Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning.

Taxonomy of the Cryptopygus complex. III. The revision of South African species of Cryptopygus and Isotominella (Collembola, Isotomidae).

Species of the genera of the Cryptopygus complex in South Africa are morphologically revised. Five new species of the genus Cryptopygus Willem, 1902 s. s. and one new species of the genus Isotominella Delamare Deboutteville, 1948 are described. Cryptopygus abulbus sp. nov. and C. bulbus sp. nov. have only one chaeta on the anterior side of dens and no chaetae on the anterior side of manubrium, the latter species being characterized by the presence of a bulb at apex of antennae; C. inflatus sp. nov. shows a rare combination of eight ocelli on each side of the head with a tridentate mucro; C. longisensillus sp. nov. has five long s-chaetae on the fifth abdominal segment; C. postantennalis sp. nov. is unique by having a very long and slender postantennal organ with strong inner denticles; Isotominella laterochaeta sp. nov. is the second member of the genus and differs from the type species by many more anterior chaetae on the manubrium and the presence of chaetae on ventral side of metathorax. The genera are discussed and a key to all species of the Cryptopygus complex recorded in South Africa is given. The focus is on the Western Cape Province where the complex is the most diverse and sampling more complete than in other provinces of South Africa.

Effects of miniaturization in the anatomy of the minute springtail Mesaphorura sylvatica (Hexapoda: Collembola: Tullbergiidae).

Smaller animals display pecular characteristics related to their small body size, and miniaturization has recently been intensely studied in insects, but not in other arthropods. Collembola, or springtails, are abundant soil microarthropods and form one of the four basal groups of hexapods. Many of them are notably smaller than 1 mm long, which makes them a good model for studying miniaturization effects in arthropods. In this study we analyze for the first time the anatomy of the minute springtail Mesaphorura sylvatica (body length 400 µm). It is described using light and scanning electron microscopy and 3D computer reconstruction. Possible effects of miniaturization are revealed based on a comparative analysis of data from this study and from studies on the anatomy of larger collembolans. Despite the extremely small size of M. sylvatica, some organ systems, e.g., muscular and digestive, remain complex. On the other hand, the nervous system displays considerable changes. The brain has two pairs of apertures with three pairs of muscles running through them, and all ganglia are shifted posteriad by one segment. The relative volumes of the skeleton, brain, and musculature are smaller than those of most microinsects, while the relative volumes of other systems are greater than or the same as in most microinsects. Comparison of the effects of miniaturization in collembolans with those of insects has shown that most of the miniaturization-related features of M. sylvatica have also been found in microinsects (shift of the brain into the prothorax, absent heart, absence of midgut musculature, etc.), but also has revealed unique features (brain with two apertures and three pairs of muscles going through them), which have not been described before.

Systematic and biogeographical study of Protura (Hexapoda) in Russian Far East: new data on high endemism of the group.

Proturan collections from Magadan Oblast, Khabarovsk Krai, Primorsky Krai, and Sakhalin Oblast are reported here. Twenty-five species are found of which 13 species are new records for Russian Far East which enrich the knowledge of Protura known for this area. Three new species Baculentulus krabbensis sp. n., Fjellbergella lazovskiensis sp. n. and Yichunentulus alpatovi sp. n. are illustrated and described. The new materials of Imadateiella sharovi (Martynova, 1977) are studied and described in details. Two new combinations, Yichunentulus borealis (Nakamura, 2004), comb. n. and Fjellbergella jilinensis (Wu & Yin, 2007), comb. n. are proposed as a result of morphological examination. Keys to species of the genera Fjellbergella and Yichunentulus are given. An annotated list of all species of Protura from Russian Far East is provided and discussed. Widely distributed species were not recorded in this area. This may be because of the high sensitivity of Protura to anthropogenic impact and low dispersal ability of the group.

A new species and new records of Pachytullbergiidae and Tullbergiidae (Collembola: Onychiuroidea) from littoral of China, with notes on the variations of postantennal organ.

Sensiphorura oligoseta sp. nov. is described from the sand beach of Pacific coast of China. It is the second member of the genus and differs from S. marshalli Rusek, 1976 by the smaller apical vesicle on antennae, and fewer setae on abdominal tergites. Psanunophorura neocaledonica Thibaud & Weiner, 1997 and Mesaphorura yosii (Rusek, 1967) are also found to be widely distributed on the coast. Chinese specimens of P. neocaledonica are described, notes to variations of its postantennal organ are given.

Redescription of arenicolous dipluran Parajapyx pauliani (Diplura, Parajapygidae) and DNA barcoding analyses of Parajapyx from China.

Littoral dipluran Parajapyx pauliani Pagés, 1959 was redescribed based on the specimens collected in Hainan Island, South China. The littoral habitat was confirmed for the species, as the first report of arenicolous dipluran in China. DNA barcoding fragment was sequenced for five Parajapyx species (18 individuals) from China, and this is the first report on DNA barcodes used for dipluran identification. The mean intra- and interspecific divergencesare 1.9% and 19.1% respectively. Synonymy of Parajapyx paucidentis and Parajapyx isabellae was confirmed.

First record of the littoral family Isotogastruridae (Collembola) in Asia.

The new species Isotogastrura trichaetosasp. n. isdescribed from a sand beach of Hainan, South China. It differs from all its congeners by 3+3 axial setae on Abd. IV (vs. 2+2) and by the presence of a pair of tubercles on Abd.VI. The geography of this strictly littoral genus is discussed.

Generic switch-over during ontogenesis in Dimorphacanthella gen. n. (Collembola, Isotomidae) with barcoding evidence.

A new genus Dimorphacanthella is established for Tetracanthella anommatos Chen and Yin, 1984 and Dimorphacanthella mediasetasp. n. from China. The new genus exhibits an unusual metamorphosis: small juveniles, previously called Uzelia anommatos Yue & Yin, 1999 get the second pair of anal spines resulted from moulting and become "Tetracanthella". Species identity of forms with two and four anal spines is proved by barcoding analysis. The derivation of anal spines is compared among genera having four anal spines.