Josef Rusek

Biodiversity of Collembola and their functional role in the ecosystem

More than 6500 species of Collembola are known from throughout the world and these are only a small part of the still undescribed species. There are many checklists and catalogues of Collembola for smaller territories and entire continents. Biogeographical analyses have been made for some genera and smaller territories. The most serious problems for a global biogeographical analysis is the lack of enough records from immense territories of all continents. Local biodiversity of Collembola can be very high, reaching over 100 species in small mountain ranges. Sampling methods do not impede documenting biodiversity on a global scale. Collembola have well differentiated ecomorphological life-forms and feeding guilds which enable the functional role that Collembola play in ecosystems to be recognised in some degree. Collembola play an important role in plant litter decomposition processes and in forming soil microstructure. They are hosts of many parasitic Protozoa, Nematoda, Trematoda and pathogenic bacteria and in turn are attacked by different predators. They utilise as food Protozoa, Nematoda, Rotatoria, Enchytraeidae, invertebrate carrion, bacteria, fungi, algae, plant litter, live plant tissues, and some plant pathogens. Soil acidification, nitrogen supply, global climate change and intensive farming have greatly impacted collembolan diversity.

Global decomposition experiment shows soil animal impacts on decomposition are climate-dependent

Climate and litter quality are primary drivers of terrestrial decomposition and, based on evidence from multisite experiments at regional and global scales, are universally factored into global decomposition models. In contrast, soil animals are considered key regulators of decomposition at local scales but their role at larger scales is unresolved. Soil animals are consequently excluded from global models of organic mineralization processes. Incomplete assessment of the roles of soil animals stems from the difficulties of manipulating invertebrate animals experimentally across large geographic gradients. This is compounded by deficient or inconsistent taxonomy. We report a global decomposition experiment to assess the importance of soil animals in C mineralization, in which a common grass litter substrate was exposed to natural decomposition in either control or reduced animal treatments across 30 sites distributed from 43°S to 68°N on six continents. Animals in the mesofaunal size range were recovered from the litter by Tullgren extraction and identified to common specifications, mostly at the ordinal level. The design of the trials enabled faunal contribution to be evaluated against abiotic parameters between sites. Soil animals increase decomposition rates in temperate and wet tropical climates, but have neutral effects where temperature or moisture constrain biological activity. Our findings highlight that faunal influences on decomposition are dependent on prevailing climatic conditions. We conclude that (1) inclusion of soil animals will improve the predictive capabilities of region- or biome-scale decomposition models, (2) soil animal influences on decomposition are important at the regional scale when attempting to predict global change scenarios, and (3) the statistical relationship between decomposition rates and climate, at the global scale, is robust against changes in soil faunal abundance and diversity.

Soil biota and upper soil layer development in two contrasting post-mining chronosequences

Abstract Density and community composition of a wide spectrum of soil organisms (fungi, algae, testate amoebae, nematodes, enchytraeids, lumbricids, oribatid mites, diplopods, terrestrial isopods, collembolans and dipteran larvae), direct counts of bacteria, rate of cellulose decomposition and microstructure of upper soil layers were studied in two chronosequences of plots reclaimed from open-cast coal mining near Cottbus (Germany) and near Sokolov (Czech Republic). German plots were characterized by acidic sandy soils and afforested with pine, while the Czech plots possessed alkaline clay soils and were afforested with alder. In both chronosequences, density and species richness in most of investigated groups of soil biota gradually increased with increasing succession age. Typical pioneer species were found in initial stands of both chronosequences. Nevertheless, the initial stands supported poorer assemblages of soil biota in the Cottbus area than did those in the Sokolov area. The Cottbus area was characterized by a moor type of humus and by gradual uniform increase of abundances and species numbers of most studied groups of soil biota. On the contrary, moder type of humus and a more variable pattern of soil biota development during the course of succession were found in the Sokolov area. Slower development of soil biota in initial stages of succession in Cottbus is caused by unfavourable physical and chemical conditions of heap substrates, and by lower input and poor quality of litter in pine plantations.

Do we have Cryptopygus — representatives (Collembola: Isotomidae) in Europe?: Proceedings of the Xth international Colloquium on Apterygota, České Budějovice 2000: Apterygota at the Beginning of the Third Millennium

A taxonomically complicated complex of genera around Isotomina and Cryptopygus was studied. Isotoma (Isotomina) agreni Borner, 1903, the type species of Isotoma (Isotomina) Borner, 1903 is a species inquirenda and therefore Isotomina is also a subgenus (or genus) inquirendus. The genera Cryptopygus Willem, 1902 (type species Cryptopygus antarcticus Willem, 1902), Hemisotoma Bagnall, 1949 (type species Isotoma thermophila Axelson, 1900) and Proisotomodes Bagnall, 1949 (type species Isotoma bipunctata Axelson, 1903) were redefined and discussed. The following species were transferred into Hemisotoma: H. orientalis (Stach, 1947) comb. nov. for Isotomina orientalis Stach, 1947, H. posteroculata (Stach, 1947) comb. nov. for Isotomina posteroculata Stach, 1947, H. bibasiosetis (Potapov & Stebaeva, 1999) comb. nov. for Cryptopygus bibasiosetis Potapov & Stebaeva, 1999 and H. tribasiosetis (Potapov & Stebaeva, 1999) comb. nov. for Cryptopygus tribasiosetis Potapov & Stebaeva, 1999. Representatives of Cryptopygus do not occur in Europe.

Taxonomy of Collembola at the beginning of the new millennium

A historical review of the development of Collembola taxonomy showed that progress was slow up to the Second World War, General shape of the body, relative lengths of the head, thorax and abdominal segments, antennae, furca and its reduction, number of ommatidia, and pigmentation were standard components of the descriptions in the period up to the end of the 19 t h century. New characters for species differentiation were increasingly used during the last decade before the Second World War. Bonet, Denis, Stach and Gisin were leading taxonomists in this second period. Stach completed his work with an extensive nine-volume monograph covering almost all groups of Collembola. Gisin introduced into the taxonomy many new characters and substantially changed the view among species of Hypogastruridae, Onychiuridae, Lepidocyrtini, Seirini and some Symphypleona, Gisin also formulated a general Synthetic Theory of Taxonomy based on his experience with collembolan classification. His Collembolenfauna Europas had an immense impact on further development of collembolan taxonomy. Many taxonomists then used complete chaetotaxy, sensilla apparatus, mouth-part structures, first larvae morphology, and other characters not only for collembolan species differentiation, but also for their higher classification and phyletic studies. Discovery of the ecomorphosis phenomenon was an important milestone in studies of ecology and taxonomy of Collembola. The main goals of collembolan taxonomy in the new millennium are enumerated.

Revision of Vesiculentomon, Nosekientomon n. g. (Protura: Acerentomidae, Nipponentominae), and a Key to Genera of Nipponentominae

ABSTRACT Based on recent reexamination of types, Vesiculentomon ruseki Nosek, 1977, differs significantly from Vesiculentomon marshalli Rusek, 1974, in composition and shape of maxillary gland, number of anterior setae on metanotum, and shape of foretarsal sensillum t1. A new genus Nosekientomon is erected for V. ruseki. Nosekientomon n. gen. is characterized by three pairs of anterior setae on the metanotum, claviform foretarsal sensillum t1, and a smooth globular vesicle on the calyx of the maxillary gland. Vesiculentomon Rusek has four pairs of anterior setae on the metanotum, baculiform foretarsal sensillum t1, and a large vesicle near the calyx with dense granulation along its narrow proximal part. The original descriptions are corrected and supplemented with new characters, including head chaetotaxy, setal lengths, and porotaxy. A key to world genera of Nipponentominae is provided.

Redefinition and Four New Species of Yavanna Szeptycki and Comparison with Nosekiella Rusek (Protura: Acerentomidae: Nipponentominae)

ABSTRACT Generic redefinitions of Yavanna Szeptycki and Nosekiella Rusek based on type species are presented. Four new species of Yavanna are described: Yavanna baikalica n. sp., Yavanna chimitovae n. sp., Yavanna babenkoi n. sp., and Yavanna stebaevae n. sp. from Siberia. Nosekiella danica (Tuxen) is redescribed, and Nosekiella behanae Nosek and Nosekiella sinensis Bu & Yin are transferred to Yavanna. A key to the Nosekiella group of genera is provided, as well as a key to the known Yavanna spp.

Review of Alaskaentomon (Protura: Acerentomidae, Nipponentominae)

ABSTRACT Our reexamination of Alaskaentomon Nosek, 1977 demonstrated that the type species, Alaskaentomon fjellbergi Nosek, 1977, and Alaskaentomon condei Nosek, 1981 are united in the presence of two granulated appendices on the calyx of the maxillary gland, filiform sensilium tl and very long sensilium a on foretarsus, presence of two pairs of A-setae on mesonotum and metanotum, and presence of medial posterior (Pc) seta on tergite VII and sternites VI–VII. They differ from each other in the position of foretarsal sensilla d and a′’, number of setae on tergite VII and sternites II–III, and position of P3 on tergites II–VI. The original descriptions are corrected and supplemented with new characters, including head chaetotaxy, seta length and porotaxy.

Revision of Nosekiella (Protura: Acerentomidae, Nipponentominae)

ABSTRACT Our recent reexamination of Nosekiella Rusek, 1974 has shown that only the type species Nosekiella danica (Condé, 1947) and Nosekiella urasi Imadaté, 1981 should remain in this genus. Nosekiella condei (Tuxen, 1955) and Nosekiella hoogstraali Nosek, 1980 differ from N. danica and N. urasi in the number of anterior setae on the metanotum. N. condei is transferred into Vesiculentomon Rusek, 1974 because of its possession of four pairs of anterior setae on the metanotum and a baculiform sensilium tl. N. hoogstraali differs from both N. danica and N. urasi in having a claviform foretarsal sensilium tl, two pairs of anterior setae on metanotum, and four pairs of anterior setae, and the anterior position of P3 on tergites II-VI. N. hoogstraali is transferred into Sugaentidus Imadaté, 1978. The original descriptions are corrected and supplemented with new characters, including head chaetotaxy, seta length, and porotaxy.

Redescription of two troglobiotic species of the genus Pseudosinella Schäffer, 1897 (Collembola, Entomobryidae) from the Western Carpathians

Two troglobiotic species of the genus Pseudosinella Schäffer, 1897 from the Western Carpathians are redescribed, P. aggtelekiensis (Stach, 1929) and P. paclti Rusek, 1961. P. aggtelekiensis has endemic distribution restricted to the SlovakAggtelek Karst region in Slovakia and Hungary. It shows higher level of troglomorphy (elongation of antennae, basal displacement of ungual teeth concurrent with their reduction) probably representing a descendant of the older phyletic Lepidocyrtus-Pseudosinella lineage. P. paclti, distributed in caves of several karstic regions in central Slovakia, is characteristic with medium level of troglomorphy.