New species of Desoria (Collembola: Isotomidae) from Korea

A new species, Desoria mulyeongariensis, shares some characters with D. choi (Lee), such as the number of setae on retinaculum and apical setae on manubrium. However, it could be easily distinguished from D. choi by the number of ommatidia. This species is also well characterized by having long and thickened smooth macrosetae on the body, and 6 basomedian setae on labium.     

Morphologically tortured: taxonomic placement of an Antarctic springtail (Collembola: Isotomidae) misguided by morphology and ecology

An endemic springtail from northern Victoria Land, Antarctica, was recently moved from Desoria to the new genus Chionobora, erected for a new species C. amila from lakes in the central highland plateau of Tasmania. This new combination for klovstadi was based on characters similar to both species (although not definitive) and an apparent preference for aquatic habitats. Here we show that neither of these inferences are valid. We sampled from two lake localities to obtain C. amila, and in doing so, we describe its habitat as riparian, not aquatic. We compared specimens of C. amila with klovstadi within a phylogeny using three genes (mtDNA COI, 18S rDNA, D1‐D5 of 28S rDNA) for 59 Isotominae terminals. We show that klovstadi is not closely related to the genus Chionobora that has closest affinities to the genus Isotomurus. As previously identified, klovstadi has no close affinities to any existing genus in Isotominae. Based on additional ecological, morphological and molecular evidence, we erect a new genus for klovstadi, Kaylathalia gen. n.     

Molecular evidence for a fourth species within the Isotoma viridis group (Insecta, Collembola)

For identification of single species within the Isotoma viridis group, we present polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) as a fast and efficient DNA-based molecular method. We used five PCR primers amplifying the cytochrome oxidase II (COII) region (760 bp) of the mitochondrial DNA. The sequences clearly separated four species ( I. viridis , I. riparia , I. anglicana and I. caerulea ) out of samples from Norway, Sweden, Germany and Switzerland. Examination of genetic variation and phylogenetic relationship did not support the separation of two colour pattern forms of I. viridis into distinct species. For RFLP, several restriction enzymes were tested for their ability to produce not only species-specific restriction fragment patterns but to discriminate more than one species per enzyme used with as few cleavage sites as possible. Such a design should render a clear fragment pattern when performing a double digest. These demands appear to be fulfilled best by the combination of the restriction enzymes Mfe I, Nci I and one of Aci I, Bst EII, Nde I, or Sfc I. From the enzymes tested in a previous study, Ase I proved to be reliable, whereas Mbo I can no longer be recommended.     

Isotomiella (Isotomidae: Collembola) of China

Seven species of the genus Isotomiella Bagnall 1939 were collected in China, two of which from Hainan and Guangxi provinces (South China) are newly described and illustrated. Isotomiella longisensilla n. sp. has bidentate mucro and long sensilla on most tergites, a character never seen before in this genus. I. deharvengi n. sp. belongs to the minor group and is characterized by a pair of strongly curved sensilla on Abd. V.     

上海地区(虫兆)两新种(弹尾目:等节(虫兆)科)

本文描述了等节科的两新种,中华尾四刺Tetracanthura sinensis sp.nov.和缺眼二刺Uzelia anommatos sp.nov..其中Tetracanthura Martynova 1971为中国新记录属.     

Assessing species boundaries and evolutionary relationships in a group of south-western European species of Isotomurus (Collembola, Isotomidae) using allozyme data

In this study allozyme data were used to examine evolutionary relationships in the cosmopolitan collembolan genus Isotomurus . Fifty-six south-western European populations from 13 species were compared, with the aim of delimiting species boundaries and testing the robustness of the most frequently used morphological characters for species identification. Observed allozyme variability suggests that genetic differentiation is more pronounced than the amount of morphological variability among and within species. Convergence in models of pigmentation pattern may lead to erroneous taxonomic identification when this is the only feature used for species diagnosis. In this respect, this study confirms that diagnosis is greatly improved when assisted by biochemical or molecular analyses. Allozyme data have also been used to reconstruct evolutionary hypotheses for relationships at the species and population level. The monophyly of Isotomurus maculatus , I. unifasciatus , I. fucicolus , I. nebulosus and I. pseudopalustris was confirmed on molecular grounds. Conversely, the monophyly of I. ghibellinus and I. palustris was rejected, suggesting the presence of cryptic species.     

Experimental studies of ice nucleation in an Antarctic springtail (Collembola, Isotomidae)

Ice nucleation was studied in field-fresh and acclimated (4 degrees C without food for 11-20 days) samples of the springtail Cryptopygus antarcticus Willem (Collembola, Isotomidae) at Rothera Research Station, Adelaide Island on the Antarctic Peninsula. Ice nucleator activity (INA) was measured by a freezing droplet technique in addition to supercooling point (SCP) profiles and polyol, sugar, and water contents. Field and acclimated samples showed bimodal SCP distributions with a distinct high group (HG; mean SCP -8 to -10 degrees C) and low group (LG: mean SCP -23 to -25 degrees C), which were significantly different. Acclimation at 4 degrees C increased the proportion of individuals in the LG relative to that in the HG without significant effects on the mean SCP of both groups. INA of the HG was significantly greater than that of the LG, and acclimation further reduced the INA of the LG. The number of active ice nucleator agents (INAs) calculated for the HG of field samples increased by 23-100 times over the temperature range -5 to -8 degrees C compared to only 7 times for the LG over the same range. These differences were accentuated in the acclimation experiments. Glucose and galactose were the main carbohydrates in both field and acclimated springtails, with the latter compound occurring in almost twice the concentration in the LG compared with that in the HG. Acclimation reduced the concentration of both compounds (glucose by 77% and galactose by 54%), whereas water content increased significantly. Digestion of food may have continued during acclimation at 4 degrees C, which could reduce the LG INA. Lowering of temperature over time is more likely to elicit a cold hardening response than constant temperature acclimation. INA numbers calculated at the nucleation temperatures for C. antarcticus samples were higher in the LG than in the HG. However, inactivation of INAs may be a key mechanism underlying cold hardening in this species, either by sequestration within the cellular matrix or by being only seasonally active.     

Three new species of Arrhopalites (Collembola, Symphypleona, Arrhopalitidae) from Korea

Three new species of Arrhopalites in the Symphypleona from Korea are described and illustrated. This work also records new occurrence of Arrhopalites habei Yosii, 1956, with brief remarks. A key to the identification of the Korean species of Arrhopalites is provided.     

Folsomia (Collembola: Isotomidae) of China. II. heterocellata group

An annotated list of species of the Folsomia heterocellata group recorded in China is given. Folsomia cephalota n. sp., F. dorsomediaseta n. sp., F. longiseta n. sp., F. manubriopilosa n. sp., F. longdeica n. sp., and F. plenosensilla n. sp. are characterized by having a simple maxillary palp, four prelabral setae and no eyes. They differentiate mainly by characteristics of the furca. We report other species of the group which are recorded for the first time in China: Folsomia tianshanica Martynova, 1969, F. pseudovtorovi Potapov & Gulgenova, 2013, and F. pseudodecemoculata Stebaeva, 1971. This excludes F. wanxianensis Ji, Ding & Chen, 2007, for which we provide morphological remarks based on the type material. The group is mainly distributed in the central part of China (Chongqing, Gansu, southern part of Inner Mongolia, Ningxia and Shaanxi provinces). A key to all blind species with a simple maxillary palp is given.     

Predation ofApochthonius minimus (Pseudoscorpionida: Chthoniidae) onFolsomia canadida (Collembola: Isotomidae)

Summary We investigated the functional response of the predaceous pseudoscorpion,Apochthonius minimus, to density of the springtail,Folsomia candida, as well as the effects of temperature and prey size on handling time and attack rate. Temperature slightly altered the overall rise in response. Both the rise and shape of the response differed for two prey sizes. The changes in number of prey eaten over a 48-hour period were also examined, and the attack and feeding behaviour ofA. minimus was described and discussed in relation to the predation experiments. The pseudoscorpion preferred young adultF. candida, 0.8–1.2 mm in length, when offered prey in the range, 0.2–1.5 mm.     

A morphometric analysis of mandibular teeth in Folsomia (Collembola: Isotomidae)

Morphological variation in the apical mandibular teeth of seven Folsomia species (F. bisetosa, F. brevicauda, F. Candida, F. fimentaria, F. inoculata, F. penicula , and F. quadrioculata) was examined by canonical variates analysis of a systematic 'truss' of measurements. Differences were found between all but two species (F. brevicauda and F. quadrioculata) showing that the morphology of 'biting-type' mouthparts can be used for species recognition. The results also show that the truss system of measurement is sensitive to small-scale differences in the mandible morphology of these insects. It is suggested that variation in mouthpart morphology, and in patterns of tooth wear, reflect differences in the feeding behaviour of Folsomia species.     

西沙群岛永兴岛类符属一新种(弹尾目:等节科)

类符(虫兆)属Folsomina是由Denis(1931)建立的,至今只报道过一种,Folsominaonychiurina Denis,1931,为世界广布种。类符(虫兆)属由于触角第Ⅳ节上特殊的感觉器,缺角后器和眼,腹部第Ⅳ—Ⅵ节愈合等特征,很容易与等节(虫兆)科的其他属相区别。Gisin(1960)和Christiansen ＆ Bellinger(1980)将其归入符(虫兆)属Folsomia,但绝大多     

白符(虫兆)胚胎发育的形态观察(弹尾纲:等节(虫兆)科)

对白符(Folsomiacandida)胚胎发育全过程进行显微观察,记述了白符从卵裂、囊胚期、原肠期、组织分化期、孵化前期等不同发育阶段的形态变化和发育过程。其结果表明,白符卵为聚产,形成大小不等的卵块,卵初产时为乳白色,卵壳表面覆盖有细密的颗粒状突起,直径为110—126μm。随着白符发育的进行,胚膜直径增大到180—185μm,其卵裂方式为完全均等卵裂,整个胚胎发育历期7—10d。     

Effect of laboratory culture conditions on population growth of Proisotoma minuta (Tullberg) (Collembola: Isotomidae)

The collembolan Proisotoma minuta (Tullberg) was successfully maintained in a laboratory culture that could be used to produce large numbers of P. minuta of standard size and physiological condition. The general life history of P. minuta was studied using a substrate comprising a mixture of plaster of Paris and charcoal with baker's yeast as food. The mean time taken for eggs to hatch following oviposition was 10.6 ± 1.3 days at 17.5°C and 6 ± 0.5 days at 23°C. Conditions in the culture were very important for the production of large insect populations. Growth of the cultures was limited by the increasing population size and was probably affected by contamination of the habitat by the deposition of excretory materials. Proisotoma minuta from a population that had ceased egg production started oviposition after individuals were transferred to a fresh plaster of Paris and charcoal habitat.     

Taxonomic re-evaluation of three related species of Graphium, based on morphology, ecology and phylogeny

Two fungi associated with bark beetles, Graphium pseudormiticum (described in 1994) and Rhexographium fimbriisporum (described in 1995), have two micromorphological characters in common. Both species produce conidia with conspicuous basal frills, and the conidia align in chains, despite being produced in slime. The association of G. pseudormiticum with the pine bark beetle, Orthotomicus erosus, and the association of R. fimbriisporum with the spruce bark beetle, Ips typographus, suggest ecological differences between the two fungal species. Analyses of micromorphology and phylogenetic analyses of aligned 18S and ITS sequences suggest that these two species are congeneric and should be classified in Graphium but that they represent distinct species. A collection of strains tentatively identified as Graphium spp., isolated from Ips typographus on Picea abies, Ips cembrae on Larix decidua and Tomicus minor on Pinus sylvestris in Austria share the same unusual basal conidial frills and conidial chains. Isolates from spruce were identified as G. fimbriisporum and those from pine as G. pseudormiticum. The strains from Ips cembrae on Larix decidua, distinguished by the reddish color of their colonies, microscopic structures and molecular characteristics, are described as the new species Graphium laricis sp. nov., and the close relationship of this species with the other two species is confirmed.     

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.     

The influence of fungal food quality on the growth and fecundity of Folsomia candida (Collembola: Isotomidae)

Summary The Basidiomycete fungi Coriolus versicolor and Hypholoma fasciculare were grown in liquid media containing 2, 20, 200 and 2,000 ppm nitrogen (as asparagine) and fed to cultures of Folsomia candida. Collembola feeding on both species of fungi exhibited trends of increased moulting and egg laying rates up to 200 ppm N and an inhibition of growth and fecundity at 2,000 ppm N. The differences in moulting rates between individual treatments were small for both species of fungi and not all the pair wise comparisons of treatments were significantly different. Egg laying rates of collembola fed C. versicolor showed a highly significant response to all levels of N in the growth medium and egg production at 200 ppm N was over three times higher than at 2 ppm N. Collembola fed H. fasciculare showed a less marked fecundity response to the different nitrogen levels and egg production at 200 ppm was approximately 1.5 times higher than at 2 ppm N. Both moulting and egg laying rates were significantly affected by the species of fungus presented as food to the collembola. The patterns of growth and reproduction of starved control groups of F. candida as well as those fed the test fungi demonstrate the adaptability of this species to changes in the quality and quantity of available food.     

Experimental models for the study of chronoimmunomodulation (rhythms of the springtail Folsomia candida, Collembola: Isotomidae)

A third-generation cephalosporine, cefodizime, was tested in two experiments on the springtail, Folsomia candida, used as a model of infradian rhythmicity. Any effect on ecdysis (molt), oviposition and oviproduction was sought for 6, 20 or 60 ng of cefodizime administered with brewer's yeast every other day, as compared to controls given only the yeast. Results indicate that a 20-ng dose of cefodizime on alternate days may shorten an infradian period (of molt) in the springtail.