the production dynamics of aquatic vegetation communities depend on the water-level conditions of the lake. The data on the succession of dominant vegetation communities are given: Chara sp. and Ceratophyllum demersum → C. demersum and Lemna trisulca. At the same time, the increased proportion of C. demersum and L. trisulca pointed to an increased anthropogenic stress on the lake.     

Re-visiting phylogenetic and taxonomic relationships in the genus saga (insecta: orthoptera)

Twelve of the 13 bushcricket species of the Saga genus are bisexuals and diploids, except the parthenogenetic and tetraploid bush cricket, Saga pedo. Despite a continuous research effort stretching through the 1900s, the taxonomic relationships of the Saga species are still disputed. In this study, our primary aim was to reveal natural relationships of the European Saga species and three of their Asian relatives, with special attention to the problematic taxonomy of two subspecies: S. campbelli campbelli and S. c. gracilis. Following a phylogenetic analysis of eight species, a comprehensive study was carried out on the above three taxa by using acoustic and morphometric approaches in parallel. Our phylogenetic data showed that European Saga species evolved from a monophyletic lineage. The geographical transitional species S. cappadocica was positioned between European and Asian lineages supporting the idea that the European Saga lineage originated phylogeographically from the Asian clade. The above results showed better agreement with the morphological data than with earlier ones based either on karyology or acoustic information only. After reviewing our data, we concluded that Saga pedo has most likely evolved from S. c. gracilis and not from S. rammei or S. ephippigera, as proposed by earlier studies. S. c. gracilis shares the same ITS2 haplotype with S. pedo, indicating that the latter could have evolved from populations of the former, probably through whole genome duplication. Based on acoustic and morphometric differences, we propose to elevate the two subspecies, S. campbelli campbelli and S. c. gracilis, to species level status, as Saga gracilis Kis 1962, and Saga campbelli Uvarov 1921. The present work sets the stage for future genetic and experimental investigations of Saginae and highlights the need for additional comprehensive analysis involving more Asian Saga species.     

Middle Triassic radiolarians from the Southeastern Pamirs (Republic of Tajikistan)

Triassic radiolarians were studied from a limestone/chert succession of the Dzhangisu and Boztere formations, Southeastern Pamirs, Republic of Tajikistan. The middle part of the Dzhangisu Formation is characterized by a Late Anisian assemblage with Eptingium nakasekoi Kozur and Mostler, Archaeospongoprunum bispinosum Kozur and Mostler, A. mesotriassicum mesotriassicum Kozur and Mostler, Paroertlispongus multispinosus Kozur and Mostler, P. rarispinosus Kozur and Mostler and Hozmadia rotunda (Nakaseko and Nishimura) that belongs either to the upper part of the Tetraspinocyrtis laevis Zone or to the Spongosilicarmiger transitus Zone (Kozur, 2003). The lowermost part of the Boztere Formation is characterized by a Late Ladinian assemblage with Muelleritortis cochleata (Nakaseko and Nishimura), M. expansa (Kozur and Mostler), Spongoserrula rarauana Dumitrica that corresponds to the M. cochleata Zone. Pamirian localities have a transitional position between the Western Tethys (Alpine–Mediterranean region) and the Eastern Tethys–Pacific junction (Southern China and Thailand). The assemblages are Tethyan in affinity.     

Isolation and structure of a peptide isolated from the suboesophageal ganglion of Acheta domesticus (orthoptera)

1. A pure peptide was obtained from suboesophageal ganglia of the cricket Acheta domesticus.2. The purification procedure included 10% acetic acid extraction, filtration through Sephadex G25 and gradient chromatography on DEAE-Sephadex A25.3. The amino acid sequence was determined as follows: Ala-Ala-Ala-Pro-Phe. Its biological role is discussed.     

Long-term dynamics of phytoplankton assemblages: Microcystis-domination in Lake Taihu, a large shallow lake in China

Long-term phytoplankton assemblages in a large shallow Chineselake, Lake Taihu, were presented using the monthly monitoringdata from October 1991 to December 1999. Earlier research results(1960, 1981 and 1988) were applied to discuss the differenttrophic stages of the lake. The species composition in the lakewas more closely related to eutrophication level than to lake-size,shallowness, or turbidity. Each summer, a single peak of phytoplanktonbiovolume appeared in Meiliang Bay. The results of principalcomponents analysis showed a distinct temporal shift in speciescomposition between summer and winter. A clear spatial differencein phytoplankton occurred between Meiliang Bay and the lakecentre. Wind speed and direction affected the horizontal distributionof phytoplankton, especially Microcystis, in the lake. Temperature,underwater light climate, nutrients and grazing by zooplanktonand by fish were discussed to explain the overwhelming dominanceof Microcystis. Four nutrient-phytoplankton stages were identifiedin the lake: an oligo-mesotrophic stage with low algal biomassuntil 1981, a eutrophic situation with blooms of Microcystisduring 1988–1995, hypertrophic conditions with the dominanceof Planctonema and total phosphorus up to 200 mg m^-3 from 1996to 1997 and the restoration period after 1997. The wax and waneof the phytoplankton assemblages were mainly controlled by temperature,wind and turbidity while long-term biomass dynamics were influencedby the level of nutrients.     

The genus cephalocoema serville, 1,839 (orthoptera: proscopiidae, tetanorhynchini)

The genus Cephalocoema Serville, 1,839 is revised by the study of its type-species and additional ones. New species are described and synonymies are made. Each species is studied in its morphological features and genital characters, both male and female. Type localities are marked in Biogeographical regions map, which let us to get a pattern of distribution related with the habitat preferences of each species, for the whole genus.     

Biosynthesis of methyl branched hydrocarbons of the German cockroach Blattella germanica (L.) (orthoptera,blattellidae)

The precursors and directionality of synthesis of the methyl branched cuticular hydrocarbons and the female contact sex pheromone, 3,11-dimethyl-2-nonacosanone, of the German cockroach, Blattella germanica, were investigated by radiotracer and carbon-13 NMR techniques. The amino acids [G-³H]valine, [4,5-³H]isoleucine and [3,4-¹⁴C₂]methionine labeled the hydrocarbon fraction in a manner indicating that the carbon skeletons of all three amino acids serve as the methyl branch group donor. The incorporation of [1,4-¹⁴C₂]- and [2,3-¹⁴C₂]succinates into the hydrocarbon and acylglycerol/polar lipid fractions indicated that succinate also served as a precursor to methylmalonyl-CoA. Carbon-13 NMR analyses showed that [1-¹³C]propionate labeled the carbon adjacent to the tertiary carbon, and, for the 3,x-dimethylalkanes, that carbon-4 and not carbon-2 was enriched. [1-¹³C]Acetate labeled carbon-2 of these hydrocarbons. This indicates that the methyl branching groups of the 3,x-dimethylalkanes were inserted early in the chain elongation process. [3,4,5-¹³C₃]Valine labeled the methyl, tertiary and carbon adjacent to the tertiary carbon of the methyl branched alkanes. Thus, the methyl branched hydrocarbon was formed by the insertion of methylmalonyl units derived from propionate, isoleucine, valine, methionine and succinate early in chain elongation.