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Sample records for armata collembola onychiuridae

  1. Proteomics of cryoprotective dehydration in Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola).

    PubMed

    Thorne, M A S; Worland, M R; Feret, R; Deery, M J; Lilley, K S; Clark, M S

    2011-06-01

    The Arctic springtail, Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola), is one of the few organisms known to survive the extreme stresses of its environment by using cryoprotective dehydration. We have undertaken a proteomics study comparing M. arctica, acclimated at -2°C, the temperature known to induce the production of the anhydroprotectant trehalose in this species, and -6°C, the temperature at which trehalose expression plateaus, against control animals acclimated at +5°C. Using difference gel electrophoresis, and liquid chromatography tandem mass spectrometry, we identified three categories of differentially expressed proteins with specific functions, up-regulated in both the -2°C and -6°C animals, that were involved in metabolism, membrane transport and protein folding. Proteins involved in cytoskeleton organisation were only up-regulated in the -6°C animals. PMID:21199019

  2. Evidence of Protaphorura fimata (Collembola: Poduromorpha: Onychiuridae) feeding on germinating lettuce in the Salinas Valley of California.

    PubMed

    Joseph, Shimat V; Bettiga, Christopher; Ramirez, Christian; Soto-Adames, Felipe N

    2015-02-01

    A series of experiments were conducted to determine the impact of Protaphorura fimata Gisin (Family: Onychiuridae) feeding on seeds and germinating seedlings of lettuce, Lactuca sativa L. (Asteraceae). First, various densities of P. fimata were incubated with 25 lettuce seeds for 7 d and feeding injury was evaluated in three soilless arena experiments. As a second step, 100 P. fimata were incubated with 25 lettuce seeds in three arena experiments with soil media. Finally, in a commercial field the incidence and impact of P. fimata on recently planted lettuce was assessed following applications of pyrethroid-insecticides: 2 d before planting, at planting, and 20 d later. In experiments without soil, the number of ungerminated seeds, feeding injury sites, and plants with injury were significantly greater in arenas with P. fimata than without. Similarly, the number of germinated seedlings, shoot fresh, and dry weights, and the length and width of fully opened-leaves were greater in arenas without than with P. fimata in assays with soil. In the field, P. fimata densities were significantly lower in beds that received insecticides at 2 d before and at planting than in untreated beds. Also, the fresh and dry weights of lettuce plants were significantly greater in the beds that received insecticide than in untreated. The results clearly show that P. fimata is a pest of lettuce and can cause severe feeding injury to germinating seeds or seedlings, thereby reducing their growth rate. The potential implications of P. fimata feeding and feeding injury characteristics are discussed. PMID:26470124

  3. Brain organization in Collembola (springtails).

    PubMed

    Kollmann, Martin; Huetteroth, Wolf; Schachtner, Joachim

    2011-07-01

    Arthropoda is comprised of four major taxa: Hexapoda, Crustacea, Myriapoda and Chelicerata. Although this classification is widely accepted, there is still some debate about the internal relationships of these groups. In particular, the phylogenetic position of Collembola remains enigmatic. Some molecular studies place Collembola into a close relationship to Protura and Diplura within the monophyletic Hexapoda, but this placement is not universally accepted, as Collembola is also regarded as either the sister group to Branchiopoda (a crustacean taxon) or to Pancrustacea (crustaceans + hexapods). To contribute to the current debate on the phylogenetic position of Collembola, we examined the brains in three collembolan species: Folsomia candida, Protaphorura armata and Tetrodontophora bielanensis, using antennal backfills, series of semi-thin sections, and immunostaining technique with several antisera, in conjunction with confocal laser scanning microscopy and three-dimensional reconstructions. We identified several neuroanatomical structures in the collembolan brain, including a fan-shaped central body showing a columnar organization, a protocerebral bridge, one pair of antennal lobes with 20-30 spheroidal glomeruli each, and a structure, which we interpret as a simply organized mushroom body. The results of our neuroanatomical study are consistent with the phylogenetic position of Collembola within the Hexapoda and do not contradict the hypothesis of a close relationship of Collembola, Protura and Diplura. PMID:21420507

  4. Global Collembola on Deception Island.

    PubMed

    Greenslade, Penelope; Potapov, Mikhail; Russell, David; Convey, Peter

    2012-01-01

    Three new non-indigenous springtail species are recorded in recent collections made on Deception Island, South Shetland Islands, maritime Antarctic: Deuteraphorura (Deuteraphorura) cebennaria (Gisin) (Collembola: Onychiuridae), Mesaphorura macrochaeta Rusek (Tullbergiidae), and Proisotoma minuta Axelson (Isotomidae). One of these, D. (D.) cebennaria, is described. Additionally, two new indigenous species, Mesaphorura macrochaeta Rusek and Proisotoma minuta Axelson, are also recorded. The total number of Collembola species now known from the island is 14, comprised of eight native species and six non-indigenous species. This number of non-indigenous species recorded at Deception Island compares with only a single non-indigenous springtail recorded at any other maritime or continental Antarctic location. The reason underlying this high level of occurrence of non-indigenous species on Deception Island is likely to be a combination of the island's high level of human visitation and the presence of relatively benign terrestrial habitats associated with areas of geothermal activity. Two of the new records represent species recently assessed as being of the highest risk to become invaders in the less extreme environments of the subantarctic, thereby emphasising the importance and urgency of adopting and applying effective biosecurity measures to protect the unique and vulnerable ecosystems of this region. Also documented are the impacts on the soil fauna of the island from human trampling, which drastically reduced densities of both native and non-indigenous species to 1% of the abundance typical of non-trampled sites. PMID:23438196

  5. Global Collembola on Deception Island

    PubMed Central

    Greenslade, Penelope; Potapov, Mikhail; Russell, David; Convey, Peter

    2012-01-01

    Three new non-indigenous springtail species are recorded in recent collections made on Deception Island, South Shetland Islands, maritime Antarctic: Deuteraphorura (Deuteraphorura) cebennaria (Gisin) (Collembola: Onychiuridae), Mesaphorura macrochaeta Rusek (Tullbergiidae), and Proisotoma minuta Axelson (Isotomidae). One of these, D. (D.) cebennaria, is described. Additionally, two new indigenous species, Mesaphorura macrochaeta Rusek and Proisotoma minuta Axelson, are also recorded. The total number of Collembola species now known from the island is 14, comprised of eight native species and six non-indigenous species. This number of non-indigenous species recorded at Deception Island compares with only a single non-indigenous springtail recorded at any other maritime or continental Antarctic location. The reason underlying this high level of occurrence of non-indigenous species on Deception Island is likely to be a combination of the island's high level of human visitation and the presence of relatively benign terrestrial habitats associated with areas of geothermal activity. Two of the new records represent species recently assessed as being of the highest risk to become invaders in the less extreme environments of the subantarctic, thereby emphasising the importance and urgency of adopting and applying effective biosecurity measures to protect the unique and vulnerable ecosystems of this region. Also documented are the impacts on the soil fauna of the island from human trampling, which drastically reduced densities of both native and non-indigenous species to 1% of the abundance typical of non-trampled sites. PMID:23438196

  6. Hydrogen peroxide and ecdysone in the cryoprotective dehydration strategy of Megaphorura arctica (Onychiuridae: Collembola).

    PubMed

    Grubor-Lajšić, Gordana; Petri, Edward T; Kojić, Danijela; Purać, Jelena; Popović, Zeljko D; Worland, Roger M; Clark, Melody S; Mojović, Miloš; Blagojević, Duško P

    2013-02-01

    The Arctic springtail, Megaphorura arctica, survives sub-zero temperatures in a dehydrated state via trehalose-dependent cryoprotective dehydration. Regulation of trehalose biosynthesis is complex; based in part on studies in yeast and fungi, its connection with oxidative stress caused by exposure of cells to oxidants, such as hydrogen peroxide (H₂O₂), or dehydration, is well documented. In this respect, we measured the amount of H₂O₂ and antioxidant enzyme activities (superoxide dismutases: copper, zinc--CuZnSOD and manganese containing--MnSOD, and catalase--CAT), as the regulatory components determining H₂O₂ concentrations, in Arctic springtails incubated at 5 °C (control) versus -2 °C (threshold temperature for trehalose biosynthesis). Because ecdysone also stimulates trehalose production in insects and regulates the expression of genes involved in redox homeostasis and antioxidant protection in Drosophila, we measured the levels of the active physiological form of ecdysone--20-hydroxyecdysone (20-HE). Significantly elevated H₂O₂ and 20-HE levels were observed in M. arctica incubated at -2 °C, supporting a link between ecdysone, H₂O₂, and trehalose levels during cryoprotective dehydration. CAT activity was found to be significantly lower in M. arctica incubated at -2 °C versus 5 °C, suggesting reduced H₂O₂ breakdown. Furthermore, measurement of the free radical composition in Arctic springtails incubated at 5 °C (controls) versus -2 °C by Electron Paramagnetic Resonance spectroscopy revealed melanin-derived free radicals at -2 °C, perhaps an additional source of H₂O₂. Our results suggest that H₂O₂ and ecdysone play important roles in the cryoprotective dehydration process in M. arctica, linked with the regulation of trehalose biosynthesis. PMID:23143920

  7. New Palaearctic species of the tribe Thalassaphorurini Pomorski, 1998 (Collembola, Onychiuridae)

    PubMed Central

    Babenko, Anatoly B.; Chimitova, Ayuna B.; Stebaeva, Sophya K.

    2011-01-01

    Abstract The paper is devoted to a taxonomic revision of the genus Sensillonychiurus Pomorski & Sveenkova, 2006. Five new species of this genus, i.e. Sensillonychiurus mirus sp. n., Sensillonychiurus taimyrensis sp. n., Sensillonychiurus vegae sp. n., Sensillonychiurus vitimicus sp. n., and Sensillonychiurus amuricus sp. n., as well as three new species of the related genus Allonychiurus Yoshii, 1995, i.e. Allonychiurus subvolinensis sp. n., Allonychiurus elikonius sp. n., and Allonychiurus unisetosus sp. n. are being described from various regions of Eurasia. The diagnoses of both genera are amended to include described species. Two genera, Tantulonychiurus Pomorski, 1996 and Thibaudichiurus Weiner, 1996, are treated as junior synonyms of the genus Allonychiurus. Agraphorura eisi (Rusek, 1976) is transferred to Sensillonychiurus; Tantulonychiurus volinensis (Szeptycki, 1964) and Tantulonychiurus asiaticus Babenko, 2007 to Allonychiurus. A review of morphological peculiarities of Sensillonychiurus is performed, comparisons with the other genera of Thalassaphorurini given, and a key to the known species provided. PMID:21998539

  8. New Chinese record of the genus Spinonychiurus (Collembola, Onychiuridae), with the description of a new species

    PubMed Central

    Sun, Xin; Li, Yu

    2014-01-01

    Abstract A new collembolan species is described, Spinonychiurus sinensis sp. n., which has seven chaetae in the distal row of the tibiotarsi. It is placed in the genus Spinonychiurus due to two important characters: the two subsegments on Abd. III sternum and the absence of d0 on the head. This is the first report of the genus Spinonychiurus in China. The diagnosis of Spinonychiurus is broadened and the key to the world species is provided. PMID:25317055

  9. Collembola are Unlikely to Cause Human Dermatitis

    PubMed Central

    Lim, CSH; Lim, SL; Chew, FT; Ong, TC; Deharveng, L

    2009-01-01

    There have been several unconfirmed case reports of dermatitis caused by Collembola (springtails). We recently investigated two nurses with dermatitis suspected to be caused by Drepanura Schött (Collembola: Entomobryidae). IgE antibodies to Collembola proteins were not detected in sera from the nurses and skin tests with the Collembola extract and crushed whole Collembola were negative in both the nurses and volunteers. This study suggests that the springtail Drepanura may not cause human dermatitis and that other organisms and organic matter that are also found in the moist environment inhabited by Collembola might instead be responsible. PMID:19611235

  10. Components of evaporative water loss in the desert tenebrionid beetles, Eleodes armata and Cryptoglossa verrucosa

    SciTech Connect

    Cooper, P.D.

    1981-01-01

    Water loss in Eleodes armata and Cryptoglossa verrucosa increased with increasing temperature and decreasing vapor activity (a/sub v/). Rates of evaporative water loss were always about 4 times greater in E. armata than in C. verrucosa at the different temperatures and 0.0 a/sub v/, while as a/sub v/ increased the ratio of E. armata loss to C. verrucosa decreased from 4 at 0.0 a/sub v/ to about 2 at 0.94 a/sub v/. A method for determining mesothoracic spiracular, sub-elytral abdominal, and cuticular water loss rates was described and validated for living E. armata. Sub-elytral abdominal water loss through the caudal opening was 8.0 mg H/sub 2/O (g.d)/sup -1/, meso-thoracic spiracular water loss was approximately 7.9 mg H/sub 2/O (g.d)/sup -1/, and cuticular loss was 26.2 mg H/sub 2/O (g.d)/sup -1/ at 30 C and 0.0 a/sub v/. Evaporative water loss was shown to have two unidirectional components, efflux and influx, for both beetles with the use of tritiated water (H/sup 3/HO). Efflux was independent of a/sub v/, while influx increased linearly with a/sub v/, with both components having lower rates in C. verrucosa compared to E. armata.

  11. Production of domoic acid by laboratory culture of the red alga Chondria armata.

    PubMed

    Jiang, Shanshan; Kuwano, Kazuyoshi; Ishikawa, Nozomi; Yano, Michiko; Takatani, Tomohiro; Arakawa, Osamu

    2014-12-15

    To clarify the production mechanisms and biologic functions of domoic acid (DA) by the red alga Chondria armata, we established a laboratory culture of C. armata. The alga grew better in modified PES medium (mPES) without trace metals or manganese than in unmodified mPES (seawater + nitrate, phosphate, iron, trace metals, vitamins, and 2-[4-(2-hydroxyethyl)-1-piperazinyl]-ethanesulfonic acid), suggesting that C. armata is especially hypersensitive to the toxicity of excessive manganese. C. armata cultured in N·P·Fe medium (seawater + nitrate, phosphate, and iron) grew best (mean growth rate 828.4%) at a relative nutrient concentration of 50%. Liquid chromatography-mass spectrometry analysis of the algal extracts revealed that the DA content of the cultured explants (2273-3308 ppm) was 4-5 fold higher than that of wild specimens. The extract of pooled explants (60 g) was purified by activated charcoal treatment and several types of column chromatography to afford ca. 10 mg DA. The (1)H-nuclear magnetic resonance spectrum of the preparation was indistinguishable from the previously reported spectrum of DA, indicating that C. armata itself has an ability to produce DA. PMID:25240296

  12. Description of Pristina armata n. sp. (Clitellata: Naididae: Pristininae) from a carnivorous plant (Nepenthes sp.) in Borneo, Indonesia.

    PubMed

    Schenková, Jana; Čermák, Václav

    2013-01-01

    A new clitellate species of Pristininae (Naididae), Pristina armata n. sp., found in the pitcher of the carnivorous plant Nepenthes sp., is reported from East Kalimantan, Indonesia. P. armata n. sp. is a very small clitellate, less than 1 mm long in fixed state, and without proboscis on the prostomium. Signs of reproduction by paratomy were observed, but the generic placement remains preliminary because sexually mature individuals were not found. P. armata n. sp. is characterized by giant hook-like dorsal chaetae at IV. The description of P. armata n. sp. was based on six fixed specimens of different size and stage of development. Noteworthy is the habitat of P. armata n. sp. in Nepenthes pitchers, this being the first clitellate species described from such a habitat. P. armata n. sp. may be a member of the nepenthebionts' community, realizing its life cycle inside the digestive fluid of the Nepenthes pitcher, or it belongs to nepenthephiles, species that commonly occur in this habitat but do not specialize on it.

  13. Production of Excirolana armata (Dana, 1853) (Isopoda, Cirolanidae) on an exposed sandy beach in southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Petracco, Marcelo; Cardoso, Ricardo Silva; Turra, Alexander; Corbisier, Thais Navajas

    2012-09-01

    The somatic and gonad productions of the cirolanid isopod Excirolana armata were analyzed by taking monthly samples from December 2003 to November 2005 on Una beach, São Paulo state (24°S), southeastern Brazil. Sampling was performed along three fixed transects established from the base of the foredunes to the waterline. Weight-specific growth rate was used to estimate the E. armata somatic production for 2004 and 2005, separately. The gonad production was estimated based on the monthly reproductive potential (mean number of eggs/embryos per female × monthly abundance of ovigerous females with near-release broods) for 2004. The annual somatic production of E. armata population varied from 15.57 to 17.25 g AFDW m-1 year-1 and the somatic production/biomass ratio ( P s/ B) from 3.55 to 3.14 year-1 for 2004 and 2005, respectively. The P s/ B ratios were higher for males (4.02 and 3.19 year-1 for 2004 and 2005) than for females (3.10 year-1 for both years). The annual gonad production ( P g = 1.07 g AFDW m-1 year-1) contributed about 15 and 6% to the total production ( P s + P g) of females and the population, respectively. The proportion of gonad to somatic production of females ( P g/ P s) increased with individual size (ca 90% in the 7.5 mm size class), and the annual weight-specific gonad production ( P g/ B ratio) was estimated to 0.24 year-1. The high P s/ B ratios estimated for E. armata derive from the fast growth of individuals and show the importance of this population to the energy flow on Una beach ecosystem. However, the low percentage of juveniles verified in this population and in other studies of populations of the genus Excirolana is discussed as an important source of underestimation of P s/ B ratio.

  14. The non-native seaweed Asparagopsis armata supports a diverse crustacean assemblage.

    PubMed

    Pacios, I; Guerra-García, J M; Baeza-Rojano, E; Cabezas, M P

    2011-05-01

    This is the first study describing the crustacean fauna associated to Asparagopsis armata, a non-native, red seaweed widely distributed along western Mediterranean coasts. First found in Australia and New Zealand, it was introduced naturally through the Strait of Gibraltar and rapidly spread out. A one-year spatio-temporal study (Feb 08-Feb 09) was carried out in the Strait of Gibraltar to characterize the spatio-temporal patterns of the associated crustacean fauna. Maximum biomass of A. armata was measured during April-June, whereas the maximum crustacean abundances were registered from June-October. In total 41 crustacean species were identified. The caprellid Caprella penantis, traditionally associated to non-polluted areas, was more abundant on Tarifa Island (higher values of dissolved oxygen and pH) than in Algeciras (lower oxygen and pH). The gammarid Podocerus variegatus was dominant in Algeciras Bay while Hyale schmidti and Apherusa mediterranea were the most abundant on Tarifa Island. Among isopods, Synisoma nadejda was only found on Tarifa Island. When compared with literature of native algae of the intertidal and shallow sublittoral, the species richness of associated crustaceans was similar in A. armata and the natives. Very little is known about the influence of this algae on altering marine communities, so complete faunistic studies dealing with other groups such as polychaetes or molluscs are necessary to properly address biogeographical, ecological and management programmes dealing with this non-native species.

  15. New Neanurinae (Collembola: Neanuridae) from Central China.

    PubMed

    Wang, Ya-Ru; Wang, Wen-Bin; Jiang, Jigang

    2016-01-01

    Three new species, two of Vitronura and one of Lobellina of subfamily Neanurinae (Neanuridae, Collembola) from Central China are described. In addition a key for valid Lobellina species is included. PMID:27470797

  16. Structural Evidence in Plectroniella armata (Rubiaceae) for Possible Material Exchange between Domatia and Mites

    PubMed Central

    Tilney, Patricia M.; van Wyk, Abraham E.; van der Merwe, Chris F.

    2012-01-01

    Domatia are small structures on the lower surface of a leaf, usually taking the form of cavities, pouches, domes with an opening, or hairs (or a combination of these), and located in the axils between the main veins. They are found in many dicotyledons including certain members of the Rubiaceae. As part of an ongoing study of selected southern African members of the tribe Vanguerieae of this family, their structure in transverse section was investigated. In some taxa, such as Plectroniella armata, light microscopic (LM) observations revealed large numbers of stomata in the domatia as well as a number of channel-like structures extending across the cuticle toward the cavity of the domatia. The cuticle of the epidermis lining the domatia also appeared thicker than in other parts of the leaves. The epidermis in P. armata was also examined using transmission electron microscopy (TEM). Domatia have been shown to house mainly mites, many of which are predatory or fungivorous, in a symbiotic (mutualistic) relationship with the plant. To date, much research has focussed on the role of domatia in providing shelter for various organisms, their eggs and their young. However, the TEM study revealed the apparent “channels” and thick cuticle seen under LM to be electron dense non-cellulosic branching fibrils within pronounced, often closely spaced cuticular folds. The functional significance of these fibrils and folds requires further investigation. Folding of cell walls and membranes at ultrastructural level is usually functionally associated with an increased surface area to facilitate active exchange of compounds/metabolites. This may indicate that translocation of substances and/or other forms of communication is possible between the domatium and its inhabitants. This therefore suggests a far more active role for the leaf in the symbiotic relationship than was previously thought. More work is required to test such a possibility. PMID:22792206

  17. Subdivision of the tribe Oligaphorurini in the light of new and lesser known species from North-East Russia (Collembola, Onychiuridae, Onychiurinae)

    PubMed Central

    Babenko, Anatoly B.; Fjellberg, Arne

    2015-01-01

    Abstract The paper is devoted to a taxonomic review of Oligaphorurini from the north-eastern part of Palaearctic. Two new species, i.e. Oligaphorura ambigua sp. n. and Oligaphorura duocellata sp. n., are described. Four species, Oligaphorura nataliae (Fjellberg, 1987), Oligaphorura interrupta (Fjellberg, 1987), Oligaphorura pingicola (Fjellberg, 1987), and Micraphorura alnus (Fjellberg, 1987), are redescribed on base of the types and new material, and remarks on other species known for the region, Oligaphorura groenlandica (Tullberg, 1876), Oligaphorura ursi (Fjellberg, 1984), Oligaphorura aborigensis (Fjellberg, 1987), and Micraphorura absoloni (Börner, 1901), are given to clarify their generic affiliation. Finally, merits and disadvantages of the current subdivision of the tribe are discussed and a key to the northern species of the tribe is provided. PMID:25878523

  18. Two new species of Allonychiurus Yoshii, 1995 (Collembola, Onychiuridae) from eastern China, with a key to world species of the genus.

    PubMed

    Chang, Liang; Sun, Xin

    2016-01-01

    Two new species, Allonychiurus zhejiangensis sp. nov. and Allonychiurus pseudokimi sp. nov., have been reported from eastern China. A. zhejiangensis sp. nov. is particular in the genus as having three pso on ventral side of the head. A. pseudokimi sp. nov. is similar to A. kimi, but they can be distinguished by the number of pso on ventral side of the head, the number of chaetae along axial line on Abd. I-II, the number of chaetae on ventral tube and the presence of basal lamella on unguiculus. A key to the known species of the genus all over the world is given accordingly. PMID:27395511

  19. The mysid Siriella armata as a model organism in marine ecotoxicology: comparative acute toxicity sensitivity with Daphnia magna.

    PubMed

    Pérez, Sara; Beiras, Ricardo

    2010-01-01

    Siriella armata (Crustacea, Mysidacea) is a component of the coastal zooplankton that lives in swarms in the shallow waters of the European neritic zone, from the North Sea to the Mediterranean. Juveniles of this species were examined as standard test organisms for use in marine acute toxicity tests. The effects of reference toxicants, three trace metals (Copper, Cadmium and Zinc), and one surfactant, sodium dodecyl sulfate (SDS) were studied on S. armata neonates (\\24 h) reared in the laboratory. Acute toxicity tests were carried out with filtered sea water on individual chambers (microplate wells for metals or glass vials for SDS) incubated in an isothermal room at 20 degrees C, with 16 h light: 8 h dark photoperiod for 96 h. Each neonate was fed daily with 10-15 nauplii of Artemia salina. Acute (96 h) LC50 values, in increasing order, were 46.9 lg/L for Cu, 99.3 lg/L for Cd, 466.7 lg/L for Zn and 8.5 mg/L for SDS. The LC(10), NOEC and LOEC values were also calculated. Results were compared with Daphnia magna, a freshwater cladoceran widely used as a standard ecotoxicological test organism. Acute (48 h) LC(50) values were 56.2 lg/L for Cu, 571.5 lg/L for Cd, 1.3 mg/L for Zn and 27.3 mg/L for SDS. For all the reference toxicants studied, the marine mysid Siriella armata showed higher sensitivity than the freshwater model organism Daphnia magna, validating the use of Siriella mysids as model organisms in marine acute toxicity tests.

  20. Surface Structure and Wetting Characteristics of Collembola Cuticles

    PubMed Central

    Gundersen, Håkon; Leinaas, Hans Petter; Thaulow, Christian

    2014-01-01

    The cuticles of the arthropods Collembola (springtails) are known to be superhydrophobic, displaying such properties as water-repellence and plastron formation; overhanging surface structures have been suggested as the source of these properties. Superhydrophobicity is closely related to surface structuring and other surfaces with overhanging structures have been shown to possess robust superhydrophobic properties. In effort to correlate the wetting performance and surface structuring of the cuticles, from both a technical and evolutionary point of view, we investigated a selection of Collembola species including species from several families and covering habitats ranging from aquatic to very dry. The observed contact angles of wetting was in general larger than those predicted by the conventional models. Not all the studied Collembola were found to have superhydrophobic properties, indicating that superhydrophobicity is common, but not a universal trait in Collembola. Overhanging structures were found in some, but not all Collembola species with superhydrophobic cuticles; which leads to the conclusion that there is no direct link between overhanging surface structures and superhydrophobicity in Collembola. PMID:24498281

  1. Surface structure and wetting characteristics of Collembola cuticles.

    PubMed

    Gundersen, Håkon; Leinaas, Hans Petter; Thaulow, Christian

    2014-01-01

    The cuticles of the arthropods Collembola (springtails) are known to be superhydrophobic, displaying such properties as water-repellence and plastron formation; overhanging surface structures have been suggested as the source of these properties. Superhydrophobicity is closely related to surface structuring and other surfaces with overhanging structures have been shown to possess robust superhydrophobic properties. In effort to correlate the wetting performance and surface structuring of the cuticles, from both a technical and evolutionary point of view, we investigated a selection of Collembola species including species from several families and covering habitats ranging from aquatic to very dry. The observed contact angles of wetting was in general larger than those predicted by the conventional models. Not all the studied Collembola were found to have superhydrophobic properties, indicating that superhydrophobicity is common, but not a universal trait in Collembola. Overhanging structures were found in some, but not all Collembola species with superhydrophobic cuticles; which leads to the conclusion that there is no direct link between overhanging surface structures and superhydrophobicity in Collembola. PMID:24498281

  2. Folsomia candida (Collembola): a "standard" soil arthropod.

    PubMed

    Fountain, Michelle T; Hopkin, Steve P

    2005-01-01

    Folsomia candida Willem 1902, a member of the order Collembola (colloquially called springtails), is a common and widespread arthropod that occurs in soils throughout the world. The species is parthenogenetic and is easy to maintain in the laboratory on a diet of granulated dry yeast. F. candida has been used as a "standard" test organism for more than 40 years for estimating the effects of pesticides and environmental pollutants on nontarget soil arthropods. However, it has also been employed as a model for the investigation of numerous other phenomena such as cold tolerance, quality as a prey item, and effects of microarthropod grazing on pathogenic fungi and mycorrhizae of plant roots. In this comprehensive review, aspects of the life history, ecology, and ecotoxicology of F. candida are covered. We focus on the recent literature, especially studies that have examined the effects of soil pollutants on reproduction in F. candida using the protocol published by the International Standards Organization in 1999.

  3. Ecological risk assessment of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in marine environment using Isochrysis galbana, Paracentrotus lividus, Siriella armata and Psetta maxima.

    PubMed

    Mhadhbi, Lazhar; Rial, Diego; Pérez, Sara; Beiras, Ricardo

    2012-05-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are anthropogenic substances classified as persistent bioaccumulative compounds and are found in various environmental compartments throughout the world, from industrialized regions to remote zones far from areas of production. In this study, we assessed the effects of PFOA and PFOS on early life stages of marine test species belonging to three different trophic levels: one microalga (Isochrysis galbana), a primary consumer (Paracentrotus lividus) and two secondary consumers (Siriella armata and Psetta maxima). Acute EC(50) values for PFOS were 0.11 mg L(-1) in P. maxima, 6.9 mg L(-1) in S. armata, 20 mg L(-1) in P. lividus and 37.5 mg L(-1) in I. galbana. In the case of PFOA, the toxicity was lower but the ranking was the same; 11.9 mg L(-1) in P. maxima, 15.5 mg L(-1) in S. armata, 110 mg L(-1) in P. lividus and 163.6 mg L(-1) in I. galbana. The Predicted No Effect Concentration (PNEC) for PFOS and PFOA in marine water derived from these acute toxicity values are 1.1 μg L(-1) for PFOS and 119 μg L(-1) for PFOA. This study established a baseline dataset of toxicity of PFOS and PFOA on saltwater organisms. The data obtained suggest that PFOA pose a minor risk to these organisms through direct exposure. In the perspective of risk assessment, early life stage (ELS) endpoints provide rapid, cost-effective and ecologically relevant information, and links should be sought between these short-term tests and effects of long-term exposures in more realistic scenarios.

  4. Negative responses of Collembola in a forest soil (Alptal, Switzerland) under experimentally increased N deposition.

    PubMed

    Xu, Guo-Liang; Schleppi, Patrick; Li, Mai-He; Fu, Sheng-Lei

    2009-07-01

    The response of specific groups of organisms, like Collembola to atmospheric nitrogen (N) deposition is still scarcely known. We investigated the Collembola community in a subalpine forest (Alptal, Switzerland) as subjected for 12 years to an experimentally increased N deposition (+25 on top of ambient 12 kg N ha(-1) year(-1)). In the 0-5 cm soil layer, there was a tendency of total Collembola densities to be lower in N-treated than in control plots. The density of Isotomiella minor, the most abundant species, was significantly reduced by the N addition. A tendency of lower Collembola group richness was observed in N-treated plots. The Density-Group index (dDG) showed a significant reduction of community diversity, but the Shannon-Wiener index (H') was not significantly affected by the N addition. The Collembola community can be considered as a bioindicator of N inputs exceeding the biological needs, namely, soil N saturation.

  5. Updated list of Collembola species currently recorded from South Africa.

    PubMed

    Janion-Scheepers, Charlene; Deharveng, Louis; Bedos, Anne; Chown, Steven L

    2015-01-01

    Understanding the abundance and richness of species is one of the most fundamental steps in effecting their conservation. Despite global recognition of the significance of the below-ground component of diversity for ecosystem functioning, the soil remains a poorly studied terrestrial ecosystem. In South Africa, knowledge is increasing for a variety of soil faunal groups, but many still remain poorly understood. We have started to address this gap in the knowledge of South African soil biodiversity by focusing on the Collembola in an integrated project that encompasses systematics, barcoding and ecological assessments. Here we provide an updated list of the Collembola species from South Africa. A total of 124 species from 61 genera and 17 families has been recorded, of which 75 are considered endemic, 24 widespread, and 25 introduced. This total number of species excludes the 36 species we consider to be dubious. From the published data, Collembola species richness is high compared to other African countries, but low compared to European countries. This is largely a consequence of poor sampling in the African region, as our discovery of many new species in South Africa demonstrates. Our analyses also show that much ongoing work will be required before a reasonably comprehensive and spatially explicit picture of South Africa's springtail fauna can be provided, which may well exceed 1000 species. Such work will be necessary to help South Africa meet its commitments to biodiversity conservation, especially in the context of the 2020 Aichi targets of the Convention on Biological Diversity. PMID:26019671

  6. Updated list of Collembola species currently recorded from South Africa.

    PubMed

    Janion-Scheepers, Charlene; Deharveng, Louis; Bedos, Anne; Chown, Steven L

    2015-01-01

    Understanding the abundance and richness of species is one of the most fundamental steps in effecting their conservation. Despite global recognition of the significance of the below-ground component of diversity for ecosystem functioning, the soil remains a poorly studied terrestrial ecosystem. In South Africa, knowledge is increasing for a variety of soil faunal groups, but many still remain poorly understood. We have started to address this gap in the knowledge of South African soil biodiversity by focusing on the Collembola in an integrated project that encompasses systematics, barcoding and ecological assessments. Here we provide an updated list of the Collembola species from South Africa. A total of 124 species from 61 genera and 17 families has been recorded, of which 75 are considered endemic, 24 widespread, and 25 introduced. This total number of species excludes the 36 species we consider to be dubious. From the published data, Collembola species richness is high compared to other African countries, but low compared to European countries. This is largely a consequence of poor sampling in the African region, as our discovery of many new species in South Africa demonstrates. Our analyses also show that much ongoing work will be required before a reasonably comprehensive and spatially explicit picture of South Africa's springtail fauna can be provided, which may well exceed 1000 species. Such work will be necessary to help South Africa meet its commitments to biodiversity conservation, especially in the context of the 2020 Aichi targets of the Convention on Biological Diversity.

  7. Updated list of Collembola species currently recorded from South Africa

    PubMed Central

    Janion-Scheepers, Charlene; Deharveng, Louis; Bedos, Anne; Chown, Steven L.

    2015-01-01

    Abstract Understanding the abundance and richness of species is one of the most fundamental steps in effecting their conservation. Despite global recognition of the significance of the below-ground component of diversity for ecosystem functioning, the soil remains a poorly studied terrestrial ecosystem. In South Africa, knowledge is increasing for a variety of soil faunal groups, but many still remain poorly understood. We have started to address this gap in the knowledge of South African soil biodiversity by focusing on the Collembola in an integrated project that encompasses systematics, barcoding and ecological assessments. Here we provide an updated list of the Collembola species from South Africa. A total of 124 species from 61 genera and 17 families has been recorded, of which 75 are considered endemic, 24 widespread, and 25 introduced. This total number of species excludes the 36 species we consider to be dubious. From the published data, Collembola species richness is high compared to other African countries, but low compared to European countries. This is largely a consequence of poor sampling in the African region, as our discovery of many new species in South Africa demonstrates. Our analyses also show that much ongoing work will be required before a reasonably comprehensive and spatially explicit picture of South Africa’s springtail fauna can be provided, which may well exceed 1000 species. Such work will be necessary to help South Africa meet its commitments to biodiversity conservation, especially in the context of the 2020 Aichi targets of the Convention on Biological Diversity. PMID:26019671

  8. Ecotoxicological evaluation of four UV filters using marine organisms from different trophic levels Isochrysis galbana, Mytilus galloprovincialis, Paracentrotus lividus, and Siriella armata.

    PubMed

    Paredes, E; Perez, S; Rodil, R; Quintana, J B; Beiras, R

    2014-06-01

    Due to the concern about the negative effects of exposure to sunlight, combinations of UV filters like 4-Methylbenzylidene-camphor (4-MBC), Benzophenone-3 (BP-3), Benzophenone-4 (BP-4) and 2-Ethylhexyl-4-methoxycinnamate (EHMC) are being introduced in all kind of cosmetic formulas. These chemicals are acquiring a concerning status due to their increasingly common use and the potential risk for the environment. The aim of this study is to assess the behaviour of these compounds in seawater, the toxicity to marine organisms from three trophic levels including autotrophs (Isochrysis galbana), herbivores (Mytilus galloprovincialis and Paracentrotus lividus) and carnivores (Siriella armata), and set a preliminary assessment of potential ecological risk of UV filters in coastal ecosystems. In general, EC50 results show that both EHMC and 4-MBC are the most toxic for our test species, followed by BP-3 and finally BP-4. The most affected species by the presence of these UV filters are the microalgae I. galbana, which showed toxicity thresholds in the range of μg L(-1) units, followed by S. armata>P. Lividus>M. galloprovincialis. The UV filter concentrations measured in the sampled beach water were in the range of tens or even hundreds of ng L(-1). The resulting risk quotients showed appreciable environmental risk in coastal environments for BP-3 and 4-MBC.

  9. A new cave species of the genus Protaphorura Absolon, 1901 (Collembola, Onychiuridae) from the Western Carpathians (Slovakia) with critical comments to the Palaearctic representatives of the genus.

    PubMed

    Parimuchová, Andrea; Kováč, Ľubomír

    2016-01-01

    The new species Protaphorura borinensis sp. nov. from a cave of the Western Carpathians, Central Europe, is described. It belongs to congeners with ~40 vesicles in PAO and three pseudocelli at the base of antennae and the hind margin of head. P. borinensis sp. nov. has coarse granulation of cuticle on head, and specific distribution of "s" chaetae on abdominal terga and chaetotaxy of ventral tube. Critical comments to the Palaearctic representatives of the genus Protaphorura and an identification key to 85 species are provided. PMID:27394585

  10. Ancient Ephemeroptera-Collembola symbiosis fossilized in amber predicts contemporary phoretic associations.

    PubMed

    Penney, David; McNeil, Andrew; Green, David I; Bradley, Robert S; Jepson, James E; Withers, Philip J; Preziosi, Richard F

    2012-01-01

    X-ray computed tomography is used to identify a unique example of fossilized phoresy in 16 million-year-old Miocene Dominican amber involving a springtail being transported by a mayfly. It represents the first evidence (fossil or extant) of phoresy in adult Ephemeroptera and only the second record in Collembola (the first is also preserved in amber). This is the first record of Collembola using winged insects for dispersal. This fossil predicts the occurrence of similar behaviour in living springtails and helps explain the global distribution of Collembola today. PMID:23082186

  11. Ancient Ephemeroptera–Collembola Symbiosis Fossilized in Amber Predicts Contemporary Phoretic Associations

    PubMed Central

    Penney, David; McNeil, Andrew; Green, David I.; Bradley, Robert S.; Jepson, James E.; Withers, Philip J.; Preziosi, Richard F.

    2012-01-01

    X-ray computed tomography is used to identify a unique example of fossilized phoresy in 16 million-year-old Miocene Dominican amber involving a springtail being transported by a mayfly. It represents the first evidence (fossil or extant) of phoresy in adult Ephemeroptera and only the second record in Collembola (the first is also preserved in amber). This is the first record of Collembola using winged insects for dispersal. This fossil predicts the occurrence of similar behaviour in living springtails and helps explain the global distribution of Collembola today. PMID:23082186

  12. An introduction to Iranian Collembola (Hexapoda): an update to the species list.

    PubMed

    Shayanmehr, Masoumeh; Yahyapour, Elliyeh; Kahrarian, Morteza; Lafooraki, Elham Yoosefi

    2013-01-01

    The Collembola fauna of Iran is little known and no comprehensive examination of this group of Hexapoda is available for this region. The only notable work on Collembola was carried out by Cox (1982). Recently, studies on the Collembola fauna have started in several regions. In this paper, publications by different researchers are documented and the species that have been found in different regions of Iran until January 2013 are listed. At present, 112 species, belonging to 18 families and 57 genera are known from Iran. PMID:24146566

  13. Springtails in the Classroom: Collembola as Model Organisms for Inquiry-based Laboratories.

    ERIC Educational Resources Information Center

    Moore, John C.; Tripp, Bradley B.; Simpson, Rod T.; Coleman, David C.

    2000-01-01

    Advocates the use of springtails (Collembola) in the K-12 classroom as a model invertebrate that can easily be reared and manipulated to demonstrate key concepts in biology. Describes experimental procedures using springtails. (SAH)

  14. Three new species of Collembola from soils of Mediterranean cork-oak forests of Sicily (Italy).

    PubMed

    Giuga, Luca; Jordana, Rafael

    2013-01-01

    Three new species of soil Collembola from cork-oak (Quercus suber) forests located in eastern Sicily (Italy) are described Neonaphorura alicatai sp. nov., Friesea guarinoi sp. nov. and Arrhopalites antonioi sp. nov..

  15. Environmental correlates of species richness of European springtails (Hexapoda: Collembola)

    NASA Astrophysics Data System (ADS)

    Ulrich, Werner; Fiera, Cristina

    2009-01-01

    Our knowledge about environmental correlates of the spatial distribution of animal species stems mostly from the study of well known vertebrate and a few invertebrate taxa. The poor spatial resolution of faunistic data and undersampling prohibit detailed spatial modeling for the vast majority of arthropods. However, many such models are necessary for a comparative approach to the impact of environmental factors on the spatial distribution of species of different taxa. Here we use recent compilations of species richness of 35 European countries and larger islands and linear spatial autocorrelation modeling to infer the influence of area and environmental variables on the number of springtail (Collembola) species in Europe. We show that area, winter length and annual temperature difference are major predictors of species richness. We also detected a significant negative longitudinal gradient in the number of springtail species towards Eastern Europe that might be caused by postglacial colonization. In turn, environmental heterogeneity and vascular plant species richness did not significantly contribute to model performance. Contrary to theoretical expectations, climate and longitude corrected species-area relationships of Collembola did not significantly differ between islands and mainlands.

  16. Effects of understory structure on the abundance, richness and diversity of Collembola (Arthropoda) in southern Brazil.

    PubMed

    Ribeiro-Troian, Vera R; Baldissera, Ronei; Hartz, Sandra M

    2009-01-01

    The purpose of this study was to investigate the effects of different landscape structures on the understory Collembola community. Four different forest physiognomies were compared: Pinus spp. plantation, Eucalyptus spp. plantation, Araucaria angustifolia plantation, and a remaining native Araucaria forest. Three areas containing two sampling units (25 mx2 m each) were selected in each forest physiognomy. Understory Collembola collection was done with a 1x1 m canvas sheet held horizontally below the vegetation, which was beaten with a 1 m long stick, seasonally from September 2003 to August 2004. We evaluated the influence of forest physiognomies on the abundance, richness and diversity of Collembola communities. It was also verified if the habitat structure of each physiognomy was associated with the composition of the Collembola community. A total number of 4,111 individuals were collected belonging to the families Entomobrydae and Tomocerida (Entomobryomorpha), and Sminthuridae (Symphypleona), and divided in 12 morphospecies. Pinus plantation presented the highest richness, abundance and diversity of Collembola and it was associated to diverse understory vegetation. The abundance of Entomobrydae and Sminthuridae was associated to the presence of bushes, while Tomoceridae abundance was associated to the presence of trees. The habitat structure, measured through understory vegetation density and composition, plays an important role on the determination of the structure and composition of the Collembola community.

  17. Collembola at three alpine subarctic sites resistant to twenty years of experimental warming.

    PubMed

    Alatalo, Juha M; Jägerbrand, Annika K; Čuchta, Peter

    2015-01-01

    This study examined the effects of micro-scale, site and 19 and 21 years of experimental warming on Collembola in three contrasting alpine subarctic plant communities (poor heath, rich meadow, wet meadow). Unexpectedly, experimental long-term warming had no significant effect on species richness, effective number of species, total abundance or abundance of any Collembola species. There were micro-scale effects on species richness, total abundance, and abundance of 10 of 35 species identified. Site had significant effect on effective number of species, and abundance of six species, with abundance patterns differing between sites. Site and long-term warming gave non-significant trends in species richness. The highest species richness was observed in poor heath, but mean species richness tended to be highest in rich meadow and lowest in wet meadow. Warming showed a tendency for a negative impact on species richness. This long-term warming experiment across three contrasting sites revealed that Collembola is capable of high resistance to climate change. We demonstrated that micro-scale and site effects are the main controlling factors for Collembola abundance in high alpine subarctic environments. Thus local heterogeneity is likely important for soil fauna composition and may play a crucial role in buffering Collembola against future climate change. PMID:26670681

  18. Collembola at three alpine subarctic sites resistant to twenty years of experimental warming

    PubMed Central

    Alatalo, Juha M.; Jägerbrand, Annika K.; Čuchta, Peter

    2015-01-01

    This study examined the effects of micro-scale, site and 19 and 21 years of experimental warming on Collembola in three contrasting alpine subarctic plant communities (poor heath, rich meadow, wet meadow). Unexpectedly, experimental long-term warming had no significant effect on species richness, effective number of species, total abundance or abundance of any Collembola species. There were micro-scale effects on species richness, total abundance, and abundance of 10 of 35 species identified. Site had significant effect on effective number of species, and abundance of six species, with abundance patterns differing between sites. Site and long-term warming gave non-significant trends in species richness. The highest species richness was observed in poor heath, but mean species richness tended to be highest in rich meadow and lowest in wet meadow. Warming showed a tendency for a negative impact on species richness. This long-term warming experiment across three contrasting sites revealed that Collembola is capable of high resistance to climate change. We demonstrated that micro-scale and site effects are the main controlling factors for Collembola abundance in high alpine subarctic environments. Thus local heterogeneity is likely important for soil fauna composition and may play a crucial role in buffering Collembola against future climate change. PMID:26670681

  19. Phylogeny of Collembola based on cuticular compounds:inherent usefulness and limitation of a character type

    NASA Astrophysics Data System (ADS)

    Porco, David; Deharveng, Louis

    2009-08-01

    The phylogeny of Collembola, originally discussed from a morphological point of view, has more recently benefited from novel insights brought by molecular analyses. Both morphological and molecular characters produced a well-resolved phylogenetic hypothesis including all orders, most families, and a large number of genera. However, several conflicting points exist between molecular and morphological data, and new characters are clearly needed to resolve these inconsistencies. In this study the usefulness of a new character type not previously used in the phylogenetic study of Collembola was tested: the epicuticular chemical compounds. Our phylogenetic analysis was based on 380 compounds from 26 Collembola species. The results show good resolution for terminal branches but not for internal nodes. This is probably due to the partial involvement of epicuticular lipids in ecological functions such as water conservation and sexual attraction. Thus, this character type is appropriate for reconstructing phylogenetic relationships among recently diversified groups.

  20. A case of an apparent infestation by Proisotoma spp. springtails (Collembola: Isotomidae) in a cat.

    PubMed

    Beccati, Massimo; Gallo, Maria G; Chiavassa, Elisa; Peano, Andrea

    2012-04-01

    This case report is presumed to be the first case of infestation of a cat by springtails which are small arthropods closely related to insects. The organisms, found by skin scrapings, were identified as Proisotoma spp. (Collembola: Isotomidae). The cat presented with dermatological lesions (itchy, furfuraceous dermatitis), and we speculate that they were due to this infestation. The pathogenic role of the Collembola was hypothesized because of the large number of organisms, the presence of eggs indicating an active reproduction cycle, the lack of other pathogens (fleas, mites or lice) and the clinical recovery accompanied by the disappearance of Collembola following treatment. The owner seemed to be affected by the infestation, because a few days after having purchased the cat, she developed a pruriginous papular dermatitis on the neck and the arms, which disappeared shortly after treatment of the kitten and a careful washing of all of its toys and other accoutrements. PMID:22049948

  1. Growth and reproduction of laboratory-reared neanurid Collembola using a novel slime mould diet

    NASA Astrophysics Data System (ADS)

    Hoskins, Jessica L.; Janion-Scheepers, Charlene; Chown, Steven L.; Duffy, Grant A.

    2015-07-01

    Although significant progress has been made using insect taxa as model organisms, non-tracheated terrestrial arthropods, such as Collembola, are underrepresented as model species. This underrepresentation reflects the difficulty in maintaining populations of specialist Collembola species in the laboratory. Until now, no species from the family Neanuridae have been successfully reared. Here we use controlled growth experiments to provide explicit evidence that the species Neanura muscorum can be raised under laboratory conditions when its diet is supplemented with slime mould. Significant gains in growth were observed in Collembola given slime mould rather than a standard diet of algae-covered bark. These benefits are further highlighted by the reproductive success of the experimental group and persistence of laboratory breeding stocks of this species and others in the family. The necessity for slime mould in the diet is attributed to the ‘suctorial’ mouthpart morphology characteristic of the Neanuridae. Maintaining laboratory populations of neanurid Collembola species will facilitate their use as model organisms, paving the way for studies that will broaden the current understanding of the environmental physiology of arthropods.

  2. Growth and reproduction of laboratory-reared neanurid Collembola using a novel slime mould diet.

    PubMed

    Hoskins, Jessica L; Janion-Scheepers, Charlene; Chown, Steven L; Duffy, Grant A

    2015-07-08

    Although significant progress has been made using insect taxa as model organisms, non-tracheated terrestrial arthropods, such as Collembola, are underrepresented as model species. This underrepresentation reflects the difficulty in maintaining populations of specialist Collembola species in the laboratory. Until now, no species from the family Neanuridae have been successfully reared. Here we use controlled growth experiments to provide explicit evidence that the species Neanura muscorum can be raised under laboratory conditions when its diet is supplemented with slime mould. Significant gains in growth were observed in Collembola given slime mould rather than a standard diet of algae-covered bark. These benefits are further highlighted by the reproductive success of the experimental group and persistence of laboratory breeding stocks of this species and others in the family. The necessity for slime mould in the diet is attributed to the 'suctorial' mouthpart morphology characteristic of the Neanuridae. Maintaining laboratory populations of neanurid Collembola species will facilitate their use as model organisms, paving the way for studies that will broaden the current understanding of the environmental physiology of arthropods.

  3. Growth and reproduction of laboratory-reared neanurid Collembola using a novel slime mould diet.

    PubMed

    Hoskins, Jessica L; Janion-Scheepers, Charlene; Chown, Steven L; Duffy, Grant A

    2015-01-01

    Although significant progress has been made using insect taxa as model organisms, non-tracheated terrestrial arthropods, such as Collembola, are underrepresented as model species. This underrepresentation reflects the difficulty in maintaining populations of specialist Collembola species in the laboratory. Until now, no species from the family Neanuridae have been successfully reared. Here we use controlled growth experiments to provide explicit evidence that the species Neanura muscorum can be raised under laboratory conditions when its diet is supplemented with slime mould. Significant gains in growth were observed in Collembola given slime mould rather than a standard diet of algae-covered bark. These benefits are further highlighted by the reproductive success of the experimental group and persistence of laboratory breeding stocks of this species and others in the family. The necessity for slime mould in the diet is attributed to the 'suctorial' mouthpart morphology characteristic of the Neanuridae. Maintaining laboratory populations of neanurid Collembola species will facilitate their use as model organisms, paving the way for studies that will broaden the current understanding of the environmental physiology of arthropods. PMID:26153104

  4. Growth and reproduction of laboratory-reared neanurid Collembola using a novel slime mould diet

    PubMed Central

    Hoskins, Jessica L.; Janion-Scheepers, Charlene; Chown, Steven L.; Duffy, Grant A.

    2015-01-01

    Although significant progress has been made using insect taxa as model organisms, non-tracheated terrestrial arthropods, such as Collembola, are underrepresented as model species. This underrepresentation reflects the difficulty in maintaining populations of specialist Collembola species in the laboratory. Until now, no species from the family Neanuridae have been successfully reared. Here we use controlled growth experiments to provide explicit evidence that the species Neanura muscorum can be raised under laboratory conditions when its diet is supplemented with slime mould. Significant gains in growth were observed in Collembola given slime mould rather than a standard diet of algae-covered bark. These benefits are further highlighted by the reproductive success of the experimental group and persistence of laboratory breeding stocks of this species and others in the family. The necessity for slime mould in the diet is attributed to the ‘suctorial’ mouthpart morphology characteristic of the Neanuridae. Maintaining laboratory populations of neanurid Collembola species will facilitate their use as model organisms, paving the way for studies that will broaden the current understanding of the environmental physiology of arthropods. PMID:26153104

  5. Seasonal exposure to drought and air warming affects soil Collembola and mites.

    PubMed

    Xu, Guo-Liang; Kuster, Thomas M; Günthardt-Goerg, Madeleine S; Dobbertin, Matthias; Li, Mai-He

    2012-01-01

    Global environmental changes affect not only the aboveground but also the belowground components of ecosystems. The effects of seasonal drought and air warming on the genus level richness of Collembola, and on the abundance and biomass of the community of Collembola and mites were studied in an acidic and a calcareous forest soil in a model oak-ecosystem experiment (the Querco experiment) at the Swiss Federal Research Institute WSL in Birmensdorf. The experiment included four climate treatments: control, drought with a 60% reduction in rainfall, air warming with a seasonal temperature increase of 1.4 °C, and air warming + drought. Soil water content was greatly reduced by drought. Soil surface temperature was slightly increased by both the air warming and the drought treatment. Soil mesofauna samples were taken at the end of the first experimental year. Drought was found to increase the abundance of the microarthropod fauna, but reduce the biomass of the community. The percentage of small mites (body length ≤ 0.20 mm) increased, but the percentage of large mites (body length >0.40 mm) decreased under drought. Air warming had only minor effects on the fauna. All climate treatments significantly reduced the richness of Collembola and the biomass of Collembola and mites in acidic soil, but not in calcareous soil. Drought appeared to have a negative impact on soil microarthropod fauna, but the effects of climate change on soil fauna may vary with the soil type.

  6. Plant species richness drives the density and diversity of Collembola in temperate grassland

    NASA Astrophysics Data System (ADS)

    Sabais, Alexander C. W.; Scheu, Stefan; Eisenhauer, Nico

    2011-05-01

    Declining biodiversity is one of the most important aspects of anthropogenic global change phenomena, but the implications of plant species loss for soil decomposers are little understood. We used the experimental grassland community of the Jena Experiment to assess the response of density and diversity of Collembola to varying plant species richness, plant functional group richness and plant functional group identity. We sampled the experimental plots in spring and autumn four years after establishment of the experimental plant communities. Collembola density and diversity significantly increased with plant species and plant functional group richness highlighting the importance of the singular hypothesis for soil invertebrates. Generally, grasses and legumes beneficially affected Collembola density and diversity, whereas effects of small herbs usually were detrimental. These impacts were largely consistent in spring and autumn. By contrast, in the presence of small herbs the density of hemiedaphic Collembola and the diversity of Isotomidae increased in spring whereas they decreased in autumn. Beneficial impacts of plant diversity as well as those of grasses and legumes were likely due to increased root and microbial biomass, and elevated quantity and quality of plant residues serving as food resources for Collembola. By contrast, beneficial impacts of small herbs in spring probably reflect differences in microclimatic conditions, and detrimental effects in autumn likely were due to low quantity and quality of resources. The results point to an intimate relationship between plants and the diversity of belowground biota, even at small spatial scales, contrasting the findings of previous studies. The pronounced response of soil animals in the present study was presumably due to the fact that plant communities had established over several years. As decomposer invertebrates significantly impact plant performance, changes in soil biota density and diversity are likely

  7. Bottom-up determination of soil collembola diversity and population dynamics in response to interactive climatic factors.

    PubMed

    A'Bear, A Donald; Boddy, Lynne; Jones, T Hefin

    2013-11-01

    Soil invertebrate contributions to decomposition are climate dependent. Understanding the influence of abiotic factors on soil invertebrate population dynamics will strengthen predictions regarding ecosystem functioning under climate change. As well as being important secondary decomposers, mycophagous collembola exert a strong influence on the growth and activity of primary decomposers, particularly fungi. Species-specific grazing preferences for different fungi enable fungal community composition to influence the direct impacts of climate change on collembola populations. We investigate the interactive roles of altered abiotic conditions (warming, wetting and drying) and the identity of the dominant decomposer fungus in determining collembola community dynamics in woodland soil mesocosms. The bottom-up influence of the dominant component of the fungal resource base was an important mediator of the direct climatic impacts on collembola populations. The positive influences of warming and wetting, and the negative influence of drying, on collembola abundance and diversity were much less pronounced in fungal-inoculation treatments, in which populations were reduced compared with uninoculated mesocosms. We conclude that the thick, sclerotised cords of the competitively dominant decomposer fungi reduced the biomass of smaller, more palatable soil fungi, limiting the size of collembola populations and their ability to respond to altered abiotic conditions. PMID:23609802

  8. A quantitative protocol for DNA metabarcoding of springtails (Collembola).

    PubMed

    Saitoh, Seikoh; Aoyama, Hiroaki; Fujii, Saori; Sunagawa, Haruki; Nagahama, Hideki; Akutsu, Masako; Shinzato, Naoya; Kaneko, Nobuhiro; Nakamori, Taizo

    2016-09-01

    We developed a novel protocol with superior quantitative analysis results for DNA metabarcoding of Collembola, a major soil microarthropod order. Degenerate PCR primers were designed for conserved regions in the mitochondrial cytochrome c oxidase subunit I (mtCOI) and 16S ribosomal RNA (mt16S) genes based on published collembolan mitogenomes. The best primer pair was selected based on its ability to amplify each gene, irrespective of the species. DNA was extracted from 10 natural communities sampled in a temperate forest (with typically 25-30 collembolan species per 10 soil samples) and 10 mock communities (with seven cultured collembolan species). The two gene regions were then amplified using the selected primers, ligated with adapters for 454 technology, and sequenced. Examination of the natural community samples showed that 32 and 36 operational taxonomic units (defined at a 90% sequence similarity threshold) were recovered from the mtCOI and mt16S data, respectively, which were comparable to the results of the microscopic identification of 25 morphospecies. Further, sequence abundances for each collembolan species from the mtCOI and mt16S data of the mock communities, after normalization by using a species as the internal control, showed good correlation with the number of individuals in the samples (R = 0.91-0.99), although relative species abundances within a mock community sample estimated from sequences were skewed from community composition in terms of the number of individuals or biomass of the species. Thus, this protocol enables the comparison of collembolan communities in a quantitative manner by metabarcoding. PMID:27611697

  9. The multi-layered protective cuticle of Collembola: a chemical analysis

    PubMed Central

    Nickerl, Julia; Tsurkan, Mikhail; Hensel, René; Neinhuis, Christoph; Werner, Carsten

    2014-01-01

    Collembola, also known as springtails, are soil-dwelling arthropods that typically respire through the cuticle. To avoid suffocating in wet conditions, Collembola have evolved a complex, hierarchically nanostructured, cuticle surface that repels water with remarkable efficiency. In order to gain a more profound understanding of the cuticle characteristics, the chemical composition and architecture of the cuticle of Tetrodontophora bielanensis was studied. A stepwise removal of the different cuticle layers enabled controlled access to each layer that could be analysed separately by chemical spectrometry methods and electron microscopy. We found a cuticle composition that consisted of three characteristic layers, namely, a chitin-rich lamellar base structure overlaid by protein-rich nanostructures, and a lipid-rich envelope. The specific functions, composition and biological characteristics of each cuticle layer are discussed with respect to adaptations of Collembola to their soil habitat. It was found that the non-wetting characteristics base on a rather typical arthropod cuticle surface chemistry which confirms the decisive role of the cuticle topography. PMID:25100321

  10. The multi-layered protective cuticle of Collembola: a chemical analysis.

    PubMed

    Nickerl, Julia; Tsurkan, Mikhail; Hensel, René; Neinhuis, Christoph; Werner, Carsten

    2014-10-01

    Collembola, also known as springtails, are soil-dwelling arthropods that typically respire through the cuticle. To avoid suffocating in wet conditions, Collembola have evolved a complex, hierarchically nanostructured, cuticle surface that repels water with remarkable efficiency. In order to gain a more profound understanding of the cuticle characteristics, the chemical composition and architecture of the cuticle of Tetrodontophora bielanensis was studied. A stepwise removal of the different cuticle layers enabled controlled access to each layer that could be analysed separately by chemical spectrometry methods and electron microscopy. We found a cuticle composition that consisted of three characteristic layers, namely, a chitin-rich lamellar base structure overlaid by protein-rich nanostructures, and a lipid-rich envelope. The specific functions, composition and biological characteristics of each cuticle layer are discussed with respect to adaptations of Collembola to their soil habitat. It was found that the non-wetting characteristics base on a rather typical arthropod cuticle surface chemistry which confirms the decisive role of the cuticle topography. PMID:25100321

  11. Trophic transfer of silver nanoparticles from earthworms disrupts the locomotion of springtails (Collembola).

    PubMed

    Kwak, Jin Il; An, Youn-Joo

    2016-09-01

    Understanding how nanomaterials are transferred through food chains and evaluating their resulting toxicity is important. However, limited research has been conducted on the toxic consequences of trophically transferred nanomaterials in terrestrial ecosystems. In this study, we documented the adverse effects of trophically transferred silver nanoparticles (AgNPs) in a soil-earthworm (Eisenia andrei)-Collembola (Lobella sokamensis) food chain. We exposed E. andrei to soil with AgNPs at concentrations of 50, 200, and 500μg AgNPs/g soil dry weight and assessed their survival after 7days. Trophic-transfer containers were then prepared and E. andrei that survived the 7days test period were washed, killed in boiling water, and added to the containers with L. sokamensis. We noted negligible effects and low bioaccumulation at the lowest AgNP concentration (50μg AgNPs/g soil dry weight) in earthworms and the L. sokamensis that fed on them. The highest concentration of AgNPs (500μg AgNPs/g soil dry weight) resulted in juvenile earthworm mortality and increased transfer of AgNPs to Collembola, which subsequently inhibited their locomotion. To our knowledge, this is the first study to document the trophic transfer and adverse effects of AgNPs in a soil-earthworm-Collembola food chain, a common prey-decomposer interaction in soil ecosystems. PMID:27187058

  12. Collembola of Rapa Nui (Easter Island) with descriptions of five endemic cave-restricted species.

    PubMed

    Bernard, Ernest C; Soto-Adames, Felipe N; Wynne, J Judson

    2015-01-01

    Eight species of Collembola are reported from recent collections made in caves on the Polynesian island of Rapa Nui (Easter Island). Five of these species are new to science and apparently endemic to the island: Coecobrya aitorererere n. sp., Cyphoderus manuneru n. sp., Entomobrya manuhoko n. sp., Pseudosinella hahoteana n. sp. and Seira manukio n. sp. The Hawaiian species Lepidocyrtus olena Christiansen & Bellinger and the cosmopolitan species Folsomia candida Willem also were collected from one or more caves. Coecobrya kennethi Jordana & Baquero, recently described from Rapa Nui and identified as endemic, was collected in sympatric association with C. aitorererere n.sp. With the exception of F. candida, all species are endemic to Rapa Nui or greater Polynesia and appear to be restricted to the cave environment on Rapa Nui. A key is provided to separate Collembola species reported from Rapa Nui. We provide recommendations to aid in the conservation and management of these new Collembola, as well as the other presumed cave-restricted arthropods.

  13. Earthworms drive succession of both plant and Collembola communities in post-mining sites

    NASA Astrophysics Data System (ADS)

    Mudrák, Obdřej; Frouz, Jan

    2015-04-01

    Previous field observations indicated that earthworms promote late-successional plant species and reduce collembolan numbers at post-mining sites in the Sokolov coal mining district (Czech Republic). Here, we established a laboratory pot experiment to test the effect of earthworms (Aporrectodea caliginosa Savigny and Lumbricus rubellus Hoffm.) and litter of low, medium, and high quality (the grass Calamagrostis epigejos, the willow Salix caprea, and the alder Alnus glutinosa, respectively) on late successional plants (grasses Arrhenatherum elatius and Agrostis capillaris, legumes Lotus corniculatus and Trifolium medium, and non-leguminous dicots Centaurea jacea and Plantago lanceolata) in spoil substrate originating from Sokolov post-mining sites and naturally inhabited by abundant numbers of Collembola. The earthworms increased plant biomass, especially that of the large-seeded A. elatius, but reduced the number of plant individuals, mainly that of the small-seeded A. capillaris and both legumes. Litter quality affected plant biomass, which was highest with S. caprea litter, but did not change the number of plant individuals. Litter quality did not modify the effect of earthworms on plants; the effect of litter quality and earthworms was only additive. Species composition of Collembola community was altered by litter quality, but earthworms reduced the number of individuals, increased the number of species, and increased species evenness consistently across the litter qualities. Because the results of this experiment were consistent with the field observations, we conclude that earthworms help drive succession of both plant and Collembola communities on post-mining sites.

  14. Earthworms drive succession of both plant and Collembola communities in post-mining sites

    NASA Astrophysics Data System (ADS)

    Mudrák, Ondřej; Uteseny, Karoline; Frouz, Jan

    2016-04-01

    Previous field observations indicated that earthworms promote late-successional plant species and reduce collembolan numbers at post-mining sites in the Sokolov coal mining district (Czech Republic). Here, we established a laboratory pot experiment to test the effect of earthworms (Aporrectodea caliginosa Savigny and Lumbricus rubellus Hoffm.) and litter of low, medium, and high quality (the grass Calamagrostis epigejos, the willow Salix caprea, and the alder Alnus glutinosa, respectively) on late successional plants (grasses Arrhenatherum elatius and Agrostis capillaris, legumes Lotus corniculatus and Trifolium medium, and non-leguminous dicots Centaurea jacea and Plantago lanceolata) in spoil substrate originating from Sokolov post-mining sites and naturally inhabited by abundant numbers of Collembola. The earthworms increased plant biomass, especially that of the large-seeded A. elatius, but reduced the number of plant individuals, mainly that of the small-seeded A. capillaris and both legumes. Litter quality affected plant biomass, which was highest with S. caprea litter, but did not change the number of plant individuals. Litter quality did not modify the effect of earthworms on plants; the effect of litter quality and earthworms was only additive. Species composition of Collembola community was altered by litter quality, but earthworms reduced the number of individuals, increased the number of species, and increased species evenness consistently across the litter qualities. Because the results of this experiment were consistent with the field observations, we conclude that earthworms help drive succession of both plant and Collembola communities on post-mining sites.

  15. Collembola, the biological species concept and the underestimation of global species richness.

    PubMed

    Cicconardi, Francesco; Fanciulli, Pietro P; Emerson, Brent C

    2013-11-01

    Despite its ancient origin, global distribution and abundance in nearly all habitats, the class Collembola is comprised of only 8000 described species and is estimated to number no more than 50,000. Many morphologically defined species have broad geographical ranges that span continents, and recent molecular work has revealed high genetic diversity within species. However, the evolutionary significance of this genetic diversity is unknown. In this study, we sample five morphological species of the globally distributed genus Lepidocyrtus from 14 Panamanian sampling sites to characterize genetic diversity and test morphospecies against the biological species concept. Mitochondrial and nuclear DNA sequence data were analysed and a total of 58 molecular lineages revealed. Deep lineage diversification was recovered, with 30 molecular lineages estimated to have established more than 10 million years ago, and the origin almost all contemporary lineages preceding the onset of the Pleistocene (~2 Mya). Thirty-four lineages were sampled in sympatry revealing unambiguous cosegregation of mitochondrial and nuclear DNA sequence variation, consistent with biological species. Species richness within the class Collembola and the geographical structure of this diversity are substantially misrepresented components of terrestrial animal biodiversity. We speculate that global species richness of Collembola could be at least an order of magnitude greater than a previous estimate of 50,000 species.

  16. Soil Collembola communities within Plešné Lake and Čertovo Lake catchments, the Bohemian Forest

    NASA Astrophysics Data System (ADS)

    Čuchta, Peter

    2016-04-01

    The soil Collembola communities were studied for three years in disturbed spruce forest stands in the catchments areas of Čertovo and Plešné Lakes in the Bohemian Forest, Czech Republic. The study was focused on the impact of the windthrow, bark beetle outbreak damage and consecutive changes in the forest stands including soil environment. Four different treatments were selected for the study on both study areas: undamaged (control) forest stands, "dead" forest stands damaged by bark beetle, slightly managed windthrown forest stands left for the natural succession, and freshly harvested windthrown stands. After two years of research a total of 7,294 Collembola specimens were recorded belonging to 93 species. We recorded the highest collembolan abundance and species richness in the reference stands within catchments of both lakes, while both given parameters were considerably lower in harmed forest stands. To summarize, the disturbance led to a general decrease of Collembola communities.

  17. Collembola populations under sclerophyllous coppices in Provence (France): comparison between two types of vegetation, Quercus ilex L. and Quercus coccifera L.

    NASA Astrophysics Data System (ADS)

    Cortet, Jérôme; Poinsot-Balaguer, Nicole

    1998-10-01

    A comparative analysis of soil Collembola using two types of sclerophyllous vegetation ( Quercus ilex and Quercus coccifera) was performed at a calcareous site in Provence (France). Collembola populations were examined over a one-year period (11 successive months) in three different soil layers. Although no statistically significant differences could be observed for Collembola abundance and diversity, multivariate analyses (FCA) differentiated the two coppices. Phenologies of some species showed specific responses to the microclimate induced by edaphic conditions. Even though the two coppices were sclerophyllous, the structure of each vegetation, the quantity and quality of litter, which were different, could influence environmental conditions and thus the dynamics of collembolan populations.

  18. Austrodontella monticola sp. nov., a new species of Collembola from montane New Zealand.

    PubMed

    Babenko, Anatoly; Minor, Maria

    2015-01-01

    Collembola were collected from soil in the alpine belt (1600-1900 m a.s.l.) of the Southern Alps of New Zealand. A list of species found is provided. Austrodontella monticola sp. nov., the third species of a Odontellidae genus with a southern distribution is described. The other two species in the genus occur in southern Australia and in the Indian Ocean sector of the Subantarctic respectively. Notes on A. trispina (Womersley, 1935), the type species of the genus, are provided. PMID:26249888

  19. New genus, new species and new record of Neanurinae (Collembola, Neanuridae) for the Neotropics.

    PubMed

    Queiroz, Gabriel C; Deharveng, Louis

    2015-01-01

    A new genus and a new species of Paleonurini (Collembola, Neanurinae) are described in this paper. The new species Ectonura snowdeni sp. nov., is the first record of the austral genus Ectonura for the Neotropics. A new genus from Southeast Brazil, Itanura gen. nov., is created based mainly on head tubercles arrangement. Its type species is Neanura brasiliensis Arlé, 1959 comb. nov., which is redescribed with the designation of a lectotype. Its distribution range is expanded with two new records from high altitude mountains of Southeast Brazil. Specimens from these two localities exhibit small morphological differences with those of the type locality, which are discussed. PMID:26624092

  20. New genus, new species and new record of Neanurinae (Collembola, Neanuridae) for the Neotropics.

    PubMed

    Queiroz, Gabriel C; Deharveng, Louis

    2015-01-01

    A new genus and a new species of Paleonurini (Collembola, Neanurinae) are described in this paper. The new species Ectonura snowdeni sp. nov., is the first record of the austral genus Ectonura for the Neotropics. A new genus from Southeast Brazil, Itanura gen. nov., is created based mainly on head tubercles arrangement. Its type species is Neanura brasiliensis Arlé, 1959 comb. nov., which is redescribed with the designation of a lectotype. Its distribution range is expanded with two new records from high altitude mountains of Southeast Brazil. Specimens from these two localities exhibit small morphological differences with those of the type locality, which are discussed.

  1. The spermatogenesis and oogenesis of the springtail Podura aquatica Linné, 1758 (Hexapoda: Collembola).

    PubMed

    Fanciulli, Pietro Paolo; Gottardo, Marco; Dallai, Romano

    2013-06-01

    Podura aquatica is a springtail of uncertain systematic position. Our study dealing with the ultrastructure of the spermatogenesis and oogenesis of this species is a contribution to a better knowledge of both the reproduction and the systematics of the taxon. In the male, the spermatogenesis proceeds in a similar way to that of other Collembola. Primary spermatocytes do not show synaptonemal complexes which, instead, are found in primary oocytes. Thus a genomic recombination seems to be present only in females, as it occurs in other springtails. Degeneration of secondary spermatocytes, as reported in some families of the Symphypleona, was not observed in P. aquatica. At the end of spermiogenesis, a rolled up sperm cell provided with an anterior long appendage adhering to the acrosome is produced. In the female, the oogenesis also proceeds in a conventional way with the production of eggs rich in yolk. A branched spermatheca is present at the end of the common oviduct, close to the genital opening. It contains many sperm in its lumen. Contrary to the globular appearance of sperm cells in the male genital ducts, in the spermatheca they are straight, elongated, and lack the long anterior appendage. P. aquatica shows a spermatogenesis, sperm structure, and oogenesis similar to those of other Collembola. In agreement with the results of recent phylogenetic studies, we confirm that P. aquatica is a member of Poduridae, and it does not belong to a group close to the Symphypleona. PMID:23515073

  2. The impact of disturbance and ensuing forestry practices on Collembola in spruce forest stands

    NASA Astrophysics Data System (ADS)

    Čuchta, Peter

    2016-04-01

    Soil Collembola communities were investigated in spruce forest stands of the High Tatra Mts that had been heavily damaged by a windstorm in November 2004 and subsequently by a wildfire in July 2005. The study focused on the impact of these disturbances and forestry practices on collembolan community distribution and structure four years after the disturbance. Four different treatments were selected for this study: intact forest stands (REF), non-extracted windthrown stands (NEX), clear-cut windthrown stands (EXT) and burnt windthrown stands (FIR). From a total of 7,820 individuals, 72 species were identified. The highest total abundance mean was recorded in FIR stands followed by NEX and EXT stands and, surprisingly, the lowest in REF stands. The highest total species richness was observed in REF stands, followed by NEX stands and FIR stands and the lowest in EXT stands. In REF and NEX stands the most abundant species were Folsomia penicula and Tetracanthella fjellbergi, while in heavily damaged stands the most abundant was Anurophorus laricis. The present study shows the negative impact of windthrow on Collembola communities as reflected in decreased species richness and abundance. However, disturbance by fire caused a considerable increase in collembolan abundance three years after the event. Moreover, we found out that clearing of windthrown spruce forests after a windstorm is less favourable for communities of soil collembolans and slows down the recovery process.

  3. Sorting out non-sorted circles: Effects of winter climate change on the Collembola community of cryoturbated subarctic tundra

    NASA Astrophysics Data System (ADS)

    Krab, Eveline; Monteux, Sylvain; Becher, Marina; Blume-Werry, Gesche; Keuper, Frida; Klaminder, Jonatan; Kobayashi, Makoto; Lundin, Erik J.; Milbau, Ann; Roennefarth, Jonas; Teuber, Laurenz Michael; Weedon, James; Dorrepaal, Ellen

    2015-04-01

    Non-sorted circles (NSC) are a common type of cryoturbated (frost-disturbed) soil in the arctic and store large amounts of soil organic carbon (SOC) by the burial of organic matter. They appear as sparsely vegetated areas surrounded by denser tundra vegetation, creating patterned ground. Snowfall in the arctic is expected to increase, which will modify freezing intensity and freeze-thaw cycles in soils, thereby impacting on SOC dynamics. Vegetation, soil fauna and microorganisms, important drivers of carbon turnover, may benefit directly from the altered winter conditions and the resulting reduction in cryoturbation, but may also impact each other through trophic cascading. We investigated how Collembola, important decomposer soil fauna in high latitude ecosystems, are affected by increased winter insulation and vegetation cover. We subjected NSC in North-Swedish subarctic alpine tundra to two years of increased thermal insulation (snow fences or fiber cloth) in winter and spring, increasing soil temperatures and strongly reducing freeze-thaw frequency. From these NSC we sampled the Collembola community in: (i) the non-vegetated center, (ii) sparsely vegetated parts in the center and (iii) the vegetated domain surrounding NSC. To link changes in Collembola density and community composition to SOC dynamics, we included measurements of decomposer activity, dissolved organic carbon (DOC) and total extractable nitrogen (TN). We observed differences in Collembola density, community composition and soil fauna activity between the sampling points in the NSC. Specifically Collembola diversity increased with the presence of vegetation and density was higher in the vegetated outer domains. Increased winter insulation did not affect diversity but seemed to negatively affect density and decomposer activity in the vegetated outer domains. Interestingly, SOM distribution over NSC changed with snow addition (also to a lesser extent with fleece insulation) towards less SOM in the

  4. Population dynamics and diapause response of the springtail pest Sminthurus viridis (Collembola: Sminthuridae) in southeastern Australia.

    PubMed

    Roberts, John M K; Umina, Paul A; Hoffmann, Ary A; Weeks, Andrew R

    2011-04-01

    The springtail, Sminthurus viridis (L.) (Collembola: Sminthuridae), is an important agricultural pest across southern Australia. We investigated the seasonal abundance patterns and summer diapause response of S. viridis in southeastern Australia by using field and shadehouse (a greenhouse that offers seedlings shade) experiments. Seasonal activity patterns of S. viridis were largely consistent with previous studies, with the pest active from autumn to spring. In addition, the timing and pattern of the summer-diapausing egg stage was established, with multiple generations probably producing diapause eggs. A strong relationship between soil moisture and temperature with autumn emergence also was observed. These results suggest that S. viridis autumn pest pressure can be predicted and indicate that late-season spraying strategies currently used for a sympatric agricultural pest are unlikely to be as effective against S. viridis. PMID:21510194

  5. Effects of Season and Management of Irrigated Cotton Fields on Collembola (Hexapoda) in New South Wales, Australia.

    PubMed

    Lytton-Hitchins, James A; Greenslade, Penelope; Wilson, Lewis J

    2015-06-01

    The effects of production practices on the relative abundance of springtails (Collembola) in irrigated cotton fields of northern New South Wales (NSW) were studied over 2 yr to examine effects of farm management on these decomposer organisms. Pitfall trapping and soil core extraction was undertaken in both pseudoreplicated plots within whole fields on cotton farms and on experimental replicate plots of Envirofeast cotton and Lucerne. The relative abundance of surface-active springtails in cotton rows and densities of soil species from the rhizosphere were calculated. Twenty-three species of Collembola were collected from 5 fields, 19 in pitfall traps, and 11 in soil cores. Five species, Setogaster sp., Proisotoma minuta, Entomobrya unostrigata, Entomobrya multifasciata grp, and Lepidobrya sp. were numerically dominant on the ground at 86-96% of individuals and Mesaphorura sp., Folsomides parvulus, and Hemisotoma thermophila grp dominant in the soil. Native grassland samples contained 15 species of which a probable 10 were native and 8 were not found in cotton. Nineteen species of the 24 species identified from cotton were predominantly fungal feeders. Highest catches of Collembola occurred after flowering and soil Collembola increased with depth and during cotton growth on unsprayed plots but decreased on sprayed plots. Surface soil moistures affected daily catch rates with decomposing residues, crop stage, predator abundance, and season as secondary factors. Insecticide (endosulfan, pyrethroid, carbamate, and organophosphate) and predator effects were either negligible or unclear depending on the factor involved. Springtails appear to be predominately food limited during times of adequate soil moisture in cotton fields. PMID:26313958

  6. Assessing the potential for intrinsic recovery in a Collembola two-generation study: possible implementation in a tiered soil risk assessment approach for plant protection products.

    PubMed

    Ernst, Gregor; Kabouw, Patrick; Barth, Markus; Marx, Michael T; Frommholz, Ursula; Royer, Stefanie; Friedrich, Sabine

    2016-01-01

    Collembola are soil dwelling organisms that provide important ecosystem services within soils. To increase realism in evaluating potential effects of plant protection products a Collembola two-generation study was developed. This test assesses the potential for recovery of Collembola when exposed to plant protection products. Juvenile individuals of Folsomia candida (Willem, Ann Soc Entomol Belg 46:275-283, 1902) which hatched under conditions of exposure to a test substance in a modified OECD 232 bioassay were introduced into a second consecutive bioassay containing the same test substance aged in soil. This test system determines whether a population which was initially impacted by a substance in a 1st bioassay shows normal reproduction or survival in a 2nd bioassay after aging of the test substance in soil. An intermediate period for juvenile growth is included between the 1st and 2nd bioassay in order to reduce the control treatment variability in reproduction and mortality to fulfill the validity criteria according to the OECD 232 guideline. The Collembola two-generation study is able to differentiate between substances showing either a potential long-term risk or comprising a low risk. Comparing the results of this two generation study with data from semi-field or field studies indicates a high degree of conservatism when this test is considered within a tiered risk assessment scheme. This approach represents a valuable tool which makes the risk assessment more efficient by providing an alternative refinement option for highly conservative tier 1 Collembola risk assessment. PMID:26441339

  7. Assessing the potential for intrinsic recovery in a Collembola two-generation study: possible implementation in a tiered soil risk assessment approach for plant protection products.

    PubMed

    Ernst, Gregor; Kabouw, Patrick; Barth, Markus; Marx, Michael T; Frommholz, Ursula; Royer, Stefanie; Friedrich, Sabine

    2016-01-01

    Collembola are soil dwelling organisms that provide important ecosystem services within soils. To increase realism in evaluating potential effects of plant protection products a Collembola two-generation study was developed. This test assesses the potential for recovery of Collembola when exposed to plant protection products. Juvenile individuals of Folsomia candida (Willem, Ann Soc Entomol Belg 46:275-283, 1902) which hatched under conditions of exposure to a test substance in a modified OECD 232 bioassay were introduced into a second consecutive bioassay containing the same test substance aged in soil. This test system determines whether a population which was initially impacted by a substance in a 1st bioassay shows normal reproduction or survival in a 2nd bioassay after aging of the test substance in soil. An intermediate period for juvenile growth is included between the 1st and 2nd bioassay in order to reduce the control treatment variability in reproduction and mortality to fulfill the validity criteria according to the OECD 232 guideline. The Collembola two-generation study is able to differentiate between substances showing either a potential long-term risk or comprising a low risk. Comparing the results of this two generation study with data from semi-field or field studies indicates a high degree of conservatism when this test is considered within a tiered risk assessment scheme. This approach represents a valuable tool which makes the risk assessment more efficient by providing an alternative refinement option for highly conservative tier 1 Collembola risk assessment.

  8. The effect of the glyphosate, 2,4-D, atrazine e nicosulfuron herbicides upon the Edaphic collembola (Arthropoda: Ellipura) in a no tillage system.

    PubMed

    Lins, Vilma S; Santos, Honório R; Gonçalves, Manoel C

    2007-01-01

    The use of herbicides is a common and intensive practice in no tillage systems. The herbicides can influence, directly or indirectly, the population of edaphic arthropods. Collembola is a group that functions as a bio-indicator of soil conditions. The degree of abundance and diversity of Collembola provides the level of soil disturbance provoked by agricultural practices. This experiment was designed to compare the influence of herbicides on the population fluctuation of Collembola in a no-till soil preparation system. The work was conducted in a non irrigated no-till area at the Núcleo Experimental de Ciências Agrárias of the Universidade Federal de Mato Grosso do Sul (UFMS), Campus de Dourados, in soil planted with corn as a surface covering, during the period of December, 2002 to December, 2003. The data were analyzed according to a completely randomized model, in a split plot design. The plots received four types of herbicides: glyphosate, atrazine, 2,4-D and nicosulfuron. A fifth plot did not receive any herbicide (control), for a total of five treatment types. The sub plots were represented by their collection times (10, 20, 30 and 40 days after the herbicide applications). Both the type of herbicide and the time of data sampling influenced the Collembola population fluctuaction. The treatments with atrazine and 2,4-D caused the most reduction of the population of Collembola, depending on the time of application.

  9. Environmental physiology of three species of Collembola at Cape Hallett, North Victoria Land, Antarctica.

    PubMed

    Sinclair, Brent J; Terblanche, John S; Scott, Matthew B; Blatch, Gregory L; Jaco Klok, C; Chown, Steven L

    2006-01-01

    The environmental physiology of three speciesof Collembola: Cryptopygus cisantarcticus, Isotoma klovstadi (Isotomidae) and Friesea grisea (Neanuridae) was investigated from November 2002 to February 2003 at Cape Hallett, North Victoria Land, Antarctica. All three species were freeze avoiding, and while supercooling points were variable on seasonal and daily scales in I. klovstadi and C. cisantarcticus, they remained largely static in F. grisea. LT50 (temperature where 50% of animals are killed by cold) was -13.6, -19.1 and -19.8 degrees C for C. cisantarcticus, I. klovstadi and F. grisea, respectively. Upper lethal temperature was 34, 34 and 38 degrees C for C. cisantarcticus, I. klovstadi and F. grisea. Critical thermal minimum onset (the temperature where individuals entered chill coma) was ca. -7, -12 and -8 degrees C for C. cisantarcticus, I. klovstadi and F. grisea, and 25% of I. klovstadi individuals froze without entering chill coma. Critical thermal maximum (the onset of spasms at high temperature) was 30, 33 and 34 degrees C for C. cisantarcticus, I. klovstadi and F. grisea. Haemolymph osmolality was approximately 720 mOsm for C. cisantarcticus and 680 mOsm for I. klovstadi, and both species showed a moderate degree of thermal hysteresis, which persisted through the season. Desiccation resistance was measured as survival above silica gel, and the species survived in the rank order of C. cisantarcticus< I. klovstadi = F. grisea. Desiccation resulted in an increase in haemolymph osmolality in I. klovstadi, and water was quickly regained by desiccation-stressed individuals that had access to liquid water, but not by individuals placed in high humidity, indicating that this species is unable to absorb atmospheric water vapour. SDS-PAGE did not suggest any strong patterns in protein synthesis either seasonally or in response to temperature or desiccation stress. Microclimate temperatures were measured at sites representative of collection sites for the three

  10. Genetic diversity among populations of Antarctic springtails (Collembola) within the Mackay Glacier ecotone.

    PubMed

    Beet, Clare R; Hogg, Ian D; Collins, Gemma E; Cowan, Don A; Wall, Diana H; Adams, Byron J

    2016-09-01

    Climate changes are likely to have major influences on the distribution and abundance of Antarctic terrestrial biota. To assess arthropod distribution and diversity within the Ross Sea region, we examined mitochondrial DNA (COI) sequences for three currently recognized species of springtail (Collembola) collected from sites in the vicinity, and to the north of, the Mackay Glacier (77°S). This area acts as a transition between two biogeographic regions (northern and southern Victoria Land). We found populations of highly divergent individuals (5%-11.3% intraspecific sequence divergence) for each of the three putative springtail species, suggesting the possibility of cryptic diversity. Based on molecular clock estimates, these divergent lineages are likely to have been isolated for 3-5 million years. It was during this time that the Western Antarctic Ice Sheet (WAIS) was likely to have completely collapsed, potentially facilitating springtail dispersal via rafting on running waters and open seaways. The reformation of the WAIS would have isolated newly established populations, with subsequent dispersal restricted by glaciers and ice-covered areas. Given the currently limited distributions for these genetically divergent populations, any future changes in species' distributions can be easily tracked through the DNA barcoding of springtails from within the Mackay Glacier ecotone. PMID:27463035

  11. Cryptic Diversity in the Ubiquist Species Parisotoma notabilis (Collembola, Isotomidae): A Long-Used Chimeric Species?

    PubMed Central

    Porco, David; Potapov, Mikhail; Bedos, Anne; Busmachiu, Galina; Weiner, Wanda M.; Hamra-Kroua, Salah; Deharveng, Louis

    2012-01-01

    Parisotoma notabilis is the most common species of Collembola in Europe and is currently designated as ubiquist. This species has been extensively used in numerous studies and is considered as well characterized on a morphological ground. Despite the homogeneity of its morphology, the sequencing of the barcoding fragment (5′ end of COI) for several populations throughout Europe and North America revealed four distinct genetic lineages. The divergence found between these lineages was similar to the genetic distance among other species of the genus Parisotoma included in the analysis. All four lineages have been confirmed by the nuclear gene 28S. This congruence between mitochondrial and nuclear signals, as well as the geographical distribution pattern of lineages observed in Europe, supports the potential specific status of these lineages. Based on specimens from the type locality (Hamburg), the species name was successfully assigned to one of these lineages. This finding raises several problems as Parisotoma notabilis has been widely used in many ecological studies. Accumulation of new data for the different lineages detected, especially ecological information and life history traits, is needed to help resolve this situation. PMID:23049931

  12. Catalogue of type materials of springtails (Hexapoda, Collembola) in the Canadian National Collection of Insects, Arachnids & Nematodes.

    PubMed

    Stebaeva, Sophya; Lonsdale, Owen; Babenko, Anatoly

    2016-01-01

    The catalogue assembles and updates all data concerning the type material of Collembola kept in the Canadian National Collection of Insects, Arachnids & Nematodes in Ottawa (CNC). Information is provided for type material of 69 species. Included are holotypes of 31 species (together with 5 ones from Cretaceous amber), syntypes of 26 species (four of them are presently considered to be junior synonyms) and paratypes of 32 species (one of which is considered a junior synonym). Essential label data, references to original descriptions, and modern status including synonyms are given. PMID:27394350

  13. A comparative study of the effects of metal contamination on Collembola in the field and in the laboratory.

    PubMed

    Fountain, M T; Hopkin, S P

    2004-08-01

    We examined the species diversity and abundance of Collembola at 32 sampling points along a gradient of metal contamination in a rough grassland site (Wolverhampton, England), formerly used for the disposal of metal-rich smelting waste. Differences in the concentrations of Cd, Cu, Pb and Zn between the least and most contaminated part of the 35 metre transect were more than one order of magnitude. A gradient of Zn concentrations from 597 to 9080 microg g(-1) dry soil was found. A comparison between field concentrations of the four metals and previous studies on their relative toxicities to Collembola, suggested that Zn is likely to be responsible for any ecotoxicological effects on springtails at this site. Euedaphic (soil dwelling) Collembola were extracted by placing soil cores into Tullgren funnels and epedaphic (surface dwelling) species were sampled using pitfall traps. There was no obvious relationship between the total abundance, or a range of commonly used diversity indices, and Zn levels in soils. However, individual species showed considerable differences in abundance. Metal "tolerant" (e.g., Ceratophysella denticulata) and metal "sensitive" (e.g., Cryptopygus thermophilus) species could be identified. Epedaphic species appeared to be influenced less by metal contamination than euedaphic species. This difference is probably due to the higher mobility and lower contact with the soil pore water of epedaphic springtails in comparison to euedaphic Collembola. In an experiment exposing the standard test springtail, Folsomia candida, to soils from all 32 sampling points, adult survival and reproduction showed small but significant negative relationships with total Zn concentrations. Nevertheless, juveniles were still produced from eggs laid by females in the most contaminated soils with 9080 microg g(-1) Zn. Folsomia candida is much more sensitive to equivalent concentrations of Zn in the standard OECD soil. Thus, care should be taken in extrapolating the

  14. The toxicity of soil samples containing TNT and other ammunition derived compounds in the enchytraeid and collembola-biotest.

    PubMed

    Schäfer, R; Achazi, R K

    1999-01-01

    The effect of ammunition-like compounds and armament waste on the mortality and reproduction of terrestrial invertebrates was assayed by using two biotests: the enchytraeid-biotest with Enchytraeus crypticus and the collembola-biotest with Folsomia Candida. Toxicity was investigated by using standard soil (Lufa 2.2) spiked with 2,4,6-trinitrotoluene (TNT), hexahydro-l,3,5-trinitro-l,3,5-triazine (hexogen, RDX), octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (octogen, HMX) and 2,4,6-triaminotoluene (TAT). Ecotoxicity was investigated with ammunition-contaminated soil material from the former ammunition plant "Tanne" at Clausthal-Zellerfeld (CTNTla) and the Brandplatz (incineration site) in Torgau-Elsnig (TETNT1a), Germany. TNT increased mortality and reduced reproduction of both test organisms corresponding to the concentrations used, whereas hexogen, octogen and TAT had no effect in the tested concentrations (1000-2000 mg/kg). From the two soil materials, TETNT1a was much more toxic than CTNT1a. The LC50(7d) in the enchytraeid-biotest was 570 mg TNT/kg and the EC50(28d) 369 mg TNT/kg soil material (dw). In the collembola-biotest the LC50(7d) was 185 mg TNT/kg and the EC50(28d) 110 mg TNT/kg soil matter (dw).

  15. Diversity in plants and other Collembola ameliorate impacts of Sminthurus viridis on plant community structure

    NASA Astrophysics Data System (ADS)

    Barker, Gary M.

    2006-05-01

    Five experiments investigated the importance of herbivory by Sminthurus viridis in structuring botanical composition in developing grasslands, and how these effects may be modified by diversity in collembolan and plant species. Differential susceptibility to S. viridis feeding was demonstrated in 23 dicotyledonous and three monocotyledonous plants assayed as seedlings at the first true leaf stage. The composition of seedling communities developing from natural and artificially constructed soil seed banks varied with the level of S. viridis infestation, with plant species least susceptible to herbivory making the greatest contribution to plant biomass. The combined effect of herbivory by S. viridis and Bourletiella hortensis on Trifolium repens biomass was shown to be less than the effect of S. viridis alone, indicating competitive interference. The adverse effects of herbivory by S. viridis on T. repens biomass was reduced by increased diversity of plants growing in association with the legume, and the presence of four non-herbivorous arthropleonan Collembola. S. viridis was shown to reduce seedling numbers, species diversity and biomass in communities developing from the soil seed bank, but the presence of non-herbivorous arthropleonan species reduced the effect of S. viridis. The experiments demonstrate the potential for herbivory by S. viridis to significantly alter species composition in developing grassland communities. However, interactions with collembolan and plant species profoundly modified S. viridis herbivory impacts, either by reducing feeding intensity or enhancing plant growth. These results highlight the fact that data from simple, synthetic systems may be poor predictors of herbivory impacts under field conditions where more complex species interactions occur.

  16. Appendage patterning in the primitively wingless hexapods Thermobia domestica (Zygentoma: Lepismatidae) and Folsomia candida (Collembola: Isotomidae).

    PubMed

    Schaeper, Nina D; Wimmer, Ernst A; Prpic, Nikola-Michael

    2013-11-01

    Arthropod appendages are among the most diverse animal organs and have been adapted to a variety of functions. Due to this diversity, it can be difficult to recognize homologous parts in different appendage types and different species. Gene expression patterns of appendage development genes have been used to overcome this problem and to identify homologous limb portions across different species and their appendages. However, regarding the largest arthropod group, the hexapods, most of these studies focused on members of the winged insects (Pterygota), but primitively wingless groups like the springtails (Collembola) or silverfish and allies (Zygentoma) are underrepresented. We have studied the expression of a set of appendage patterning genes in the firebrat Thermobia domestica and the white springtail Folsomia candida. The expressions of Distal-less (Dll) and dachshund (dac) are generally similar to the patterns reported for pterygote insects. Modifications of gene regulation, for example, the lack of Dll expression in the palp of F. candida mouthparts, however, point to changes in gene function that can make the use of single genes and specific expression domains problematic for homology inference. Such hypotheses should therefore not rely on a small number of genes and should ideally also include information about gene function. The expression patterns of homothorax (hth) and extradenticle (exd) in both species are similar to the patterns of crustaceans and pterygote insects, but differ from those in chelicerates and myriapods. The proximal specificity of hth thus appears to trace from a common hexapod ancestor and also provides a link to the regulation of this gene in crustaceans. PMID:23873479

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

    PubMed

    Block, W; Worland, M R

    2001-05-01

    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

  18. Appendage patterning in the primitively wingless hexapods Thermobia domestica (Zygentoma: Lepismatidae) and Folsomia candida (Collembola: Isotomidae).

    PubMed

    Schaeper, Nina D; Wimmer, Ernst A; Prpic, Nikola-Michael

    2013-11-01

    Arthropod appendages are among the most diverse animal organs and have been adapted to a variety of functions. Due to this diversity, it can be difficult to recognize homologous parts in different appendage types and different species. Gene expression patterns of appendage development genes have been used to overcome this problem and to identify homologous limb portions across different species and their appendages. However, regarding the largest arthropod group, the hexapods, most of these studies focused on members of the winged insects (Pterygota), but primitively wingless groups like the springtails (Collembola) or silverfish and allies (Zygentoma) are underrepresented. We have studied the expression of a set of appendage patterning genes in the firebrat Thermobia domestica and the white springtail Folsomia candida. The expressions of Distal-less (Dll) and dachshund (dac) are generally similar to the patterns reported for pterygote insects. Modifications of gene regulation, for example, the lack of Dll expression in the palp of F. candida mouthparts, however, point to changes in gene function that can make the use of single genes and specific expression domains problematic for homology inference. Such hypotheses should therefore not rely on a small number of genes and should ideally also include information about gene function. The expression patterns of homothorax (hth) and extradenticle (exd) in both species are similar to the patterns of crustaceans and pterygote insects, but differ from those in chelicerates and myriapods. The proximal specificity of hth thus appears to trace from a common hexapod ancestor and also provides a link to the regulation of this gene in crustaceans.

  19. [Distribution and diversity of springtails (Hexapoda: Collembola) on the altitudinal gradient of a temperate forest in Mexico].

    PubMed

    García-Gómez, Arturo; Castaño-Meneses, Gabriela; Palacios-Vargas, José G

    2011-03-01

    Mountain ecosystems have shown slow mineralization activity due to weather conditions, and to some groups with arthropods with special roles. The Collembola is an important group for litter fragmentation, showing different distribution patterns. The objective of the present study was to determine the diversity of Collembola along a volcano altitudinal gradient. For this, four sampling expeditions evaluated four altitudinal levels (I = 2 753, II = 3 015, III = 3 250 and IV = 3 687 masl) in Iztaccihuatl Volcano, from November 2003, and March, June and August 2004. Shannon diversity (H'), Pielou evenness (J') and Simpson dominance (1/lambda) indices were calculated. The similarity between the associations of springtails between the sampling sites was evaluated by a cluster analysis using the Pearson correlation coefficient, as distance and the unpaired arithmetic averages (UPGMA) as amalgamation method. A total of 24 075 springtails, distributed in 12 families, 46 genera and 86 species was collected. The higher species abundance was found at the altitudinal area II. The lowest diversity value was recorded in IV, while the higher diversity values were found in III. Significant differences between Shannon indices were found between zones II-III (t(0.01, 187) = 4.11, p < 0.05) and between III-IV (t(0.01, 187) = 3.8, p < 0.05) according to modified t-test. When considering sampling dates, no significant differences were found. The dendrogram showed that in composition the level I is more homogeneous throughout the year. In conclusion, a statistically significant seasonal variation in springtail abundances was not found, but it was observed that, the lower altitude (I) resulted more homogeneous along the studied period, followed by level II and III. There is a particular assemblage of springtails community in each altitudinal area studied; in general, the sites with low slope resulted more diverse in Collembola communities. These results show that there are important

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

    PubMed

    Block, W; Worland, M R

    2001-05-01

    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

  1. The Influence of Soil Characteristics on the Toxicity of Oil Refinery Waste for the Springtail Folsomia candida (Collembola).

    PubMed

    Reinecke, Adriaan J; van Wyk, Mia; Reinecke, Sophie A

    2016-06-01

    We determined the toxicity of oil refinery waste in three soils using the springtail Folsomia candida (Collembola) in bioassays. Sublethal exposure to a concentration series of API-sludge presented EC50's for reproduction of 210 mg/kg in site soil; 880 mg/kg in LUFA2.2- and 3260 mg/kg in OECD-soil. The sludge was the least toxic in the OECD-soil with the highest clay and organic matter content, the highest maximum water holding capacity, and the least amount of sand. It was the most toxic in the reference site soil with the lowest organic matter content and highest sand content. The results emphasized the important role of soil characteristics such as texture and organic matter content in influencing toxicity, possibly by affecting bioavailability of toxicants. PMID:27048278

  2. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

    PubMed

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-08-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  3. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola

    PubMed Central

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-01-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  4. Polarization sensitivity in Collembola: an experimental study of polarotaxis in the water-surface-inhabiting springtail Podura aquatica.

    PubMed

    Egri, Ádám; Farkas, Alexandra; Kriska, György; Horváth, Gábor

    2016-08-15

    The ventral eye of the water-surface-inhabiting springtail Podura aquatica has six ommatidia with horizontal and vertical microvilli and perceives light from the ventral, frontal and frontodorsal regions, whereas the dorsal eye possesses two upward-looking ommatidia with vertical microvilli. The ventral eye may detect water by its polarization sensitivity, even if the insect is resting with its head slightly tipped down on a raised surface. The polarization sensitivity and polarotaxis in springtails (Collembola) have not been investigated. Therefore, we performed behavioural choice experiments to study them in P. aquatica We found that the strength of phototaxis in P. aquatica depends on the polarization characteristics of stimulating light. Horizontally and vertically polarized light were the most and least attractive, respectively, while unpolarized stimulus elicited moderate attraction. We show that horizontally polarized light attracts more springtails than unpolarized, even if the polarized stimulus was 10 times dimmer. Thus, besides phototaxis, P. aquatica also performs polarotaxis with the ability to measure or at least estimate the degree of polarization. Our results indicate that the threshold d* of polarization sensitivity in P. aquatica is between 10.1 and 25.5%. PMID:27312471

  5. Intraspecific Phenotypic Variation and Morphological Divergence of Strains of Folsomia candida (Willem) (Collembola: Isotomidae), the "Standard" Test Springtaill.

    PubMed

    Tully, Thomas; Potapov, Mikhail

    2015-01-01

    We describe and compare the external morphology of eleven clonal strains and one sexual lineage of the globally distributed Folsomia candida, known as "standard" test Collembola. Of the 18 morphological characters studied, we measured 14 to have significant between-strains genetic variations, 9 of these had high heritabilities (>78%). The quantified morphological polymorphism was used to analyse the within-species relationships between strains by using both a parsimony analysis and a distance tree. These two detailed morphological phylogenies have revealed that the parthenogenetic strains grouped themselves into two major clades. However the exact position of the sexual strain remains unclear and further analysis is needed to confirm its exact relationship with the parthenogenetic ones. The two morphologically based clades were found to be the same as the ones previously described using molecular analysis. This shows that despite large within-strain variations, morphological characters can be used to differentiate some strains that have diverged within a single morphospecies. We discuss the potential evolutionary interpretations and consequences of these different levels of phenotypic variability. PMID:26355293

  6. Within-species variation in long-term trajectories of growth, fecundity and mortality in the Collembola Folsomia candida.

    PubMed

    Mallard, F; Farina, M; Tully, T

    2015-12-01

    Senescence--the progressive deterioration of organisms with age--affects many traits of which survival and reproduction are the most commonly studied. Recent comparative studies have revealed a remarkable amount of variation in the patterns of ageing across the tree of life. This between-species diversity raises many questions about the evolution of senescence and of the shapes of the life-history age trajectories. Here, we study how the different components of the shapes of these life-history age trajectories can vary within a single species to shed light on the possible constraints involved in their evolution. To do so, we closely followed in controlled laboratory conditions, and for more than 450 days, the mortality, body length and fecundity of small cohorts of two clonal lineages of the Collembola Folsomia candida. We studied three components of the adult mortality trajectory: the baseline mortality, onset and speed of senescence. We found that they can differ between strains of a single species in such a way that, remarkably, an increased life expectancy is not synonymous with a delayed senescence: the strain that grows bigger has the longest life expectancy but suffers from a precocious senescence. We observed marked differences between the strains in the asymptotic body length and reproductive investment. More generally, our results highlight the importance of finely describing the long-term trajectories of several life-history traits in order to better understand how the patterns of senescence have been shaped by natural selection. PMID:26348879

  7. Deep phylogeographic divisions and long-term persistence of forest invertebrates (Hexapoda: Collembola) in the North-Western Mediterranean basin.

    PubMed

    Cicconardi, F; Nardi, F; Emerson, B C; Frati, F; Fanciulli, P P

    2010-01-01

    The North-Western Mediterranean basin is well known for its high number of relictual endemic taxa, and has been indicated as one of the world's major biodiversity hotspots at the species level. A possible contributing factor may be long-term persistence of populations and their prolonged stability. This study was designed to investigate the phylogeographic structure of three common species of the genus Lepidocyrtus (Hexapoda: Collembola), soil-dwelling arthropods characterized by limited dispersal capabilities and generally associated with forest habitats. We observed a remarkable geographic structure, with numerous deeply divergent genetic lineages occupying islands as well as mainland sites with no apparent gene flow among most sites, even across distances of only tens of kilometres. The reconstructed time frame for the evolution of these lineages suggests divergence between 5 and 15 Ma. This indicates a remarkably ancient origin and long-term persistence of individual lineages over a fine geographic scale despite the occurrence of abrupt sea level and climatic fluctuations in the area. This further suggests that currently recognized morphological species might be a serious underestimation of the true springtail biodiversity within this region. PMID:20015142

  8. Genetic structure and long-distance dispersal in populations of the wingless pest springtail, Sminthurus viridis (Collembola: Sminthuridae).

    PubMed

    Roberts, John M K; Weeks, Andrew R

    2011-02-01

    The lucerne flea, Sminthurus viridis (Collembola: Sminthuridae) (L.) is a major pest of broadacre agriculture across southern Australia. Few molecular studies have been conducted on S. viridis and none have examined its population genetics, despite the importance for developing effective control strategies. Here, we characterize the genetic structure of Australian populations using three allozyme and eight microsatellite loci, as well as sequencing a fragment of the mitochondrial DNA cytochrome oxidase I gene. We found that S. viridis in Australia are diploid, sexually reproducing and exhibit significant population structure as a result of limited gene flow. Despite significant differentiation between populations, there was very low cytochrome oxidase subunit I (COI) gene sequence variation, indicating the presence of a single species in Australia. The observed structure only marginally complied with an 'isolation by distance' model with human-mediated long-distance dispersal likely occurring. Allozymes and microsatellites gave very similar FST estimates, although differences found for novel alternative estimates of differentiation suggest that the allozymes did not capture the full extent of the population structure. These results highlight that control strategies may need to vary for locally adapted S. viridis populations and strategies aimed at limiting the spread of any future pesticide resistance will need to manage the effects of human-mediated dispersal. PMID:21219669

  9. Intraspecific Phenotypic Variation and Morphological Divergence of Strains of Folsomia candida (Willem) (Collembola: Isotomidae), the "Standard" Test Springtaill

    PubMed Central

    Tully, Thomas; Potapov, Mikhail

    2015-01-01

    We describe and compare the external morphology of eleven clonal strains and one sexual lineage of the globally distributed Folsomia candida, known as “standard” test Collembola. Of the 18 morphological characters studied, we measured 14 to have significant between-strains genetic variations, 9 of these had high heritabilities (>78%). The quantified morphological polymorphism was used to analyse the within-species relationships between strains by using both a parsimony analysis and a distance tree. These two detailed morphological phylogenies have revealed that the parthenogenetic strains grouped themselves into two major clades. However the exact position of the sexual strain remains unclear and further analysis is needed to confirm its exact relationship with the parthenogenetic ones. The two morphologically based clades were found to be the same as the ones previously described using molecular analysis. This shows that despite large within-strain variations, morphological characters can be used to differentiate some strains that have diverged within a single morphospecies. We discuss the potential evolutionary interpretations and consequences of these different levels of phenotypic variability. PMID:26355293

  10. Avoidance tests with Collembola and earthworms as early screening tools for site-specific assessment of polluted soils.

    PubMed

    da Luz, Tiago Natal; Ribeiro, Rui; Sousa, José Paulo

    2004-09-01

    Avoidance tests with earthworms and collembolans were conducted to demonstrate their feasibility as early screening tools for assessing the toxic potential of metal-polluted soils. Four different soils, with different degrees of metal contamination, were obtained from an abandoned mining area. All possible paired combinations were assessed for an avoidance response by the organisms. Data revealed that both species were able to avoid the most contaminated soils at the center of the ore extraction and treatment areas compared to those collected further away from the mine. However, earthworms and springtails differed in sensitivity to metals, especially when testing the two most polluted soils that had different contamination profiles. Earthworms exhibited a more consistent, less variable response than springtails. Overall results showed that avoidance tests with collembolans and earthworms have the potential to be used as screening tools in ecological risk assessment schemes for contaminated land, to trigger other tests in case of concern. However, further method development is needed to reduce variability in the data, particularly in the Collembola assays, and to gain knowledge about the possible effects of soil properties on the outcome of the tests. PMID:15378996

  11. The impact of disturbance and ensuing forestry practices on Collembola in monitored stands of windthrown forest in the Tatra National Park (Slovakia).

    PubMed

    Čuchta, Peter; Miklisová, Dana; Kováč, Lubomír

    2013-06-01

    Soil Collembola communities were investigated in spruce forest stands of the High Tatra Mts that had been heavily damaged by a windstorm in November 2004 and subsequently by a wildfire in July 2005. The study focused on the impact of these disturbances and forestry practices on collembolan community distribution and structure 4 years after the disturbance. Four different treatments were selected for this study: intact forest stands (REF), non-extracted windthrown stands (NEX), clear-cut windthrown stands (EXT) and burnt windthrown stands (FIR). From a total of 7,820 individuals, 72 species were identified. The highest total abundance mean was recorded in FIR stands followed by NEX and EXT stands and, surprisingly, the lowest in REF stands. The highest total species richness was observed in REF stands, followed by NEX stands and FIR stands and the lowest in EXT stands. In REF and NEX stands, the most abundant species were Folsomia penicula and Tetracanthella fjellbergi, while in heavily damaged stands, the most abundant was Anurophorus laricis. The ordination method used demonstrated a significant influence of treatment on the abundance of Collembola. ANOVA used confirmed significant differences for all dominant species between treatments. The present study shows the negative impact of windthrow on Collembola communities as reflected in decreased species richness and abundance. However, disturbance by fire caused a considerable increase in collembolan abundance 3 years after the event. Moreover, we show that clearing of windthrown spruce forests after a windstorm is less favourable for communities of soil collembolans and slows down the recovery process.

  12. Co-occurrence analyses show that non-random community structure is disrupted by fire in two groups of soil arthropods (Isopoda Oniscidea and Collembola)

    NASA Astrophysics Data System (ADS)

    Pitzalis, Monica; Luiselli, Luca; Bologna, Marco A.

    2010-01-01

    In this paper, we tested the hypothesis that natural catastrophes may destroy non-random community structure in natural assemblages of organisms. As a study system, we selected fire as the catastrophic event, and two groups of soil arthropods (Collembola and Isopoda Oniscidea) as target organisms. By co-occurrence analyses and Monte Carlo simulations of niche overlap analysis (C-score, with fixed-equiprobable model; RA2 and RA3 algorithms) we evaluated whether the community structure of these two groups were random/non-random at three unburnt sites and at three neighbour burnt sites that were devastated by a large-scale fire in summer 2000. Both taxa experienced a remarkable reduction in the number of species sampled in burnt versus unburnt sites, but the difference among sites was not statistically significant for Oniscidea. We determined that community structure was clearly non-random at the unburnt sites for both Collembola (according to RA3 algorithm) and Isopoda Oniscidea (according to co-occurrence analysis) and that, as predicted by theory, the catastrophic event did deeply alter the community structure by removing the non-random organization of the species interactions. We also observed a shift from segregation to aggregation/randomness in soil arthropods communities affected by fire, a pattern that was similar to that observed in natural communities of organisms perturbed by the introduction of alien species, thus indicating that this pattern may be generalizable when alteration of communities may occur.

  13. Revealing pancrustacean relationships: Phylogenetic analysis of ribosomal protein genes places Collembola (springtails) in a monophyletic Hexapoda and reinforces the discrepancy between mitochondrial and nuclear DNA markers

    PubMed Central

    2008-01-01

    Background In recent years, several new hypotheses on phylogenetic relations among arthropods have been proposed on the basis of DNA sequences. One of the challenged hypotheses is the monophyly of hexapods. This discussion originated from analyses based on mitochondrial DNA datasets that, due to an unusual positioning of Collembola, suggested that the hexapod body plan evolved at least twice. Here, we re-evaluate the position of Collembola using ribosomal protein gene sequences. Results In total 48 ribosomal proteins were obtained for the collembolan Folsomia candida. These 48 sequences were aligned with sequence data on 35 other ecdysozoans. Each ribosomal protein gene was available for 25% to 86% of the taxa. However, the total sequence information was unequally distributed over the taxa and ranged between 4% and 100%. A concatenated dataset was constructed (5034 inferred amino acids in length), of which ~66% of the positions were filled. Phylogenetic tree reconstructions, using Maximum Likelihood, Maximum Parsimony, and Bayesian methods, resulted in a topology that supports monophyly of Hexapoda. Conclusion Although ribosomal proteins in general may not evolve independently, they once more appear highly valuable for phylogenetic reconstruction. Our analyses clearly suggest that Hexapoda is monophyletic. This underpins the inconsistency between nuclear and mitochondrial datasets when analyzing pancrustacean relationships. Caution is needed when applying mitochondrial markers in deep phylogeny. PMID:18366624

  14. Nonconsumptive Predator-Prey Interactions: Sensitivity of the Detritivore Sinella curviseta (Collembola: Entomobryidae) to Cues of Predation Risk From the Spider Pardosa milvina (Araneae: Lycosidae).

    PubMed

    Sitvarin, Michael I; Romanchek, Christian; Rypstra, Ann L

    2015-04-01

    Predators can affect prey indirectly when prey respond to cues indicating a risk of predation by altering activity levels. Changes in prey behavior may cascade through the food web to influence ecosystem function. The response of the collembolan Sinella curviseta Brook (Collembola: Entomobryidae) to cues indicating predation risk (necromones and cues from the wolf spider Pardosa milvina (Hentz) (Araneae: Lycosidae)) was tested. Additionally, necromones and predator cues were paired in a conditioning experiment to determine whether the collembolan could form learned associations. Although collembolans did not alter activity levels in response to predator cues, numerous aspects of behavior differed in the presence of necromones. There was no detectable conditioned response to predator cues after pairing with necromones. These results provide insight into how collembolans perceive and respond to predation threats that vary in information content. Previously detected indirect impacts of predator cues on ecosystem function are likely due to changes in prey other than activity level. PMID:26313189

  15. Nonconsumptive Predator-Prey Interactions: Sensitivity of the Detritivore Sinella curviseta (Collembola: Entomobryidae) to Cues of Predation Risk From the Spider Pardosa milvina (Araneae: Lycosidae).

    PubMed

    Sitvarin, Michael I; Romanchek, Christian; Rypstra, Ann L

    2015-04-01

    Predators can affect prey indirectly when prey respond to cues indicating a risk of predation by altering activity levels. Changes in prey behavior may cascade through the food web to influence ecosystem function. The response of the collembolan Sinella curviseta Brook (Collembola: Entomobryidae) to cues indicating predation risk (necromones and cues from the wolf spider Pardosa milvina (Hentz) (Araneae: Lycosidae)) was tested. Additionally, necromones and predator cues were paired in a conditioning experiment to determine whether the collembolan could form learned associations. Although collembolans did not alter activity levels in response to predator cues, numerous aspects of behavior differed in the presence of necromones. There was no detectable conditioned response to predator cues after pairing with necromones. These results provide insight into how collembolans perceive and respond to predation threats that vary in information content. Previously detected indirect impacts of predator cues on ecosystem function are likely due to changes in prey other than activity level.

  16. Molecular phylogeny supports S-chaetae as a key character better than jumping organs and body scales in classification of Entomobryoidea (Collembola)

    PubMed Central

    Zhang, Feng; Sun, Dan-Dan; Yu, Dao-Yuan; Wang, Bei-Xin

    2015-01-01

    The jumping organ (furcula) is the most characteristic structure among collembolans, and it is of great taxonomical values at higher levels. The largest superfamily Entomobryoidea is traditionally classified into four families only by the morphology of the furcula. Actually, many taxa among these families are strikingly similar in morphology without considering furcula. The phylogeny of Entomobryoidea was reconstructed here based on mitochondrial and ribosomal fragments. This indicated that both Paronellidae and Cyphoderidae were ingroups within Entomobryidae with the former polyphyletic. Topology tests, which used the likelihood and Bayesian approaches, also rejected the traditional hypotheses relying on furcula morphology. Further ancestral state reconstructions have revealed that traditional taxonomical characters, i.e., furcula and body scales, had multiple independent origins in Entomobryoidea whereas tergal specialized chaetae (S-chaetae) exhibited strong phylogenetic signals. By integrating both molecular and morphological evidence, the results of this study drastically undermine the present classification of Entomobryoidea. Tergal S-chaetotaxic pattern in combination with other characters are more reasonable in taxonomy at suprageneric levels than convergent furcula. This study provides new insights of the jumping organ, which could be adaptively modified during evolution of Collembola. PMID:26212216

  17. Two new genera and five new species of Tullbergiidae (Collembola) from the southern Appalachian Mountains of North America, with redescription of Tullbergia clavata Mills.

    PubMed

    Bernard, Ernest C

    2016-01-01

    Two new genera and five new species of Tullbergiidae (Collembola) are described from the North American Appalachian zone in eastern Tennessee and western North Carolina. Ameritulla n. gen. is established for species with 15 setae on the middle tibiotarsus, blunt papilla A on the labial palpus, two long rows of vesicles in the postantennal organ (PAO), two dorsal sensilla on the third antennal segment and crescentic pseudocelli. Ameritulla clavata (Mills, 1934) n. comb. (=Tullbergia clavata Mills, 1934) is designated as type species and redescribed from type specimens, and A. obscura n. sp. is described. On Mixturatulla ozwini n. gen., n. sp. papillae A and B of the labial palpus are thick and blunt, the second row of the PAO is laterally broken into numerous spherical vesicles, and the dorsum of Abd. VI has two rows of large, coalesced tubercles. Psammophorura miniclavata n. sp. lacks pseudocelli on the third abdominal segment, which are present in previously described species. Stenaphorura shaconage n. sp. is the first species of its genus reliably recorded from North America. It differs from its Palaearctic relatives in having 2+2 pseudocelli on most body segments. Tullbergia nearctica n. sp. resembles T. arctica (Wahlgren, 1900) but differs in several chaetotaxic characters. Sensilliform setae traditionally considered as ordinary pointed setae are recognized and charted. A new setal nomenclature is proposed for the ventral setae of the sixth abdominal segment. PMID:27615985

  18. Two new genera and five new species of Tullbergiidae (Collembola) from the southern Appalachian Mountains of North America, with redescription of Tullbergia clavata Mills.

    PubMed

    Bernard, Ernest C

    2016-01-01

    Two new genera and five new species of Tullbergiidae (Collembola) are described from the North American Appalachian zone in eastern Tennessee and western North Carolina. Ameritulla n. gen. is established for species with 15 setae on the middle tibiotarsus, blunt papilla A on the labial palpus, two long rows of vesicles in the postantennal organ (PAO), two dorsal sensilla on the third antennal segment and crescentic pseudocelli. Ameritulla clavata (Mills, 1934) n. comb. (=Tullbergia clavata Mills, 1934) is designated as type species and redescribed from type specimens, and A. obscura n. sp. is described. On Mixturatulla ozwini n. gen., n. sp. papillae A and B of the labial palpus are thick and blunt, the second row of the PAO is laterally broken into numerous spherical vesicles, and the dorsum of Abd. VI has two rows of large, coalesced tubercles. Psammophorura miniclavata n. sp. lacks pseudocelli on the third abdominal segment, which are present in previously described species. Stenaphorura shaconage n. sp. is the first species of its genus reliably recorded from North America. It differs from its Palaearctic relatives in having 2+2 pseudocelli on most body segments. Tullbergia nearctica n. sp. resembles T. arctica (Wahlgren, 1900) but differs in several chaetotaxic characters. Sensilliform setae traditionally considered as ordinary pointed setae are recognized and charted. A new setal nomenclature is proposed for the ventral setae of the sixth abdominal segment.

  19. Laboratory assessment of the impacts of transgenic Bt rice on the ecological fitness of the soil non-target arthropod, Folsomia candida (Collembola: Isotomidae).

    PubMed

    Yuan, Yiyang; Xiao, Nengwen; Krogh, Paul Henning; Chen, Fajun; Ge, Feng

    2013-08-01

    Transgenic rice expressing Bacillus thuringiensis (Bt) endotoxins (Bt rice) for pest control is considered an important solution to food security in China. However, tests for potential effects on non-target soil organisms are required for environmental risk assessment. The soil collembolan Folsomia candida L. (Collembola: Isotomidae) is a potential non-target arthropod that is often used as a biological indicator in bio-safety assessments of transgenic crops. In the present study, the roots, stems, and leaves of Bt rice were exposed to F. candida under laboratory conditions, with survival, reproduction and growth of the collembolan as ecological fitness parameters. Significant differences in ecological fitness were found among the different treatments, including differences in the plant parts and varieties of non-Bt rice, presumably as the result of three factors: gene modification, plant parts and rice varieties. The fitness of F. candida was less affected by the different diets than by the exposure to the same materials mixed with soil. Our results clearly showed that there was no negative effect of different Bt rice varieties on the fitness of F. candida through either diet or soil exposure.

  20. Short-term biochemical ill effects of insect growth regulator (IGR) pesticides in Cyphoderus javanus Borner (Collembola: Insecta) as potential biomarkers of soil pollution.

    PubMed

    Saha, Ipsita; Joy, V C

    2016-02-01

    The insect growth regulator (IGR) chemicals are considered as safe alternatives to synthetic organic pesticides, but only scant information are available on their possible impact on non-target and ecologically important soil insect fauna of croplands. Previous studies by the authors showed that recommended agricultural doses of IGRs buprofezin (Applaud 25SC at 250 g a.i. ha(-1)), flubendiamide (Takumi 20WG at 50 g a.i. ha(-1)) and novaluron (Rimon 10EC at 100 g a.i. ha(-1)) produced less mortality of adults of a non-target soil insect Cyphoderus javanus Borner (Collembola) but decreased major life history parameters namely moulting, fecundity and egg hatching success. This detritivorous microarthropod is very sensitive to soil characteristics and is ecologically relevant to the tropical soils. Present microcosm study showed strong biochemical impact of the above doses of IGRs on tissue nutrient levels and digestive enzyme activities in C. javanus within 7 days of exposure to treated sandy loam soil. The levels of tissue proteins, carbohydrates, lipids and free amino acids declined significantly and persistently in the specimens reared in IGR-treated soils than in the specimens of untreated soil. Similarly, α-amylase, cellulase and protease activities declined significantly in the specimens of IGR-treated soil. These nutritional scarcities would reduce metabolism, growth and reproduction in the affected insects. Therefore, the observed biochemical responses, especially the levels of tissue proteins, carbohydrates and α-amylase activity in C. javanus are early warning indices and potential biomarkers of soil pollution in croplands.

  1. Short-term biochemical ill effects of insect growth regulator (IGR) pesticides in Cyphoderus javanus Borner (Collembola: Insecta) as potential biomarkers of soil pollution.

    PubMed

    Saha, Ipsita; Joy, V C

    2016-02-01

    The insect growth regulator (IGR) chemicals are considered as safe alternatives to synthetic organic pesticides, but only scant information are available on their possible impact on non-target and ecologically important soil insect fauna of croplands. Previous studies by the authors showed that recommended agricultural doses of IGRs buprofezin (Applaud 25SC at 250 g a.i. ha(-1)), flubendiamide (Takumi 20WG at 50 g a.i. ha(-1)) and novaluron (Rimon 10EC at 100 g a.i. ha(-1)) produced less mortality of adults of a non-target soil insect Cyphoderus javanus Borner (Collembola) but decreased major life history parameters namely moulting, fecundity and egg hatching success. This detritivorous microarthropod is very sensitive to soil characteristics and is ecologically relevant to the tropical soils. Present microcosm study showed strong biochemical impact of the above doses of IGRs on tissue nutrient levels and digestive enzyme activities in C. javanus within 7 days of exposure to treated sandy loam soil. The levels of tissue proteins, carbohydrates, lipids and free amino acids declined significantly and persistently in the specimens reared in IGR-treated soils than in the specimens of untreated soil. Similarly, α-amylase, cellulase and protease activities declined significantly in the specimens of IGR-treated soil. These nutritional scarcities would reduce metabolism, growth and reproduction in the affected insects. Therefore, the observed biochemical responses, especially the levels of tissue proteins, carbohydrates and α-amylase activity in C. javanus are early warning indices and potential biomarkers of soil pollution in croplands. PMID:26780417

  2. The Gut of the Soil Microarthropod Folsomia candida (Collembola) Is a Frequently Changeable but Selective Habitat and a Vector for Microorganisms

    PubMed Central

    Thimm, Torsten; Hoffmann, Andrea; Borkott, Heinz; Charles Munch, Jean; Tebbe, Christoph C.

    1998-01-01

    Interaction potentials between soil microarthropods and microorganisms were investigated with Folsomia candida (Insecta, Collembola) in microcosm laboratory experiments. Microscopic analysis revealed that the volumes of the simple, rod-shaped guts of adult specimens varied with their feeding activity, from 0.7 to 11.2 nl. A dense layer of bacterial cells, associated with the peritrophic membrane, was detected in the midgut by scanning electron microscopy. Depending on the molting stage, which occurred at intervals of approximately 4 days, numbers of heterotrophic, aerobic gut bacteria changed from 4.9 × 102 to 2.3 × 106 CFU per specimen. A total of 11 different taxonomic bacterial groups and the filamentous fungus Acremonium charticola were isolated from the guts of five F. candida specimens. The most abundant isolate was related to Erwinia amylovora (96.2% DNA sequence similarity to its 16S rRNA gene). F. candida preferred to feed on Pseudomonas putida and three indigenous gut isolates rather than eight different type culture strains. When luciferase reporter gene-tagged bacterial strains were pulse fed to F. candida, gut isolates were continuously shed for 8 days to several weeks but Escherichia coli HB101 was shed for only 1 day. Ratios of ingested to released bacterial cells demonstrated that populations of nonindigenous gut bacteria like Sinorhizobium meliloti L33 and E. coli HB101 were reduced by more than 4 orders of magnitude but that the population of gut isolate Alcaligenes faecalis HR4 was reduced only 500-fold. This work demonstrates that F. candida represents a frequently changeable but selective habitat for bacteria in terrestrial environments and that microarthropods have to be considered factors that modify soil microbial communities. PMID:9647845

  3. Two new Megalothorax species of the minimus group (Collembola, Neelidae).

    PubMed

    Schneider, Clément; Porco, David; Deharveng, Louis

    2016-01-01

    Two new Megalothorax species, Megalothorax potapovi sp. n. from the Russian Far East and Megalothorax sanguineus sp. n. from the French Pyrénées are described. The two new species have a set of morphological characters (including a smooth mucro) that places them among the minimus group sensu Schneider and D'Haese (2013). Megalothorax potapovi characteristics include dorsal protuberance on forehead, peculiar chaetotaxy of antenna III and strong lanceolate chaetae on body. Megalothorax sanguineus characteristics include strong red pigmentation, large network of integumentary channels on head and elongated apex of the two postero-distal spines of dens. The DNA barcodes (cytochrome oxidase subunit I-COI) of the two species are also provided and analyzed among a broader sampling of the genus in order to support further their specific status. A special focus is given to the labral morphological characteristics. Pseudopores-like elements are reported for the first time in the genus. Positions of the τ-chaetae near the dorsal sensory field of thorax II are compared for several species of the genus. PMID:26877679

  4. Entomobryoidea (Collembola) from Himachal Pradesh (India) in the Himalayas.

    PubMed

    Baquero, Enrique; Mandal, Gurupada; Jordana, Rafael

    2015-01-01

    Collections made during March-April, 2010, October-November, 2010 and 2011 from different districts of Himachal Pradesh, India, by the Apterygota section of the Zoological Survey of India contained new species of Entomobryoidea. Localities sampled were Solan, Shimla, Kullu, Bilaspur, Kagra, Chamba and Sirmaur districts of Himachal Pradesh. Collections were mainly made using an aspirator from leaf litter, mosses, under stones, flowering garden plants and river embankments, wetlands and rotting logs. Sixteen species were found, belonging to genera: Entomobrya, Himalanura, Homidia, Sinella, Willowsia, Lepidocyrtus (Acrocyrtus), Lepidocyrtus (Cinctocyrtus), Seira, Drepanosira and Salina. Twelve of these have been described as new species. PMID:26624165

  5. Pax6 in Collembola: Adaptive Evolution of Eye Regression.

    PubMed

    Hou, Ya-Nan; Li, Sheng; Luan, Yun-Xia

    2016-01-01

    Unlike the compound eyes in insects, collembolan eyes are comparatively simple: some species have eyes with different numbers of ocelli (1 + 1 to 8 + 8), and some species have no apparent eye structures. Pax6 is a universal master control gene for eye morphogenesis. In this study, full-length Pax6 cDNAs, Fc-Pax6 and Cd-Pax6, were cloned from an eyeless collembolan (Folsomia candida, soil-dwelling) and an eyed one (Ceratophysella denticulata, surface-dwelling), respectively. Their phylogenetic positions are between the two Pax6 paralogs in insects, eyeless (ey) and twin of eyeless (toy), and their protein sequences are more similar to Ey than to Toy. Both Fc-Pax6 and Cd-Pax6 could induce ectopic eyes in Drosophila, while Fc-Pax6 exhibited much weaker transactivation ability than Cd-Pax6. The C-terminus of collembolan Pax6 is indispensable for its transactivation ability, and determines the differences of transactivation ability between Fc-Pax6 and Cd-Pax6. One of the possible reasons is that Fc-Pax6 accumulated more mutations at some key functional sites of C-terminus under a lower selection pressure on eye development due to the dark habitats of F. candida. The composite data provide a first molecular evidence for the monophyletic origin of collembolan eyes, and indicate the eye degeneration of collembolans is caused by adaptive evolution. PMID:26856893

  6. Two new Megalothorax species of the minimus group (Collembola, Neelidae)

    PubMed Central

    Schneider, Clément; Porco, David; Deharveng, Louis

    2016-01-01

    Abstract Two new Megalothorax species, Megalothorax potapovi sp. n. from the Russian Far East and Megalothorax sanguineus sp. n. from the French Pyrénées are described. The two new species have a set of morphological characters (including a smooth mucro) that places them among the minimus group sensu Schneider and D’Haese (2013). Megalothorax potapovi characteristics include dorsal protuberance on forehead, peculiar chaetotaxy of antenna III and strong lanceolate chaetae on body. Megalothorax sanguineus characteristics include strong red pigmentation, large network of integumentary channels on head and elongated apex of the two postero-distal spines of dens. The DNA barcodes (cytochrome oxidase subunit I–COI) of the two species are also provided and analyzed among a broader sampling of the genus in order to support further their specific status. A special focus is given to the labral morphological characteristics. Pseudopores-like elements are reported for the first time in the genus. Positions of the τ-chaetae near the dorsal sensory field of thorax II are compared for several species of the genus. PMID:26877679

  7. A new genus of Neelidae (Collembola) from Mexican caves.

    PubMed

    Papáč, Vladimír; Palacios-Vargas, José G

    2016-01-01

    The new genus Spinaethorax, whose proposal is based on specimens of Megalothorax spinotricosus Palacios-Vargas & Sánchez, 1999, is given a new name combination and a redescription. The type species comes from two caves in Campeche State, México. A new combination is also suggested for Megalothorax tonoius Palacios-Vargas & Sánchez, 1999. The new genus is similar to Megalothorax Willem, 1900 and Neelus Folsom, 1896, but it clearly differs from all genera within family Neelidae by a peculiar combination of characters and the presence of some new features, e.g. globular sensillum on Ant. III, sword-like macrosetae on oral fold. A comparative table and an identification key for all Neelidae genera as well as some summary tables of antennae chaetotaxy and legs setation for type species are provided. PMID:27110149

  8. Arrhopalites potapovi sp. nov. (Collembola, Symphypleona) from Russia.

    PubMed

    Vargovitsh, Robert S

    2015-01-01

    A new springtail species of the family Arrhopalitidae, Arrhopalites potapovi sp. nov., is described. It belongs to the caecus species group characterized by 3,2,1,1,1 anterior setae on dens and separates from Arrhopalites caecus (Tullberg) and other congeners by strongly differentiated cuticular spines on sixth abdominal segment, shape of female subanal appendages and foot complex. It was found under the loose bark of trees from two localities along Lake Baikal and it is the second representative of the genus Arrhopalites Börner sensu stricto in Russia. PMID:25947839

  9. A new genus of Neelidae (Collembola) from Mexican caves

    PubMed Central

    Papáč, Vladimír; Palacios-Vargas, José G.

    2016-01-01

    Abstract The new genus Spinaethorax, whose proposal is based on specimens of Megalothorax spinotricosus Palacios-Vargas & Sánchez, 1999, is given a new name combination and a redescription. The type species comes from two caves in Campeche State, México. A new combination is also suggested for Megalothorax tonoius Palacios-Vargas & Sánchez, 1999. The new genus is similar to Megalothorax Willem, 1900 and Neelus Folsom, 1896, but it clearly differs from all genera within family Neelidae by a peculiar combination of characters and the presence of some new features, e.g. globular sensillum on Ant. III, sword-like macrosetae on oral fold. A comparative table and an identification key for all Neelidae genera as well as some summary tables of antennae chaetotaxy and legs setation for type species are provided. PMID:27110149

  10. Gene expression analysis of collembola in cadmium containing soil.

    PubMed

    Nota, Benjamin; Timmermans, Martijn J T N; Franken, Oscar; Montagne-Wajer, Kora; Mariën, Janine; De Boer, Muriel E; De Boer, Tjalf E; Ylstra, Bauke; Van Straalen, Nico M; Roelofs, Dick

    2008-11-01

    Increasing concern about pollution of our environment calls for advanced and rapid methods to estimate ecological toxicity. The use of gene expression microarrays in environmental studies can potentially meet this challenge. We present a novel method to examine soil toxicity. We exposed the collembolan Folsomia candida to soil containing an ecologically relevant cadmium concentration, and found a cumulative total of 1586 differentially expressed transcripts across three exposure durations, including transcripts involved in stress response, detoxification, and hypoxia. Additional enrichment analysis of gene ontology (GO) terms revealed that antibiotic biosynthesis is important at all time points examined. Interestingly, genes involved in the "penicillin and cephalosporin biosynthesis pathway" have never been identified in animals before, but are expressed in F. candida's tissue. The synthesis of antibiotics can possibly be a response to increased cadmium-induced susceptibility to invading pathogens, which might be caused by repression of genes involved in the immune-system (C-type lectins and Toll receptor). This study presents a first global view on the environmental stress response of an arthropod species exposed to contaminated soil, and provides a mechanistic basis for the development of a gene expression soil quality test. PMID:19031917

  11. Pax6 in Collembola: Adaptive Evolution of Eye Regression

    PubMed Central

    Hou, Ya-Nan; Li, Sheng; Luan, Yun-Xia

    2016-01-01

    Unlike the compound eyes in insects, collembolan eyes are comparatively simple: some species have eyes with different numbers of ocelli (1 + 1 to 8 + 8), and some species have no apparent eye structures. Pax6 is a universal master control gene for eye morphogenesis. In this study, full-length Pax6 cDNAs, Fc-Pax6 and Cd-Pax6, were cloned from an eyeless collembolan (Folsomia candida, soil-dwelling) and an eyed one (Ceratophysella denticulata, surface-dwelling), respectively. Their phylogenetic positions are between the two Pax6 paralogs in insects, eyeless (ey) and twin of eyeless (toy), and their protein sequences are more similar to Ey than to Toy. Both Fc-Pax6 and Cd-Pax6 could induce ectopic eyes in Drosophila, while Fc-Pax6 exhibited much weaker transactivation ability than Cd-Pax6. The C-terminus of collembolan Pax6 is indispensable for its transactivation ability, and determines the differences of transactivation ability between Fc-Pax6 and Cd-Pax6. One of the possible reasons is that Fc-Pax6 accumulated more mutations at some key functional sites of C-terminus under a lower selection pressure on eye development due to the dark habitats of F. candida. The composite data provide a first molecular evidence for the monophyletic origin of collembolan eyes, and indicate the eye degeneration of collembolans is caused by adaptive evolution. PMID:26856893

  12. New species of Pseudachorutes (Collembola: Neanuridae) from Northeastern Algeria.

    PubMed

    Zoughailech, Abdelmalek; Hamra-Kroua, Salah; Deharveng, Louis

    2016-01-01

    Three new species of Pseudachorutes are described from the Collo massif in northeastern Algeria, all three with morphological features unique or rare in the genus. P. deficiens sp. nov. lacks chaeta E on the labium, a character only retrieved in P. ouatilouensis Najt & Weiner, 1997 from New Caledonia, from which it differs by the presence of chaeta a2 on Th. II and of chaeta M on tibiotarsus. P. octosensillatus sp. nov. is the only species of the genus that have 8 S-chaetae on Ant IV. P. labiatus sp. nov. has 3 x-papillae on the labium, like P. cf. indiana Christiansen & Bellinger, 1980 from Alaska, from which it differs by the presence of chaeta a2 on Th. II and a lower number of vesicles in PAO (5-6 vs 10-14). PMID:27615903

  13. Two new species of Tomocerus ocreatus complex (Collembola, Tomoceridae) from Nanjing, China.

    PubMed

    Yu, Daoyuan; Yao, Jin; Hu, Feng

    2016-01-01

    Two new species of Tomocerus Nicolet, 1842 are described from Nanjing, China. Tomocerus qinae sp. nov. is similar to the Vietnamese species Tomocerus ocreatus, but is different from the latter mainly in the colour pattern, the length of antennae, and the pattern of ungual teeth. Tomocerus qixiaensis sp. nov. is similar to Tomocerus ocreatus and Tomocerus qinae sp. nov., but can be distinguished from them by the short antennae and the blunt prominent macrochaetae on manubrium and dens. DNA barcode sequences of the new species are provided. PMID:27394254

  14. Endonura Cassagnau in Iran, with a key to species of the genus (Collembola, Neanuridae, Neanurinae)

    PubMed Central

    Smolis, Adrian; Kahrarian, Morteza; Piwnik, Agata; Skarżyński, Dariusz

    2016-01-01

    Abstract Three new species of Endonura are described from Iran. Endonura dichaeta sp. n. can be recognized by an ogival labrum, head without chaetae O and E, chaeta D connected with tubercle Cl, tubercle Dl with five chaetae on head, absence of tubercles Di on thorax I and tubercle (Di+Di) of thorax V with 2+2 chaetae. Endonura ceratolabralis sp. n. is characterized by large body size, reduction of labral chaetotaxy, ogival labrum, head without chaeta O and fusion of tubercles Di and De on first thoracic segment. Endonura persica sp. n. is distinguished from its congeners by a nonogival labrum, absence of chaeta O, tubercles Dl and (L+So) with five and eight chaetae respectively and claw with inner tooth. The key to all species of the genus is given. PMID:26877671

  15. Two new species of Willowsia (Collembola: Entomobryidae) from Guizhou Province, China.

    PubMed

    Ma, Yitong

    2016-01-01

    The genus Willowsia Shoebotham, 1917 belongs to the family Entomobryidae. Within the family it is characterised by having 4-segmented antennae, 8+8 eyes, spines and scales absent from dens, claw with unpaired inner teeth, bidentate mucro and scales on body. Twenty-six species have been described in the genus worldwide including eight species from China. Two new species, Willowsia pseudoshi sp. nov. and W. variabilis sp. nov., from China are described here. The former species has pale yellow antennae except for distal part of Antenna IV which has some blue pigment and 4 macrochaetae are present on Abdomen I. The latter species has the whole antenna pigmented blue and 7-8 macrochaetae present on Abdomen I. A key to Chinese species of Willowsia is given. PMID:27615876

  16. On the genus Paralobella (Collembola: Neanuridae: Lobellini) with description of a new Chinese species.

    PubMed

    Luo, Yongzheng; Palacios-Vargas, José G

    2016-01-01

    Remarks on the genus Paralobella Cassagnau & Deharveng, 1984 and a key to world species is provided. P. breviseta sp. nov. is described from Eastern China, it is distinguished from all known members of the genus by its biggest size, digitate body dorsolateral and lateral tubercles and very short setae on dorso-internal tubercles. PMID:27395557

  17. Euedaphic and hemiedaphic Collembola suffer larger damages than epedaphic species to nitrogen input.

    PubMed

    Song, Lihong; Liu, Jing; Yan, Xiumin; Chang, Liang; Wu, Donghui

    2016-01-01

    Wetlands are commonly limited in available nitrogen. But marshes in the Sanjiang Plain, Northeastern China suffer large amounts of exogenous nitrogen from agriculture fertilization after wetland reclamation. This paper focuses on the ecological effects of a short-term increase of nitrogen input on collembolan communities. Our results show a significant decrease in collembolan abundance and Shannon diversity index, and the abundance of euedaphic and hemiedaphic collembolans decreased faster than epedaphic collembolans. These results indicate that euedaphic or hemiedaphic fauna suffer more biodiversity loss caused by nitrogen deposition than epedaphic fauna and call for more researches on trait-based approaches under environmental stress in the future. PMID:26549750

  18. A new species and new records of Arrhopalitidae (Collembola: Symphypleona) from the Republic of Moldova.

    PubMed

    Vargovitsh, Robert S; Buşmachiu, Galina

    2015-01-01

    Eight species of the family Arrhopalitidae Stach, 1956 are listed from the Republic of Moldova. A new species, Arrhopalites prutensis sp. nov. is described. It belongs to the diversus group of species with 3, 2, 1, 1 anterior setae on dens, possesses neosminthuroid seta on the furca base region-a character rarely noted for the family. The new species is closely related to A. baccettii Dallai, 1969 and A. antonioi Giuga & Jordana, 2013 described from Sicily. Five species of the family are firstly recorded for the country. PMID:26249876

  19. Synonymy of Katianna coeruleocephala Handschin, 1920 (Collembola: Katiannidae) with Bourletiella viridescens (Bourletiellidae).

    PubMed

    Greenslade, Penelope

    2016-01-01

    Katianna coeruleocephala was described by Handschin in 1920 from Poespo, Java. It was collected in December, 1896 by Dr. Zehntner with the collecting details given as rotten "Louv" (leaves?) from live orchard. Handschin (1920) labelled his figures of the species (p. 146) as Katianna coerulescephala but the first spelling of the species name (p. 145) has priority. Katianna coeruleocephala has never been recollected. The only mention of the species in the literature since 1920 has been by Suhardjono (1989) in a check list for Indonesia and Suhardjono (2012) who listed it as present on Java and provided the main characteristics of the genus Katianna Börner, 1923. She stated it was a "new" (translate as endemic?) species in Java with a preferred habitat in cold and damp litter but no comment was made on the taxonomic status of the Indonesian species. PMID:27395532

  20. Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae).

    PubMed

    Xu, Guo-Liang; Chen, Wei-Yu

    2016-01-01

    Two new blind species of Sinella are described from Guangdong Province, China. Sinella colubra sp. n. possesses minute smooth postlabial chaetae, long mucronal spine, and 4+4(5) lateral mac on Abd. IV, and can be distinguished from two closely related species by the postlabial chaetae and the dorsal macrochaetotaxy. Sinella zhangi sp. n. is also described and can be diagnosed by having minute labial chaeta r and postlabial chaetae X and X4, 5+5 mac on Abd. I, 4+4 central mac on Abd. II, and 4+4 central and 5+5 lateral mac on Abd. IV. PMID:27594797

  1. Endonura Cassagnau in Iran, with a key to species of the genus (Collembola, Neanuridae, Neanurinae).

    PubMed

    Smolis, Adrian; Kahrarian, Morteza; Piwnik, Agata; Skarżyński, Dariusz

    2016-01-01

    Three new species of Endonura are described from Iran. Endonura dichaeta sp. n. can be recognized by an ogival labrum, head without chaetae O and E, chaeta D connected with tubercle Cl, tubercle Dl with five chaetae on head, absence of tubercles Di on thorax I and tubercle (Di+Di) of thorax V with 2+2 chaetae. Endonura ceratolabralis sp. n. is characterized by large body size, reduction of labral chaetotaxy, ogival labrum, head without chaeta O and fusion of tubercles Di and De on first thoracic segment. Endonura persica sp. n. is distinguished from its congeners by a nonogival labrum, absence of chaeta O, tubercles Dl and (L+So) with five and eight chaetae respectively and claw with inner tooth. The key to all species of the genus is given. PMID:26877671

  2. A new genus of Entomobryinae (Collembola, Entomobryidae) from Brazilian Amazon with body scales and dental spines.

    PubMed

    Cipola, Nikolas Gioia; Morais, José Wellington De; Bellini, Bruno Cavalcante

    2016-01-01

    A new monotypic genus of Entomobryinae from Brazilian Amazon is described and illustrated. Amazhomidia gen. nov. is similar to other genera of the subfamily, especially to Sinhomidia Zhang, in presence of apically pointed scales on body dorsally and spines on dens. It differs from all other genera of Entomobryinae by the combination of: bifurcate prelabral chaetae, cephalic groove with scale-like chaetae and two transverse rows macrochaetae present on anterior central region of the abdominal IV segment. Amazhomidia ducke sp. nov., the type species of the new genus is described. An identification key to the genera of Entomobryidae with scales and dental spines is also provided. PMID:27394776

  3. Taxonomy of the Proisotoma complex. V. Sexually dimorphic Ephemerotoma gen. nov. (Collembola: Isotomidae).

    PubMed

    Potapov, Mikhail; Kahrarian, Morteza; Deharveng, Louis; Shayanmehr, Masoumeh

    2015-01-01

    A new genus is proposed based on a new species from Iran, Ephemerotoma skarzynskii gen. et sp. nov., and three known species: E. huadongensis (Chen, 1985) comb. nov., E. multituberculata (Martynova, 1971) comb. nov. and E. porcella (Ellis, 1976) comb. nov. The genus shares the characters of Subisotoma Stach and Proctostephanus Börner and is distributed in southern areas of Eurasia (Eastern Mediterranean, Iran, Tajikistan, China). Ephemerotoma gen. nov. belongs to the Proisotoma-complex and is characterized by a simple maxillary palp, only 4 guards on labial papilla E and 2 prelabral chaetae. Four s-chaetae on Abd.V are arranged in two rows, two anterior and two posterior chaetae. All members of Ephemerotoma gen. nov. are redescribed or discussed based on type or fresh material, and a key to species of the genus is given. Scutisotoma potapovi Xie & Chen, 2008 is considered a synonym of E. huadongensis, while Proisotoma anopolitana is moved to the genus Proctostephanus. Sexual dimorphism is described for three species. PMID:26701434

  4. New species of Lepidocyrtus Bourlet and Entomobrya Rondani (Collembola: Entomobryoidea: Entomobryidae) from Brazil.

    PubMed

    Bellini, Bruno C; Cipola, Nikolas G; Godeiro, Nerivânia N

    2015-01-01

    The taxonomic comprehension of Brazilian entomobryids had several contributions during the last decade, but the absence of detailed chaetotaxic schemes to most of endemic species difficult identifications and probably hides undescribed species in surveys across the country. Herein we describe two new species of the family and provide detailed dorsal chaetotaxy of them, in hope to guide future identifications and descriptions within the genera in Brazil and Neotropical Region. Lepidocyrtus sotoi sp. nov. is possibly more related to L. biphasis due to the lack of antennal and leg scales, but presents a unique dorsal head chaetotaxy among the Neotropical species of the genus. Entomobrya bahiana sp. nov. presents an uncommon color pattern and dorsal chaetotaxy in Th. II-III, Abd. II and IV when compared to other Entomobrya spp. from Neotropical Region. PMID:26624176

  5. New blind species and new records of Sinella from Nanjing, China (Collembola, Entomobryidae).

    PubMed

    Xu, Heng; Zhang, Feng

    2016-01-01

    Two new blind species of Sinella are described from Nanjing, China. Sinella quinseta sp. n. from Purple Mountain possesses unique 5+5 central macrochaetae on Abd. II, and can be distinguished from other species of the genus by the postlabial chaetae and the dorsal chaetotaxy. Sinella qixiaensis sp. n. from Qixia Mountain is characterized by the paddle-like S-chaetae of Ant. III organ and the smooth straight chaetae on the manubrium and base of dens; it differs from two closely related species by the smooth manubrial chaetae, the labial chaetae, the Ant. III organ, and the macrochaetae on Abd. II. Sinella fuyanensis Chen & Christiansen and Sinella quinocula Chen & Christiansen were also newly recorded from Nanjing. PMID:27551205

  6. A new genus and a new species of Sminthuridae (Collembola: Symphypleona) from Atlantic Forest of Brazil.

    PubMed

    Da Silva, Diego Dias; Palacios-Vargas, José G; Bellini, Bruno Cavalcante

    2015-01-01

    Sminthuridae comprises approximately 240 species distributed worldwide. In Brazil it is represented only by 11 species and four genera. Herein we describe a new genus and species of subfamily Sminthurinae from Atlantic Forest of Rio Grande do Norte State, Northeastern Brazil. The new described genus is similar to Gisinurus, Songhaica, Dietersminthurus and Soqotrasminthurus, especially in its unguis shape, with open cavity; but differs from all other genera of Sminthuridae by the presence of a single pretarsal chaeta in anterior side, smooth mucronal edges and a unique head chaetotaxy. PMID:26250241

  7. A new species of Metacoelura (Collembola: Paronellidae) from Australia, and redescription of Metacoelura articulata.

    PubMed

    Ma, Yitong; Zhao, Chun; Greenslade, Penelope

    2016-01-01

    The genus Metacoelura Salmon, 1951 is unusual as it possesses some characters typical of the family Entomobryidae and others of the Paronellidae. Three species and subspecies have been described, all from Australasian tropical regions. Metacoelura articulata is redescribed and a new species, Metacoelura majeri sp. nov., is described based on material collected in Australia. A key to species of the genus is provided. PMID:27394786

  8. Three new species and one new record of Tullbergiidae (Collembola: Onychiuroidea) from Tierra del Fuego.

    PubMed

    Arbea, Javier I

    2016-01-01

    Three new species, Tullbergia rapoporti sp. nov., Dinaphorura nerudai sp. nov. and Dinaphorura najtae sp. nov., and one new record, Tullbergia meridionalis Cassagnau & Rapoport, 1962 are described based on specimens from Tierra del Fuego. Tullbergia rapoporti sp. nov. is similar to T. crozetensis, but can be distinguished from it by the presence of an empodial appendage and the chaetotaxy of Abd VI. Dinaphorura nerudai sp. nov. is diagnosed by the dorsal pso formula, the seven spiniform processes on Abd VI, an elongate PAO, the absence of vesicle on Ant IV and the dorsal chaetotaxy. Dinaphorura najtae sp. nov. is characterised by the dorsal pso formula, the seven spiniform processes on Abd VI, a triangular PAO, the absence of vesicle on Ant IV and the dorsal chaetotaxy. PMID:27394481

  9. Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species.

    PubMed

    Katz, Aron D; Giordano, Rosanna; Soto-Adames, Felipe

    2015-01-01

    The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya's profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae. PMID:26487816

  10. Impact of metal pools and soil properties on metal accumulation in Folsomia candida (Collembola).

    PubMed

    Vijver, M; Jager, T; Posthuma, L; Peijnenburg, W

    2001-04-01

    Soil-dwelling organisms are exposed to metals in different ways. Evidence exists for predominant pore water uptake of metals by soft-bodied oligochaete species. In the present research, uptake kinetics of metals and the metalloid As by the semi-soft-bodied springtail Folsomia candida were studied, for which uptake via the pore water is less obvious. Springtails were exposed in 16 field soils and in metal-spiked artificial Organization for Economic Cooperation and Development (Paris, France) soil (OECD soil). Subsequently, accumulation parameters were statistically related to soil metal pools and soil properties. In Cd-spiked OECD soil, internal Cd levels were linearly related to external Cd concentrations, whereas the springtails maintained fixed internal levels of Cu and Zn regardless of spiked concentrations. In the field soils, all body concentrations of the elements As, Cr, and Ni were below detection limit. The essential metals Cu and Zn were presumably regulated, and no influence of soil characteristics could be demonstrated. For Cd and Pb, accumulation patterns were correlated mainly to solid-phase soil characteristics. The presence of these explanatory variables in the multiple correlations suggests that an uptake mechanism that is solely determined by pore water concentrations should not be taken as a universally applicable principle in risk assessments of metals for soil invertebrates. Cadmium in OECD soils was more available for uptake than in the field soils. The difference remained when extractability was taken into account. The results suggest that experiments in OECD soil cannot be used directly in risk assessment for nonessential metals (at least for F. candida), although a reduction of uncertainties in metal risk assessment can be reached by consistent use of body residues rather than external concentrations. PMID:11345445

  11. Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae)

    PubMed Central

    Xu, Guo-Liang; Chen, Wei-Yu

    2016-01-01

    Abstract Two new blind species of Sinella are described from Guangdong Province, China. Sinella colubra sp. n. possesses minute smooth postlabial chaetae, long mucronal spine, and 4+4(5) lateral mac on Abd. IV, and can be distinguished from two closely related species by the postlabial chaetae and the dorsal macrochaetotaxy. Sinella zhangi sp. n. is also described and can be diagnosed by having minute labial chaeta r and postlabial chaetae X and X4, 5+5 mac on Abd. I, 4+4 central mac on Abd. II, and 4+4 central and 5+5 lateral mac on Abd. IV.

  12. New cave species of Sinella Brook, 1882 from China (Collembola: Entomobryidae).

    PubMed

    Zhao, Lina; Zhang, Feng

    2016-01-01

    Springtails, especially entomobryids, are abundant in Karst faunas. Five new species of Sinella Brook are described here from caves in southern China: S. liuae sp. nov., S. hunanica sp. nov., S. tigris sp. nov., S. minuta sp. nov. and S. tiani sp. nov. A new record of Sinella sineocula Chen & Christiansen, is also recorded. These species differ in claw structure, chaetae on ventral side of the head, and body chaetotaxy. An updated key to cave species of Sinella from China is provided. PMID:27615947

  13. Euedaphic and hemiedaphic Collembola suffer larger damages than epedaphic species to nitrogen input.

    PubMed

    Song, Lihong; Liu, Jing; Yan, Xiumin; Chang, Liang; Wu, Donghui

    2016-01-01

    Wetlands are commonly limited in available nitrogen. But marshes in the Sanjiang Plain, Northeastern China suffer large amounts of exogenous nitrogen from agriculture fertilization after wetland reclamation. This paper focuses on the ecological effects of a short-term increase of nitrogen input on collembolan communities. Our results show a significant decrease in collembolan abundance and Shannon diversity index, and the abundance of euedaphic and hemiedaphic collembolans decreased faster than epedaphic collembolans. These results indicate that euedaphic or hemiedaphic fauna suffer more biodiversity loss caused by nitrogen deposition than epedaphic fauna and call for more researches on trait-based approaches under environmental stress in the future.

  14. A new species of Tullbergia (Collembola, Tullbergiidae) from Buenos Aires, Argentina

    PubMed Central

    Palacios-Vargas, José G.; Martínez, Ana E. Salazar

    2014-01-01

    Abstract A new species of Tullbergia from Argentina is described and illustrated; it is differentiated from Tullbergia paranensis by the number of vesicles of postantennal organ, pseudocelli shape and its formulae and the number of dorsal sensilla on Ant. IV. In addition a key for the identification of the members of the family from Argentina is included. PMID:25061344

  15. Predation of Notiophilus (Coleoptera: Carabidae) on Collembola as a Predator-Prey Teaching Model.

    ERIC Educational Resources Information Center

    Higgins, R. C.

    1982-01-01

    The carabid beetle (Notiophilus) preys readily on an easily-cultured collembolan in simple experimental conditions. Some features of this predator-prey system are outlined to emphasize its use in biology instruction. Experiments with another potential collembolan are described in the context of developing the method for more advanced studies.…

  16. Two new species of Willowsia (Collembola: Entomobryidae) from Guizhou Province, China.

    PubMed

    Ma, Yitong

    2016-01-01

    The genus Willowsia Shoebotham, 1917 belongs to the family Entomobryidae. Within the family it is characterised by having 4-segmented antennae, 8+8 eyes, spines and scales absent from dens, claw with unpaired inner teeth, bidentate mucro and scales on body. Twenty-six species have been described in the genus worldwide including eight species from China. Two new species, Willowsia pseudoshi sp. nov. and W. variabilis sp. nov., from China are described here. The former species has pale yellow antennae except for distal part of Antenna IV which has some blue pigment and 4 macrochaetae are present on Abdomen I. The latter species has the whole antenna pigmented blue and 7-8 macrochaetae present on Abdomen I. A key to Chinese species of Willowsia is given.

  17. Tricholoma matsutake 1-Ocen-3-ol and methyl cinnamate repel mycophagous Proisotoma minuta (Collembola: Insecta).

    PubMed

    Sawahata, Takuo; Shimano, Satoshi; Suzuki, Masahiro

    2008-02-01

    Two major volatiles produced by the mycelia and fruiting bodies of Tricholoma matsutake (1-octen-3-ol and methyl cinnamate) repel a mycophagous collembolan, Proisotoma minuta. Aggregation of the collembolans on their diet was significantly inhibited by exposure to 1 ppm methyl cinnamate or 10 to 100 ppm 1-octen-3-ol. The aggregation activity decreased dose-dependently upon exposure to 1-octen-3-ol at concentrations higher than 0.01 ppm. Aggregation in the presence of methyl cinnamate exhibited three phases: no significant effect at concentrations ranging from 0.001 to 0.1 ppm, significant inhibition from 1 to 100 ppm, and strong inhibition at 1,000 ppm. These results may explain why certain collembolan species do not prefer T. matsutake fruiting bodies.

  18. A new species of Lepidocyrtus (Collembola, Entomobryidae) from the Börzsöny Mountains, Hungary.

    PubMed

    Winkler, Daniel

    2016-01-01

    The genus Lepidocyrtus was previously represented by 17 species in Hungary, including four species with locus typicus in this country. Opportunistic sampling in mid-mountain grassland and forest habitats resulted in records of several species from the L. lignorum group and allowed to describe the new species L. traseri sp. nov. The L. lignorum group, established and named after the eponymic species, is composed by a total of 11 species. The main characteristics shared by every species in this group are the dorsal body macrochaetotaxy R0R1R2/00/0101+3 and the presence of scales on the antennae and legs. The new species is close to L. lignorum (Fabricius, 1793) and L. violaceus (Geoffroy, 1762) but differs from them by the color pattern, number of interocular scales, type of labral papillae and the number of inner setae on the manubrial plate. An identification key is given for differentiating all species of this group. PMID:27615681

  19. New species of Isotomiella Bagnall, 1939 from Southeast of Brazil (Collembola, Isotomidae).

    PubMed

    de Mendonça, Maria Cleide; Abrantes, Eduardo A; Neves, Ana Carolina R

    2012-01-01

    Two new species of the genus Isotomiella Bagnall, 1939 are described and illustrated, the first: Isotomiella macedoisp. n., based on males and females, from the "Parque Nacional da Serra dos Órgãos" (Teresópolis municipality, State of Rio de Janeiro) differs from the other by tibiotarsus III thickened and blunt and two antero-lateral chaetae of labrum strongly thickened. The second species Isotomiella uaisp. n. from "Serra da Gandarela", (Caeté municipality, State of Minas Gerais) differs from the other by presence of short sensilla on antennal IV and tergites, two anterolabral chaetae thickened and falcate mucro.

  20. Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species

    PubMed Central

    Katz, Aron D.; Giordano, Rosanna; Soto-Adames, Felipe

    2015-01-01

    Abstract The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya’s profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae. PMID:26487816

  1. New troglomorphic species of Tomocerus with well-developed postantennal organs (Collembola: Tomoceridae).

    PubMed

    Yu, Daoyuan; Li, Youbang

    2016-01-01

    Three new troglobitic species of Tomocerus are described from the southwestern karsts of China. All of them have well developed postantennal organs. Tomocerus dong sp. nov. is similar to Tomocerus postantennalis Yu, Zhang & Deharveng and Tomocerus deharvengi sp. nov., but is different from them mainly in the number of prelabral chaetae and the dorsal body chaetotaxy. T. deharvengi sp. nov. is very similar to T. postantennalis but differs from the latter in the cephalic chaetotaxy, the number of manubrial pseudopores and the number of dental spines. T. cthulhu sp. nov. is peculiar for the multi-furcated vesicles of ventral tube, and is different from the three aforementioned species mainly in the dorsal body chaetotaxy. The position of the new species and the relationships between them are discussed. PMID:27615979

  2. A new species and new records of Arrhopalitidae (Collembola: Symphypleona) from the Republic of Moldova.

    PubMed

    Vargovitsh, Robert S; Buşmachiu, Galina

    2015-01-01

    Eight species of the family Arrhopalitidae Stach, 1956 are listed from the Republic of Moldova. A new species, Arrhopalites prutensis sp. nov. is described. It belongs to the diversus group of species with 3, 2, 1, 1 anterior setae on dens, possesses neosminthuroid seta on the furca base region-a character rarely noted for the family. The new species is closely related to A. baccettii Dallai, 1969 and A. antonioi Giuga & Jordana, 2013 described from Sicily. Five species of the family are firstly recorded for the country.

  3. A new species of Furculanurida (Collembola: Neanuridae) from Ivory Coast, with comments on related genera.

    PubMed

    Zon, Serge Demeango; Tano, Yao; Deharveng, Louis

    2014-10-29

    A new species of Pseudachorutinae, Furculanurida emucronata sp. nov., is described from Lamto in the Ivory Coast. It differs from all known Pseudachorutinae species by the presence of a strong lateral tooth on the claw of leg I, and from other species of the genus Furculanurida by the absence of a mucro. It is provisionally assigned to the genus Furculanurida which is redefined accordingly. The heterogeneity of the genus is stressed, and its relationships with Arlesiella, Kenyura, Pseudachorutes and Stachorutes are discussed.

  4. New Method for Automatic Body Length Measurement of the Collembolan, Folsomia candida Willem 1902 (Insecta: Collembola)

    PubMed Central

    Bánszegi, Oxána; Kosztolányi, András; Bakonyi, Gábor; Szabó, Borbála; Dombos, Miklós

    2014-01-01

    The collembolan, Folsomia candida, is widely used in soil ecotoxicology. In recent years, growth rate of collembolans has become as frequently used endpoint as reproduction rate in ecotoxicological studies. However, measuring collembolan body sizes to estimate growth rate is a complicated and time-consuming task. Here we present a new image analysis method, which facilitates and accelerates the body length measurement of the collembolan Folsomia candida. The new software package, called CollScope, consists of three elements: 1) an imaging device; 2) photographing software; 3) an ImageJ macro for image processing, measurement and data analysis. We give a complete description of the operation of the software, the image analyzing process and describe its accuracy and reliability. The software with a detailed usage manual is attached as Supplementary Material. We report a case study to demonstrate that the automated measurement of collembolan body sizes is highly correlated with the traditional manual measurements (estimated measuring accuracy 0.05 mm). Furthermore, we performed a dose-response ecotoxicity test using cadmium-sulfate by using CollScope as well as classical methods for size measurement. Size data measured by CollScope or manually did not differ significantly. Furthermore the new software package decreased time consumption of the measurements to 42% when tested on 35 animals. Consequently, methodological investigations performed in this study should be regarded as a recommendation for any other routine dose-response study where body growth is an endpoint. PMID:24901322

  5. Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae)

    PubMed Central

    Xu, Guo-Liang; Chen, Wei-Yu

    2016-01-01

    Abstract Two new blind species of Sinella are described from Guangdong Province, China. Sinella colubra sp. n. possesses minute smooth postlabial chaetae, long mucronal spine, and 4+4(5) lateral mac on Abd. IV, and can be distinguished from two closely related species by the postlabial chaetae and the dorsal macrochaetotaxy. Sinella zhangi sp. n. is also described and can be diagnosed by having minute labial chaeta r and postlabial chaetae X and X4, 5+5 mac on Abd. I, 4+4 central mac on Abd. II, and 4+4 central and 5+5 lateral mac on Abd. IV. PMID:27594797

  6. New troglomorphic species of Tomocerus with well-developed postantennal organs (Collembola: Tomoceridae).

    PubMed

    Yu, Daoyuan; Li, Youbang

    2016-09-09

    Three new troglobitic species of Tomocerus are described from the southwestern karsts of China. All of them have well developed postantennal organs. Tomocerus dong sp. nov. is similar to Tomocerus postantennalis Yu, Zhang & Deharveng and Tomocerus deharvengi sp. nov., but is different from them mainly in the number of prelabral chaetae and the dorsal body chaetotaxy. T. deharvengi sp. nov. is very similar to T. postantennalis but differs from the latter in the cephalic chaetotaxy, the number of manubrial pseudopores and the number of dental spines. T. cthulhu sp. nov. is peculiar for the multi-furcated vesicles of ventral tube, and is different from the three aforementioned species mainly in the dorsal body chaetotaxy. The position of the new species and the relationships between them are discussed.

  7. Katianna maryae n. sp. (Collembola: Katiannidae), a southern Appalachian species of a Gondwanan genus.

    PubMed

    Bernard, Ernest C

    2014-01-14

    Katianna maryae n. sp. is described from turf and grassy fields in eastern Tennessee, USA. This species is the first of its genus to be noted from temperate North America. It is distinguished from other described Katianna spp. by a combination of the following characters: color pattern of body an intricate mosaic of purple-brown, yellow-orange and white; copper-brown median stripe between eye patches; fourth antennal segment annuliform but not subsegmented; region between interantennal and clypeal region devoid of setae, clypeal region with six rows of setae; fore and middle feet with 8 clavate tenent hairs, hind foot with 6; apical filament of unguiculus long on fore and middle tibiotarsi, short on hind tibiotarsus; unguis with intricate multidentate pseudonychia; posterior face of dens with one proximal seta and a pair of subapical setae.

  8. A new genus of Entomobryinae (Collembola, Entomobryidae) from Brazilian Amazon with body scales and dental spines.

    PubMed

    Cipola, Nikolas Gioia; Morais, José Wellington De; Bellini, Bruno Cavalcante

    2016-04-21

    A new monotypic genus of Entomobryinae from Brazilian Amazon is described and illustrated. Amazhomidia gen. nov. is similar to other genera of the subfamily, especially to Sinhomidia Zhang, in presence of apically pointed scales on body dorsally and spines on dens. It differs from all other genera of Entomobryinae by the combination of: bifurcate prelabral chaetae, cephalic groove with scale-like chaetae and two transverse rows macrochaetae present on anterior central region of the abdominal IV segment. Amazhomidia ducke sp. nov., the type species of the new genus is described. An identification key to the genera of Entomobryidae with scales and dental spines is also provided.

  9. New species of Lepidocyrtus Bourlet and Entomobrya Rondani (Collembola: Entomobryoidea: Entomobryidae) from Brazil.

    PubMed

    Bellini, Bruno C; Cipola, Nikolas G; Godeiro, Nerivânia N

    2015-10-02

    The taxonomic comprehension of Brazilian entomobryids had several contributions during the last decade, but the absence of detailed chaetotaxic schemes to most of endemic species difficult identifications and probably hides undescribed species in surveys across the country. Herein we describe two new species of the family and provide detailed dorsal chaetotaxy of them, in hope to guide future identifications and descriptions within the genera in Brazil and Neotropical Region. Lepidocyrtus sotoi sp. nov. is possibly more related to L. biphasis due to the lack of antennal and leg scales, but presents a unique dorsal head chaetotaxy among the Neotropical species of the genus. Entomobrya bahiana sp. nov. presents an uncommon color pattern and dorsal chaetotaxy in Th. II-III, Abd. II and IV when compared to other Entomobrya spp. from Neotropical Region.

  10. A new genus and a new species of Sminthuridae (Collembola: Symphypleona) from Atlantic Forest of Brazil.

    PubMed

    Da Silva, Diego Dias; Palacios-Vargas, José G; Bellini, Bruno Cavalcante

    2015-07-27

    Sminthuridae comprises approximately 240 species distributed worldwide. In Brazil it is represented only by 11 species and four genera. Herein we describe a new genus and species of subfamily Sminthurinae from Atlantic Forest of Rio Grande do Norte State, Northeastern Brazil. The new described genus is similar to Gisinurus, Songhaica, Dietersminthurus and Soqotrasminthurus, especially in its unguis shape, with open cavity; but differs from all other genera of Sminthuridae by the presence of a single pretarsal chaeta in anterior side, smooth mucronal edges and a unique head chaetotaxy.

  11. Joint toxic action of binary metal mixtures of copper, manganese and nickel to Paronychiurus kimi (Collembola).

    PubMed

    Son, Jino; Lee, Yun-Sik; Kim, Yongeun; Shin, Key-Il; Hyun, Seunghun; Cho, Kijong

    2016-10-01

    The joint toxic effects of binary metal mixtures of copper (Cu), manganese (Mn) and nickel (Ni) on reproduction of Paronhchiurus kimi (Lee) was evaluated using a toxic unit (TU) approach by judging additivity across a range of effect levels (10-90%). For all metal mixtures, the joint toxic effects of metal mixtures on reproduction of P. kimi decreased in a TU-dependent manner. The joint toxic effects of metal mixtures also changed from less than additive to more than additive at an effect level lower than or equal to 50%, while a more than additive toxic effects were apparent at higher effect levels. These results indicate that the joint toxicity of metal mixtures is substantially different from that of individual metals based on additivity. Moreover, the close relationship of toxicity to effect level suggests that it is necessary to encompass a whole range of effect levels rather than a specific effect level when judging mixture toxicity. In conclusion, the less than additive toxicity at low effect levels suggests that the additivity assumption is sufficiently conservative to warrant predicting joint toxicity of metal mixtures, which may give an additional margin of safety when setting soil quality standards for ecological risk assessment. PMID:27318557

  12. Manganese toxicity in soil for Eisenia fetida, Enchytraeus crypticus (Oligochaeta), and Folsomia candida (Collembola).

    PubMed

    Kuperman, R G; Checkai, R T; Simini, M; Phillips, C T

    2004-01-01

    The U.S. Environmental Protection Agency is developing Ecological Soil Screening Level (Eco-SSL) benchmarks for ecological risk assessment (ERA) of contaminants at Superfund sites. Eco-SSLs are developed from published values whenever sufficient quantity and quality of data exist. Because insufficient information was available to generate an Eco-SSL for Mn, standardized toxicity testing was undertaken to fill the data gaps. Tests included the earthworm (Eisenia fetida) cocoon production test, the enchytraeid (Enchytraeus crypticus) reproduction test, and the collembolan (Folsomia candida) reproduction test, all conducted in Sassafras sandy loam soil that supports a relatively high bioavailability of metals. Weathering and aging of manganese-amended soil were carried out to more closely simulate exposure effects at Superfund sites on soil invertebrates. Data were analyzed by nonlinear regression to determine EC20 and EC50 values based on concentration-response relationships. The toxicity order for manganese in Sassafras sandy loam was E. crypticus>E. fetida>F. candida, with EC20 values of 116, 629, and 1209 mg kg(-1), respectively. The Eco-SSL requirement for the testing of multiple representative species is well justified. All study results will be submitted to the Eco-SSL Task Group for quality control review prior to inclusion in the Eco-SSL database.

  13. Holoblastic early cleavage of Tetrodontophora bielanensis (Collembola) eggs, with special reference to its irregularity.

    PubMed

    Klag, J; Jura, C; Krzysztofowicz, A; Kisiel, E

    1999-01-01

    The fertilized eggs of Tetrodontophora bielanensis start to cleave 6 to 8 days after oviposition and initially only karyokineses occur. The cytokinesis begins after two karyokineses, when four nuclei are observed in the ooplasm. Two cleavage furrows, perpendicular to each other, appear simultaneously at the egg poles where polar bodies are located and gradually the furrows encompass the whole egg diameter. The furrow formation is initiated by the bundle of microfilaments that contract and pull superficial fragments of the oolemma into the yolk and subsequently new membranes, separating the daughter cells, start to form. However, they do not grow towards the egg centre but bifurcate, leaving the central part of the ooplasm outside of the newly formed blastomeres. Starting from the fourth or fifth cleavage division, the bifurcations permanently occur and multiple cleavage furrows are formed on the embryo surface. Moreover, fragments of the ooplasm, enclosed within the cell membrane but devoid of cell nucleus are observed. During further development such cell fragments become reincorporated into the embryo. This mode of cleavage leads eventually to the formation of cellular blastoderm on the embryo surface. The results presented in the paper suggest that the control of cleavage in T. bielanensis acts not at the level of cytoplasmic determinants but rather at the level of positional information of blastomeres. PMID:10482251

  14. New blind species and new records of Sinella from Nanjing, China (Collembola, Entomobryidae)

    PubMed Central

    Xu, Heng; Zhang, Feng

    2016-01-01

    Abstract Two new blind species of Sinella are described from Nanjing, China. Sinella quinseta sp. n. from Purple Mountain possesses unique 5+5 central macrochaetae on Abd. II, and can be distinguished from other species of the genus by the postlabial chaetae and the dorsal chaetotaxy. Sinella qixiaensis sp. n. from Qixia Mountain is characterized by the paddle-like S-chaetae of Ant. III organ and the smooth straight chaetae on the manubrium and base of dens; it differs from two closely related species by the smooth manubrial chaetae, the labial chaetae, the Ant. III organ, and the macrochaetae on Abd. II. Sinella fuyanensis Chen & Christiansen and Sinella quinocula Chen & Christiansen were also newly recorded from Nanjing. PMID:27551205

  15. A new relictual and highly troglomorphic species of Tomoceridae (Collembola) from a deep Croatian cave

    PubMed Central

    Lukić, Marko; Houssin, Céline; Deharveng, Louis

    2010-01-01

    Abstract Tritomurus veles sp. n. (Tomoceridae) is described from a Croatian cave. It is characterized by troglomorphic features (absence of eyes, reduced pigmentation, slender claw, pointed tibiotarsal tenent hairs) that only compare, among Tomoceridae, to the microendemic species Tritomurus falcifer from the Pyrénées. Tritomurus veles also shares with Tritomurus falcifer the absence of macrochaetae on head, a presumably non-adaptive character that within Tomoceridae is unique to these two species. Both species have no known epigean relatives in their respective distribution areas and can be considered as relictual. PMID:21594037

  16. Three new species and one new record of Tullbergiidae (Collembola: Onychiuroidea) from Tierra del Fuego.

    PubMed

    Arbea, Javier I

    2016-03-20

    Three new species, Tullbergia rapoporti sp. nov., Dinaphorura nerudai sp. nov. and Dinaphorura najtae sp. nov., and one new record, Tullbergia meridionalis Cassagnau & Rapoport, 1962 are described based on specimens from Tierra del Fuego. Tullbergia rapoporti sp. nov. is similar to T. crozetensis, but can be distinguished from it by the presence of an empodial appendage and the chaetotaxy of Abd VI. Dinaphorura nerudai sp. nov. is diagnosed by the dorsal pso formula, the seven spiniform processes on Abd VI, an elongate PAO, the absence of vesicle on Ant IV and the dorsal chaetotaxy. Dinaphorura najtae sp. nov. is characterised by the dorsal pso formula, the seven spiniform processes on Abd VI, a triangular PAO, the absence of vesicle on Ant IV and the dorsal chaetotaxy.

  17. Grazing preference and utilization of soil fungi by Folsomia candida (Collembola)

    NASA Astrophysics Data System (ADS)

    Hedenec, Petr; Frouz, Jan

    2016-04-01

    Soil fungi are important food resources for soil fauna. Here we ask whether the collembolan Folsomia candida shows selectivity in grazing between four saprophytic fungi (Penicillium chrysogenum, Penicillium expansum, Absidia glauca, and Cladosporium herbarum), whether grazing preference corresponds to effects on collembolan reproduction, and whether the effects of fungi on grazing and reproduction depends on the fungal substrate, which included three kinds of litter (Alnus glutinosa, Salix caprea, and Quercus robur) and one kind of agar (yeast extract). On agar, Cladosporium herbarum and Absidia glauca were the most preferred fungi and supported the highest collembolan reproduction. On fungal-colonized litter, grazing preference was more affected by litter type than by fungal species whereas collembolan reproduction was affected by both litter type and fungal species. On fungal-colonized litter, the litter type that was most preferred for grazing did not support the highest reproduction, i.e., there was an inconsistency between food preference and suitability. Alder and willow were preferred over oak for grazing, but alder supported the least reproduction.

  18. Joint toxic action of binary metal mixtures of copper, manganese and nickel to Paronychiurus kimi (Collembola).

    PubMed

    Son, Jino; Lee, Yun-Sik; Kim, Yongeun; Shin, Key-Il; Hyun, Seunghun; Cho, Kijong

    2016-10-01

    The joint toxic effects of binary metal mixtures of copper (Cu), manganese (Mn) and nickel (Ni) on reproduction of Paronhchiurus kimi (Lee) was evaluated using a toxic unit (TU) approach by judging additivity across a range of effect levels (10-90%). For all metal mixtures, the joint toxic effects of metal mixtures on reproduction of P. kimi decreased in a TU-dependent manner. The joint toxic effects of metal mixtures also changed from less than additive to more than additive at an effect level lower than or equal to 50%, while a more than additive toxic effects were apparent at higher effect levels. These results indicate that the joint toxicity of metal mixtures is substantially different from that of individual metals based on additivity. Moreover, the close relationship of toxicity to effect level suggests that it is necessary to encompass a whole range of effect levels rather than a specific effect level when judging mixture toxicity. In conclusion, the less than additive toxicity at low effect levels suggests that the additivity assumption is sufficiently conservative to warrant predicting joint toxicity of metal mixtures, which may give an additional margin of safety when setting soil quality standards for ecological risk assessment.

  19. Isotomidae (Collembola) of Buryat Republic. III. The genera Vertagopus and Agrenia, with a note on 'Claw index'.

    PubMed

    Potapov, Mikhail; Gulgenova, Ayuna; Babykina, Marina

    2016-01-01

    Two genera are revised based on material from Buryatia (Russia, East Siberia). Vertagopus ceratus sp. nov. and V. asiaticus sp. nov. are described of which the former species is strictly alpine and is defined by pale colouration, the presence of chaetae on the anterior side of the ventral tube, and abundant sensillar chaetotaxy. V. asiaticus sp. nov. is widely distributed in Asia and is unusual due to only 9 chaetae in apical whorl on tibiotarsi. A key to species of Vertagopus Börner, recorded in the republic is given, and notes on morphology, distribution, and ecology are provided. In the genus Agrenia Börner, a form similar with A. bidenticulata was recorded in mountainous areas. Buryatian populations considerably differ from the diagnosis of the typical arctic A.bidenticulata (Tullberg) by a much longer claw. A conception of A. bidenticulata sensu lato complex is temporarily proposed basing on available materials from Palearctic, including High Arctic, sub-Arctic and South Siberian mountains. The complex consists of several local forms which are different in Claw index and associated Tibiotarsus/Claw ratio, while the dependence of the two indexes on the latitude is shown. PMID:27394328

  20. Supplementary descriptive notes of the Sinella and Coecobrya (Collembola: Entomobryidae) species from North America, Hawaii and Japan.

    PubMed

    Wu, Jun; Yan, Qibao; Zhang, Feng

    2016-01-01

    Many known collembolan species lack sufficient descriptive details so that further taxonomical comparison cannot be achieved. When sorting documents and materials from Prof. Jian-Xiu CHEN, Nanjing University, we found many old but valuable drafts on Sinella and Coecobrya species from North America, Hawaii and Japan. Supplementary descriptions, particularly chaetotaxy, were provided for the following species: S. agna Christiansen & Bellinger, 1980, S. alata Christiansen, 1960, S. baca Christiansen & Bellinger, 1980, S. barri Christiansen, 1960, S. hoffmani Wray, 1952, S. sexoculata (Schött, 1896), S. straminea (Folsom, 1899), S. yosiia Christiansen & Bellinger, 1992, C. akiyoshiana Yosii, 1956, C. borerae Christiansen & Bellinger, 1992, C. ishikawai Yosii, 1956, C. kukae Christiansen & Bellinger, 1992, C. lua Christiansen & Bellinger, 1992, C. nupa Christiansen & Bellinger, 1992, C. tibiotarsalis Yosii, 1964. Sinella cavernarum (Packard, 1888) was redescribed based on topotypes and more additional materials. PMID:27394318

  1. Ag Nanoparticles (Ag NM300K) in the Terrestrial Environment: Effects at Population and Cellular Level in Folsomia candida (Collembola).

    PubMed

    Mendes, Luís André; Maria, Vera L; Scott-Fordsmand, Janeck J; Amorim, Mónica J B

    2015-10-01

    The effects of nanomaterials have been primarily assessed based on standard ecotoxicity guidelines. However, by adapting alternative measures the information gained could be enhanced considerably, e.g., studies should focus on more mechanistic approaches. Here, the environmental risk posed by the presence of silver nanoparticles (Ag NM300K) in soil was investigated, anchoring population and cellular level effects, i.e., survival, reproduction (28 days) and oxidative stress markers (0, 2, 4, 6, 10 days). The standard species Folsomia candida was used. Measured markers included catalase (CAT), glutathione reductase (GR), glutathione S-transferase (GST), total glutathione (TG), metallothionein (MT) and lipid peroxidation (LPO). Results showed that AgNO₃ was more toxic than AgNPs at the population level: reproduction EC₂₀ and EC₅₀ was ca. 2 and 4 times lower, respectively. At the cellular level Correspondence Analysis showed a clear separation between AgNO₃ and AgNP throughout time. Results showed differences in the mechanisms, indicating a combined effect of released Ag⁺ (MT and GST) and of AgNPs (CAT, GR, TG, LPO). Hence, clear advantages from mechanistic approaches are shown, but also that time is of importance when measuring such responses. PMID:26473892

  2. Two new species of Homidia (Collembola, Entomobryidae) and a key to species in the genus from Zhejiang Province, China.

    PubMed

    Pan, Zhi-Xiang

    2015-01-01

    Two new species of Homidia are described from Yandang Mountain, China: H. yandangensis sp. nov. and H. quadrimaculata sp. nov. The new species are diagnosed by their unique colour patterns, the number of macrochaetae on areas A8-10 of abdominal segment IV, the relative position of specialised microchaetae/specialised ordinary chaetae on abdominal segment I and specialised ordinary chaetae/macrochaeta m3 on abdominal segment V. Specimens from two localities of H. yandangensis sp. nov. differ in the macrochaeta a5 on area A9 of abdominal segment IV. Descriptions of the subadult dorsal thoracic and abdominal chaetotaxy of H. yandangensis sp. nov. and a key to species of Homidia from Zhejiang Province are provided here. PMID:26624455

  3. Paratullbergia Womersley in China: the description of a new species and a key to the genus (Collembola, Tullbergiidae).

    PubMed

    Bu, Yun; Gao, Yan

    2015-01-01

    The genus Paratullbergia Womersley, 1930 is recorded for the first time from China. Paratullbergia changfengensis sp. n. from Shanghai is described and illustrated. It is characterized by the presence of 1+1 pseudocelli on thoracic segment I, with two pairs of pseudocelli on each of thoracic segments II and III, presence of seta px on abdominal segment IV, seta a2 and p4 on abdominal segment V as microsetae, and less differentiated sensory seta p3 on abdominal segment V. Both sexes present. The new species can be easily distinguished from its congeners by the presence of pseudocelli on thoracic segment I. An updated key to the world species of the genus Paratullbergia is provided. PMID:26668547

  4. A new species of the genus Xenylla Tullberg, 1869 (Collembola: Hypogastruridae) from Korea, with a key for East Asian species.

    PubMed

    Park, Kyung-Hwa

    2016-01-01

    A new species of Hypogastruridae from Korea, Xenylla namia sp. nov., is described and illustrated. The new species is easily distinguished from previously described Xenylla species by a combination of the following characters: labral setae arrangement of 2/5,5,4, labial papilla E with one guard seta (e3), head without c2 seta, thoracic sterna II and III with a pair of medial setae, abdominal sternum III with 1 median seta above the retinaculum, abdominal sternum IV with seta m1. An identification key to East Asian species of Xenylla with detailed differences between East Asian Xenylla species is provided. PMID:27395598

  5. Genus Neelus Folsom, 1896 (Hexapoda, Collembola) reveals its diversity in cave habitats: two new species from Croatia.

    PubMed

    Papáč, Vladimír; Lukić, Marko; Kováč, Ľubomír

    2016-01-01

    Two new species of the genus Neelus Folsom, 1896, N. cvitanovici sp. nov. and N. lackovici sp. nov., are described from caves of Croatia. N. lackovici sp. nov. exhibit marked troglomorphic features such as extremely elongated ungua and antennae, larger body among others. Descriptions are completed with comparative tables for chaetotaxy of antennae and legs. Diagnostic table for the congeners and identification key to the world species are provided. Distribution records of other Neelus species in Croatian caves are added. Threats of troglobiotic Neelus species in Croatia are discussed. PMID:27394325

  6. Paratullbergia Womersley in China: the description of a new species and a key to the genus (Collembola, Tullbergiidae)

    PubMed Central

    Bu, Yun; Gao, Yan

    2015-01-01

    Abstract The genus Paratullbergia Womersley, 1930 is recorded for the first time from China. Paratullbergia changfengensis sp. n. from Shanghai is described and illustrated. It is characterized by the presence of 1+1 pseudocelli on thoracic segment I, with two pairs of pseudocelli on each of thoracic segments II and III, presence of seta px on abdominal segment IV, seta a2 and p4 on abdominal segment V as microsetae, and less differentiated sensory seta p3 on abdominal segment V. Both sexes present. The new species can be easily distinguished from its congeners by the presence of pseudocelli on thoracic segment I. An updated key to the world species of the genus Paratullbergia is provided. PMID:26668547

  7. The genus Drepanura (Collembola: Entomobryidae) in Australia: descriptions of two new species and redescriptions of five known species.

    PubMed

    Ma, Yitong; Chun, Zhao; Greenslade, Penelope

    2015-01-01

    Seven Australian species of the genus Drepanura are reported. Two of the seven are new and five are redescribed. The new species are: D. liuae sp. nov. and D. polychaeta sp. nov. Redescriptions are given for D. albocoerulea (Schött, 1917), D. cinquilineata Womersley, 1934, D. citricola Womersley, 1934, D. cobaltina (Schött, 1917) and D. coeruleopicta (Schött, 1917). The chaetotaxy is described and a key to the Australian species of the genus is given. PMID:26701533

  8. Diversity of Paranura Axelson, 1902 (Collembola: Neanuridae: Neanurinae) in Pacific Region of Russia and United States.

    PubMed

    Smolis, Adrian; Deharveng, Louis

    2015-01-01

    Eight new species of the genus Paranura are described from temperate zone of Holarctic. Five of them: Paranura reticulata sp. nov., Paranura oregonensis sp. nov., Paranura reducta sp. nov., Paranura cassagnaui sp. nov. and Paranura microchaetosa sp. nov. were found in coniferous forests of Oregon state, USA. Three others: Paranura kedrovayensis sp. nov., Paranura setosa sp. nov. and Paranura conjuncta sp. nov. were collected in mixed woods of Russian Far East. All new species are illustrated in detail and compared with existing taxa. P. reticulata sp. nov. is characterised by having three ocular chaetae, relatively short chaeta F on head, four ordinary chaetae De on th. III and three chaetae Di in abd. V (in s-uenoi two chaetae). The presence of only one ordinary chaeta De on abdomen IV is the most characteristic and recognizable character of P. oregonensis sp. nov. P. reducta sp. nov. is most diagnostically recognized by labral chaetotaxy, with only 4 chaetae. The species is true saproxylic form living inside decayed logs of coniferous trees only. P. cassagnaui sp. nov. is easy to distinguish by the presence of complete chaetotaxy of central area of head, presence of microchaetae on furcal remnant and the fusion of tubercles Di on abd. V. P. microchaetosa sp. nov. and P. kedrovayensis sp. nov. are superficially very similar to each other in dorsal chaetotaxy, and differ in number of ordinary chaetae De on abd. IV, trochanter and labium, and in the presence/absence of microchaetae on furcal remnant. P. setosa sp. nov. can be easily identified by one or two additional chaetae on central area of head, a character unknown in other species of the genus. P. conjuncta sp. nov. is characterised by the fusion of tubercles Di on abdomen V, the presence of microchaetae on furcal remnant and developed tubercle on central area of head. In addition, P. mjohjangensis Deharveng & Weiner, 1984 is newly recorded from Russia. An updated key to all world species of Paranura is also provided. PMID:26624400

  9. A revision of Pseudoparonella, Plumachaetas, Parachaetoceras and Lawrenceana (Collembola: Paronellidae), with description of three new species from New Caledonia.

    PubMed

    Zhang, Feng; Deharveng, Louis

    2015-01-01

    The relationship of Pseudoparonella to other paronellid genera is currently unresolved. Authors have proposed different taxonomical systems for which the proposed subgeneric divisions have not been compared. We compared these genera in detail and conclude here that antennal length is a reliable diagnostic character. The antennae of species in the genera Plumachaetas and Parachaetoceras, are longer than body and bear long chaetae but are not longer than body in Pseudoparonella. The subapical chaeta on the maxillary outer lobe is another character potentially discriminant as it is pointed in Pseudoparonella but thick and blunt in Plumachaetas. The subgenus Lawrenceana is synonymised here with Plumachaetas because of long antennae. Three new species, Pseudoparonella seminigra sp. nov., Plumachaetas yoshii sp. nov., and Plumachaetas sunae sp. nov., are described from New Caledonia. Variation in colour patterns of Pseudoparonella griseocoerulea Yoshii is reported. New records of Pseudoparonella tanimbarica Yoshii & Suhardjono and Ps. shibatai Yosii, as well as a key to genera, are also provided. PMID:26701546

  10. The dorsal chaetotaxy of first instar Trogolaphysa jataca, with description of twelve new species of Neotropical Trogolaphysa (Hexapoda: Collembola: Paronellidae).

    PubMed

    Soto-Adames, Felipe N

    2015-01-01

    Adult members of tribe Paronellini are characterized by a substantially reduced idiochaetotaxy and as a result chaeta homology determination is often ambiguous. To evaluate previous hypotheses of chaetae homology in adult Trogolaphysa, a complete description of the dorsal chaetotaxy of first instar Trogolaphysa jataca (Wray, 1953b), supplemented with observations on first instar Trogolaphysa paracarpenteri sp. nov., is presented. It is showed that first instar Trogolaphysa carries an almost complete set of dorsal chaetae and that the reduction in adult idiochaetotaxy is secondary. In addition, the organization of primary chaetae in T. jataca points to a closer relationship with genera in subfamily Entomobryinae than to Orchesellinae. Based on chaetae correspondence between first instar and adult T. jataca it is established that the inner median chaetae on adult head corresponds to M1 instead of S1, the mesothorax p3 complex includes chaetae p1-p4, and on the fourth abdominal segment, anterior macrochaeta on column A corresponds to A3, and the secondary bothriotrix corresponds to D3p. In addition, T. relicta (Palacios-Vargas, Ojeda & Christiansen, 1985) is re-described based on a paratype, and 12 new species are described: from Mexico, T. stannardi sp. nov., T. dimorphica sp. nov., T. laterolineata sp. nov., T. marieloiseae sp. nov., T. clarencei sp. nov., T. ocellata sp. nov., T. paracarpenteri sp. nov., T. palaciosi sp. nov., T. octosetosa sp. nov., and T. trioculata sp. nov.; from Jamaica, T. balteata sp. nov.; and from Argentina, T. entreriosensis sp. nov. PMID:26624337

  11. Ecotoxicity of mercury to Folsomia candida and Proisotoma minuta (Collembola: Isotomidae) in tropical soils: Baseline for ecological risk assessment.

    PubMed

    Buch, Andressa Cristhy; Niemeyer, Júlia Carina; Fernandes Correia, Maria Elizabeth; Silva-Filho, Emmanoel Vieira

    2016-05-01

    Mercury (Hg) is a highly toxic nonessential trace metal. Despite its natural occurrence in the Earth's Crust, its concentrations have been steadily increasing in the environment due to anthropogenic sources. Recent studies have showed great concern about soil fauna, once the potential adverse effects of mercury concentrations in the environment of these invertebrates are still poorly understood, especially when linked to forest soils and tropical biota. Different collembolan species can show distinct toxicity effects to the contaminants, impairing its developing lifelong and affecting its diversity and abundance in the environment. Laboratory studies were performed to evaluate the ecotoxicity of Hg(II) to collembolan species collected in Brazil, Proisotoma minuta (autochthonous) and Folsomia candida (allochthonous), as a tool to predict effects in ecological risk assessment of tropical regions. Behavioral, acute and chronic tests were carried under temperatures of 20°C and 24°C using two test soils, natural and artificial, spiked with increasing mercury concentrations. F. candida was more sensitive to mercury contamination than P. minuta, presenting the most restrictive values of EC50 and LC50. Reproduction was a considerably more sensitive endpoint than avoidance and mortality. The 28-day lower EC50 values were found in chronic tests for F. candida in natural soil to 24°C (3.32mgHgkg(-1)), while for P. minuta was in tropical artificial soil to 20°C (4.43mgHgkg(-1)). There were similarity for each collembolan species to respond at the Hg(II) effects when exposed at 20°C and 24°C. F. candida can be suitable as a bioindicator species to mercury ecotoxicity tests in tropical forest soils. PMID:26796529

  12. The ultrastructure of the ejaculatory duct in the springtail Orchesella villosa (Geoffroy) (Hexapoda, Collembola) and the formation of the spermatophore.

    PubMed

    Fanciulli, Pietro Paolo; Zizzari, Zaira Valentina; Frati, Francesco; Dallai, Romano

    2012-02-01

    The initial part of the ejaculatory duct of Orchesella villosa contains a "valve" and a "sorter" avoiding respectively the reflow and allowing the separation of the secretion for the spermatophore stalk from the sperm fluid. For most of its length, the ejaculatory duct lumen is divided into two parts: in the dorsal part the sperm fluid flows while in the ventral district the secretion for the stalk occurs. Laterally, on both sides of the duct, longitudinal muscle fibers are present. The epithelium of the dorsal region consists of two types of long secretory cells; the most peculiar of them are those provided with extracellular cisterns flowing directly into the duct lumen as it occurs in 1st type of epidermal cells. These cells could be involved in the control of the viscosity of the sperm fluid. The second type of cells produce a secretion probably involved in the formation of the outer coat of the apical sperm droplet. The ventral epithelium consists of short cells contributing to the enrichment of the secretion for the spermatophore stalk and perhaps also to the viscosity of the secretion flowing in the lumen. In the distal part of the ejaculatory duct, the ventral district is provided with a thick layer of muscle fibers and with 3+3 cuticular laminae dividing the lumen into a series of slits through which the secretion of the stalk is squeezed out into filaments. This organization allows the twisting and hardening of these filaments. A drop of sperm fluid is laid on top of the long and rigid spermatophore stalk. PMID:22056322

  13. Interactive effects of λ-cyhalothrin, soil moisture, and temperature on Folsomia candida and Sinella curviseta (Collembola).

    PubMed

    Bandow, Cornelia; Coors, Anja; Karau, Nora; Römbke, Jörg

    2014-03-01

    The authors investigated whether and how 2 environmental factors could influence the toxicity of a pyrethroid to 2 representatives of an important group of soil organisms. The impacts of different temperatures (20 °C and 26 °C) and soil moisture levels (30%, 50%, and 70% of water holding capacity) were investigated in combination with the insecticide λ-cyhalothrin on the reproduction success of Folsomia candida and Sinella curviseta in a full factorial design. Testing was based on the standard collembolan reproduction test (Organisation for Economic Co-operation and Development, guideline 232) following an effect concentration design. The results showed an effect of environmental and chemical factors on the number of juveniles of these animals. Particularly in dry soil, the reproduction of both species was reduced, while higher soil moisture levels influenced the number of juveniles positively compared with the middle soil moisture level. In general, however, higher soil moisture led to increased sensitivity to λ-cyhalothrin. In both organisms, temperature affected the toxicity of the pesticide but in different directions: high temperature led to higher toxicity in F. candida but to lower toxicity in S. curviseta. PMID:24288263

  14. A new species of the genus Xenylla Tullberg, 1869 (Collembola: Hypogastruridae) from Korea, with a key for East Asian species.

    PubMed

    Park, Kyung-Hwa

    2016-01-01

    A new species of Hypogastruridae from Korea, Xenylla namia sp. nov., is described and illustrated. The new species is easily distinguished from previously described Xenylla species by a combination of the following characters: labral setae arrangement of 2/5,5,4, labial papilla E with one guard seta (e3), head without c2 seta, thoracic sterna II and III with a pair of medial setae, abdominal sternum III with 1 median seta above the retinaculum, abdominal sternum IV with seta m1. An identification key to East Asian species of Xenylla with detailed differences between East Asian Xenylla species is provided.

  15. The dorsal chaetotaxy of Trogolaphysa (Collembola, Paronellidae), with descriptions of two new species from caves in Belize

    PubMed Central

    Soto-Adames, Felipe N.; Taylor, Steven J.

    2013-01-01

    Abstract Species diagnosis in Trogolaphysa has been based, until now, almost exclusively on number of eyes and shape of claws and mucro. Chaetotaxy, a character system important to diagnose species in other genera of scaled Entomobryoidea, has been described only for a few Trogolaphysa species. Here the complete dorsal chaetotaxy of six species of Trogolaphysa is described using the AMS and Szeptycki’s systems for head and body, respectively. A morphology-based parsimony analysis was performed to evaluate whether chaetotaxic characters overcome the influence of putatively cave adaptive convergent characters to resolve species level relationships, and to evaluate the evolution of the dorsal macrochaetae of the head. Phylogenetic analysis using only putative cave-adaptive characters support clades of unrelated taxa, but the addition of chaetotaxy overcomes the influence of convergent characters. A phylogeny based on all characters supports a trend towards reduced head macrochaetae number. Head macrochaetae are lost beginning with A3 and followed, in order, by S5, S3 and M3. In addition, a checklist of New World Trogolaphysa is provided and two new species, Trogolaphysa giordanoae sp. n. and Trogolaphysa jacobyi sp. n., are described on the basis of material collected in six caves in southern Belize. PMID:24003314

  16. Description and conservation status of a new species of Australotomurus (Collembola: Entomobryidae: Orchesellinae) from urban Perth remnant bushland.

    PubMed

    Greenslade, Penelope; Jordana, Rafael

    2014-01-01

    A new species of the Australian endemic genus Australotomurus Stach, 1947 A. morbidus sp. nov., is described from four urban remnants in Perth. Australotomurus morbidus sp. nov. is the first species in the genus found to possess male secondary sexual characters on antennal segment III as well as I. The males of all other described species in the genus occurring in south-eastern Australia have secondary sexual characters on antennal segments I and II rather than I and III. Typical habitats for Australotomurus species are long undisturbed native grasslands and heathland at low and high elevations. The new species extends the known distribution of the genus ca. 2,000 km west. Australotomurus morbidus sp. nov. is the only species in the genus currently vulnerable to extinction because of its restricted distribution to only four localities, all of which are subject to considerable human disturbance. This species was listed as critically endangered when it was known (but not yet described) from only one locality but was delisted a few years later when three other locations for the species were found. The history and records of A. morbidus sp. nov. suggest that listing species using current Western Australian legislation does not necessarily protect vulnerable species. The new species is described here and new records for some other Australian species of Orchesellinae provided, including the first Australian record of Heteromurus major (Moniez, 1889). PMID:25544101

  17. Interactive effects of λ-cyhalothrin, soil moisture, and temperature on Folsomia candida and Sinella curviseta (Collembola).

    PubMed

    Bandow, Cornelia; Coors, Anja; Karau, Nora; Römbke, Jörg

    2014-03-01

    The authors investigated whether and how 2 environmental factors could influence the toxicity of a pyrethroid to 2 representatives of an important group of soil organisms. The impacts of different temperatures (20 °C and 26 °C) and soil moisture levels (30%, 50%, and 70% of water holding capacity) were investigated in combination with the insecticide λ-cyhalothrin on the reproduction success of Folsomia candida and Sinella curviseta in a full factorial design. Testing was based on the standard collembolan reproduction test (Organisation for Economic Co-operation and Development, guideline 232) following an effect concentration design. The results showed an effect of environmental and chemical factors on the number of juveniles of these animals. Particularly in dry soil, the reproduction of both species was reduced, while higher soil moisture levels influenced the number of juveniles positively compared with the middle soil moisture level. In general, however, higher soil moisture led to increased sensitivity to λ-cyhalothrin. In both organisms, temperature affected the toxicity of the pesticide but in different directions: high temperature led to higher toxicity in F. candida but to lower toxicity in S. curviseta.

  18. Adaptations and Predispositions of Different Middle European Arthropod Taxa (Collembola, Araneae, Chilopoda, Diplopoda) to Flooding and Drought Conditions

    PubMed Central

    Marx, Michael Thomas; Guhmann, Patrick; Decker, Peter

    2012-01-01

    Simple Summary This review summarizes adaptations and predispositions of different arthropod taxa (springtails, web spiders, millipedes and centipedes) to flood and drought conditions. The main focus sis directed to arthropod species, which are living in Middle European floodplain forests and wetlands, because of the fast change of flood and drought conditions in these habitats. Furthermore the effects of the predicted regional climate change like increasing aperiodic summer flooding and decreasing winter and spring floods are also discussed. Abstract Floodplain forests and wetlands are amongst the most diverse and species rich habitats on earth. Arthropods are a key group for the high diversity pattern of these landscapes, due to the fact that the change between flooding and drought causes in different life cycles and in a variety of adaptations in the different taxa. The floodplain forests and wetlands of Central Amazonia are well investigated and over the last 50 years many adaptations of several hexapod, myriapod and arachnid orders were described. In contrast to Amazonia the Middle European floodplains were less investigated concerning the adaptations of arthropods to flood and drought conditions. This review summarizes the adaptations and predispositions of springtails, web spiders, millipedes and centipedes to the changeable flood and drought conditions of Middle European floodplain forests and wetlands. Furthermore the impact of regional climate change predictions like increasing aperiodic summer floods and the decrease of typical winter and spring floods are discussed in this article. PMID:26487164

  19. Assessment of Potential Risks of Dietary RNAi to a Soil Micro-arthropod, Sinella curviseta Brook (Collembola: Entomobryidae).

    PubMed

    Pan, Huipeng; Xu, Linghua; Noland, Jeffrey E; Li, Hu; Siegfried, Blair D; Zhou, Xuguo

    2016-01-01

    RNAi-based genetically engineered (GE) crops for the management of insect pests are likely to be commercialized by the end of this decade. Without a workable framework for conducting the ecological risk assessment (ERA) and a standardized ERA protocol, however, the utility of RNAi transgenic crops in pest management remains uncertain. The overall goal of this study is to assess the risks of RNAi-based GE crops on a non-target soil micro-arthropod, Sinella curviseta, which could be exposed to plant-protected dsRNAs deposited in crop residues. Based on the preliminary research, we hypothesized that insecticidal dsRNAs targeting at the western corn rootworm, Diabrotica virgifera virgifera, a billion-dollar insect pest, has no adverse impacts on S. curviseta, a soil decomposer. Following a tiered approach, we tested this risk hypothesis using a well-designed dietary RNAi toxicity assay. To create the worst-case scenario, the full-length cDNA of v-ATPase subunit A from S. curviseta were cloned and a 400 bp fragment representing the highest sequence similarity between target pest and non-target arthropods was selected as the template to synthesize insecticidal dsRNAs. Specifically, 10-days-old S. curviseta larvae were subjected to artificial diets containing v-ATPase A dsRNAs from both D. v. virgifera (dsDVV) and S. curviseta (dsSC), respectively, a dsRNA control, β-glucuronidase, from plant (dsGUS), and a vehicle control, H2O. The endpoint measurements included gene expression profiles, survival, and life history traits, such as developmental time, fecundity, hatching rate, and body length. Although, S. curviseta larvae developed significantly faster under the treatments of dsDVV and dsSC than the vehicle control, the combined results from both temporal RNAi effect study and dietary RNAi toxicity assay support the risk hypothesis, suggesting that the impacts of ingested arthropod-active dsRNAs on this representative soil decomposer are negligible. PMID:27471512

  20. Two metal-binding peptides from the insect Orchesella cincta (Collembola) as a result of metallothionein cleavage.

    PubMed

    Hensbergen, P J; Donker, M H; Hunziker, P E; van der Schors, R C; van Straalen, N M

    2001-10-01

    Metallothionein (MT) is an ubiquitous heavy metal-binding protein which has been identified in animals, plants, protists, fungi and bacteria. In insects, primary structures of MTs are known only for Drosophila and the collembolan, Orchesella cincta. The MT cDNA from O. cincta encodes a 77 amino acid protein with 19 cysteines. Isolations of the protein itself have demonstrated the presence of two smaller metal-binding peptides, whose amino acid sequences correspond to parts of the cDNA, and which apparently result from cleavage of the native protein. The present study was undertaken to complete the picture of cleavage sites within the MT protein by applying protein isolation techniques in combination with mass spectrometry and N-terminal sequence analysis. Further, recombinant expression allowed us to study the intrinsic stability of the MT and to perform in vitro cleavage studies. The results show that the MT from O. cincta is specifically cleaved at two sites, both after the amino acid sequence Thr-Gln (TQ). One of these sites is located in the N-terminal region and the other in the linker region between two putative metal-binding clusters. When expressed in Escherichia coli, the recombinant O. cincta MT can be isolated in an uncleaved form; however, this protein can be cleaved in vitro by the proteolytic activity of O. cincta. In combination with other studies, the results suggest that the length of the linker region is important for the stability of MT as a two domain metal-binding protein.

  1. Adaptations and Predispositions of Different Middle European Arthropod Taxa (Collembola, Araneae, Chilopoda, Diplopoda) to Flooding and Drought Conditions.

    PubMed

    Marx, Michael Thomas; Guhmann, Patrick; Decker, Peter

    2012-01-01

    Floodplain forests and wetlands are amongst the most diverse and species rich habitats on earth. Arthropods are a key group for the high diversity pattern of these landscapes, due to the fact that the change between flooding and drought causes in different life cycles and in a variety of adaptations in the different taxa. The floodplain forests and wetlands of Central Amazonia are well investigated and over the last 50 years many adaptations of several hexapod, myriapod and arachnid orders were described. In contrast to Amazonia the Middle European floodplains were less investigated concerning the adaptations of arthropods to flood and drought conditions. This review summarizes the adaptations and predispositions of springtails, web spiders, millipedes and centipedes to the changeable flood and drought conditions of Middle European floodplain forests and wetlands. Furthermore the impact of regional climate change predictions like increasing aperiodic summer floods and the decrease of typical winter and spring floods are discussed in this article. PMID:26487164

  2. Ag Nanoparticles (Ag NM300K) in the Terrestrial Environment: Effects at Population and Cellular Level in Folsomia candida (Collembola)

    PubMed Central

    Mendes, Luís André; Maria, Vera L.; Scott-Fordsmand, Janeck J.; Amorim, Mónica J. B.

    2015-01-01

    The effects of nanomaterials have been primarily assessed based on standard ecotoxicity guidelines. However, by adapting alternative measures the information gained could be enhanced considerably, e.g., studies should focus on more mechanistic approaches. Here, the environmental risk posed by the presence of silver nanoparticles (Ag NM300K) in soil was investigated, anchoring population and cellular level effects, i.e., survival, reproduction (28 days) and oxidative stress markers (0, 2, 4, 6, 10 days). The standard species Folsomia candida was used. Measured markers included catalase (CAT), glutathione reductase (GR), glutathione S-transferase (GST), total glutathione (TG), metallothionein (MT) and lipid peroxidation (LPO). Results showed that AgNO3 was more toxic than AgNPs at the population level: reproduction EC20 and EC50 was ca. 2 and 4 times lower, respectively. At the cellular level Correspondence Analysis showed a clear separation between AgNO3 and AgNP throughout time. Results showed differences in the mechanisms, indicating a combined effect of released Ag+ (MT and GST) and of AgNPs (CAT, GR, TG, LPO). Hence, clear advantages from mechanistic approaches are shown, but also that time is of importance when measuring such responses. PMID:26473892

  3. Assessment of Potential Risks of Dietary RNAi to a Soil Micro-arthropod, Sinella curviseta Brook (Collembola: Entomobryidae)

    PubMed Central

    Pan, Huipeng; Xu, Linghua; Noland, Jeffrey E.; Li, Hu; Siegfried, Blair D.; Zhou, Xuguo

    2016-01-01

    RNAi-based genetically engineered (GE) crops for the management of insect pests are likely to be commercialized by the end of this decade. Without a workable framework for conducting the ecological risk assessment (ERA) and a standardized ERA protocol, however, the utility of RNAi transgenic crops in pest management remains uncertain. The overall goal of this study is to assess the risks of RNAi-based GE crops on a non-target soil micro-arthropod, Sinella curviseta, which could be exposed to plant-protected dsRNAs deposited in crop residues. Based on the preliminary research, we hypothesized that insecticidal dsRNAs targeting at the western corn rootworm, Diabrotica virgifera virgifera, a billion-dollar insect pest, has no adverse impacts on S. curviseta, a soil decomposer. Following a tiered approach, we tested this risk hypothesis using a well-designed dietary RNAi toxicity assay. To create the worst-case scenario, the full-length cDNA of v-ATPase subunit A from S. curviseta were cloned and a 400 bp fragment representing the highest sequence similarity between target pest and non-target arthropods was selected as the template to synthesize insecticidal dsRNAs. Specifically, 10-days-old S. curviseta larvae were subjected to artificial diets containing v-ATPase A dsRNAs from both D. v. virgifera (dsDVV) and S. curviseta (dsSC), respectively, a dsRNA control, β-glucuronidase, from plant (dsGUS), and a vehicle control, H2O. The endpoint measurements included gene expression profiles, survival, and life history traits, such as developmental time, fecundity, hatching rate, and body length. Although, S. curviseta larvae developed significantly faster under the treatments of dsDVV and dsSC than the vehicle control, the combined results from both temporal RNAi effect study and dietary RNAi toxicity assay support the risk hypothesis, suggesting that the impacts of ingested arthropod-active dsRNAs on this representative soil decomposer are negligible. PMID:27471512

  4. New diagnosis for species of Plutomurus Yosii (Collembola, Tomoceridae), with descriptions of two new species from Georgian caves.

    PubMed

    Barjadze, Shalva; Baquero, Enrique; Soto-Adames, Felipe N; Giordano, Rosanna; Jordana, Rafael

    2016-01-01

    Two new species of the genus Plutomurus, P. revazi sp. nov. from Prometheus and Satsurblia caves and P. eristoi sp. nov. from Satevzia Cave are described, illustrated and differentiated from other morphologically closely related species. A high variability in the number of teeth in the claw, unguiculus and mucro of P. revazi sp. nov. demonstrate that these characters are not useful for species diagnosis. However, dorsal chaetotaxy was shown to be stable character for this purpose. Analysis of DNA sequences for the COI and 28S genes is congruent with species-level groups delimited by chaetotaxy, and provide additional support for chaetotaxy as the most reliable morphological character system to distinguish species in Plutomurus. A key to species of the genus Plutomurus found in Georgia is provided, which for the first time includes characters of the macrochaetotaxy. PMID:27395573

  5. Responses of Folsomia fimetaria (Collembola: Isotomidae) to copper under different soil copper contamination histories in relation to risk assessment

    SciTech Connect

    Scott-Fordsmand, J.J.; Krogh, P.H.; Weeks, J.M.

    2000-05-01

    The collembolan Folsomia fimetaria L. was exposed in the laboratory to a range of elevated soil copper concentrations under two different contamination histories. These results were compared with the in situ abundance of F. fimetaria in a copper-contaminated field site. In the laboratory studies, an EC10 of 337 mg Cu/kg was observed for soil spiked with copper 1 d before the experiment. Using soil from a field site contaminated with copper more than 70 years previously, no effect was observed at concentrations as great as 2,911 mg Cu/kg. Reproduction was threefold more sensitive than mortality or growth. Differences in copper sensitivity between sexes and between juvenile clutches were also indicated. The abundance of F. fimetaria showed no change with soil copper concentrations during the first year (spring sampling) of in situ observations. During the second year (autumn sampling), a reduced number per area was observed with increasing soil copper concentrations. Both the presence and abundance of other euedaphic collembolans generally exhibited distribution patterns similar to those of F. fimetaria. Thus, the contamination history and the toxicological endpoint were very important for interpreting the outcome of the standard laboratory toxicity test. Laboratory studies to some extent reflected the in situ abundance, but this depended on the contamination history and the field sampling time. Laboratory experiments using new copper-spiked soil provided the lowest effect levels.

  6. Diversity of Paranura Axelson, 1902 (Collembola: Neanuridae: Neanurinae) in Pacific Region of Russia and United States.

    PubMed

    Smolis, Adrian; Deharveng, Louis

    2015-10-22

    Eight new species of the genus Paranura are described from temperate zone of Holarctic. Five of them: Paranura reticulata sp. nov., Paranura oregonensis sp. nov., Paranura reducta sp. nov., Paranura cassagnaui sp. nov. and Paranura microchaetosa sp. nov. were found in coniferous forests of Oregon state, USA. Three others: Paranura kedrovayensis sp. nov., Paranura setosa sp. nov. and Paranura conjuncta sp. nov. were collected in mixed woods of Russian Far East. All new species are illustrated in detail and compared with existing taxa. P. reticulata sp. nov. is characterised by having three ocular chaetae, relatively short chaeta F on head, four ordinary chaetae De on th. III and three chaetae Di in abd. V (in s-uenoi two chaetae). The presence of only one ordinary chaeta De on abdomen IV is the most characteristic and recognizable character of P. oregonensis sp. nov. P. reducta sp. nov. is most diagnostically recognized by labral chaetotaxy, with only 4 chaetae. The species is true saproxylic form living inside decayed logs of coniferous trees only. P. cassagnaui sp. nov. is easy to distinguish by the presence of complete chaetotaxy of central area of head, presence of microchaetae on furcal remnant and the fusion of tubercles Di on abd. V. P. microchaetosa sp. nov. and P. kedrovayensis sp. nov. are superficially very similar to each other in dorsal chaetotaxy, and differ in number of ordinary chaetae De on abd. IV, trochanter and labium, and in the presence/absence of microchaetae on furcal remnant. P. setosa sp. nov. can be easily identified by one or two additional chaetae on central area of head, a character unknown in other species of the genus. P. conjuncta sp. nov. is characterised by the fusion of tubercles Di on abdomen V, the presence of microchaetae on furcal remnant and developed tubercle on central area of head. In addition, P. mjohjangensis Deharveng & Weiner, 1984 is newly recorded from Russia. An updated key to all world species of Paranura is also provided.

  7. Taxonomy of the Proisotoma complex. VI. Mobile forms of Proisotoma s.str. with the description of a new species from East Siberia (Collembola: Isotomidae).

    PubMed

    Potapov, Mikhail; Bogomolov, Maxim

    2016-01-01

    Phenotypic dimorphism of four species of the genus Proisotoma s.str. is described. The modified specimens are characterized by protruding corneas of eyes, stronger pigmentation, enlarged and more chitinized furca, and extension of clavate tenent hairs in the distal part of the tibiotarsi. The characteristics of the modified specimens indicate higher mobile activity. Both sexes are affected by the dimorphism, with the "mobile" forms mostly co-occuring during the cold season with normal specimens. Proisotoma dualis sp. nov. is described from Buryat Republic. PMID:27394339

  8. New record of the genus Israelimeria Weiner & Kaprus', 2005 (Collembola: Neanuridae: Pseudachorutinae) from Iran, with description of a new species.

    PubMed

    Alijani, Masoumeh; Shayanmehr, Masoumeh; Skarżyński, Dariusz; Piwnik, Agata; Smolis, Adrian

    2015-01-01

    Israelimeria persica sp. nov. is described from Iran. The genus Israelimeria can be easily identified due to a reduction of the number of eyes and the complete absence of the postantennal organ and the furca. The new taxon, and also the second species of the genus, differs from I. poliakovae Weiner & Kaprus', 2005, known only from Judean Mts. in Israel, in size and shape of mandibles and many chaetotactic characters, especially number of setae in ocular area of the head, ventral tube, subcoxae "1" and microchaetae number in furcal area. PMID:26623613

  9. New cave-dwelling species of Tomoceridae from China, with a study on the pattern of mesothoracic bothriotricha in Tomocerinae (Collembola, Entomobryomorpha).

    PubMed

    Yu, Daoyuan; Yan, Qibao; Liu, Manqiang

    2016-01-01

    Two new troglobitic species of Tomoceridae are described from Guizhou and Guangxi provinces, China. Tomocerus tiani sp. n. resembles Tomocerus kinoshitai Yosii, 1954, Tomocerus caecus Yu & Deharveng, 2015 and Tomocerus similis Chen & Ma, 1997 but differs from them mainly in the body colour, the cephalic chaetotaxy and the number of manubrial pseudopores. Monodontocerus cinereus sp. n. is similar to Monodontocerus mulunensis Yu, Deharveng & Zhang, 2014 but is different from the latter in the body colour, the length of antennae, the number of ungual teeth and the chaetotaxy on Abd. III and Abd. IV. Special remarks are made on the mesothoracic bothriotricha in Tomocerinae. PMID:27110179

  10. A new species of Deutonura (Collembola: Neanuridae: Neanurinae) from Algeria, with revised diagnosis of the genus and key to western Palaearctic species.

    PubMed

    Deharveng, Louis; Mouloud, Salah Ait; Bedos, Anne

    2015-01-01

    Deutonura adriani sp. nov. is described from the region of Tizi-Ouzou (Algeria). The species is morphologically similar to D. deficiens deficiens Deharveng, 1979 from southwestern France, differing by not having De3 chaetae integrated into the dorso-external tubercle on abdominal tergites I and II. The genus Deutonura is re-diagnosed and a key to its Western Palaearctic species is provided. PMID:26623737

  11. New cave-dwelling species of Tomoceridae from China, with a study on the pattern of mesothoracic bothriotricha in Tomocerinae (Collembola, Entomobryomorpha)

    PubMed Central

    Yu, Daoyuan; Yan, Qibao; Liu, Manqiang

    2016-01-01

    Abstract Two new troglobitic species of Tomoceridae are described from Guizhou and Guangxi provinces, China. Tomocerus tiani sp. n. resembles Tomocerus kinoshitai Yosii, 1954, Tomocerus caecus Yu & Deharveng, 2015 and Tomocerus similis Chen & Ma, 1997 but differs from them mainly in the body colour, the cephalic chaetotaxy and the number of manubrial pseudopores. Monodontocerus cinereus sp. n. is similar to Monodontocerus mulunensis Yu, Deharveng & Zhang, 2014 but is different from the latter in the body colour, the length of antennae, the number of ungual teeth and the chaetotaxy on Abd. III and Abd. IV. Special remarks are made on the mesothoracic bothriotricha in Tomocerinae. PMID:27110179

  12. Towards understanding Lepidocyrtus Bourlet, 1839 (Collembola, Entomobryidae) I: diagnosis of the subgenus Setogaster,
    new records and redescriptions of species.

    PubMed

    Mateos, Eduardo

    2015-01-01

    The taxonomic status of the subgenera of Lepidocyrtus Bourlet is confused. Currently ten subgenera are recognised but their separation, using the existing set of diagnostic characters, is not clear. Collections over the last forty years have shown that species of Setogaster Salmon, originally described as a genus (Trichogaster Handschin) and currently considered a subgenus of Lepidocyrtus, are common and widespread in Australia. The diagnostic characters of Setogaster, as given by Handschin, are: 1) the basal mucronal spine with spinelet; 2) lack of scales on antennae, legs, ventral tube and dorsal region of manubrium; and, for some species, 3) tufts of long filaments laterally on abdomen III. These three diagnostic characters for Setogaster are shared with some other subgenera, making their delimitation unclear. We provide here an array of new characters that are associated with Handschin's characters which separate Setogaster from all European species of the subgenera Lanocyrtus and Lepidocyrtus s. str. On this basis we define subgenus Setogaster more in detail, redescribe some species in the subgenus, corroborate the presence of the subgenus in many Australian localities, and confirm three records of exotic, introduced species in Australia. Lepidocyrtus nigrofasciatus Womersley, Lepidocyrtus praecisus Schött, and the Hawaiian Lepidocyrtus kuakea Christiansen & Bellinger, are placed in Setogaster subgenus; Lepidocyrtus (Trichogaster) pallida Salmon from Singapore is placed in the subgenus Acrocyrtus; Merapicyrtus Yoshii & Suhardjono is considered a synonym of Setogaster. PMID:26624705

  13. A new species of Janusius Bretfeld, 2010 (Collembola, Sminthuridae) from the Korean Peninsula, with a key to the species of the genus.

    PubMed

    Dányi, László; Park, Kyung-Hwa

    2016-01-01

    Janusius geumgangensis sp. nov. is described and illustrated based on specimens from North Korea. The new species is characterised by having 3 spatulate chaetae on all tibiotarsus, 4 chaetae on retinaculum, smooth anal appendage, anterior chaetotaxy of dens 3,3,3,2,2,1,1, colouration with one pair brownish lateral spot and presence of mucronal chaeta. The genus Janusius Bretfeld, 2010 is first mentioned from the Korean Peninsula, although another species described from there as Sminthurus annulatus Kang & Lee, 2005 is recognised here as belonging to this genus (Janusius annulatus (Kang & Lee, 2005) comb. nov.), too. A key including all known species of the genus is presented as well. PMID:27615861

  14. A new species of Campylothorax Schött, 1893 (Collembola, Paronellidae) from Brazilian Amazon, with an identification key to the genus.

    PubMed

    Cipola, Nikolas Gioia; Oliveira, Fábio Gonçalves De Lima

    2016-01-01

    A new species of Campylothorax from Brazilian Amazon is described and illustrated. Campylothorax plagatus sp. nov. resembles another Neotropical species, C. cubanus, by abdomen with two transverse bands and pattern of dorsal chaetotaxy. However, the new species differs by unguis with one unpaired apical tooth, unguiculi III truncate, and abdomen IV with 5+5 posterior central macrochaetae. This is the first species of Campylothorax originally described from Brazilian Amazon. A generic key to the 14 species of Campylothorax is provided. PMID:27394881

  15. Phylogeny of the genus Willemia (Collembola: Hypogastruridae) and biogeography of the W. buddenbrocki-group with description of a new species from Ivory Coast (western Africa).

    PubMed

    Zon, Serge Déméango; Bedos, Anne; D'Haese, Cyrille A

    2015-01-01

    Willemia tondoh sp. nov. from the Ivory Coast (western Africa) is described and illustrated. The new species is the 14th in the buddenbrocki-group and is defined with two large globular sensilla placed in a cavity and covered in part by tegumental fold on antennal segment IV, 7 chaetae on antennal segment I, postantennal organ with 9 vesicles, s-chaetae subcylindrical and acuminate on abdominal terga and chaetae a1 absent on abdominal sternum IV. A phylogeny for all the 46 species of the genus Willemia is proposed. Based on the phylogentic framework, the biogeography of the buddenbrocki-group is discussed. An identification key for all 46 known species of the genus is provided. PMID:26249949

  16. Redescription of Protanura papillata Cassagnau & Delamare Deboutteville, 1955 (Collembola, Neanuridae, Neanurinae), with new records from Middle East, and with supplemented diagnosis and key to the genus.

    PubMed

    Smolis, Adrian; Skarżyński, Dariusz; Kahrarian, Morteza; Kaprus, Ighor J

    2016-01-01

    The poorly known Neanurini genus Protanura is rediagnosed and briefly compared with Lathriopyga. Protanura papillata Cassagnau & Delamare Deboutteville, 1955, known to date only from Lebanon, is redescribed based on the lectotype and new extensive material from Middle East. PMID:27394457

  17. The puzzling distribution of Heteromurus (Verhoeffiella) absoloni Kseneman, 1938 (Collembola: Entomobryidae: Heteromurinae) resolved: detailed redescription of the nominal species and description of a new species from Catalonia (Spain).

    PubMed

    Lukić, Marko; Porco, David; Bedos, Anne; Deharveng, Louis

    2015-01-01

    The species Heteromurus (Verhoeffiella) absoloni Kseneman, 1938 is redescribed in detail and characterized by its barcode, based on specimens from its type locality in Montenegro. A neotype is designated. Dorsal S-chaetotaxy is given for the first time in the subgenus Verhoeffiella. Chaeta morphology and distribution are thoroughly analyzed, in particular on antennae where 12 chaetal types are recognized. Several morphological features are newly described for the genus and for Heteromurinae. The widely disjunct distribution of the species is approached through morphological and molecular comparison of specimens from the type locality in Montenegro and from the Catalan population. We established that this last record is a new species described here as  Heteromurus (Verhoeffiella) gamae sp. nov. New combination is proposed Heteromurus (Verhoeffiella) constantinellus (Ćurčić & Lučić in Lučić, Ćurčić & Mitić 2007) comb. nov. A table of all species of the subgenus is provided. The taxonomic status of Verhoeffiella and the problems of species discriminations in the subgenus are discussed. PMID:26624478

  18. Chaetotaxy of Neotropical Cyphoderus caetetus sp. nov. with comments on the taxonomic position of Cyphoderinae within Paronellidae (Collembola, Entomobryoidea).

    PubMed

    Zeppelini, Douglas; Oliveira, João V L C

    2016-01-01

    The description of a new species, Cyphoderus caetetus sp. nov., led to comparisons among Paronellidae (Cyphoderinae and Paronellinae), which showed that the chaetotaxy of the first abdominal segment is very similar in Cyphoderus, Troglobius (Cyphoderinae) and Trogolaphysa (Paronellini), and much reduced in relation to that seen in Lepidonella (Paronellinae, Bromacanthini), Pseudosinella and Seira (Entomobryidae). This feature, along with the presence of pseudopores behind the posterior row of setae on the fourth abdominal segment as seen in Troglopedetes, Trogolaphysa and Cyphoderinae (absent in Lepidonella and Entomobryidae), suggests that Cyphoderinae is more closely related to tribe Paronellini than Paronellini is to Bromacanthini and Entomobryidae, and that the subfamily Paronellinae is paraphyletic if Cyphoderinae is excluded. We propose including Cyphoderini as the apical group in Paronellinae together with Paronellini (Trogolaphysa and Troglopedetes). PMID:27394601

  19. Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a polder habitat.

    PubMed

    Lessel, Tanja; Marx, Michael Thomas; Eisenbeis, Gerhard

    2011-01-01

    Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder "Ingelheim" to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder "Ingelheim". These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design. PMID:21738425

  20. A new species of Deutonura (Collembola: Neanuridae: Neanurinae) from Algeria, with revised diagnosis of the genus and key to western Palaearctic species.

    PubMed

    Deharveng, Louis; Mouloud, Salah Ait; Bedos, Anne

    2015-08-18

    Deutonura adriani sp. nov. is described from the region of Tizi-Ouzou (Algeria). The species is morphologically similar to D. deficiens deficiens Deharveng, 1979 from southwestern France, differing by not having De3 chaetae integrated into the dorso-external tubercle on abdominal tergites I and II. The genus Deutonura is re-diagnosed and a key to its Western Palaearctic species is provided.

  1. Two new species of Dicranocentrus Schött, 1893 (Collembola:Entomobryidae) from Serra do Gandarela, Minas Gerais State, Brazil.

    PubMed

    Xisto, Thiago; Mendonça, Maria Cleide De

    2016-01-01

    Two new species of Dicranocentrus from Southeastern Brazil are described: D. melinus sp. nov. and D. cuprum sp. nov., both from "Parque Nacional da Serra do Gandarela" (Minas Gerais State), Brazil. These species can be included to gracilis-group due to the absence of chaeta A1, S2, Ps and up to 6+6 chaetae P on dorsal head. A male genital plate is for the first time illustrated for the genus.

  2. A new species of Campylothorax Schött, 1893 (Collembola, Paronellidae) from Brazilian Amazon, with an identification key to the genus.

    PubMed

    Cipola, Nikolas Gioia; Oliveira, Fábio Gonçalves De Lima

    2016-05-10

    A new species of Campylothorax from Brazilian Amazon is described and illustrated. Campylothorax plagatus sp. nov. resembles another Neotropical species, C. cubanus, by abdomen with two transverse bands and pattern of dorsal chaetotaxy. However, the new species differs by unguis with one unpaired apical tooth, unguiculi III truncate, and abdomen IV with 5+5 posterior central macrochaetae. This is the first species of Campylothorax originally described from Brazilian Amazon. A generic key to the 14 species of Campylothorax is provided.

  3. Two new species of Dicranocentrus Schött, 1893 (Collembola:Entomobryidae) from Serra do Gandarela, Minas Gerais State, Brazil.

    PubMed

    Xisto, Thiago; Mendonça, Maria Cleide De

    2016-01-01

    Two new species of Dicranocentrus from Southeastern Brazil are described: D. melinus sp. nov. and D. cuprum sp. nov., both from "Parque Nacional da Serra do Gandarela" (Minas Gerais State), Brazil. These species can be included to gracilis-group due to the absence of chaeta A1, S2, Ps and up to 6+6 chaetae P on dorsal head. A male genital plate is for the first time illustrated for the genus. PMID:27396001

  4. New species of springtails in the Proisotoma genus complex from Vermont and New York, USA with descriptive notes on Ballistura alpa Christiansen & Bellinger 1980 (Hexapoda, Collembola, Isotomidae).

    PubMed

    Soto-Adames, Felipe N; Giordano, Rosanna

    2011-01-01

    Three new species of Isotomidae springtails are described from the Lake Champlain Basin (Vermont and New York, USA), Lake Willoughby and Greater Averril Pond in Vermont. Subisotoma joyceisp. n. and Scutisotoma champisp. n. were collected in sandy beaches whereas Ballistura rossisp. n. was found only in a constructed wetland built and managed by the University of Vermont. Scutisotoma champisp. n. was found in Lakes Champlain and Willoughby, and Greater Averril Pond and is probably present in most lakes and large ponds in the area. Subisotoma joyceisp. n. was found only along the southern and eastern coast of South Hero, and the mainland coast facing eastern South Hero. Ballistura alpa is redescribed and transferred to the genus Pachyotoma based on the absence of tibiotarsal seta B4/B5, the presence of secondary cuticular granules, 4 prelabral setae, a full complement of guard setae on labial papilla E and in having a bifurcate outer maxillary lobe with 4 sublobal setae.

  5. First record of the genus Australonura Cassagnau 1980 (Collembola: Neanuridae) in the New World, with description of a new species from Paraguay.

    PubMed

    Palacios-Vargas, José G; Deharveng, Louis

    2014-03-13

    The genus Australonura Cassagnau 1980 is newly recorded from South America. The Patagonian species Paleonura limnophila (Cassagnau & Rapoport, 1962) and Paleonura friasica Cassagnau & Oliveira, 1990 are redescribed from type material and recombined in Australonura. A new species, A. paraguayensis sp. nov., is described from Paraguay and assigned to Australonura for its head tubercle arrangement. It differs from other species of the genus by its adjacent but separate dorso-internal tubercles of Abd. V.

  6. Phylogeny of the genus Willemia (Collembola: Hypogastruridae) and biogeography of the W. buddenbrocki-group with description of a new species from Ivory Coast (western Africa).

    PubMed

    Zon, Serge Déméango; Bedos, Anne; D'Haese, Cyrille A

    2015-06-29

    Willemia tondoh sp. nov. from the Ivory Coast (western Africa) is described and illustrated. The new species is the 14th in the buddenbrocki-group and is defined with two large globular sensilla placed in a cavity and covered in part by tegumental fold on antennal segment IV, 7 chaetae on antennal segment I, postantennal organ with 9 vesicles, s-chaetae subcylindrical and acuminate on abdominal terga and chaetae a1 absent on abdominal sternum IV. A phylogeny for all the 46 species of the genus Willemia is proposed. Based on the phylogentic framework, the biogeography of the buddenbrocki-group is discussed. An identification key for all 46 known species of the genus is provided.

  7. Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a polder habitat

    PubMed Central

    Lessel, Tanja; Marx, Michael Thomas; Eisenbeis, Gerhard

    2011-01-01

    Abstract Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder “Ingelheim”. These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design. PMID:21738425

  8. Effects of the antibacterial agents tiamulin, olanquindox and metronidazole and the anthelmintic ivermectin on the soil invertebrate species Folsomia fimetaria (Collembola) and Enchytraeus crypticus (Enchytraeidae).

    PubMed

    Jensen, John; Krogh, Paul Henning; Sverdrup, Line E

    2003-01-01

    Veterinary pharmaceutical products such as antibacterial agents and antiparasitics are widely used to control diseases and promote production in the agricultural sector. Exposure of non-target organisms are a likely result of using manure from treated live stocks or from dung dropped on the field by grazing animals. The aim of this study was to determine the toxic threshold levels of three antibacterial agents (tiamulin, olanquindox and metronidazole) and one anthelmintic (ivermectin) to two species of soil dwelling organisms (springtails and enchytraeids), that are often found in bio-solids such as manure or dung. The antibacterial agents were not toxic to adults and effects on reproduction occurred generally above concentrations normally found in soil or dung. The threshold values for toxicity (10% reduced reproduction or EC10 values) were in the range of 61-111 mg kg(-1) dry soil for springtails and 83-722 mg kg(-1) dry soil for enchytraeids. Ivermectin was significantly more toxic with EC10 values of 0.26 mg kg(-1) dry soil for the springtails and 14 mg kg(-1) dry soil for the enchytraeids. A comparison of these results with rough estimates of likely and worse case environmental concentrations indicates a potential risk of ivermectin to non-target species such as springtails and enchytraeids, whereas direct toxic effect of antibacterial agents is very unlikely to occur at environmental realistic concentrations. However, indirect effects of antibacterial agents driven through changes in the food web cannot be abolished at this stage. PMID:12656265

  9. Microarray detection and qPCR screening of potential biomarkers of Folsomia candida (Collembola: Isotomidae) exposed to Bt proteins (Cry1Ab and Cry1Ac).

    PubMed

    Yuan, Yiyang; Krogh, Paul Henning; Bai, Xue; Roelofs, Dick; Chen, Fajun; Zhu-Salzman, Keyan; Liang, Yuyong; Sun, Yucheng; Ge, Feng

    2014-01-01

    The impact of Bt proteins on non-target arthropods is less understood than their effects on target organisms where the mechanism of toxic action is known. Here, we report the effects of two Bt proteins, Cry1Ab and Cry1Ac, on gene expression in the non-target collembolan, Folsomia candida. A customized microarray was used to study gene expression in F. candida specimens that were exposed to Cry1Ab and Cry1Ac. All selected transcripts were subsequently confirmed by qPCR. Eleven transcripts were finally verified, and three of them were annotated. The responses of all eleven transcripts were tested in specimens for both Cry1Ab and Cry1Ac at a series of concentrations. These transcripts were separated into two and three groups for Cry1Ab and Cry1Ac, respectively, depend on their expression levels. However, those eleven transcripts did not respond to the Bt proteins in Bt-rice residues.

  10. New species of springtails in the Proisotoma genus complex from Vermont and New York, USA with descriptive notes on Ballistura alpa Christiansen & Bellinger 1980 (Hexapoda, Collembola, Isotomidae).

    PubMed

    Soto-Adames, Felipe N; Giordano, Rosanna

    2011-01-01

    Three new species of Isotomidae springtails are described from the Lake Champlain Basin (Vermont and New York, USA), Lake Willoughby and Greater Averril Pond in Vermont. Subisotoma joyceisp. n. and Scutisotoma champisp. n. were collected in sandy beaches whereas Ballistura rossisp. n. was found only in a constructed wetland built and managed by the University of Vermont. Scutisotoma champisp. n. was found in Lakes Champlain and Willoughby, and Greater Averril Pond and is probably present in most lakes and large ponds in the area. Subisotoma joyceisp. n. was found only along the southern and eastern coast of South Hero, and the mainland coast facing eastern South Hero. Ballistura alpa is redescribed and transferred to the genus Pachyotoma based on the absence of tibiotarsal seta B4/B5, the presence of secondary cuticular granules, 4 prelabral setae, a full complement of guard setae on labial papilla E and in having a bifurcate outer maxillary lobe with 4 sublobal setae. PMID:22371662

  11. New record of the genus Israelimeria Weiner & Kaprus', 2005 (Collembola: Neanuridae: Pseudachorutinae) from Iran, with description of a new species.

    PubMed

    Alijani, Masoumeh; Shayanmehr, Masoumeh; Skarżyński, Dariusz; Piwnik, Agata; Smolis, Adrian

    2015-01-01

    Israelimeria persica sp. nov. is described from Iran. The genus Israelimeria can be easily identified due to a reduction of the number of eyes and the complete absence of the postantennal organ and the furca. The new taxon, and also the second species of the genus, differs from I. poliakovae Weiner & Kaprus', 2005, known only from Judean Mts. in Israel, in size and shape of mandibles and many chaetotactic characters, especially number of setae in ocular area of the head, ventral tube, subcoxae "1" and microchaetae number in furcal area.

  12. Seasonal fluctuation of different edaphic microarthropod population densities in relation to soil moisture and temperature in a pine, Pinus kesiya Royle plantation ecosystem

    NASA Astrophysics Data System (ADS)

    Reddy, M. Vikram

    1984-03-01

    Seasonal fluctuations of soil and litter microarthropod populations in a pine, Pinus kesiya Royle plantation of North Eastern India were investigated between November 1976 and November 1977. Three major groups were recognized: (a) Collembola, (b) Acarina and (c) miscellaneous. Collembola was the most abundant group and was dominated by Isotoma trispinata (MacGillivray). The total microarthropod density ranged from 26,800 per m2 to 145,200 per m2. Collembola densities ranged from 10,000 to 121,200 per m2, Acarina densities ranged from 8,800 to 41,600 per m2, and the miscellaneous group ranged from 1,200 to 6,400 per m2. Soil moisture was positively correlated with total arthropod, Collembola and Acarina densities. Soil temperature was positively correlated only with Acarina. Densities of Collembola and Acarina were negatively correlated.

  13. The Heteromurini Absolon & Ksenemann (Collembola, Entomobryidae):
    a review of the genera status and diagnoses, keys for species of Alloscopus Börner and Heteromurtrella Mari Mutt and description of a new species.

    PubMed

    Cipola, Nikolas Gioia; Oliveira, Fabio Gonçalves De Lima; Morais, José Wellington De; Bellini, Bruno Cavalcante

    2016-01-01

    The status of Heteromurini Absolon & Ksenemann is analyzed and a new diagnosis is proposed to the tribe. New chaetotaxic characteres were added to distinguish Dicranocentrus Schött and Pseudodicranocentrus Mari Mutt. Alloscopus Börner, Heteromurtrella Mari Mutt and Verhoeffiella Absolon, originally proposed as subgenera of Heteromurus Wankel, are reviewed and a new diagnosis and generic status are proposed. The presence of the postantennal organ becomes the main characteristic to distinguish Alloscopus (present) and Heteromurtrella (absent). Alloscopus yosiius Mari Mutt, anteriorly synonymized with Alloscopus tenuicornis Börner, is revalidated. The absence of S0 macrochaeta on head of Heteromurus is reported now as a characteristic also shared with Heteromurtrella. Heteromurtrella zairensis Tshelnokov comb. nov. is transferred from Heteromurus by the presence of macrochaetae on abdomen I. Heteromurtrella anae sp. nov. from Brazilian Amazon is described and illustrated, including detailed dorsal chaetotaxy. This is the first record of Heteromurtrella in Brazil. Heteromurus now has 17, Alloscopus 10 and Heteromurtrella 20 valid species worldwide. An identification key and diagnosis for the six genera of Heteromurini and species of Alloscopus and Heteromurtrella are provided. PMID:27394258

  14. The Heteromurini Absolon & Ksenemann (Collembola, Entomobryidae):
    a review of the genera status and diagnoses, keys for species of Alloscopus Börner and Heteromurtrella Mari Mutt and description of a new species.

    PubMed

    Cipola, Nikolas Gioia; Oliveira, Fabio Gonçalves De Lima; Morais, José Wellington De; Bellini, Bruno Cavalcante

    2016-02-25

    The status of Heteromurini Absolon & Ksenemann is analyzed and a new diagnosis is proposed to the tribe. New chaetotaxic characteres were added to distinguish Dicranocentrus Schött and Pseudodicranocentrus Mari Mutt. Alloscopus Börner, Heteromurtrella Mari Mutt and Verhoeffiella Absolon, originally proposed as subgenera of Heteromurus Wankel, are reviewed and a new diagnosis and generic status are proposed. The presence of the postantennal organ becomes the main characteristic to distinguish Alloscopus (present) and Heteromurtrella (absent). Alloscopus yosiius Mari Mutt, anteriorly synonymized with Alloscopus tenuicornis Börner, is revalidated. The absence of S0 macrochaeta on head of Heteromurus is reported now as a characteristic also shared with Heteromurtrella. Heteromurtrella zairensis Tshelnokov comb. nov. is transferred from Heteromurus by the presence of macrochaetae on abdomen I. Heteromurtrella anae sp. nov. from Brazilian Amazon is described and illustrated, including detailed dorsal chaetotaxy. This is the first record of Heteromurtrella in Brazil. Heteromurus now has 17, Alloscopus 10 and Heteromurtrella 20 valid species worldwide. An identification key and diagnosis for the six genera of Heteromurini and species of Alloscopus and Heteromurtrella are provided.

  15. Influence of organic matter on collembolan communities in reedbed habitats

    NASA Astrophysics Data System (ADS)

    Uteseny, K.; Drapela, T.; Frouz, J.

    2009-04-01

    The combination of the organic matter, micro-climatic environments and plant cover belongs to important factors for the distribution of soil meso-fauna, especially Collembola. There are no studies attending to these factors on collembolan communities in reedbed vegetation. The main goals of our investigation were therefore to compare diversity of Collembola in redbed habitats of Lake Neudsiedl, eastern Austria, and to assess particularly the role of organic matter with regard to the collembolan community structure. Soil samples were taken from April 1997 to October 1997 at fifteen study sites covered with Phragmatis australis of different age. Changes in the structure and composition of the assemblages of Collembola were examined.

  16. Analyzing predation of hoverflies (Diptera: Syrphidae) in Mediterranean lettuce crops using molecular techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hoverflies are generalist predators of a great variety of primary pests. Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are two common pests in Mediterranean lettuce crops, where they occur alongside alternative prey (e.g., Collembola). ...

  17. Toxicity of Pb and of Pb/Cd combination on the springtail Folsomia candida in natural soils: reproduction, growth and bioaccumulation as indicators.

    PubMed

    Bur, T; Crouau, Y; Bianco, A; Gandois, L; Probst, A

    2012-01-01

    The toxicity of Pb and Cd+Pb was assessed on the Collembola F. candida in two cultivated soils (SV and AU) with low organic matter (OM) content and circumneutral to basic pH, and an acid forested soil (EPC) with high OM content. Collembola reproduction and growth as well as metal content in Collembola body, in soil, exchangeable fraction and soil solutions, pH and DOC were investigated. Pb and Cd+Pb were the highest in exchangeable fraction and soil solution of the acidic soils. Soil solution pH decreased after metal spiking in every soil due to metal adsorption, which was similar for Cd and the highest in AU for Pb. With increasing Pb and Cd+Pb, the most important reproduction decrease was in EPC soil. The LOEC for reproduction after metal addition was 2400 (Pb) and 200/2400 (Cd/Pb), 1200 and 100/1200, 300 and 100/1200 μg g(-1) for AU, SV and EPC, respectively. The highest and the lowest Pb toxicity was observed for EPC and AU bulk soil, respectively. The metal in Collembola increased with increasing soil concentration, except in AU, but the decreasing BF(solution) with increasing concentrations indicates a limited metal transfer to Collembola or an increased metal removal. Loading high Pb concentrations decreases Cd absorption by the Collembola, but the reverse was not true. The highest Pb toxicity in EPC can be explained by pH and OM content. Because of metal complexation, OM might have a protective role but its ingestion by Collembola lead to higher toxicity. Metal bioavailability in Collembola differs from soil solution indicating that soil solution is not sufficient to evaluate toxicity in soil organisms. The toxicity as a whole decreased when metals were combined, except for Pb in AU, due to adsorption competition between Cd and Pb on clay particles and OM sites in AU and EPC soils, respectively. PMID:22113108

  18. A new species of crinoid-associated Periclimenes from Honduras (Crustacea: Decapoda: Palaemonidae).

    PubMed

    De Grave, Sammy

    2014-05-02

    A new species of crinoid associated Periclimenes, P. rincewindi sp. nov. is described from the Bay Islands (Honduras) in the Caribbean. The species associates with the swimming crinoid, Analcidometra armata and displays a unique colour pattern. Morphologically, the new species is closely related to the other known crinoid associates in the Caribbean, specifically Periclimenes crinoidalis, from which it can be distinguished by a suite of relatively minor morphological features.

  19. Influence of edge on predator prey distribution and abundance

    NASA Astrophysics Data System (ADS)

    Ferguson, Steven H.

    2004-03-01

    I investigated the effect of spatial configuration on distribution and abundance of invertebrate trophic groups by counting soil arthropods under boxes (21 × 9.5 cm) arranged in six different patterns that varied in the amount of edge (137-305 cm). I predicted fewer individuals from the consumer trophic group (Collembola) in box groups with greater amount of edge. This prediction was based on the assumption that predators (mites, ants, spiders, centipedes) select edge during foraging and thereby reduce abundance of the less mobile consumer group under box patterns with greater edge. Consumer abundance (Collembola) was not correlated with amount of edge. Among the predator groups, mite, ant and centipede abundance related to the amount of edge of box groups. However, in contrast to predictions, abundance of these predators was negatively correlated with amount of edge in box patterns. All Collembola predators, with the exception of ants, were less clumped in distribution than Collembola. The results are inconsistent with the view that predators used box edges to predate the less mobile consumer trophic group. Alternative explanations for the spatial patterns other than predator-prey relations include (1) a negative relationship between edge and moisture, (2) a positive relationship between edge and detritus decomposition (i.e. mycelium as food for the consumer group), and (3) a negative relationship between edge and the interstices between adjacent boxes. Landscape patterns likely affect microclimate, food, and predator-prey relations and, therefore, future experimental designs need to control these factors individually to distinguish among alternative hypotheses.

  20. Cyphoderus (Cyphoderidae) as a major component of collembolan cave fauna in Thailand, with description of two new species.

    PubMed

    Jantarit, Sopark; Satasook, Chutamas; Deharveng, Louis

    2014-01-01

    Distinguishing features of Cyphoderus Collembola of the bidenticulati group are described. Taxonomic problems in the bidenticulati group of Cyphoderus are emphasized, and new characters of taxonomic value are introduced and discussed. Two new species are described from caves of Thailand, differing mainly in claw morphology.

  1. Terrestrial model food chain and environmental chemicals. I. Transfer of sodium (/sup 14/C)pentachlorophenate between springtails and carabids

    SciTech Connect

    Gruttke, H.; Kratz, W.; Weigmann, G.; Haque, A.

    1988-06-01

    A model soil food chain of a ruderal ecosystem has been constructed in order to study the uptake, transfer, and accumulation of (/sup 14/C)pentachlorophenate (PCP-Na). The model was based on three food levels, viz. baker's yeast, collembola, and carabid beetles, and the contaminant chemical introduced was via initial food. Continuous exposure of the organisms to the test chemical resulted in a significant uptake and transfer of radiocarbon into the food chain elements. Bioaccumulation of radiocarbon in the body tissues of the organisms was low, as large amounts taken up were quickly eliminated through the excrements. The radiocarbon level of prey animals was about 100 times higher than that of their predators, but there was only small difference in concentration between collembolas and yeast. This was probably because of a faster excretion of the chemical by the beetles than by the collembolas. During the test period no conversion of (/sup 14/C)PCP-Na took place in the yeast, but the collembolas and beetles metabolized 50 and 59%, respectively. Criteria are proposed for successful implementation of food chain models.

  2. Parasitic fauna of a yellow-legged gull colony in the island of Escombreras (South-eastern Mediterranean) in close proximity to a landfill site: potential effects on cohabiting species.

    PubMed

    Parejo, Sandra Hervías; Martínez-Carrasco, Carlos; Diaz, Julia I; Chitimia, Lidia; Ortiz, Juana; Mayo, Elvira; Ybáñez, Rocío Ruiz de

    2015-06-01

    We identified the ectoparasites and helminth fauna of yellow-legged gulls (Larus michahellis michahellis), breeding near to a solid waste landfill, and compared infection levels with those of other yellow-legged gull colonies. Moreover, we analysed correlations between parasites and sex and body condition of yellow-legged gulls, co-infections and the helminth community structure in order to propose the role of this species as reservoir of certain parasites. We also discuss the potential transmission of parasites between the yellow-legged gull and the endangered Audouin's gull, because interactions between these two species, such as kleptoparasitism and predation, occur frequently around colonies. The following species were recorded: Ornithodorus capensis (Arthropoda); Cosmocephalus obvelatus, Paracuaria adunca, Eucoleus contortus, Tetrameres skrjabini and Contracaecum sp. (Nematoda); Tetrabothrius cylindraceus (Cestoda); Acanthotrema armata, Cardiocephaloides longicollis and Ornithobilharzia intermedia (Digenea). Tetrabothrius cylindraceus, A. armata and O. capensis are new parasite records for this host. The dependence of yellow-legged-gulls on fishery discards is supported by the dominance of parasites transmitted through marine intermediate hosts with interest to fisheries in the study area. However, the shift in diet from natural resources to food derived from human activities seems not to affect the parasitic fauna of yellow-legged gull. Besides of direct physical contact between individuals in nesting and resting habitats, the high availability of fishery discards could increase the risk of Audouin's gulls to be infected by common parasites of yellow-legged gull. PMID:26203998

  3. Parasitic fauna of a yellow-legged gull colony in the island of Escombreras (South-eastern Mediterranean) in close proximity to a landfill site: potential effects on cohabiting species.

    PubMed

    Parejo, Sandra Hervías; Martínez-Carrasco, Carlos; Diaz, Julia I; Chitimia, Lidia; Ortiz, Juana; Mayo, Elvira; Ybáñez, Rocío Ruiz de

    2015-06-01

    We identified the ectoparasites and helminth fauna of yellow-legged gulls (Larus michahellis michahellis), breeding near to a solid waste landfill, and compared infection levels with those of other yellow-legged gull colonies. Moreover, we analysed correlations between parasites and sex and body condition of yellow-legged gulls, co-infections and the helminth community structure in order to propose the role of this species as reservoir of certain parasites. We also discuss the potential transmission of parasites between the yellow-legged gull and the endangered Audouin's gull, because interactions between these two species, such as kleptoparasitism and predation, occur frequently around colonies. The following species were recorded: Ornithodorus capensis (Arthropoda); Cosmocephalus obvelatus, Paracuaria adunca, Eucoleus contortus, Tetrameres skrjabini and Contracaecum sp. (Nematoda); Tetrabothrius cylindraceus (Cestoda); Acanthotrema armata, Cardiocephaloides longicollis and Ornithobilharzia intermedia (Digenea). Tetrabothrius cylindraceus, A. armata and O. capensis are new parasite records for this host. The dependence of yellow-legged-gulls on fishery discards is supported by the dominance of parasites transmitted through marine intermediate hosts with interest to fisheries in the study area. However, the shift in diet from natural resources to food derived from human activities seems not to affect the parasitic fauna of yellow-legged gull. Besides of direct physical contact between individuals in nesting and resting habitats, the high availability of fishery discards could increase the risk of Audouin's gulls to be infected by common parasites of yellow-legged gull.

  4. The genus Loimia Malmgren, 1866 (Annelida: Terebellidae) off the Brazilian coast, with description of three new species and notes on some morphological characters of the genus.

    PubMed

    Carrerette, Orlemir; Nogueira, João Miguel De Matos

    2015-01-01

    Three new species of Loimia were collected along the Brazilian coast, during some independent projects, from shallow to deep waters off the continental slope. These species are L. megaoculata sp. nov., L. armata sp. nov., and L. brasiliensis sp. nov., all herein described and compared with the morphologically most similar congeners. Loimia megaoculata sp. nov., is characterized by having large, dark eyespots, progressively smaller from dorso-laterally towards lateral basal part of prostomium; lobes of segment 1 are distally rounded, roughly circular, barely reaching mid-length of upper lip; uncini have up to 6-7 teeth, including basal-most tooth. Loimia armata sp. nov., lacks eyespots; stout lobes of segment 1 nearly reach level of upper lip; uncini have up to 7-8 teeth, including basal-most tooth. Loimia brasiliensis sp. nov., has two narrow rows of eyespots; lobes of segment 1 are thin, reaching mid-length of upper lip; uncini have 5-6 teeth, including basal-most tooth. We provide a brief discussion on the main morphological characters useful for the taxonomy of this genus, such as presence of eyespots, and morphology of lobes of segments 1 and 3, of mid-ventral pads and neurochaetae. Up to now only two species had been recorded from Brazil, namely L. grubei and L. medusa, both doubtful records, as discussed along this paper. PMID:26250323

  5. A Greener Arctic: Vascular Plant Litter Input in Subarctic Peat Bogs Changes Soil Invertebrate Diets and Decomposition Patterns

    NASA Astrophysics Data System (ADS)

    Krab, E. J.; Berg, M. P.; Aerts, R.; van Logtestijn, R. S. P.; Cornelissen, H. H. C.

    2014-12-01

    Climate-change-induced trends towards shrub dominance in subarctic, moss-dominated peatlands will most likely have large effects on soil carbon (C) dynamics through an input of more easily decomposable litter. The mechanisms by which this increase in vascular litter input interacts with the abundance and diet-choice of the decomposer community to alter C-processing have, however, not yet been unraveled. We used a novel 13C tracer approach to link invertebrate species composition (Collembola), abundance and species-specific feeding behavior to C-processing of vascular and peat moss litters. We incubated different litter mixtures, 100% Sphagnum moss litter, 100% Betula leaf litter, and a 50/50 mixture of both, in mesocosms for 406 days. We revealed the transfer of C from the litters to the soil invertebrate species by 13C labeling of each of the litter types and assessed 13C signatures of the invertebrates Collembola species composition differed significantly between Sphagnum and Betula litter. Within the 'single type litter' mesocosms, Collembola species showed different 13C signatures, implying species-specific differences in diet choice. Surprisingly, the species composition and Collembola abundance changed relatively little as a consequence of Betula input to a Sphagnum based system. Their diet choice, however, changed drastically; species-specific differences in diet choice disappeared and approximately 67% of the food ingested by all Collembola originated from Betula litter. Furthermore, litter decomposition patterns corresponded to these findings; mass loss of Betula increased from 16.1% to 26.2% when decomposing in combination with Sphagnum, while Sphagnum decomposed even slower in combination with Betula litter (1.9%) than alone (4.7%). This study is the first to empirically show that collective diet shifts of the peatland decomposer community from mosses towards vascular plant litter may drive altered decomposition patterns. In addition, we showed that

  6. [Community structure and seasonal change of soil micro-arthropodes in the Lower Reaches of Liaohe River Plain under different land utilization].

    PubMed

    Ke, Xin; Liang, Wenju; Yu, Wantai; Xie, Rongdong; Weng, Chaolian; Yang, Yiming; Yin, Wenying

    2004-04-01

    The data on the soil micro-arthropodes under four land utilization types (fallow, forest, upland field and paddy) in the Lower Reaches of Liaohe River Plain were collected in a period from October 2000 to October 2001. Using the community parameters of population density, group richness, diversity index and evenness, the community structure and its seasonal changes were described. There were 12 groups of soil micro-arthropodes in this region, and of the groups, Collembola and Acarina were dominant, and Diptera, Coleoptera and Hymenoptera were often seen in fallow, forest and upland field, while Collembola, Acarina and Diptera were dominant in paddy. Both land utilization and seasonal change influenced the population density, group richness and diversity index of soil micro-arthropodes. The vertical distribution in both density and group number of arthropods in soil was in the order of surface > middle > bottom.

  7. Cascading effects of belowground predators on plant communities are density-dependent.

    PubMed

    Thakur, Madhav Prakash; Herrmann, Martina; Steinauer, Katja; Rennoch, Saskia; Cesarz, Simone; Eisenhauer, Nico

    2015-10-01

    Soil food webs comprise a multitude of trophic interactions that can affect the composition and productivity of plant communities. Belowground predators feeding on microbial grazers like Collembola could decelerate nutrient mineralization by reducing microbial turnover in the soil, which in turn could negatively influence plant growth. However, empirical evidences for the ecological significance of belowground predators on nutrient cycling and plant communities are scarce. Here, we manipulated predator density (Hypoaspis aculeifer: predatory mite) with equal densities of three Collembola species as a prey in four functionally dissimilar plant communities in experimental microcosms: grass monoculture (Poa pratensis), herb monoculture (Rumex acetosa), legume monoculture (Trifolium pratense), and all three species as a mixed plant community. Density manipulation of predators allowed us to test for density-mediated effects of belowground predators on Collembola and lower trophic groups. We hypothesized that predator density will reduce Collembola population causing a decrease in nutrient mineralization and hence detrimentally affect plant growth. First, we found a density-dependent population change in predators, that is, an increase in low-density treatments, but a decrease in high-density treatments. Second, prey suppression was lower at high predator density, which caused a shift in the soil microbial community by increasing the fungal: bacterial biomass ratio, and an increase of nitrification rates, particularly in legume monocultures. Despite the increase in nutrient mineralization, legume monocultures performed worse at high predator density. Further, individual grass shoot biomass decreased in monocultures, while it increased in mixed plant communities with increasing predator density, which coincided with elevated soil N uptake by grasses. As a consequence, high predator density significantly increased plant complementarity effects indicating a decrease in

  8. Collembolan Transcriptomes Highlight Molecular Evolution of Hexapods and Provide Clues on the Adaptation to Terrestrial Life

    PubMed Central

    Faddeeva, A.; Studer, R. A.; Kraaijeveld, K.; Sie, D.; Ylstra, B.; Mariën, J.; op den Camp, H. J. M.; Datema, E.; den Dunnen, J. T.; van Straalen, N. M.; Roelofs, D.

    2015-01-01

    Background Collembola (springtails) represent a soil-living lineage of hexapods in between insects and crustaceans. Consequently, their genomes may hold key information on the early processes leading to evolution of Hexapoda from a crustacean ancestor. Method We assembled and annotated transcriptomes of the Collembola Folsomia candida and Orchesella cincta, and performed comparative analysis with protein-coding gene sequences of three crustaceans and three insects to identify adaptive signatures associated with the evolution of hexapods within the pancrustacean clade. Results Assembly of the springtail transcriptomes resulted in 37,730 transcripts with predicted open reading frames for F. candida and 32,154 for O. cincta, of which 34.2% were functionally annotated for F. candida and 38.4% for O. cincta. Subsequently, we predicted orthologous clusters among eight species and applied the branch-site test to detect episodic positive selection in the Hexapoda and Collembola lineages. A subset of 250 genes showed significant positive selection along the Hexapoda branch and 57 in the Collembola lineage. Gene Ontology categories enriched in these genes include metabolism, stress response (i.e. DNA repair, immune response), ion transport, ATP metabolism, regulation and development-related processes (i.e. eye development, neurological development). Conclusions We suggest that the identified gene families represent processes that have played a key role in the divergence of hexapods within the pancrustacean clade that eventually evolved into the most species-rich group of all animals, the hexapods. Furthermore, some adaptive signatures in collembolans may provide valuable clues to understand evolution of hexapods on land. PMID:26075903

  9. Direct and indirect effects of ants on a forest-floor food web.

    PubMed

    Moya-Laraño, Jordi; Wise, David H

    2007-06-01

    Interactions among predators that prey on each other and are potential competitors for shared prey (intraguild [IG] predators) are widespread in terrestrial ecosystems and have the potential to strongly influence the dynamics of terrestrial food webs. Ants and spiders are abundant and ubiquitous terrestrial IG predators, yet the strength and consequences of interactions between them are largely unknown. In the leaf-litter food web of a deciduous forest in Kentucky (USA), we tested the direct and indirect effects of ants on spiders and a category of shared prey (Collembola) by experimentally subsidizing ants in open plots in two field experiments. In the first experiment, ant activity was increased, and the density of ants in the litter was doubled, by placing carbohydrate and protein baits in the center of each plot. Gnaphosa spiders were almost twice as abundant and Schizocosa spiders were half as abundant in baited plots relative to controls. There were more tomocerid Collembola in baited plots, suggesting possible indirect effects on Collembola caused by ant-spider interactions. The second experiment, in which screening of two mesh sizes selectively excluded large and small worker ants from a sugar bait, revealed that the large ants, primarily Camponotus, could alone induce similar effects on spiders. Gnaphosa biomass density was almost twice as high in the plots where large ants were more active, whereas Schizocosa biomass density was reduced by half in these plots. Although tomocerid densities did not differ between treatments, tomocerid numbers were negatively correlated with the activity of Formica, another large ant species. Path analysis failed to support the hypothesis that the ant Camponotus indirectly affected tomocerid Collembola through effects on densities of spiders. However, path analysis also revealed other indirect effects of Camponotus affecting tomocerids. These results illustrate the complexity of interactions between and within two major IG

  10. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    PubMed

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices. PMID:24505991

  11. Longer-term effects of selective thinning on microarthropod communities in a late-successional coniferous forest

    USGS Publications Warehouse

    Peck, R.W.; Niwa, C.G.

    2005-01-01

    Microarthropod densities within late-successional coniferous forests thinned 16-41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent, prostigmatid mites, were reduced in thinned stands compared with unthinned stands. No differences were found for Collembola in the forest floor or for any mite suborder within the soil. Family level examination of mesostigmatid and prostigmatid mites revealed significant differences between stand types for both horizons. At the species level, thinning influenced numerous oribatid mites and Collembola. For oribatid mites, significant or marginally significant differences were found for seven of 15 common species in the forest floor and five of 16 common species in soil. Collembola were affected less, with differences found for one of 11 common species in the forest floor and three of 13 common species in soil. Multivariate analysis of variance and ordination indicated that forest thinning had little influence on the composition of oribatid mite and collembolan communities within either the forest floor or soil. Differences in microclimate or in the accumulation of organic matter on the forest floor were likely most responsible for the observed patterns of abundance. Considering the role that microarthropods play in nutrient cycling, determining the functional response of a wide range of taxa to thinning may be important to effective ecosystem management.

  12. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    PubMed

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices.

  13. Effects of metal-contaminated forest soils from the Canadian shield to terrestrial organisms.

    PubMed

    Feisthauer, Natalie C; Stephenson, Gladys L; Princz, Juliska I; Scroggins, Richard P

    2006-03-01

    The effects of elevated metal concentrations in forest soils on terrestrial organisms were investigated by determining the toxicity of six site soils from northern Ontario and Quebec, Canada, using a battery of terrestrial toxicity tests. Soils were collected from three sites on each of two transects established downwind of nickel (Sudbury, ON, Canada) and copper (Rouyn-Noranda, PQ, Canada) smelting operations. Site soils were diluted to determine if toxicity estimates for the most-contaminated site soils could be quantified as a percent of site soil. Rouyn-Noranda soils were toxic following acute exposure (14 d) to plants, but not to invertebrates (7 d for collembola and 14 d for earthworms). However, Rouyn-Noranda soils were toxic to all species following chronic exposure (21, 35, and 63 d for plants, collembola, and earthworms, respectively). The toxicity of the Rouyn-Noranda site soils did not correspond to the gradient of metal concentrations in soil. Metal-contaminated Sudbury soils were toxic to plants but not to invertebrates, following acute exposure. Chronic exposure to Sudbury soils caused adverse effects to plant growth and invertebrate survival and reproduction. The toxicity of Sudbury soils corresponded to the metal concentration gradient, with one exception: The reference soil collected in October was toxic to collembola following acute and chronic exposure. This study evaluated the applicability of the new Environment Canada terrestrial toxicity test methods, developed using agricultural soils, to forest soils and also provided useful data to assess the ecological risk associated with mixtures of metals in soil.

  14. Discovery of living Potamolepidae (Porifera: Spongillina) from Nearctic freshwater with description of a new genus.

    PubMed

    Copeland, John; Pronzato, Roberto; Manconi, Renata

    2015-01-01

    We report here the first record of a living Potamolepidae (Cherokeesia n. gen.) from the Nearctic Region and from the northern hemisphere. The new species Cherokeesia armata from southern Appalachians diverges at generic and specific level from all the other known taxa of the family Potamolepidae in its unique combination of diagnostic traits: gemmular theca armed by gemmuloscleres ranging from small strongyle-like spicules to stout, large oxeas; absence of pneumatic layer; spiny oxeas as main skeleton megascleres; irregular, slender pauci- to uni-spicular skeletal network. The most similar species belong to the genera Potamophloios and Oncosclera. The circumtropical biogeographic pattern of extant Potamolepidae, previously considered of Gondwanian to Gondwanian-like origin, is enlarged to the Nearctic. The present Tennessee discovery confirms a wider range of the family. An updated species inventory of Nearctic Spongillina, a checklist of the family Potamolepidae at the global level together with a key to the genera of Potamolepidae are also provided. PMID:26249051

  15. The decapod fauna (Axiidea, Anomura, Brachyura) from the Late Pleistocene of Trumbacà, Reggio Calabria (Calabria, southern Italy)

    PubMed Central

    Garassino, Alessandro; Pasini, Giovanni; De Angeli, Antonio; Hyžný, Matúš

    2015-01-01

    We report a rich faunal assemblage from the Tyrrhenian (Late Pleistocene) of Trumbacà, located in the southern area of Reggio Calabria (Calabria, southern Italy). The only brachyuran reported to date from this locality is Ranilia constricta (A. Milne Edwards, 1880) by Vazzana (2008). The studied specimens have been assigned, as follows: ?Corallianassa sp., Dardanus arrosor (Herbst, 1796), Dardanus substriatus (A. Milne Edwards, 1861), Paguristes cf. P. syrtensis de Saint Laurent 1970, Anapagurus sp., Ranilia constricta (A. Milne Edwards, 1880), Ranina propinqua Ristori, 1891, Ebalia cf. E. deshayesi Lucas, 1846, Ilia nucleus (Linnaeus, 1758), Medorippe lanata (Linnaeus, 1767), Calappa granulata (Linnaeus, 1758), Pisa armata (Latreille, 1803), Derilambrus cf. D. angulifrons (Latreille, 1825), Atelecyclus undecimdentatus (Herbst, 1783), Carcinus sp., Pilumnus hirtellus (Linnaeus, 1761), and Xantho cf. X. incisus (Leach, 1814). The studied assemblage enlarges our knowledge on the evolution of the Mediterranean decapod faunas. PMID:26689358

  16. On the longevity of desert plants and the production of new fine roots

    NASA Astrophysics Data System (ADS)

    Vargas, R.; Czimczik, C. I.; Bullock, S.; Xu, X.; Djuricin, S.

    2012-12-01

    There is evidence that some plants in arid regions can live for several hundreds of years suggesting a strong resilience to climate variability including drought events. Therefore, an important question is: Which are the physiological mechanisms of survival that are present in long-lived plants? Recent studies have shown that plants are able to store nonstructural carbon (NSC) for several years and then allocate them for production of new structures such as fine roots. We established an experiment to measure the radiocarbon age of new fine roots of desert plants between 150 and 400 years old. The study site was located at the Central Desert of Baja California, Mexico and included individuals of Brahea armata, Washingtonia robusta, and Pachycereus pringlei. Our results showed that on average all the plant species were able to use stored old carbon for production of new fine roots. These results suggest that NSC pools are important in determining belowground responses of long-lived desert plants.

  17. Discovery of living Potamolepidae (Porifera: Spongillina) from Nearctic freshwater with description of a new genus.

    PubMed

    Copeland, John; Pronzato, Roberto; Manconi, Renata

    2015-05-13

    We report here the first record of a living Potamolepidae (Cherokeesia n. gen.) from the Nearctic Region and from the northern hemisphere. The new species Cherokeesia armata from southern Appalachians diverges at generic and specific level from all the other known taxa of the family Potamolepidae in its unique combination of diagnostic traits: gemmular theca armed by gemmuloscleres ranging from small strongyle-like spicules to stout, large oxeas; absence of pneumatic layer; spiny oxeas as main skeleton megascleres; irregular, slender pauci- to uni-spicular skeletal network. The most similar species belong to the genera Potamophloios and Oncosclera. The circumtropical biogeographic pattern of extant Potamolepidae, previously considered of Gondwanian to Gondwanian-like origin, is enlarged to the Nearctic. The present Tennessee discovery confirms a wider range of the family. An updated species inventory of Nearctic Spongillina, a checklist of the family Potamolepidae at the global level together with a key to the genera of Potamolepidae are also provided.

  18. The Moss Flora of Akdağ Mountain (Amasya, Turkey)

    PubMed Central

    Canli, Kerem; Çetin, Barbaros

    2014-01-01

    The moss flora of Akdağ Mountain (Amasya, Turkey) was investigated. At the result of identifications of 1500 moss specimens, collected from the research area, 178 taxa belonging to 69 genera and 26 families were determined. Among them, 94 taxa are new for A3 grid square according to the Turkey grid system which was adopted by Henderson. The location data of Grimmia crinitoleucophaea Cardot and Barbula enderesii Garov. are the first records for Turkey, and Encalypta spathulata Müll. Hal., Schistidium dupretii (Thér.) W. A. Weber, Weissia condensa var. armata (Thér. & Trab.) M. J. Cano, Ros & J. Guerra, Tortella bambergeri (Schimp.), Barbula enderesii Garov., Hedwigia ciliata var. leucophaea Bruch & Schimp., and Campyliadelphus elodes (Lindb.) Kanda are recorded for the second time to the byroflora of Turkey. PMID:25587573

  19. Host and Environmental Specificity in Bacterial Communities Associated to Two Highly Invasive Marine Species (Genus Asparagopsis).

    PubMed

    Aires, Tânia; Serrão, Ester A; Engelen, Aschwin H

    2016-01-01

    As habitats change due to global and local pressures, population resilience, and adaptive processes depend not only on their gene pools but also on their associated bacteria communities. The hologenome can play a determinant role in adaptive evolution of higher organisms that rely on their bacterial associates for vital processes. In this study, we focus on the associated bacteria of the two most invasive seaweeds in southwest Iberia (coastal mainland) and nearby offshore Atlantic islands, Asparagopsis taxiformis and Asparagopsis armata. Bacterial communities were characterized using 16S rRNA barcoding through 454 next generation sequencing and exploratory shotgun metagenomics to provide functional insights and a backbone for future functional studies. The bacterial community composition was clearly different between the two species A. taxiformis and A. armata and between continental and island habitats. The latter was mainly due to higher abundances of Acidimicrobiales, Sphingomonadales, Xanthomonadales, Myxococcales, and Alteromonadales on the continent. Metabolic assignments for these groups contained a higher number of reads in functions related to oxidative stress and resistance to toxic compounds, more precisely heavy metals. These results are in agreement with their usual association with hydrocarbon degradation and heavy-metals detoxification. In contrast, A. taxiformis from islands contained more bacteria related to oligotrophic environments which might putatively play a role in mineralization of dissolved organic matter. The higher number of functional assignments found in the metagenomes of A. taxiformis collected from Cape Verde Islands suggest a higher contribution of bacteria to compensate nutrient limitation in oligotrophic environments. Our results show that Asparagopsis-associated bacterial communities have host-specificity and are modulated by environmental conditions. Whether this environmental effect reflects the host's selective requirements or

  20. Host and Environmental Specificity in Bacterial Communities Associated to Two Highly Invasive Marine Species (Genus Asparagopsis)

    PubMed Central

    Aires, Tânia; Serrão, Ester A.; Engelen, Aschwin H.

    2016-01-01

    As habitats change due to global and local pressures, population resilience, and adaptive processes depend not only on their gene pools but also on their associated bacteria communities. The hologenome can play a determinant role in adaptive evolution of higher organisms that rely on their bacterial associates for vital processes. In this study, we focus on the associated bacteria of the two most invasive seaweeds in southwest Iberia (coastal mainland) and nearby offshore Atlantic islands, Asparagopsis taxiformis and Asparagopsis armata. Bacterial communities were characterized using 16S rRNA barcoding through 454 next generation sequencing and exploratory shotgun metagenomics to provide functional insights and a backbone for future functional studies. The bacterial community composition was clearly different between the two species A. taxiformis and A. armata and between continental and island habitats. The latter was mainly due to higher abundances of Acidimicrobiales, Sphingomonadales, Xanthomonadales, Myxococcales, and Alteromonadales on the continent. Metabolic assignments for these groups contained a higher number of reads in functions related to oxidative stress and resistance to toxic compounds, more precisely heavy metals. These results are in agreement with their usual association with hydrocarbon degradation and heavy-metals detoxification. In contrast, A. taxiformis from islands contained more bacteria related to oligotrophic environments which might putatively play a role in mineralization of dissolved organic matter. The higher number of functional assignments found in the metagenomes of A. taxiformis collected from Cape Verde Islands suggest a higher contribution of bacteria to compensate nutrient limitation in oligotrophic environments. Our results show that Asparagopsis-associated bacterial communities have host-specificity and are modulated by environmental conditions. Whether this environmental effect reflects the host's selective requirements or

  1. The More We Search, the More We Find: Discovery of a New Lineage and a New Species Complex in the Genus Asparagopsis

    PubMed Central

    Dijoux, Laury; Viard, Frédérique; Payri, Claude

    2014-01-01

    In the past few decades, in the marine realm in particular, the use of molecular tools has led to the discovery of hidden taxonomic diversity, revealing complexes of sister species. A good example is the red algal genus Asparagopsis. The two species (A. armata and A. taxiformis) recognized in this genus have been introduced in many places around the world. Within the nominal species A. taxiformis, previous molecular analyses have uncovered several lineages, suggesting the existence of sister species or subspecies. Although the genus has been well studied in some regions (e.g., the Mediterranean Sea and Hawaii), it remains poorly investigated in others (e.g., South Pacific). Our study mainly focused on these latter areas to clarify lineages and better determine lineage status (i.e., native vs. introduced). A total of 188 specimens were collected from 61 sites, 58 of which had never been sampled before. We sequenced the DNA from samples for three markers and obtained 112 sequences for the chloroplastic RuBisCo spacer, 118 sequences for the nuclear LSU rRNA gene, and 174 for the mitochondrial spacer cox2-3. Phylogenetic analyses using all three markers suggested the existence of two cryptic sister species with the discovery of a new clade within A. armata. This clade was found only in Western Australia, Tasmania and New Zealand, and is thus restricted to a subregional biogeographic unit. We also discovered a new, fifth lineage for A. taxiformis restricted to the South Pacific and Western Australia. Except for this newly described lineage, all other lineages showed a global distribution influenced by introduction events. These results illustrate the difficulty in accurately defining cosmopolitan species. Our findings also highlight the need for targeted (i.e., in poorly studied areas) and geographically extensive sampling efforts when studying taxa that have been introduced globally and that are likely to hide species complexes. PMID:25076489

  2. Host and Environmental Specificity in Bacterial Communities Associated to Two Highly Invasive Marine Species (Genus Asparagopsis).

    PubMed

    Aires, Tânia; Serrão, Ester A; Engelen, Aschwin H

    2016-01-01

    As habitats change due to global and local pressures, population resilience, and adaptive processes depend not only on their gene pools but also on their associated bacteria communities. The hologenome can play a determinant role in adaptive evolution of higher organisms that rely on their bacterial associates for vital processes. In this study, we focus on the associated bacteria of the two most invasive seaweeds in southwest Iberia (coastal mainland) and nearby offshore Atlantic islands, Asparagopsis taxiformis and Asparagopsis armata. Bacterial communities were characterized using 16S rRNA barcoding through 454 next generation sequencing and exploratory shotgun metagenomics to provide functional insights and a backbone for future functional studies. The bacterial community composition was clearly different between the two species A. taxiformis and A. armata and between continental and island habitats. The latter was mainly due to higher abundances of Acidimicrobiales, Sphingomonadales, Xanthomonadales, Myxococcales, and Alteromonadales on the continent. Metabolic assignments for these groups contained a higher number of reads in functions related to oxidative stress and resistance to toxic compounds, more precisely heavy metals. These results are in agreement with their usual association with hydrocarbon degradation and heavy-metals detoxification. In contrast, A. taxiformis from islands contained more bacteria related to oligotrophic environments which might putatively play a role in mineralization of dissolved organic matter. The higher number of functional assignments found in the metagenomes of A. taxiformis collected from Cape Verde Islands suggest a higher contribution of bacteria to compensate nutrient limitation in oligotrophic environments. Our results show that Asparagopsis-associated bacterial communities have host-specificity and are modulated by environmental conditions. Whether this environmental effect reflects the host's selective requirements or

  3. Climate change effects on soil microarthropod abundance and community structure

    SciTech Connect

    Kardol, Paul; Reynolds, W. Nicholas; Norby, Richard J; Classen, Aimee T

    2011-01-01

    Long-term ecosystem responses to climate change strongly depend on how the soil subsystem and its inhabitants respond to these perturbations. Using open-top chambers, we studied the response of soil microarthropods to single and combined effects of ambient and elevated atmospheric [CO{sub 2}], ambient and elevated temperatures and changes in precipitation in constructed old-fields in Tennessee, USA. Microarthropods were assessed five years after treatments were initiated and samples were collected in both November and June. Across treatments, mites and collembola were the most dominant microarthropod groups collected. We did not detect any treatment effects on microarthropod abundance. In November, but not in June, microarthropod richness, however, was affected by the climate change treatments. In November, total microarthropod richness was lower in dry than in wet treatments, and in ambient temperature treatments, richness was higher under elevated [CO{sub 2}] than under ambient [CO{sub 2}]. Differential responses of individual taxa to the climate change treatments resulted in shifts in community composition. In general, the precipitation and warming treatments explained most of the variation in community composition. Across treatments, we found that collembola abundance and richness were positively related to soil moisture content, and that negative relationships between collembola abundance and richness and soil temperature could be explained by temperature-related shifts in soil moisture content. Our data demonstrate how simultaneously acting climate change factors can affect the structure of soil microarthropod communities in old-field ecosystems. Overall, changes in soil moisture content, either as direct effect of changes in precipitation or as indirect effect of warming or elevated [CO{sub 2}], had a larger impact on microarthropod communities than did the direct effects of the warming and elevated [CO{sub 2}] treatments. Moisture-induced shifts in soil

  4. Effects of metal-contaminated forest soils from the Canadian shield to terrestrial organisms.

    PubMed

    Feisthauer, Natalie C; Stephenson, Gladys L; Princz, Juliska I; Scroggins, Richard P

    2006-03-01

    The effects of elevated metal concentrations in forest soils on terrestrial organisms were investigated by determining the toxicity of six site soils from northern Ontario and Quebec, Canada, using a battery of terrestrial toxicity tests. Soils were collected from three sites on each of two transects established downwind of nickel (Sudbury, ON, Canada) and copper (Rouyn-Noranda, PQ, Canada) smelting operations. Site soils were diluted to determine if toxicity estimates for the most-contaminated site soils could be quantified as a percent of site soil. Rouyn-Noranda soils were toxic following acute exposure (14 d) to plants, but not to invertebrates (7 d for collembola and 14 d for earthworms). However, Rouyn-Noranda soils were toxic to all species following chronic exposure (21, 35, and 63 d for plants, collembola, and earthworms, respectively). The toxicity of the Rouyn-Noranda site soils did not correspond to the gradient of metal concentrations in soil. Metal-contaminated Sudbury soils were toxic to plants but not to invertebrates, following acute exposure. Chronic exposure to Sudbury soils caused adverse effects to plant growth and invertebrate survival and reproduction. The toxicity of Sudbury soils corresponded to the metal concentration gradient, with one exception: The reference soil collected in October was toxic to collembola following acute and chronic exposure. This study evaluated the applicability of the new Environment Canada terrestrial toxicity test methods, developed using agricultural soils, to forest soils and also provided useful data to assess the ecological risk associated with mixtures of metals in soil. PMID:16566168

  5. Ecosystem linkages revealed by experimental lake-derived isotope signal in heathland food webs.

    PubMed

    Hoekman, David; Bartrons, Mireia; Gratton, Claudio

    2012-11-01

    Cross-ecosystem movement of nutrients and biomass can have important effects on recipient systems. Emerging aquatic insects are subsidies to terrestrial ecosystems and can influence foodweb interactions in riparian systems. In a 2-year field experiment, we simulated aquatic insect deposition by adding adult midge carcasses (150 g dry mass m(-2) year(-1)) to 1-m(2) heathland plots at a site with low natural midge deposition. We established four levels of midge-addition treatments and measured stable isotopes (δ(13)C and δ(15)N) in plants and arthropods within each treatment. We used a multiple-source isotope Bayesian mixing model to estimate the terrestrial versus aquatic contribution to the diets of arthropods. Aquatic resources were incorporated into plant, detritivore, and predator biomass. Detritivorous Collembola showed the greatest difference in isotope values (+3 ‰ δ(15)N and +4 ‰ δ(13)C) between midge-addition and reference treatments. Isotope values of small spiders followed the same trend of enrichment as Collembola while other arthropods (mites and large spiders) were only enriched after 2 years of midge addition. Although predator diets did not change, they became isotopically enriched via their likely prey (Collembola). Plants also had elevated δ(15)N (+1 ‰) in midge-addition treatments. The time required and amount of midge-derived C and N detected varied and depended on trophic position. Midge-derived nutrients were no longer present in arthropod biomass in the year following midge addition. Aquatic insect carcasses can be rapidly incorporated into terrestrial food webs in nearshore habitats, and repeated inputs can be detected at multiple trophic levels, thus highlighting the importance of the detrital pathway for aquatic to terrestrial cross-ecosystem subsidies.

  6. Toxicity of methyl tert butyl ether to soil invertebrates (springtails: Folsomia candida, Proisotoma minuta, and Onychiurus folsomi) and lettuce (Lactuca sativa).

    PubMed

    Dodd, Matthew; Addison, Janet A

    2010-02-01

    Experiments were conducted to assess the toxicity of methyl tert butyl ether (MTBE) to three species of Collembola (Proisotoma minuta, Folsomia candida, and Onychiurus folsomi) and lettuce (Lactuca sativa L.) using an artificial Organization for Economic Cooperation and Development (OECD) soil and field-collected sandy loam and silt loam soil samples. Soil invertebrate tests were carried out in airtight vials to prevent volatilization of MTBE out of the test units and to allow for direct head-space sampling and gas chromatography-mass spectrometry (GC-MS) analysis for residual MTBE. The use of the airtight vial protocol proved to be very successful, in that the measured MTBE concentrations at the beginning of the experiments were within 95% of nominal concentrations. The test methods used in this study could be used to test the toxicity of other volatile organic compounds to Collembola. The soil invertebrates tested had inhibitory concentration (ICx) and lethal concentration (LCx) values that ranged from 242 to 844 mg MTBE/kg dry soil. When the three test species of Collembola were tested under identical conditions in the artificial OECD soil, O. folsomi was the most sensitive collembolan, with a median inhibitory concentration (IC50; reproduction) of 296 mg MTBE/kg dry soil. The most sensitive endpoint for lettuce was an IC50 for root length of 81 mg MTBE/kg dry soil after 5 d of germination in OECD soil. Data on the loss of MTBE from the three test soils over time indicated that MTBE was retained in the silt loam soil longer than in either the sandy loam or the artificial OECD soil. PMID:20821452

  7. Epigeal fauna of a degraded soil treated with mineral fertilizer and compound cellulose cultivated of tree species

    NASA Astrophysics Data System (ADS)

    Giácomo, R. G.; de Arruda, O. G.; Souto Filho, S. N.; Alves, M. C.; Pereira, M. G.; Frigério, G. C.

    2012-04-01

    The aim of this study was to investigate the behavior of the epigeal fauna in a degraded soil in the recovery process after one year of cultivated with tree species. The experiment was established in February 2010 in Mato Grosso do Sul, Brazil. The experimental design was randomized blocks in split plots with five treatments and four replications. In the main plots, pure cultivation of Eucalyptus urograndis (exotic species - hybrids) and Mabea fistulifera Mart. (native species) and the subplot treatments: Control; D0 - without fertilization; DM - mineral fertilizer according to crop need; DC - with compost manure according to crop need (10 t ha-1); D15 - 15 t ha-1 and D20 - 20 t ha-1 of the compound. In February of the years 2010 and 2011 were installed in the central region of each treatment two traps "pitt fall" which remained for seven days in the field. We calculated Shannon diversity and Pielou evenness indices, and richness of wildlife activity groups. The results were analyzed by ANOVA and Scott Knott test at 5% significance level. In 2010, the area with M. fistulifera, was captured a total of 2697 organisms distributed mainly in: Hymenoptera with 45.83% of the total collected, Collembola (36.93%), Hemiptera Heteroptera (6.56%). In the area with E. urograndis, 1938 organisms were captured, being 50.67% of the order Hymenoptera, Collembola 26.83%, 7.59% Hemiptera Heteroptera. It was found that there was no significant difference between treatments and between species for all variables. Collected in 2011 were 4970 organisms in 56.22% of the order Hymenoptera, Collembola 18.49% and 7.12% beetle in the area of M. fistulifera. In the area of E. urograndis were 4200 organisms, 55.29% (Hymenoptera), 23.79% (Collembola) and 5.86% (Coleoptera). It appears that the activity values and richness of the fauna groups were significantly higher in treatments with organic fertilization in both cultive. It is concluded that after one year there was a variation of the dominant

  8. Multitrophic effects of nutrient addition in upland grassland.

    PubMed

    Fountain, M T; Brown, V K; Gange, A C; Symondson, W O C; Murray, P J

    2008-06-01

    Although the effects of nutrient enhancement on aquatic systems are well documented, the consequences of nutritional supplements on soil food webs are poorly understood, and results of past research examining bottom-up effects are often conflicting. In addition, many studies have failed to separate the effects of nutrient enrichment and the physical effects of adding organic matter. In this field study, we hypothesised that the addition of nitrogen to soil would result in a trophic cascade, through detritivores (Collembola) to predators (spiders), increasing invertebrate numbers and diversity. Nitrogen and lime were added to plots in an upland grassland in a randomised block design. Populations of Collembola and spiders were sampled by means of pitfall traps and identified to species. Seventeen species of Collembola were identified from the nitrogen plus lime (N+L) and control plots. Species assemblage, diversity, richness, evenness and total number were not affected by nutrient additions. However, there was an increase in the number of Isotomidae juveniles and Parisotoma anglicana trapped in the N+L plots. Of the 44 spider species identified, over 80% were Linyphiidae. An effect on species assemblage from the addition of N+L to the plots was observed on two of the four sampling dates (July 2002 and June 2003). The linyphiid, Oedothorax retusus, was the only species significantly affected by the treatments and was more likely to be trapped in the control plots.The increased number of juvenile Collembola, and change in community composition of spiders, were consequences of the bottom-up effect caused by nutrient inputs. However, despite efforts to eliminate the indirect effects of nutrient inputs, a reduction in soil moisture in the N+L plots cannot be eliminated as a cause of the invertebrate population changes observed. Even so, this experiment was not confounded by the physical effects of habitat structure reported in most previous studies. It provides evidence

  9. Ecotoxicity of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil.

    PubMed

    Eom, I C; Rast, C; Veber, A M; Vasseur, P

    2007-06-01

    Soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (PAHs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. The total concentration of the 16 PAHs listed as priority pollutants by the US Environmental Protection Agency (US-EPA) was 2634+/-241 mg/kgdw in soil samples. The toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (Vibrio fischeri; Microtox test, Daphnia magna) and chronic (Pseudokirchneriella subcapitata, Ceriodaphnia dubia) bioassays and the EC values were expressed as percentage water extract in the test media (v/v). Algal growth (EC50-3d=2.4+/-0.2% of the water extracts) and reproduction of C. dubia (EC50-7d=4.3+/-0.6%) were the most severely affected, compared to bacterial luminescence (EC50-30 min=12+/-3%) and daphnid viability (EC50-48 h=30+/-3%). The Ames and Mutatox tests indicated mutagenicity of water extracts, while no response was found with the umu test. The toxicity of the soil samples was assessed on the survival and reproduction of earthworms (Eisenia fetida) and collembolae (Folsomia candida), and on the germination and growth of higher plants (Lactuca sativa L.: lettuce and Brassica chinensis J.: Chinese cabbage). The EC50 values were expressed as percentage contaminated soil in ISO soil test medium (weight per weight-w/w) and indicated severe effects on reproduction of the collembola F. candida (EC50-28 d=5.7%) and the earthworm E. fetida (EC50-28 d=18% and EC50-56 d=8%, based on cocoon and juvenile production, respectively). Survival of collembolae was already affected at a low concentration of the contaminated soil (EC50-28 d=11%). The viability of juvenile earthworms was inhibited at much lower concentrations of the cokery soil (EC50-14 d=28%) than the viability of adults (EC50-14 d=74%). Only plant growth was inhibited (EC50-17d=26%) while germination was not. Chemical analyses of water extracts allowed

  10. Food web structure of deep-sea macrozooplankton and micronekton off the Catalan slope: Insight from stable isotopes

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Cartes, J. E.; Papiol, V.

    2011-07-01

    Food web structure of the macroplankton/micronekton fauna on the continental slope of the Catalan Sea (Balearic basin, NW Mediterranean) was investigated using carbon and nitrogen stable isotope tracers on a total of 34 taxa. Samples were collected close to Barcelona, Spain, on the middle slope, at a seasonal scale. Mean δ 13C values ranged from - 22.1‰ ( Salpa maxima) to - 16.9‰ (the mysid Eucopia hanseni). Values of δ 15N ranged from 2.5‰ (the hyperiid Vibilia armata) to 9.8‰ (the pelagic polychaete Tomopteris sp.). The stable isotope ratios of this fauna displayed a continuum of values over the δ 15N range of 7‰, confirming a wide spectrum of feeding strategies (from filter feeders to predators). High annual mean δ 15N values were found among carnivorous large zooplankton and micronekton, including species that prey on gelatinous plankton (i.e. salps, siphonophores), euphausiids, natantian decapod crustaceans and fish (i.e. myctophids and stomiiformes). In agreement with the available information on diets of planktonic taxa, the lowest isotope ratios were found for filter feeders ( V. armata, S. maxima, the pteropods Cymbulia peroni and Cavolinia inflexa, ostracods and the thaliacean Pyrosoma atlanticum), all of which feed on particulate organic matter. We found three trophic levels in macroplankton/micronekton food webs based on a 15N-enrichment factor of ~ 2.5‰ per level. The range of δ 13C was particularly wide among carnivores (- 20.7‰ to - 16.6‰), suggesting predation on a variety of prey from gelatinous zooplankton (which displayed more depleted δ 13C signatures) to small fishes and decapods. Correlation between δ 13C-δ 15N was generally weak, likely due to the consumption of different kinds of sinking particles (e.g. marine snow, phytodetritus), some constituted of multiply recycled particulate organic matter (POM). However, higher δ 13C-δ 15N correlations were observed during winter and spring, periods of water column

  11. Impact of Grassland Reseeding, Herbicide Spraying and Ploughing on Diversity and Abundance of Soil Arthropods

    PubMed Central

    Liu, Wei; Zhang, Junling; Norris, Stuart L.; Murray, Philip J.

    2016-01-01

    In order to determine the interactive effect of reseeding, herbicide spraying and ploughing on soil fauna communities, we conducted a grassland reseeding experiment combined with pre-reseed management to examine how with the whole reseeding process affects soil faunal composition. Sampling occasions and exact treatments were as follows: (1) before chemical herbicide spray; (2) after spray but before ploughing; (3) after ploughing but before reseeding; and (4) after 1 year of recovery. Our results demonstrate that, Acari and Collembola were the two soil fauna taxa with the highest abundance and accounted for around 96% of the relative total abundance among the various managements. Herbicide application tended to increase soil invertebrate abundance. Conversely, subsequent ploughing significantly reduced soil invertebrate abundance and had an obvious negative effect on soil primary and secondary decomposers, which were mainly due to the variations of Acari (especially Oribatida) and Coleoptera group abundance. Moreover, reseeding also reduced the individual number of the groups mentioned above, and favored those predators with a larger body size and individual weight. After 1 year recovery, Collembola abundance recovered to the pre-treatment levels, while with Arthropod and Acari groups were still fluctuating. PMID:27555863

  12. Lethal ovitrap deployment for Aedes aegypti control: potential implications for non-target organisms.

    PubMed

    Long, Sharron A; Jacups, Susan P; Ritchie, Scott A

    2015-06-01

    In Australia, dengue control combines source reduction with lethal ovitraps to reduce Aedes aegypti populations during outbreaks. Lethal ovitraps are considered a sustainable and environmentally friendly method of controlling container-inhabiting mosquitoes, however, to-date, this claim has not been quantified. This study assesses the potential impact of lethal ovitraps on non-target organisms when used to control Ae. aegypti in tropical Australia. For retention of specimens, we substituted standard sticky ovitraps for lethal ovitraps. We collected 988 Ae. aegypti and 44,132 non-target specimens over 13 months from 16 sites. Although Ae. aegypti comprised only 2.2% of the total collection, they were were the eighth most dominant taxa collected, on the 93(rd) percentile. Of the non-target organisms, Collembola were the dominant taxa, 44.2%, with 36.8% and 10.5% Diptera and Hymenoptera, respectively. Of the Dipterans, 61% were family Phoridae. Lethal ovitraps were visited by 90 insect or invertebrate families in total. Ovitraps are attractive to Collembola, Phoridae, Sciaridae, Formicidae, and Culicidae, with minimal attraction by Apidae and other commonly monitored non-target organisms. For container-inhabiting mosquitoes, LOs are cost effective operationally, requiring minimal staff resources for placement and retrieval. PMID:26047194

  13. Impact of Grassland Reseeding, Herbicide Spraying and Ploughing on Diversity and Abundance of Soil Arthropods.

    PubMed

    Liu, Wei; Zhang, Junling; Norris, Stuart L; Murray, Philip J

    2016-01-01

    In order to determine the interactive effect of reseeding, herbicide spraying and ploughing on soil fauna communities, we conducted a grassland reseeding experiment combined with pre-reseed management to examine how with the whole reseeding process affects soil faunal composition. Sampling occasions and exact treatments were as follows: (1) before chemical herbicide spray; (2) after spray but before ploughing; (3) after ploughing but before reseeding; and (4) after 1 year of recovery. Our results demonstrate that, Acari and Collembola were the two soil fauna taxa with the highest abundance and accounted for around 96% of the relative total abundance among the various managements. Herbicide application tended to increase soil invertebrate abundance. Conversely, subsequent ploughing significantly reduced soil invertebrate abundance and had an obvious negative effect on soil primary and secondary decomposers, which were mainly due to the variations of Acari (especially Oribatida) and Coleoptera group abundance. Moreover, reseeding also reduced the individual number of the groups mentioned above, and favored those predators with a larger body size and individual weight. After 1 year recovery, Collembola abundance recovered to the pre-treatment levels, while with Arthropod and Acari groups were still fluctuating. PMID:27555863

  14. ELF communications system ecological monitoring program: Soil arthropods and earthworms

    NASA Astrophysics Data System (ADS)

    Snider, Richard J.; Snider, Renate M.

    1995-04-01

    Based on analysis of years grouped by pre-ELF and operational periods, density fluctuations of arthropods (Collembola and mites) were, in some taxa, significantly different between sites; in others, differences between year groups were significant within either of the study sites. No consistent patterns were seen at the level of species or higher taxa. In some species, effects of the 1988 drought may have carried over into 1989, the first year of antenna operation. Surface-active Collembola, velvet mites and carabid beetles did not alter their activity patterns following antenna activation (e.g., species predominantly spring-active remained spring-active). Although analyses routinely yielded significant differences with respect to total numbers captured in Test and Control, numbers alone were found to be unreliable estimators for disturbance, because a variety of potentially important factors other than EM fields were present. Weekly changes in relative numbers captured, however, showed that increases and decreases in activity were synchronous in the study sites. Carabid beetle activity, which is highly seasonal and governed mainly by reproductive processes, was not affected by EM fields.

  15. Soil mesofauna in disturbed spruce forest stands near Čertovo and Plešné Lakes, the Bohemian Forest: preliminary results

    NASA Astrophysics Data System (ADS)

    Čuchta, Peter; Starý, Jozef

    2016-04-01

    The soil microarthropod communities were studied in disturbed spruce forest stands in the catchments areas of Čertovo (CT) and Plešné (PL) Lakes in the Bohemian Forest, Czech Republic. The study is focused on the impact of the windthrow, bark beetle outbreak damage and consecutive changes in the forest stands including soil environment. Within the soil microarthropods, two main groups, Collembola (Hexapoda) and Oribatida (Acari) are analysed. Four different treatments were selected for the study on both study areas: CT1 and PL1 stands - undamaged control forest stands, CT2 and PL2 stands - "dead" forest stands damaged by bark beetle, CT3 and PL3 stands - slightly managed windthrown forest stands left for the natural succession, and CT4 and PL4 stands - harvested windthrown stands. Soil samples were taken in June (CT1/PL1 - CT3/PL3), July and October (CT1/PL1 - CT4/PL4) 2012 from each treatment. Microarthropods were subsequently extracted in a modified high-gradient apparatus in the laboratory for seven days. Finally, the comparison of the microarthropod assemblages found at different treatment stands was performed. The most abundant groups in both study areas (Čertovo and Plešné Lakes) were Collembola and Oribatida with considerable diferences within particular treatments and in time as well.

  16. Metal toxicity and biodiversity in serpentine soils: application of bioassay tests and microarthropod index.

    PubMed

    Visioli, Giovanna; Menta, Cristina; Gardi, Ciro; Conti, Federica Delia

    2013-01-01

    Eco-toxicological or bioassay tests have been intensively discussed as tools for the evaluation of soil quality. Tests using soil organisms, including microarthropods and plants, allow direct estimates to be made of important soil characteristics and functions. In this study we compared the results obtained by two in vitro standard bioassays following ISO or OECD guidelines: (i) the short term-chronic phytotoxicity germination and root elongation test using three different plant species Cucumis sativus L. (Cucurbitaceae), Lepidium sativum L. (Brassicaceae), and Medicago sativa L. (Fabaceae) and (ii) the inhibition of reproduction of Folsomia candida (Collembola) by soil pollutants to investigate the toxicity of a serpentine soil present in the Italian Apennines, rich in heavy metals such as Ni, Cr, and Co. In addition, microarthropod communities were characterised to evaluate the effects of metal contents on the soil fauna in natural conditions. Abundances, Acari/Collembola ratio, biodiversity indices and the QBS-ar index were calculated. Our results demonstrate that the two in vitro tests distinguish differences correlated with metal and organic matter contents in four sub-sites within the serpentinite. Soil fauna characterisation, not previously performed on serpentine soils, revealed differences in the most vulnerable and adapted groups of microarthropods to soil among the four sub-sites: the microarthropod community was found to be rich in term of biodiversity in the sub-site characterised by a lower metal content and a higher organic matter content and vegetation.

  17. Intraguild predation in pioneer predator communities of alpine glacier forelands

    PubMed Central

    Raso, Lorna; Sint, Daniela; Mayer, Rebecca; Plangg, Simon; Recheis, Thomas; Brunner, Silvia; Kaufmann, Rüdiger; Traugott, Michael

    2014-01-01

    Pioneer communities establishing themselves in the barren terrain in front of glacier forelands consist principally of predator species such as carabid beetles and lycosid spiders. The fact that so many different predators can co-inhabit an area with no apparent primary production was initially explained by allochthonous material deposited in these forelands. However, whether these populations can be sustained on allochthonous material alone is questionable and recent studies point towards this assumption to be flawed. Intraguild predation (IGP) might play an important role in these pioneer predator assemblages, especially in the very early successional stages where other prey is scarce. Here, we investigated IGP between the main predator species and their consumption of Collembola, an important autochthonous alternative prey, within a glacier foreland in the Ötztal (Austrian Alps). Multiplex PCR and stable isotope analysis were used to characterize the trophic niches in an early and late pioneer stage over 2 years. Results showed that intraguild prey was consumed by all invertebrate predators, particularly the larger carabid species. Contrary to our initial hypothesis, the DNA detection frequency of IGP prey was not significantly higher in early than in late pioneer stage, which was corroborated by the stable isotope analysis. Collembola were the most frequently detected prey in all of the predators, and the overall prey DNA detection patterns were consistent between years. Our findings show that IGP appears as a constant in these pioneer predator communities and that it remains unaffected by successional changes. PMID:24383765

  18. Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods.

    PubMed Central

    Haughton, A J; Champion, G T; Hawes, C; Heard, M S; Brooks, D R; Bohan, D A; Clark, S J; Dewar, A M; Firbank, L G; Osborne, J L; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Woiwod, I P; Birchall, C; Skellern, M P; Walker, J H; Baker, P; Browne, E L; Dewar, A J G; Garner, B H; Haylock, L A; Horne, S L; Mason, N S; Sands, R J N; Walker, M J

    2003-01-01

    The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management. PMID:14561319

  19. Intraguild predation in pioneer predator communities of alpine glacier forelands.

    PubMed

    Raso, Lorna; Sint, Daniela; Mayer, Rebecca; Plangg, Simon; Recheis, Thomas; Brunner, Silvia; Kaufmann, Rüdiger; Traugott, Michael

    2014-08-01

    Pioneer communities establishing themselves in the barren terrain in front of glacier forelands consist principally of predator species such as carabid beetles and lycosid spiders. The fact that so many different predators can co-inhabit an area with no apparent primary production was initially explained by allochthonous material deposited in these forelands. However, whether these populations can be sustained on allochthonous material alone is questionable and recent studies point towards this assumption to be flawed. Intraguild predation (IGP) might play an important role in these pioneer predator assemblages, especially in the very early successional stages where other prey is scarce. Here, we investigated IGP between the main predator species and their consumption of Collembola, an important autochthonous alternative prey, within a glacier foreland in the Ötztal (Austrian Alps). Multiplex PCR and stable isotope analysis were used to characterize the trophic niches in an early and late pioneer stage over 2 years. Results showed that intraguild prey was consumed by all invertebrate predators, particularly the larger carabid species. Contrary to our initial hypothesis, the DNA detection frequency of IGP prey was not significantly higher in early than in late pioneer stage, which was corroborated by the stable isotope analysis. Collembola were the most frequently detected prey in all of the predators, and the overall prey DNA detection patterns were consistent between years. Our findings show that IGP appears as a constant in these pioneer predator communities and that it remains unaffected by successional changes.

  20. Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods.

    PubMed

    Haughton, A J; Champion, G T; Hawes, C; Heard, M S; Brooks, D R; Bohan, D A; Clark, S J; Dewar, A M; Firbank, L G; Osborne, J L; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Woiwod, I P; Birchall, C; Skellern, M P; Walker, J H; Baker, P; Browne, E L; Dewar, A J G; Garner, B H; Haylock, L A; Horne, S L; Mason, N S; Sands, R J N; Walker, M J

    2003-11-29

    The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management. PMID:14561319

  1. Soil cultivation in vineyards alters interactions between soil biota and soil physical and hydrological properties

    NASA Astrophysics Data System (ADS)

    Zaller, Johann G.; Buchholz, Jacob; Querner, Pascal; Winter, Silvia; Kratschmer, Sophie; Pachinger, Bärbel; Strauss, Peter; Bauer, Thomas; Stiper, Katrin; Potthoff, Martin; Guernion, Muriel; Scimia, Jennifer; Cluzeau, Daniel

    2016-04-01

    Several ecosystem services provided by viticultural landscapes result from interactions between soil organisms and soil parameters. However, to what extent different soil cultivation intensities in vineyards compromise soil organisms and their interactions between soil physical and hydrological properties is not well understood. In this study we examined (i) to what extent different soil management intensities affect the activity and diversity of soil biota (earthworms, Collembola, litter decomposition), and (ii) how soil physical and hydrological properties influence these interactions, or vice versa. Investigating 16 vineyards in Austria, earthworms were assessed by hand sorting, Collembola via pitfall trapping and soil coring, litter decomposition by using the tea bag method. Additionally, soil physical (water infiltration, aggregate stability, porosity, bulk density, soil texture) and chemical (pH, soil carbon content, cation exchange capacity, potassium, phosphorus) parameters were assessed. Results showed complex ecological interactions between soil biota and various soil characteristics altered by management intensity. These investigations are part of the transdisciplinary BiodivERsA project VineDivers and will ultimately lead into management recommendations for various stakeholders.

  2. Lethal ovitrap deployment for Aedes aegypti control: potential implications for non-target organisms.

    PubMed

    Long, Sharron A; Jacups, Susan P; Ritchie, Scott A

    2015-06-01

    In Australia, dengue control combines source reduction with lethal ovitraps to reduce Aedes aegypti populations during outbreaks. Lethal ovitraps are considered a sustainable and environmentally friendly method of controlling container-inhabiting mosquitoes, however, to-date, this claim has not been quantified. This study assesses the potential impact of lethal ovitraps on non-target organisms when used to control Ae. aegypti in tropical Australia. For retention of specimens, we substituted standard sticky ovitraps for lethal ovitraps. We collected 988 Ae. aegypti and 44,132 non-target specimens over 13 months from 16 sites. Although Ae. aegypti comprised only 2.2% of the total collection, they were were the eighth most dominant taxa collected, on the 93(rd) percentile. Of the non-target organisms, Collembola were the dominant taxa, 44.2%, with 36.8% and 10.5% Diptera and Hymenoptera, respectively. Of the Dipterans, 61% were family Phoridae. Lethal ovitraps were visited by 90 insect or invertebrate families in total. Ovitraps are attractive to Collembola, Phoridae, Sciaridae, Formicidae, and Culicidae, with minimal attraction by Apidae and other commonly monitored non-target organisms. For container-inhabiting mosquitoes, LOs are cost effective operationally, requiring minimal staff resources for placement and retrieval.

  3. Sewage sludge effects on mesofauna and cork oak (Quercus suber L.) leaves decomposition in a Mediterranean forest firebreak.

    PubMed

    Pernin, Céline; Cortet, Jérôme; Joffre, Richard; Le Petit, Jean; Torre, Franck

    2006-01-01

    Effects of sewage sludge on litter mesofauna communities (Collembola and Acari) and cork oak (Quercus suber L.) leaf litter decomposition have been studied during 18 mo using litterbags in an in situ experimental forest firebreak in southeastern France. The sludge (2.74 t DM ha(-1) yr(-1)) was applied to fertilize and maintain a pasture created on the firebreak. Litterbag colonization had similar dynamics on both the control and fertilized plots and followed a typical Mediterranean pattern showing a greater abundance in spring and autumn and a lower abundance in summer. After 9 mo of litter colonization, Collembola and Acari, but mainly Oribatida, were more abundant on the sludge-fertilized plot. Leaf litter decomposition showed a similar pattern on both plots, but it was faster on the control plot. Furthermore, leaves from the fertilized plot were characterized by greater nitrogen content. Both chemical composition of leaves and sludges and the decomposition state of leaves have significantly affected the mesofauna community composition from each plot.

  4. Prospective ecological risk assessment of sediment resuspension in an estuary.

    PubMed

    Rial, Diego; Beiras, Ricardo

    2012-08-01

    This study assesses potential ecological risk of resuspended sediment in the water column during the construction of a viaduct in the estuary of the Ulla river (Galicia, NW Iberian Peninsula), a shellfish production area. Chemical analyses and toxicity bioassays with elutriates were performed with sediments from the area where the three pillars of the viaduct will be located (CT1, CT2 and CT3) and a reference sediment (A2). Acute toxicity of the elutriate was evaluated in five species of three trophic levels (Isochrysis galbana, Paracentrotus lividus, Mytilus galloprovincialis, Venerupis pullastra and Siriella armata). The sediments of the pillars showed moderate levels of contamination by trace elements (Cu, Cr). Clam and sea urchin embryo-larval toxicity tests showed slightly higher sensitivity than mussel embryo tests, and toxicity was not detected for phytoplankton and mysid bioassays. The predicted no-effect environmental concentration (PNEC) was calculated from the arithmetic mean of the lowest calculated EC(50)s for each sampling site. The predicted environmental concentration (PEC) was estimated from a simple dilution model and the PEC/PNEC ratio was calculated according to different scenarios of resuspension. Negligible ecological risk in the water column is expected during construction of the pillars.

  5. Paridris kieffer of the new world (hymenoptera, platygastroidea, platygastridae).

    PubMed

    Talamas, Elijah J; Masner, Lubomír; Johnson, Norman F

    2012-01-01

    Paridris in the New World is revised (Hymenoptera: Platygastridae). Fifteen species are described, of which 13 are new. Paridris aenea (Ashmead)(Mexico (Tamaulipas) and West Indies south to Bolivia and southern Brazil (Rio de Janeiro state)), Paridris armata Talamas, sp. n. (Venezuela), Paridris convexa Talamas, sp. n. (Costa Rica, Panama), Paridris dnophos Talamas, sp. n. (Mexico (Vera Cruz) south to Bolivia and central Brazil (Goiás)), Paridris gongylos Talamas & Masner, sp. n. (United States: Appalachian Mountains of Virginia, Tennessee, South Carolina), Paridris gorn Talamas & Masner, sp. n. (United States: Ohio south to Alabama, Georgia), Paridris invicta Talamas & Masner, sp. n. (Brazil: São Paulo), Paridris isabelicae Talamas & Masner, sp. n. (Cuba, Dominican Republic), Paridris lemete Talamas & Masner, sp. n. (Puerto Rico), Paridris minor Talamas, sp. n. (Cuba), Paridris nayakorum Talamas, sp. n. (Costa Rica), Paridris pallipes (Ashmead)(southeastern Canada, United States south to Costa Rica, also Brazil (São Paulo), Paridris psydrax Talamas & Masner, sp. n. (Argentina, Mexico, Paraguay, United States, Venezuela), Paridris saurotos Talamas, sp. n. (Jamaica), Paridris soucouyant Talamas & Masner, sp. n. (Colombia, Trinidad and Tobago, Venezuela). Paridris brevipennis Fouts, Paridris laeviceps (Ashmead), and Paridris nigricornis (Fouts) are treated as junior synonyms of Paridris pallipes; Paridris opaca is transferred to Probaryconus. Lectotypes are designated for Idris aenea Ashmead and Caloteleia aenea Ashmead. PMID:23226959

  6. Acute toxicity of a shoreline cleaner, CytoSol, mixed with oil and ecological risk assessment of its use on the Galician Coast.

    PubMed

    Rial, Diego; Beiras, Ricardo; Vázquez, José A; Murado, Miguel A

    2010-10-01

    The application of embryo-larval bioassay with the purple sea urchin Paracentrotus lividus and the mussel Mytilus galloprovincialis at 48 hours, and with neonates of the mysid Siriella armata at 96 hours, was used to evaluate the acute toxicities of the following preparations: (1) the shoreline cleaning agent CytoSol; (2) the water-accommodated fraction of CytoSol plus a light crude oil; and (3) the runoff from a pilot-scale treatment with CytoSol of a rocky coastal substrate impregnated with residues from the Prestige oil spill (which occurred on November 19, 2002). The mussel was the most sensitive organism to CytoSol and runoff effects (EC(50) = 8.0 microL/L and 64.3 mL/L, respectively), and the mysid was the least sensitive to the runoff (EC(50) > 200 mL/L). The predicted no-effect environmental concentration (PNEC) was calculated from the no observed-effect concentration of the species most sensitive to the runoff. The predicted environmental concentration (PEC) was estimated from a simple and reasonable dilution model, and the PEC/PNEC ratio was calculated according to the area treated and the values of the variables considered in the model. Implications for the management of the treatment operations are discussed. PMID:20217060

  7. Lower Mississippian trilobites from southern New Mexico

    USGS Publications Warehouse

    Brezinski, D.K.

    2000-01-01

    Twenty-three species of trilobites are recognized in the lower Mississippian Caballero and Lake Valley Formations of southern New Mexico. Species exhibit a segregation into shelf and off-shelf faunas, and can be subdivided into three distinct stratigraphic faunas. Species found in the Caballero Formation are similar to those found in the Chouteau Formation of Missouri. A second fauna, comprising species found in the Alamogordo, Nunn, and Tierra Blanca Members of the Lake Valley Formation, is correlated with the Fern Glen and Burlington Formations of Missouri. The third fauna found in the Arcente and Dona Aha Members of the Lake Valley Formation is correlated with the Warsaw and Salem Formations of the United States midcontinent region. Named species from the Kinderhookian Caballero Formation include: Dixiphopyge armata (Vogdes, 1891), Comptonaspis swallowi (Shumard, 1855), Brachymetopus indianwellsensis new species, Ameropiltonia perplexa new species, Griffithidella caballeroensis new species, and Kollarcephalus granatai new genus and new species. Named species from the Lake Valley Formation include: Pudoproetus fernglenensis (Weller, 1909), Breviphillipsia semiteretis Hessler, 1963, Griffithidella doris (Hall 1860), Phillibole planucauda (Brezinski, 1998), Piltonia carlakertisae new species, Australosutura llanoensis Brezinski, 1998, Thigriffides triangulatus new species, Thigriffides? alamogordoensis new species, Namuropyge newmexicoensis new species, Nunnaspis stitti new genus and new species, Hesslerides arcentensis new genus and new species, as well as an unnamed species of Proetides Hessler, 1962, Namuropyge Brezinski, 1988, and Thigriffides Hessler, 1965.

  8. Biological pollution in the Mediterranean Sea: invasive versus introduced macrophytes.

    PubMed

    Boudouresque, Charles François; Verlaque, Marc

    2002-01-01

    The authors have listed 85 species of macrophytes that have probably been introduced to the Mediterranean. Among them, nine species can be considered as invasive, i.e., playing a conspicuous role in the recipient ecosystems, taking the place of keystone species and/or being economically harmful: Acrothamnion preissii, Asparagopsis armata, Lophocladia lallemandii, Womersleyella setacea (Rhodophyta), Sargassum muticum, Stypopodium schimperi (Fucophyceae), Caulerpa racemosa, Caulerpa taxifolia and Halophila stipulacea (Plantae). These data fit well the Williamson and Fitter's "tens rule", which states that, on average, 1 out of 10 introduced species becomes invasive. Though some features (e.g. life traits, geographical origin) can increase the likelihood of a successful invasion, the success of invaders is far from being predictable. Since the beginning of the 20th century, the number of introduced species to the Mediterranean has nearly doubled every 20 years. Should these kinetics continue, and according to the tens rule, it can be expected that 5-10 newly introduced macrophytes shall become invasive in the next 20 years. PMID:11883681

  9. Nuclear DNA Content Variation in Life History Phases of the Bonnemasoniaceae (Rhodophyta)

    PubMed Central

    Salvador Soler, Noemi; Gómez Garreta, Amelia; Ribera Siguan, Mª Antonia; Kapraun, Donald F.

    2014-01-01

    Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4′, 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15–1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome. PMID:24465835

  10. Nuclear DNA content variation in life history phases of the Bonnemasoniaceae (Rhodophyta).

    PubMed

    Salvador Soler, Noemi; Gómez Garreta, Amelia; Ribera Siguan, Ma Antonia; Kapraun, Donald F

    2014-01-01

    Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4', 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome.

  11. Domoic Acid Toxicologic Pathology: A Review

    PubMed Central

    Pulido, Olga M.

    2008-01-01

    Domoic acid was identified as the toxin responsible for an outbreak of human poisoning that occurred in Canada in 1987 following consumption of contaminated blue mussels [Mytilus edulis]. The poisoning was characterized by a constellation of clinical symptoms and signs. Among the most prominent features described was memory impairment which led to the name Amnesic Shellfish Poisoning [ASP]. Domoic acid is produced by certain marine organisms, such as the red alga Chondria armata and planktonic diatom of the genus Pseudo-nitzschia. Since 1987, monitoring programs have been successful in preventing other human incidents of ASP. However, there are documented cases of domoic acid intoxication in wild animals and outbreaks of coastal water contamination in many regions world-wide. Hence domoic acid continues to pose a global risk to the health and safety of humans and wildlife. Several mechanisms have been implicated as mediators for the effects of domoic acid. Of particular importance is the role played by glutamate receptors as mediators of excitatory neurotransmission and the demonstration of a wide distribution of these receptors outside the central nervous system, prompting the attention to other tissues as potential target sites. The aim of this document is to provide a comprehensive review of ASP, DOM induced pathology including ultrastructural changes associated to subchronic oral exposure, and discussion of key proposed mechanisms of cell/tissue injury involved in DOM induced brain pathology and considerations relevant to food safety and human health. PMID:18728725

  12. Different speciation for bromine in brown and red algae, revealed by in vivo X-ray absorption spectroscopic studies.

    PubMed

    Küpper, Frithjof C; Leblanc, Catherine; Meyer-Klaucke, Wolfram; Potin, Philippe; Feiters, Martin C

    2014-08-01

    Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron-based technique, X-ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G. gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores - including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G. dura and C. crispus and the brown alga F. serratus are present as Br(-) defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses. PMID:26988449

  13. Stable C and N isotopic composition of cold-water corals from the Newfoundland and Labrador continental slope: Examination of trophic, depth and spatial effects

    NASA Astrophysics Data System (ADS)

    Sherwood, Owen A.; Jamieson, Robyn E.; Edinger, Evan N.; Wareham, Vonda E.

    2008-10-01

    With the aim of understanding of the trophic ecology of cold-water corals, this paper explores the tissue δ13C and δ15N values of 11 'coral' species (8 alcyonacean, 1 antipatharian, 1 pennatulacean, 1 scleractinian) collected along the Newfoundland and Labrador continental slope. Isotopic results delimit species along continua of trophic level and food lability. With an isotopic signature similar to macrozooplankton, Paragorgia arborea occupies the lowest trophic level and most likely feeds on fresh phytodetritus. Primnoa resedaeformis occupies a slightly higher trophic level, likely supplementing its diet with microzooplankton. Bathypathes arctica, Pennatulacea and other alcyonaceans ( Acanella arbuscula, Acanthogorgia armata, Anthomastus grandiflorus, Duva florida, Keratoisis ornata, Paramuricea sp.) had higher δ13C and δ15N values, suggesting these species feed at higher trophic levels and on a greater proportion of more degraded POM. Flabellum alabastrum had an isotopic signature similar to that of snow crab, indicating a primarily carnivorous diet. Isotopic composition did not vary significantly over a depth gradient of 50-1400 m. Coral δ13C increased slightly (<1‰) from the Hudson Strait to the southern Grand Banks, but δ15N did not. By modulating the availability and quality of suspended foods, substrate likely exerts a primary influence on the feeding habits of cold-water corals.

  14. Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes).

    PubMed

    Golombek, Anja; Tobergte, Sarah; Struck, Torsten H

    2015-05-01

    Gnathostomulida is a taxon of small marine worms, which exclusively inhabit the interstitium. The evolution of Gnathostomulida has been discussed for decades. Originally regarded as primitive animals with affinities to flatworms, the phylogenetic position of Gnathostomulida has been debated. Given the lack of an anus a close relationship to Platyhelminthes has been maintained (i.e., Plathelminthomorpha hypothesis). Alternative hypotheses proposed Gnathostomulida as being close to Gastrotricha due to the presence of a monociliary epidermis (i.e., Monokonta/Neotrichozoa hypothesis) or to Syndermata based on the complicated jaw apparatus (i.e., Gnathifera hypothesis). Molecular analyses using only few genes were inconclusive. Recent phylogenomic studies brought some progress by placing Gnathostomulida as sister to Syndermata, but support for this relationship was low and depended on the analytical strategy. Herein we present the first data of complete or nearly complete mitochondrial genomes for two gnathostomulids (Gnathostomula paradoxa &G. armata), one gastrotrich (Lepidodermella squamata) and one polyclad flatworm (Stylochoplana maculata) to address the uncertain phylogenetic affinity of Gnathostomulida. Our analyses found Gnathostomulida as sister to Syndermata (Gnathifera hypothesis). Thorough sensitivity analyses addressing taxon instability, branch length heterogeneity (also known as long branch attraction) and base composition heterogeneity showed that the position of Gnathostomulida is consistent across the different analyses and, hence, independent of potential misleading biases. Moreover, by ameliorating these different biases nodal support values could be increased to maximum values. Thus, our data support the hypothesis that the different jaw apparatuses of Syndermata and Gnathostomulida are indeed homologous structures as proposed by the Gnathifera hypothesis.

  15. Different speciation for bromine in brown and red algae, revealed by in vivo X-ray absorption spectroscopic studies.

    PubMed

    Küpper, Frithjof C; Leblanc, Catherine; Meyer-Klaucke, Wolfram; Potin, Philippe; Feiters, Martin C

    2014-08-01

    Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron-based technique, X-ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G. gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores - including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G. dura and C. crispus and the brown alga F. serratus are present as Br(-) defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses.

  16. Macroalgal assemblages of disturbed coastal detritic bottoms subject to invasive species

    NASA Astrophysics Data System (ADS)

    Klein, Judith C.; Verlaque, Marc

    2009-04-01

    Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea.

  17. The evolvability of growth form in a clonal seaweed.

    PubMed

    Monro, Keyne; Poore, Alistair G B

    2009-12-01

    Although modular construction is considered the key to adaptive growth or growth-form plasticity in sessile taxa (e.g., plants, seaweeds and colonial invertebrates), the serial expression of genes in morphogenesis may compromise its evolutionary potential if growth forms emerge as integrated wholes from module iteration. To explore the evolvability of growth form in the red seaweed, Asparagopsis armata, we estimated genetic variances, covariances, and cross-environment correlations for principal components of growth-form variation in contrasting light environments. We compared variance-covariance matrices across environments to test environmental effects on heritable variation and examined the potential for evolutionary change in the direction of plastic responses to light. Our results suggest that growth form in Asparagopsis may constitute only a single genetic entity whose plasticity affords only limited evolutionary potential. We argue that morphological integration arising from modular construction may constrain the evolvability of growth form in Asparagopsis, emphasizing the critical distinction between genetic and morphological modularity in this and other modular taxa.

  18. Meniscus-climbing insects

    NASA Astrophysics Data System (ADS)

    Hu, David L.; Kreider, Tim; Bush, John W. M.; Mit Department Of Mathematics Team

    2003-11-01

    Many millimetric water-walking insects are unable to climb the meniscii that border land and emerging vegetation using their traditional means of propulsion. We explore the novel means by which some insects succeed in so doing through a combined experimental and theoretical investigation. The grub Collembola ascends by distorting the free surface in order to generate a net horizontal surface tension force. The water treader Mesovelia climbs the meniscus by exploiting the Coulomb-like attraction between like-signed menisci: by lifting the free surface with its front and rear pairs of feet, it generates a tangential force that draws it up the slope. We examine the required force and torque balances on the body in order to calculate optimal leg configurations for meniscus climbers that are consistent with those observed.

  19. The terrestrial bioluminescent animals of Japan.

    PubMed

    Oba, Yuichi; Branham, Marc A; Fukatsu, Takema

    2011-11-01

    Light production by organisms, or bioluminescence, has fascinated not only scientists but also ordinary people all over the world, and it has been especially so in Japan. Here we review the biological information available to date for all luminous terrestrial animals known from Japan, particularly focusing on their diversity and systematics, their biology and ecology in Japan, and putative function and biochemistry of their luminescence. In total 58 luminous terrestrial animals have been described from Japan, which consist of 50 fireflies (Coleoptera: Lampyridae), one glowworm beetle (Coleoptera: Phengodidae), two fungus gnats (Diptera: Keroplatidae), one springtail (Collembola), one millipede (Diplopoda), one centipede (Chilopoda) and two earthworms (Oligochaeta). For all except some firefly species, the DNA "barcode" sequences of a cytochrome oxidase subunit I region are provided. We also introduce how intricately the seasonal appearance and glimmering of luminous insects, in particular those of fireflies, have been interwoven into the culture, art, literature and mentality of Japanese people. PMID:22035300

  20. A 9 kDa antifreeze protein from the Antarctic springtail, Gomphiocephalus hodgsoni.

    PubMed

    Hawes, T C; Marshall, C J; Wharton, D A

    2014-08-01

    A 9 kDA antifreeze protein (AFP) was isolated and purified from the Antarctic springtail, Gomphiocephalus hodgsoni. By combining selective sampling procedures and a modified ice affinity purification protocol it was possible to directly isolate a single AFP protein without recourse to chromatographic separation techniques. Mass spectrometry identified a single 9 kDa component in the purified ice fraction. Intramolecular disulphide bonding was suggested by the presence of 12 cysteine residues. The specific amino acid composition is unique, particularly with regard to the presence of histidine (11.5%). But it also shows noticeable commonalities with insect AFPs in the abundance of cysteine (13.8%), while simultaneously hinting, through the presence of glycine (11.5%), that the metabolic building blocks of AFPs in Collembola may have a phylogenetically-determined component. PMID:25025820

  1. Terrestrial short-term ecotoxicity of a green formicide.

    PubMed

    Tiepo, Erasmo N; Corrêa, Albertina X R; Resgalla, Charrid; Cotelle, Sylvie; Férard, Jean-François; Radetski, Claudemir M

    2010-07-01

    When ants become annoying, large quantities of formicide are applied to terrestrial ecosystems in tropical regions, but awareness of the health and environmental impacts related to the use of synthetic pesticides has been increasing. The use of green pesticides to combat target organisms could reduce these impacts. In this regard, terrestrial ecotoxicity tests with higher plants (Brassica olaracea, Lactuca sativa and Mucuna aterrima), annelids (Eisenia foetida), Collembola (Folsomia candida) and soil enzyme activity analysis (diacetate fluorescein hydrolysis) were used to evaluate short-term terrestrial ecotoxicity of a green pesticide prepared from naturally-occurring organic compounds. At the highest formicide concentration tested in these experiments (i.e., 50 g kg(-1) soil) no toxicity toward terrestrial organisms was observed. The lack of short-term terrestrial ecotoxicity suggest that this green formicide can be classed as an environmentally friendly product as compared to the ecotoxicity of the most commonly used commercialized formicides.

  2. [Community diversity of soil arthropods in forest-steppe ecotone].

    PubMed

    Zhu, Xin-yu; Gao, Bao-ji; Bi, Hua-ming; Wang, Wen-xun; Yuan, Sheng-liang; Hu, Yun-chuan

    2007-11-01

    An investigation on the community diversity of soil arthropods in the forest-steppe ecotone of north Hebei Province was conducted. A total of 10 420 individuals of soil arthropods were collected, which belonged to 25 groups, 6 classes and 24 orders. Acarina and Collembola were the dominant orders, and there were 8 groups of frequent orders and 15 groups of rare orders. The diversity index (H'), DG index, and evenness of soil arthropod community were relatively higher in forest zone, but lower in meadow-steppe zone. Soil pH had a higher degree of interconnection with the numbers of soil arthropod groups, while soil temperature and moisture content had a higher degree of interconnection with the numbers of soil arthropod individuals.

  3. Protozoan pulses unveil their pivotal position within the soil food web.

    PubMed

    Crotty, Felicity V; Adl, Sina M; Blackshaw, Rod P; Murray, Philip J

    2012-05-01

    Protozoa are one of the most abundant groups of bacterivores within the soil and are responsible for mineralisation of bacterial biomass, having a large impact on C and N cycling. Little is known of their contribution to soil nutrient transfers or the identity of their consumers. Here, for the first time indigenous flagellates and ciliates, enriched to 83 atom% for (13)C and 10 atom% for (15)N, were introduced to soil cores from two different land managements, grassland and woodland with the same soil type, to trace the flow of protozoan C and N through the soil food web. Nematodes, Collembola, earthworms and insect larvae obtained the greatest amounts of C and N of protozoan origin, either through direct consumption or uptake of biomass post-cell death. Our results show that changes in management, affect the functioning of the soil food web and the utilisation of protozoa as a food source.

  4. Is evenness altered by fire in natural assemblages of soil arthropods?

    NASA Astrophysics Data System (ADS)

    Pitzalis, Monica; Bologna, Marco A.; Luiselli, Luca

    2013-05-01

    We studied evenness and species richness in two assemblages of soil arthropods at six contiguous study plots in Mediterranean ecosystems of central Italy, three of these plots being burnt and three unburnt. We analysed these aspects of community structure by diversity-dominance diagrams comparisons made through analysis of covariance on respective slopes and ordinate intercepts. We observed consistent patterns in both Collembola and Oniscidea assemblages, either in burnt and unburnt plots. Evenness did not change among study plots and across habitats, either before or after fire, whereas species' composition was significantly altered by fire. Results from our study implied that evenness and species diversity are clearly affected in a different and independent way by fire. Hence, it is not acceptable to focus on only the evenness when looking at the effects of controlled fires for environmental management reasons.

  5. Ecotoxicological evaluation of in situ bioremediation of soils contaminated by the explosive 2,4,6-trinitrotoluene (TNT).

    PubMed

    Frische, Tobias

    2003-01-01

    To evaluate the environmental relevance of in situ bioremediation of contaminated soils, effective and reliable monitoring approaches are of special importance. The presented study was conducted as part of a research project investigating in situ bioremediation of topsoils contaminated by the explosive 2,4,6-trinitrotoluene (TNT). Changes in soil toxicity within different experimental fields at a former ordnance factory were evaluated using a battery of five bioassays (plant growth, Collembola reproduction, soil respiration, luminescent bacteria acute toxicity and mutagenicity test) in combination to chemical contaminant analysis. Resulting data reveal clear differences in sensitivities between methods with the luminescent bacteria assay performed with soil leachates as most sensitive toxicity indicator. Complete test battery results are presented in so-called soil toxicity profiles to visualise and facilitate the interpretation of data. Both biological and chemical monitoring results indicate a reduction of soil toxicity within 17 months of remediation.

  6. Characterization of soil microarthropod communities in Italian beech forest

    NASA Astrophysics Data System (ADS)

    Conti, F. D.; Menta, C.; Piovesan, G.

    2009-04-01

    The contribution of soil organisms to ecosystem functions such as decomposition, nutrient recycling and the maintenance of physico-chemical properties is well recognised, as is the fact that soil fauna plays an important role in the formation and stabilisation of soil structure. The diversity of soil fauna includes a quarter of described living species, the majority of which are insects and arachnids. Soil fauna plays an essential role in forests and agro-ecosystems by maintaining their functionality and productivity. The aim of this study is to evaluate the biodiversity of soil microarthropods communities in different Italian beech forest. Particular attention is paid to the role of fossorial microarthropods in the maintenance of soil structure and in the organic matter movements. Three beech forests are studied, two located in the North and one in the Centre of Italy. Microarthropods are extracted from litter and soil with a Berlese-Tullgren funnel, identified to order level (class level for myriapods) and counted using a microscope. Relative order abundance and biodiversity are expressed using the Shannon-Weaver diversity index (H) and evenness index (J). Soil biological quality is expressed using the QBS-ar index and Acari/Collembola ratio. The results show a richness of microarthropods: several orders, till 19 different groups, are determined and identified. Acari and collembola are the main represented taxa and, especially in litter samples, pseudoscorpions, different specimens of diplopods (or millipedes) and chilopods (centipedes) are found. Thus the presence in particular of diplopods offers the possibility of studying fossorial microarthropods functions in detail. Furthermore, both in soil and in litter samples, adapted groups are recognized, such as pauropods, symphyla, proturans and diplurans, with specific morphological characteristics that these species suited to soil habitat. Therefore they attest a good level of soil quality and high natural value

  7. Effects of prey quality and predator body size on prey DNA detection success in a centipede predator.

    PubMed

    Eitzinger, B; Unger, E M; Traugott, M; Scheu, S

    2014-08-01

    Predator body size and prey quality are important factors driving prey choice and consumption rates. Both factors might affect prey detection success in PCR-based gut content analysis, potentially resulting in over- or underestimation of feeding rates. Experimental evidence, however, is scarce. We examined how body size and prey quality affect prey DNA detection success in centipede predators. Due to metabolic rates increasing with body size, we hypothesized that prey DNA detection intervals will be shorter in large predators than in smaller ones. Moreover, we hypothesized that prey detection intervals of high-quality prey, defined by low carbon-to-nitrogen ratio will be shorter than in low-quality prey due to faster assimilation. Small, medium and large individuals of centipedes Lithobius spp. (Lithobiidae, Chilopoda) were fed Collembola and allowed to digest prey for up to 168 h post-feeding. To test our second hypothesis, medium-sized lithobiids were fed with either Diptera or Lumbricidae. No significant differences in 50% prey DNA detection success time intervals for a 272-bp prey DNA fragment were found between the predator size groups, indicating that body size does not affect prey DNA detection success. Post-feeding detection intervals were significantly shorter in Lumbricidae and Diptera compared to Collembola prey, apparently supporting the second hypothesis. However, sensitivity of diagnostic PCR differed between prey types, and quantitative PCR revealed that concentration of targeted DNA varied significantly between prey types. This suggests that both DNA concentration and assay sensitivity need to be considered when assessing prey quality effects on prey DNA detection success.

  8. Aquatic Insects of New York Salt Marsh Associated with Mosquito Larval Habitat and their Potential Utility as Bioindicators

    PubMed Central

    Rochlin, Ilia; Dempsey, Mary E.; Iwanejko, Tom; Ninivaggi, Dominick V.

    2011-01-01

    The aquatic insect fauna of salt marshes is poorly characterized, with the possible exception of biting Diptera. Aquatic insects play a vital role in salt marsh ecology, and have great potential importance as biological indicators for assessing marsh health. In addition, they may be impacted by measures to control mosquitoes such as changes to the marsh habitat, altered hydrology, or the application of pesticides. Given these concerns, the goals of this study were to conduct the first taxonomic survey of salt marsh aquatic insects on Long Island, New York, USA and to evaluate their utility for non-target pesticide impacts and environmental biomonitoring. A total of 18 species from 11 families and five orders were collected repeatedly during the five month study period. Diptera was the most diverse order with nine species from four families, followed by Coleoptera with four species from two families, Heteroptera with three species from three families, then Odonata and the hexapod Collembola with one species each. Water boatmen, Trichocorixa verticalis Fieber (Heteroptera: Corixidae) and a shore fly, Ephydra subopaca Loew (Diptera: Ephydridae), were the two most commonly encountered species. An additional six species; Anurida maritima Guérin-Méneville (Collembola: Neanuridae), Mesovelia mulsanti White (Heteroptera: Mesovelidae), Enochrus hamiltoni Horn (Coleoptera: Hydrophilidae), Tropisternus quadristriatus Horn (Coleoptera: Hydrophilidae), Dasyhelea pseudocincta Waugh and Wirth (Diptera: Ceratopogonidae), and Brachydeutera argentata Walker (Diptera: Ephydridae), were found regularly. Together with the less common Erythrodiplax berenice Drury (Odonata: Libellulidae), these nine species were identified as the most suitable candidates for pesticide and environmental impact monitoring due to abundance, position in the food chain, and extended seasonal occurrence. This study represents a first step towards developing an insectbased index of biological integrity for

  9. Effects of prey quality and predator body size on prey DNA detection success in a centipede predator.

    PubMed

    Eitzinger, B; Unger, E M; Traugott, M; Scheu, S

    2014-08-01

    Predator body size and prey quality are important factors driving prey choice and consumption rates. Both factors might affect prey detection success in PCR-based gut content analysis, potentially resulting in over- or underestimation of feeding rates. Experimental evidence, however, is scarce. We examined how body size and prey quality affect prey DNA detection success in centipede predators. Due to metabolic rates increasing with body size, we hypothesized that prey DNA detection intervals will be shorter in large predators than in smaller ones. Moreover, we hypothesized that prey detection intervals of high-quality prey, defined by low carbon-to-nitrogen ratio will be shorter than in low-quality prey due to faster assimilation. Small, medium and large individuals of centipedes Lithobius spp. (Lithobiidae, Chilopoda) were fed Collembola and allowed to digest prey for up to 168 h post-feeding. To test our second hypothesis, medium-sized lithobiids were fed with either Diptera or Lumbricidae. No significant differences in 50% prey DNA detection success time intervals for a 272-bp prey DNA fragment were found between the predator size groups, indicating that body size does not affect prey DNA detection success. Post-feeding detection intervals were significantly shorter in Lumbricidae and Diptera compared to Collembola prey, apparently supporting the second hypothesis. However, sensitivity of diagnostic PCR differed between prey types, and quantitative PCR revealed that concentration of targeted DNA varied significantly between prey types. This suggests that both DNA concentration and assay sensitivity need to be considered when assessing prey quality effects on prey DNA detection success. PMID:24383982

  10. PAH biotransformation in terrestrial invertebrates--a new phase II metabolite in isopods and springtails.

    PubMed

    Stroomberg, Gerard J; Zappey, Herman; Steen, Ruud J C A; van Gestel, Cornelis A M; Ariese, Freek; Velthorst, Nel H; van Straalen, Nico M

    2004-06-01

    Soil-living invertebrates are exposed to high concentrations of contaminants accumulating in dead organic matter, such as polycyclic aromatic hydrocarbons (PAHs). The capacity for PAH biotransformation is not equally developed in all invertebrates. In this paper, we compare three species of invertebrates, Porcellio scaber (Isopoda), Eisenia andrei (Lumbricidae) and Folsomia candida (Collembola), for the metabolites formed upon exposure to pyrene. Metabolic products of pyrene biotransformation in extracts from whole animals or isopod hepatopancreas were compared to those found in fish bile (flounder and plaice). An optimized HPLC method was used with fluorescence detection; excitation/emission spectra were compared to reference samples of 1-hydroxypyrene and enzymatically synthesized conjugates. Enzymatic hydrolysis after fractionation was used to demonstrate that the conjugates originated from 1-hydroxypyrene. All three invertebrates were able to oxidize pyrene to 1-hydroxypyrene, however, isopods and collembolans stood out as more efficient metabolizers compared to earthworms. In contrast to fish, none of the invertebrates produced pyrene-1-glucuronide as a phase II conjugate. Both Collembola and Isopoda produced significant amounts of pyrene-1-glucoside, whereas isopods also produced pyrene-1-sulfate. A third, previously unknown, conjugate was found in both isopods and springtails, and was analysed further using electrospray and atmospheric pressure chemical ionisation mass spectrometry. Based on the obtained mass spectra, a new conjugate is proposed: pyrene-1-O-(6"-O-malonyl)glucoside. The use of glucose-malonate as a conjugant in animal phase II biotransformation has not been described before, but is understandable in the microenvironment of soil-living invertebrates. In the earthworm, three other pyrene metabolites were observed, none of which was shared with the arthropods, although two were conjugates of 1-hydroxypyrene. Our study illustrates the great

  11. Hesionidae Grube, 1850 (Annelida: Polychaeta) from South-Southeastern Brazil, with descriptions of four new species.

    PubMed

    Rizzo, Alexandra E; Salazar-Vallejo, Sergio I

    2014-01-01

    On the basis of extensive intertidal and subtidal samplings in South-Southeastern Brazil, five hesionid species were found; four are newly described and Podarkeopsis levisfuscina Perkins, 1984 is redescribed. Micropodarke pleijeli n. sp. differs from the other species because it lacks eyes, and by having a large number of pharynx papillae and by neurochaetal features; this species differs from M. dubia (Hessle, 1925) by lacking eyes, having a pharynx with more papillae, and by the neurochaetal features. Syllidia amaralae n. sp. resembles more closely S. armata sensu Day, 1967 (non S. armata de Quatrefages, 1865) because both have dorsal and tentacular cirri annulated or moniliform, and 10-15 pharyngeal papillae. However, S. amaralae n. sp. specimens differ from Day's ones because they have a quadrangular prostomium, by the relative size and arrangement of eyes, and by a reduced number of chaetae which are disposed in two bundles; these features are consistent and present in juveniles and mature specimens. Neogyptis nonatoi n. sp. is distinguishable from the others by having four types of neurochaetae; this species resembles N. crypta (Pleijel, 1993), and N. plurisetis (Hilbig, 1992). It differs from N. crypta by having a few acicular notochaetae with blunt tip, a small number of compound neurochaetae, simple capillary neurochaetae distally curved, and much slender notopodial and neuropodial lobes. The new species also differs from N. plurisetis by having four types of neurochaetae instead of having only falciger chaetae; there are less pharyngean papillae and they are far apart to each other, conical and shorter in N. plurisetis when compared to those of N. nonatoi n. sp., which are fringed, longer and closer among them, having some other longer lateral papillae. Oxydromus lanai n. sp. resembles O. obscurus (Verrill, 1873) as recorded by Uebelacker (1984), O. pugettensis by Hilbig (1994), O. guanicus by Hoagland (1919), and O. cf. guanicus by Hartman (1951). The

  12. Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes).

    PubMed

    Golombek, Anja; Tobergte, Sarah; Struck, Torsten H

    2015-05-01

    Gnathostomulida is a taxon of small marine worms, which exclusively inhabit the interstitium. The evolution of Gnathostomulida has been discussed for decades. Originally regarded as primitive animals with affinities to flatworms, the phylogenetic position of Gnathostomulida has been debated. Given the lack of an anus a close relationship to Platyhelminthes has been maintained (i.e., Plathelminthomorpha hypothesis). Alternative hypotheses proposed Gnathostomulida as being close to Gastrotricha due to the presence of a monociliary epidermis (i.e., Monokonta/Neotrichozoa hypothesis) or to Syndermata based on the complicated jaw apparatus (i.e., Gnathifera hypothesis). Molecular analyses using only few genes were inconclusive. Recent phylogenomic studies brought some progress by placing Gnathostomulida as sister to Syndermata, but support for this relationship was low and depended on the analytical strategy. Herein we present the first data of complete or nearly complete mitochondrial genomes for two gnathostomulids (Gnathostomula paradoxa &G. armata), one gastrotrich (Lepidodermella squamata) and one polyclad flatworm (Stylochoplana maculata) to address the uncertain phylogenetic affinity of Gnathostomulida. Our analyses found Gnathostomulida as sister to Syndermata (Gnathifera hypothesis). Thorough sensitivity analyses addressing taxon instability, branch length heterogeneity (also known as long branch attraction) and base composition heterogeneity showed that the position of Gnathostomulida is consistent across the different analyses and, hence, independent of potential misleading biases. Moreover, by ameliorating these different biases nodal support values could be increased to maximum values. Thus, our data support the hypothesis that the different jaw apparatuses of Syndermata and Gnathostomulida are indeed homologous structures as proposed by the Gnathifera hypothesis. PMID:25796325

  13. Assessing a quick monitoring method using rocky intertidal communities as a bioindicator: a multivariate approach in Algeciras Bay.

    PubMed

    Guerra-García, J M; Maestre, M J; González, A R; García-Gómez, J C

    2006-05-01

    A multivariate approach was used to test the value of intertidal communities as a bioindicator of environmental conditions at Algeciras Bay, southern Spain. The study area is located in the Strait of Gibraltar and it is subjected to a variety of anthropic impacts. Eight localities (5 inside and 3 outside the bay) were selected, and four transects were undertaken in each locality to characterise the fauna and flora. The spatial distribution of the intertidal species reflected the physico-chemical conditions of Algeciras Bay. The stations located outside the bay, characterised by high hydrodynamism and dissolved oxygen and low sedimentation and turbidity, had a higher diversity and species richness than the inner stations. According to the BIO-ENV procedure and CCA, water turbidity was the factor which best correlated with the intertidal assemblages. SIMPER showed that the molluscs Chtamalus stellatus, Mytilus cf edulis, Littorina neritoides and Balanus perforatus, and the algae Gelidium pusillum, Corallina elongata, Asparagopsis armata, Colpomenia sinuosa and Fucus spiralis were the species that most contributed to the dissimilarity between internal and external sites. The present study, based on the spatial distribution of intertidal taxa, yielded similar results to those previously obtained in the area with costly physico-chemical analysis based on complex matrices of subtidal epifaunal communities. Consequently, the intertidal sampling method proposed in this study is presented here as a quick, effective alternative strategy, and can be useful in environmental monitoring programs, since these communities are easily accessible and amenable to sample, and the sessile nature of the majority of the species makes future, long-term monitoring relatively simple. PMID:16779601

  14. Diet and activity pattern of howler monkeys (Alouatta palliata) in Los Tuxtlas, Mexico: effects of habitat fragmentation and implications for conservation.

    PubMed

    Cristóbal-Azkarate, Jurgi; Arroyo-Rodríguez, Víctor

    2007-09-01

    Accelerated deforestation is causing the rapid loss and fragmentation of primary habitat for primates. Although the genus Alouatta is one of the most studied primate taxa under these circumstances, some results are contradictory and responses of howlers to habitat fragmentation are not yet clear. In this paper, we conduct a cross-study of the available researches on mantled howlers (Alouatta palliata) in forest fragments in Los Tuxtlas, Mexico, to (1) describe the diet and activity pattern of howlers; (2) analyze the similarity in the diet across studies; and (3) relate both fragment size and howler population density with different characteristics of their diet, home range size, and activity pattern. Howlers consumed 181 plant species belonging to 54 families. Ficus was the most important taxa in the howlers' diet, followed by primary species such as Pterocarpus rohrii, Nectandra ambigens, Poulsenia armata, and Brosimum alicastrum. Secondary and non-secondary light-demanding plant species, which are representatives of disturbed habitat, contributed with a high percentage of their feeding time. Only 23% of the species consumed were the same across all the studies, suggesting that howlers adapt their diet to the food availability of their respective habitats. Population density is the best predictor of howlers' ecological and behavioral changes in response to forest fragmentation, probably owing to its relationship with food availability. Howlers respond to the increase in population densities by increasing the (1) diversity of food species in the diet; (2) consumption of non-tree growth forms; and (3) consumption of new plant items. Home range size is also predicted by population density, but fragment size is a better predictor, probably owing to the fact that howler groups can overlap their home ranges. Our results emphasize the importance of conserving the larger fragments and increasing the size of small and medium-sized ones.

  15. Ecological risks of Aluminum production and contaminated area by red mud in Western Hungary (Ajka)

    NASA Astrophysics Data System (ADS)

    Rasulov, Oqil; Horváth, Adrienn; Bidló, András; Winkler, Dániel

    2016-04-01

    In October 2010, Hungary experienced one of the most severe environmental disasters: the dam wall of a red mud depository of an alumina plant in collapsed and more than 1 million m3 of toxic sludge flooded the surrounding area. Red mud is a strongly alkaline (pH of 9-12.5) by-product due to the high NaOH content. Apart from residual minerals and oxides, its components also include heavy metals such as Cu, Zn, Cd, Hg, Pb, Ni, Co. As it has already been assessed, red mud had considerable effect on soil properties and thus on soil biodiversity. The aim of our study was to determine the aftereffects of red mud pollution on the soil mesofauna (Collembola). Study plots were selected in the area affected by the toxic flood, in agricultural and grassland habitats, at different distances (0.3 to 12.5 km) from the contamination source. Control plots of each habitat types were selected for comparative analyses. Soil samples were taken during the summer of 2015, five years after the red mud disaster. From each of the selected plots, 5 soil cores of 100 cm3 volume (3.6 cm in diameter and 10 cm in depth) were sampled from which springtails were extracted within 14 days using a modified Tullgren apparatus. Simultaneously with the Collembola sampling, we collected soil samples on each plots in order to determine soil properties (pH, CaCO3, particle size distribution) and the degree of heavy metal pollution. 25 heavy metals were measured (including total Hg) following the method of total (cc. HNO3 + H2O2-soluble) and bioavailable (NH4-acetate + EDTA-soluble) element content using ICP-OES and AMA 254. The studied habitats presented neutral to moderately alkaline soils (pH 7.2-8.1). Total metal content was higher in the plots formerly affected by red mud flood. The Hg concentration ranged from 0.023 to 1.167 mg.kg-1, exceeding the threshold concentration (0.5 mg.kg-1) defined by Hungarian legislation for toxic trace metals in soil. The collected 1442 Collembola specimens belong to 32

  16. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan.

    PubMed

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops (p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  17. Effects of habitat age and plant species on predatory mites (Acari, Mesostigmata) in grassy arable fallows in Eastern Austria

    PubMed Central

    Wissuwa, Janet; Salamon, Jörg-Alfred; Frank, Thomas

    2012-01-01

    Density, diversity and assemblage structure of Mesostigmata (cohorts Gamasina and Uropodina) were investigated in nine grassy arable fallows according to a factorial design with age class (2–3, 6–8, 12–15 years) and plant species (legume: Medicago sativa, herb: Taraxacum officinale, grass: Bromus sterilis) as factors. The response of Mesostigmata to habitat age and plant species was explored because this group belongs to the dominant acarine predators playing a crucial role in soil food webs and being important as biological control agents. To our knowledge, this combination of factors has never been studied before for Mesostigmata. A further rarely applied aspect of the present study is the micro-scale approach investigating the Mesostigmata assemblage of the soil associated with single plants. Four plots were randomly chosen at each fallow in May 2008. At each plot plant roots and the adjacent soil of five randomly selected plant individuals per plant species were dug out with steel cylinders for heat extraction of soil fauna and measurement of environmental parameters. In total, 83 mite taxa were identified, with 50 taxa being new to Austria. GLM analysis revealed a significant effect of plant species on mite density, with significantly more mites in B. sterilis than in T. officinale samples, and M. sativa samples being intermediate. This was in contrast to the assumption that the mite density is highest in M. sativa samples due to the propagation of plant quality effects to higher trophic levels. These results were probably caused by a higher amount of fine roots in grass samples leading to high densities of Collembola, which are preferred prey of predatory mites. Mite density did not significantly differ between the three age classes. A canonical analysis of principal coordinates (CAP) showed that the mite assemblage exhibited a weak yet significant separation between plant species, and a highly significant separation between age classes. Accordingly

  18. The complete mitochondrial sequence of the"living fossil" Tricholepidion gertschi: structure, phylogenetic implications, and the description of a novel A/T asymmetrical bias

    SciTech Connect

    Nardi, F.; Frati, F.; Carapelli, A.; Dallai, R.; Boore, J.

    2002-06-23

    Traditionally, the 'Apterygota' has been thought to consist of five orders of wingless hexapods (Protura, Collembola, Diplura, Microcoryphia and Zygentoma) believed to be collectively basal to insects (i.e., the Pterygota). However, some studies have questioned this affinity with insects (Dallai, Abele, Spears, Nardi). Further, within these groups are hotly debated issues, including the monophyly of Entognata (Koch, 1997; Kukalova Peck, 1987), the monophyly of Diplura (Bilinski, 1993; Stys and Bilinski, 1990), the affinity between Collembola and Protura (Dallai, 1994; Kristensen, 1981) and the position of Lepidotrichidae (below). In fact, these relationships constitute one of the most debated issues in hexapod phylogeny. The family Lepidotrichidae was first described by (Silvestri, 1912) (1912: 'Lepidothricinae') from a Baltic Amber fossil (Lepidothrix pilifera Menge). The only living representative of this family is Tricholepidion gertschi Wygodzinski. Since this species was first described (Wygodzinsky, 1961) its phylogenetic position has been difficult to establish, due to an 'array of unique characters' that are difficult to interpret in a phylogenetic framework. Tricholepidion (and therefore the whole family Lepidotrichidae) has been considered either as belonging to the order Zygentoma (Kristensen, 1997; Wygodzinsky, 1961), or basal to the rest of the Zygentoma plus the Pterygota (Beutel, 2001; Bitsch and Bitsch, 2000; Staniczek, 2000), although the significance of some of the morphological characters on which these analyses are based have been questioned (Dallai et al., 2001; Kristensen, 1997). If the latter hypothesis proved to be true, the family Lepidotrichidae, would better deserve the ordinal rank. Since studies based on morphological characters have failed to give a satisfactory answer, a broad scale molecular study is under way ((Nardi et al., 2001), Frati et al, submitted, il Gomphiocephalus) in order to use mitochondrial genome sequences to study

  19. [Characteristics of floor litter and soil arthropod community in different types ot subtropical forest in Ailao Mountain of Yunnan, Southwest China].

    PubMed

    Yang, Zhao; Yang, Xiao-Dong

    2011-11-01

    By using line transect method, an investigation was conducted on the floor litter and soil arthropod community in a mid mountain wet evergreen broad-leaved forest, a mossy dwarf forest, and a Populus bonatii forest in Ailao Mountain of Yunnan in April (dry and hot season), June (rainy season), and December (dry and cold season), 2005. In both dry and rainy seasons, the existing floor litter mass, C storage, and C/N ratio in the three forests all increased in the order of mossy dwarf forest > P. bonatii forest > evergreen broad-leaved forest, but the N storage had less difference. In the floor litter layer of the forests, Acari and Collembola were the dominant groups of soil arthropod community, while Diptera larvae, Coleoptera, ants, and Homoptera were the common groups. The Sorenson coefficients of soil arthropod community in the three forests were extremely great. No significant differences were observed in the soil arthropod density (ind x m(-2)) in the floor litter layer among the three forests, but the relative density (ind x g(-1)) of soil arthropods was higher in the evergreen broad-leaved forest and P. bonatii forest than in the mossy dwarf forest. In the three forests, the density of soil arthropods was significantly higher in dry season than in rainy season, but the Shannon diversity index had less difference. There were significant positive correlations between the existing floor litter mass and the individual density (ind x m(-2)) and dominant groups of soil arthropod communities in dry and hot season (April), but negative correlations between the existing floor litter mass and the relative density (ind x g(-1)) of soil arthropod communities and Acari in dry and cold season (December). The individual densities of Collembola and Coleoptera also had positive correlations with the N storage of the existing floor litter mass in the three forests. It was considered that the floor litter and the development of soil arthropod community in the litter layer of

  20. [Effect of pine plantations on soil arthropods in a high Andean forest].

    PubMed

    León-Gamboa, Alba Lucía; Ramos, Carolina; García, Mary Ruth

    2010-09-01

    One of the most common problems in the Colombian mountains has been the replacement of native vegetation by pine plantations. Soil arthropods are a fundamental component of forest ecosystem, since they participate in the organic matter fragmentation, previous to decomposition. This role is more valuable in high altitude environments, where low temperatures limit the dynamics of biological processes, where the effects of pine plantations on soil arthropods are still not well-known. In a remnant of high-andean forest (Neusa - Colombia) and a pine plantation of about 50 years-old, it was evaluated the composition, richness and abundance of arthropods at surface (S), organic horizon (O) and mineral horizon (A) of soil, to establish the differences associated to the soil use transformation. It was used "Pitfall" sampling to register the movement of the epigeous fauna, and extraction by funnel Berlese for determining the fauna density from O and A horizons. The Shannon and Simpson indexes estimated the diversity at different places and horizons, and the trophic structure of the community was evaluated. Overall, there were collected 38 306 individuals from forest and 17 386 individuals from pine plantation, mainly distributed in Collembola (42.4%), Acari (27%), Diptera (17.6%) and Coleoptera (4.6%). The most important differences were given in the surface, where the mobilization in forest (86 individuals/day) almost triplicates the one in pine plantation (33 individuals/day). The differences in composition were given in Collembola, Araneae, Hemiptera, Homoptera and Hymenoptera. The dynamics of richness and abundance along the year had significant high values in the native forest than in the pine plantation. The general trophic structure was dominated by saprophagous (75%), followed by predators (14%) and phytophagous (9%), but in two layers of the pine plantation soil (S and O) this structural pattern was not given. Based on the results, it was concluded that pine

  1. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan

    NASA Astrophysics Data System (ADS)

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops ( p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  2. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan.

    PubMed

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops (p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  3. Evaluation of different agronomic managements on rice mesofauna: a case study in Piedmont (North Italy)

    NASA Astrophysics Data System (ADS)

    Landi, Silvia; d'Errico, Giada; Gagnarli, Elena; Barzanti, Gian Paolo; Cito, Annarita; Papini, Rossella; Simoni, Sauro; Roversi, Pio Federico

    2014-05-01

    parasites groups. Dry land was more suitable to development of bacterial feeders and predators. On the whole, MI values ranged between 2 and 3, registered in organic farming and conventional management, respectively. The Acari represented the main group of microarthropods (about 43%), then Diptera (33%), Collembola (19%) and the others. The only euedaphic groups are Acari and Collembola. The BSQar value was 48 (sBC II) in IPM rice field, 71 in organic farming (sBC II/III), 95 in conventional management (sBC III). On all situation tested, the analysis of soil quality, by the study of mesofauna, reflects low differentiation in the arthropod communities' structure. In general, the results relative to the soil mesofauna biodiversity indicated a quite high level of disturbance and a low level of biodiversity. Future studies on this subject could help preserve, or even enhance, the biodiversity and soil quality.

  4. Development of Metrics to Assess Effectiveness of Stream Restoration in Second-Growth Forests

    NASA Astrophysics Data System (ADS)

    Stockwell, E.; Johnson, A. C.; Edwards, R.

    2010-12-01

    This project was designed to develop and test metrics to assess whether stream restoration work in second growth riparian areas produces measurable changes in ecosystem function. Proposed metrics evaluate anadramadous fish and the trophic basis for their production. These metrics consist of: measuring benthic chlorophyll a and photosynthetically active radiation (PAR) to detect changes in primary production, computing invertebrate litterfall as allochthonous food inputs into the streams, evaluating transient storage, counting the number and depth of pools, counting the number of pieces of large wood, and determining the substrate size of the stream to detect changes in channel retentiveness and habitat availability. Data were collected prior to restoration treatment. Restoration work is expected to increase growth and survival of anadramous fish by increasing availability of high quality habitat and food. Although there is large variation in the data collected, preliminary results show a positive correlation between the number of invertebrates, especially of the subclass collembola, collected in the litterfall and the percent of PAR reaching the stream. There is also a correlation between an increase in the percent of PAR reaching the stream and an increase in the amount of alder in the riparian area. This suggests that riparian areas with a majority of alder trees could provide more invertebrate food for fish in the streams.

  5. The Influence of Habitat Manipulations on Beneficial Ground-Dwelling Arthropods in a Southeast US Organic Cropping System.

    PubMed

    Fox, Aaron F; Orr, David B; Cardoza, Yasmin J

    2015-02-01

    Habitat manipulations, intentional provisioning of natural vegetation along crop edges, have been shown to enhance beneficial epigaeic invertebrate activity in many agricultural settings, but little research has been conducted on this practice in the southeast United States. We conducted a field-scale study to determine if habitat manipulations along the field edges of an organic crop rotation increase the activity-density of beneficial ground-dwelling invertebrates. Pitfall traps were used to collect micro and macro ground-dwelling organisms in nine organic crop fields (three each of maize, soybeans, and hay; 2.5-4.0 ha each) surrounded by four experimental habitat manipulations (planted native grass and prairie flowers, planted prairie flowers only, fallow vegetation, or mowed vegetation) during 2009 and 2010 in eastern North Carolina. Beneficial macro and micro invertebrates collected in these pitfall traps consisted primarily of Carabidae, Araneae, Collembola, and mite species. Results show that habitat manipulations had little effect on the activity-density of the dominant epigaeic invertebrates in our study system. Our results suggest that the activity-density of these organisms were instead determined by a combination of in-field characteristics, such as crop type, weed management practices, and within-field resources, along with the diversity of crop type in neighboring fields and the availability of other resources in the area. PMID:26308813

  6. Collembolan assemblages in Lesvos, Greece. Effects of differences in vegetation and precipitation

    NASA Astrophysics Data System (ADS)

    Detsis, Vassilis; Diamantopoulos, John; Kosmas, Constantinos

    2000-03-01

    Epigeic Collembola were studied in a number of sites in Lesvos island in the north-eastern Aegean, Greece. The aim of the study was to detect differences, either at the species level or in the structure of the assemblage that can be attributed to environmental factors. Sites with two vegetation types, deciduous oak woodland and phrygana, under three different precipitation regimes were studied. Cluster analysis was applied and characteristic species were identified for the clusters produced. Geographic proximity was found to be the major grouping factor. Characteristic species were also identified for the different vegetation types revealing that species have individualistic responses and do not necessarily follow the classification obtained for the whole assemblages by cluster analysis. The relative abundance patterns observed showed two distinct features: a great number of extreme subordinate species in the oak sites and a change in dominance patterns also in the same sites with more abundant species becoming more strongly dominant at more humid sites. Assemblages from phrygana sites have a much more even species-abundance distribution. Differences were observed at the species level that can be attributed to environmental factors, but the geographic distance between sites should be taken into account in order to arrive at safe conclusions. At the assemblage level, the relative abundance patterns observed in the more humid oak sites were distinct from the patterns observed in sites less favourable in terms of vegetation cover and precipitation.

  7. Can cyanobacterial biomass applied to soil affect survival and reproduction of springtail Folsomia candida?

    PubMed

    Lána, Jan; Hofman, Jakub; Bláha, Luděk

    2011-05-01

    Biomass of cyanobacterial water blooms including cyanobacterial toxins may enter soils, for example, when harvested water bloom is directly applied as an organic fertilizer or when water with massive cyanobacterial biomass is used for irrigation. In spite of this, no information is available about the potential effects on soil arthropods. The objective of this pilot study was to evaluate the effects of water bloom biomass sampled in five different fresh water lakes on the soil dwelling arthropod, springtail Folsomia candida (Collembola). These samples contained different dominant species of cyanobacteria and varied significantly in microcystin content (21-3662 μg/g dw biomass). No adverse effects on survival or reproduction were observed for any tested sample at concentration up to 4 g dw biomass/kg dw soil. Despite the known hazardous properties of water blooms in aquatic ecosystems, our pilot results suggest that cyanobacterial biomass might have no significant impact on arthropods in soil. It remains a question, if this is due to low bioavailability of cyanobacterial toxins in soil. PMID:21176962

  8. Effects of mercury on reproduction, avoidance, and heat shock protein gene expression of the soil springtail Folsomia candida.

    PubMed

    Liu, Yu-Rong; Zheng, Yuan-Ming; Zhang, Li-Mei; Luan, Yun-Xia; He, Ji-Zheng

    2010-03-01

    Based on the Cambisols of Beijing (used as agricultural soils), toxicity tests were conducted to investigate the effects of mercury (Hg) on reproduction and avoidance of Folsomia candida (Hexapoda: Collembola), as well as the transcriptional responses of the hsp70 gene, under different Hg concentrations and at different exposure times. Results showed that the hsp70 gene of the springtail was the most sensitive parameter to soil Hg stress, with a half-maximal effective concentration (EC50) of 0.42 mg/kg. The EC50 values based on reproduction and avoidance tests were 9.29 and 3.88 mg/kg, respectively. The expression level of the hsp70 gene was significantly up-regulated when soil Hg concentration was over 0.25 mg/kg (lowest-observed-effect concentration [LOEC]). In addition, responses of this gene expression were strongly induced after 48 h exposure under 1 mg/kg soil Hg, which probably was due to the fast and sensitive response of the gene transcription to Hg stress. Thus, the results suggested that the responses of the hsp70 gene and individual-level effects (reproduction and avoidance) could be integrated to provide helpful information for environmental monitoring and assessment of contaminated soils. PMID:20821491

  9. Biogeography of circum-Antarctic springtails.

    PubMed

    McGaughran, Angela; Stevens, Mark I; Holland, Barbara R

    2010-10-01

    We examine the effects of isolation over both ancient and contemporary timescales on evolutionary diversification and speciation patterns of springtail species in circum-Antarctica, with special focus on members of the genus Cryptopygus (Collembola, Isotomidae). We employ phylogenetic analysis of mitochondrial DNA (cox1), and ribosomal DNA (18S and 28S) genes in the programmes MrBayes and RAxML. Our aims are twofold: (1) we evaluate existing taxonomy in light of previous work which found dubious taxonomic classification in several taxa based on cox1 analysis; (2) we evaluate the biogeographic origin of our chosen suite of springtail species based on dispersal/vicariance scenarios, the magnitude of genetic divergence among lineages and the age and accessibility of potential habitat. The dubious taxonomic characterisation of Cryptopygus species highlighted previously is confirmed by our multi-gene phylogenetic analyses. Specifically, according to the current taxonomy, Cryptopygus antarcticus subspecies are not completely monophyletic and neither are Cryptopygus species in general. We show that distribution patterns among species/lineages are both dispersal- and vicariance-driven. Episodes of colonisation appear to have occurred frequently, the routes of which may have followed currents in the Southern Ocean. In several cases, the estimated divergence dates among species correspond well with the timing of terrestrial habitat availability. We conclude that these isotomid springtails have a varied and diverse evolutionary history in the circum-Antarctic that consists of both ancient and recent elements and is reflected in a dynamic contemporary fauna. PMID:20558307

  10. Using a toxicokinetics approach to explain the effect of soil pH on cadmium bioavailability to Folsomia candida.

    PubMed

    Ardestani, Masoud M; van Gestel, Cornelis A M

    2013-09-01

    The aim of this study was to improve our understanding of metal bioavailability in soil by linking the biotic ligand approach with toxicokinetics modelling. We determined cadmium bioaccumulation kinetics in Folsomia candida (Collembola) as a function of soil pH. Animals were exposed for 21 days to LUFA 2.2 soil at 5 or 20 μg Cd g(-1) dry soil followed by 21 days elimination in clean soil. Internal cadmium concentrations were modelled using a first-order one-compartment model, relating uptake rate constants (k1) to total soil, water or 0.01 M CaCl2 extractable and porewater concentrations. Based on total soil concentrations, k1 was independent of soil pH while it strongly increased with increasing pH based on porewater concentrations explaining the reduced competition of H(+) ions making cadmium more bioavailable in pore water at high pH. This shows that the principles of biotic ligand modelling are applicable to predict cadmium accumulation kinetics in soil-living invertebrates. PMID:23747820

  11. The influence of calcium and pH on the uptake and toxicity of copper in Folsomia candida exposed to simplified soil solutions.

    PubMed

    Ardestani, Masoud M; Verweij, Rudo A; van Gestel, Cornelis A M

    2013-10-15

    The aim of the present study was to investigate the influence of Ca and pH on the uptake and effects of Cu in Folsomia candida (Collembola). Assuming that soil pore water is the main route of exposure, F. candida were exposed for seven days to Cu in simplified soil solutions at different Ca concentrations and different pH levels. A hormetic-type effect was seen for the effect of Cu on F. candida survival. Toxicity of Cu was slightly decreased and Cu uptake increased at the highest Ca concentrations. Cu toxicity and uptake were not significantly affected by pH. Conditional binding constants for Cu(2+), Ca(2+) and H(+), calculated with a Langmuir isotherm, were used to relate Cu toxicity to the fraction of occupied binding sites (BL). The estimated 50% effect level (fCu-BL50) was 0.14 when all data were combined. To verify the Langmuir parameters, binding constants calculated based on internal Cu concentrations were used to estimate predicted effects and compared with the measured values. A good correlation between predicted and measured survival indicated that the principles of a biotic ligand model may be applicable to explain Cu toxicity to F. candida in simplified soil solutions. PMID:23973473

  12. The springtail cuticle as a blueprint for omniphobic surfaces.

    PubMed

    Hensel, René; Neinhuis, Christoph; Werner, Carsten

    2016-01-21

    Omniphobic surfaces found in nature have great potential for enabling novel and emerging products and technologies to facilitate the daily life of human societies. One example is the water and even oil-repellent cuticle of springtails (Collembola). The wingless arthropods evolved a highly textured, hierarchically arranged surface pattern that affords mechanical robustness and wetting resistance even at elevated hydrostatic pressures. Springtail cuticle-derived surfaces therefore promise to overcome limitations of lotus-inspired surfaces (low durability, insufficient repellence of low surface tension liquids). In this review, we report on the liquid-repellent natural surfaces of arthropods living in aqueous or temporarily flooded habitats including water-walking insects or water spiders. In particular, we focus on springtails presenting an overview on the cuticular morphology and chemistry and their biological relevance. Based on the obtained liquid repellence of a variety of liquids with remarkable efficiency, the review provides general design criteria for robust omniphobic surfaces. In particular, the resistance against complete wetting and the mechanical stability strongly both depend on the topographical features of the nano- and micropatterned surface. The current understanding of the underlying principles and approaches to their technological implementation are summarized and discussed. PMID:26239626

  13. Cryoprotective dehydration is widespread in Arctic springtails.

    PubMed

    Sørensen, Jesper Givskov; Holmstrup, Martin

    2011-08-01

    Cryoprotective dehydration (CPD) is a cold tolerance strategy employed by small invertebrates that readily lose water by evaporation when subjected to sub-zero temperatures in the presence of ice. Until now, relatively few species have been investigated using methods by which CPD can be shown. In the present study we investigated the cold tolerance strategy of seven soil arthropod species from the high Arctic Spitzbergen, and compared water content and water loss, body fluid melting points (MP) and survival under cold and desiccating conditions. We tested the hypothesis that CPD is a commonly occurring cold hardiness strategy among soil arthropods. We found that four springtail species (Hypogastrura viatica, Folsomia quadrioculata, Oligaphorura groenlandica and Megaphorura arctica; Collembola) went through severe dehydration and MP equilibration with ambient temperature, and thus overwinter by employing CPD, whereas a beetle (Atheta graminicola) and one of the springtails (Isotoma anglicana) were typical freeze avoiding species over-wintering by supercooling. Desiccation tolerance of the red velvet mite (Neomolgus littoralis) was also investigated; very low water loss rates of this species indicated that it does not survive winter by use of CPD. All in all, the results of the present study confirm the hypothesis that CPD is an effective over-wintering strategy which is widespread within soil arthropods. PMID:21396373

  14. Transcriptional profiling of the soil invertebrate Folsomia candida in pentachlorophenol-contaminated soil.

    PubMed

    Qiao, Min; Wang, Guang-Peng; Zhang, Cai; Roelofs, Dick; van Straalen, Nico M; Zhu, Yong-Guan

    2015-06-01

    Pentachlorophenol (PCP), a widely used pesticide, is considered to be an endocrine disruptor. The molecular effects of chemicals with endocrine-disrupting potential on soil invertebrates are largely unknown. In the present study, the authors explored the transcriptional expression changes of collembola (Folsomia candida) in response to PCP contamination. A total of 92 genes were significantly differentially expressed at all exposure times, and the majority of them were found to be downregulated. In addition to the transcripts encoding cytochrome P450s and transferase enzymes, chitin-binding protein was also identified in the list of common differentially expressed genes. Analyses of gene ontology annotation and enrichment revealed that cell cycle-related transcripts were significantly induced by PCP, indicating that PCP can stimulate cell proliferation in springtail, as has been reported in human breast cancer cells. Enrichment of functional terms related to steroid receptors was observed, particularly in 20 significant differentially expressed genes involved in chitin metabolism in response to PCP exposure. Combined with confirmation by quantitative polymerase chain reaction, the results indicate that the adverse effects on reproduction of springtails after exposure to PCP can be attributed to a chemical-induced delay in the molting cycle and that molting-associated genes may serve as possible biomarkers for assessing toxicological effects. PMID:25703271

  15. Maximized PUFA measurements improve insight in changes in fatty acid composition in response to temperature.

    PubMed

    van Dooremalen, Coby; Pel, Roel; Ellers, Jacintha

    2009-10-01

    A general mechanism underlying the response of ectotherms to environmental changes often involves changes in fatty acid composition. Theory predicts that a decrease in temperature causes an increase in unsaturation of fatty acids, with an important role for long-chain poly-unsaturated fatty acids (PUFAs). However, PUFAs are particularly unstable and susceptible to peroxidation, hence subtle differences in fatty acid composition can be challenging to detect. We determined the fatty acid composition in springtail (Collembola) in response to two temperatures (5 degrees C and 25 degrees C). First, we tested different sample preparation methods to maximize PUFAs. Treatments consisted of different solvents for primary lipid extraction, mixing with antioxidant, flushing with inert gas, and using different temperature exposures during saponification. Especially slow saponification at low temperature (90 min at 70 degrees C) in combination with replacement of headspace air with nitrogen during saponification and methylation maximized PUFAs for GC analysis. Applying these methods to measure thermal responses in fatty acid composition, the data showed that the (maximized) proportion of C(20) PUFAs increased at low acclimation temperature. However, C(18) PUFAs increased at high acclimation temperature, which is contrary to expectations. Our study illustrates that PUFA levels in lipids may often be underestimated and this may hamper a correct interpretation of differential responses of fatty acid composition. PMID:19557745

  16. New light shed on the oldest insect.

    PubMed

    Engel, Michael S; Grimaldi, David A

    2004-02-12

    Insects are the most diverse lineage of all life in numbers of species, and ecologically they dominate terrestrial ecosystems. However, how and when this immense radiation of animals originated is unclear. Only a few fossils provide insight into the earliest stages of insect evolution, and among them are specimens in chert from Rhynie, Scotland's Old Red Sandstone (Pragian; about 396-407 million years ago), which is only slightly younger than formations harbouring the earliest terrestrial faunas. The most well-known animal from Rhynie is the springtail Rhyniella praecursor (Entognatha; Collembola), long considered to be the oldest hexapod. For true insects (Ectognatha), the oldest records are two apparent wingless insects from later in the Devonian period of North America. Here we show, however, that a fragmentary fossil from Rhynie, Rhyniognatha hirsti, is not only the earliest true insect but may be relatively derived within basal Ectognatha. In fact, Rhyniognatha has derived characters shared with winged insects, suggesting that the origin of wings may have been earlier than previously believed. Regardless, Rhyniognatha indicates that insects originated in the Silurian period and were members of some of the earliest terrestrial faunas.

  17. The Influence of Habitat Manipulations on Beneficial Ground-Dwelling Arthropods in a Southeast US Organic Cropping System.

    PubMed

    Fox, Aaron F; Orr, David B; Cardoza, Yasmin J

    2015-02-01

    Habitat manipulations, intentional provisioning of natural vegetation along crop edges, have been shown to enhance beneficial epigaeic invertebrate activity in many agricultural settings, but little research has been conducted on this practice in the southeast United States. We conducted a field-scale study to determine if habitat manipulations along the field edges of an organic crop rotation increase the activity-density of beneficial ground-dwelling invertebrates. Pitfall traps were used to collect micro and macro ground-dwelling organisms in nine organic crop fields (three each of maize, soybeans, and hay; 2.5-4.0 ha each) surrounded by four experimental habitat manipulations (planted native grass and prairie flowers, planted prairie flowers only, fallow vegetation, or mowed vegetation) during 2009 and 2010 in eastern North Carolina. Beneficial macro and micro invertebrates collected in these pitfall traps consisted primarily of Carabidae, Araneae, Collembola, and mite species. Results show that habitat manipulations had little effect on the activity-density of the dominant epigaeic invertebrates in our study system. Our results suggest that the activity-density of these organisms were instead determined by a combination of in-field characteristics, such as crop type, weed management practices, and within-field resources, along with the diversity of crop type in neighboring fields and the availability of other resources in the area.

  18. Maximized PUFA measurements improve insight in changes in fatty acid composition in response to temperature.

    PubMed

    van Dooremalen, Coby; Pel, Roel; Ellers, Jacintha

    2009-10-01

    A general mechanism underlying the response of ectotherms to environmental changes often involves changes in fatty acid composition. Theory predicts that a decrease in temperature causes an increase in unsaturation of fatty acids, with an important role for long-chain poly-unsaturated fatty acids (PUFAs). However, PUFAs are particularly unstable and susceptible to peroxidation, hence subtle differences in fatty acid composition can be challenging to detect. We determined the fatty acid composition in springtail (Collembola) in response to two temperatures (5 degrees C and 25 degrees C). First, we tested different sample preparation methods to maximize PUFAs. Treatments consisted of different solvents for primary lipid extraction, mixing with antioxidant, flushing with inert gas, and using different temperature exposures during saponification. Especially slow saponification at low temperature (90 min at 70 degrees C) in combination with replacement of headspace air with nitrogen during saponification and methylation maximized PUFAs for GC analysis. Applying these methods to measure thermal responses in fatty acid composition, the data showed that the (maximized) proportion of C(20) PUFAs increased at low acclimation temperature. However, C(18) PUFAs increased at high acclimation temperature, which is contrary to expectations. Our study illustrates that PUFA levels in lipids may often be underestimated and this may hamper a correct interpretation of differential responses of fatty acid composition.

  19. The effects of PAH contamination on soil invertebrate communities

    SciTech Connect

    Snow-Ashbrook, J.L.; Erstfeld, K.M.

    1995-12-31

    Soils were collected from an abandoned industrial site to study the effects of historic polycyclic aromatic hydrocarbons (PAHs) on soil invertebrate communities. Nematode abundance and diversity, microarthropod abundance (orders Collembola and Acarina) and earthworm growth were evaluated. Physical and chemical characteristics of soils may affect both invertebrate community structure and the mobility/bioavailability of pollutants in soils. Soil characteristics were measured and included with PAH data in multiple regression analyses to identify factors which influences the responses observed in the soil invertebrate community. Positive associations were observed between eight invertebrate community endpoints and soil PAH content. For all of these endpoints but one, a higher degree of variability was explained when both PAH content and soil characteristics were considered. It is theorized that the positive response to soil PAH content may be the result of an increased abundance of PAH-degrading soil microbes. Increased microbial abundance could stimulate invertebrate communities by providing a direct food source or increasing the abundance of microbially-produced nutrients. These results suggest that both PAH content and soil characteristics significantly influenced the soil invertebrate community. It is not clear whether these factors influenced the invertebrate community independently, or whether differences in soil characteristics affected the community response by influencing the mobility or bioavailability of PAHs.

  20. Effects of the benzoxazolinone BOA, selected degradation products and structure related pesticides on soil organisms.

    PubMed

    Coja, Tamara; Idinger, Jacqueline; Blümel, Sylvia

    2006-02-01

    The benzoxazolinone BOA and the degradation products APO, AAPO and HPAA, as well as four structure related compounds to BOA, were tested for their lethal and sublethal effects on the collembola Folsomia candida and on the carabid beetle Poecilus cupreus applying validated standard laboratory methods. According to the results of the recommended risk assessment for plant protection products (EPPO, 2003), BOA and its structure related compounds carbendazim, benoxacor and benazolin (and additionally the formulated product Cresopur) were classified as low risk compounds for both test organisms. Phosalone was of high risk for F. candida. APO, AAPO and HPAA were of medium risk for F. candida, but were rated as low risk compounds for P. cupreus at the tested rates of about 2 mg/kg substrate. However, as the BOA degradation products have been found to occur at field rates below 0.2 mg/kg substrate or are often even not detectable, it is assumed that their potential risk for both non-target soil organisms in the field will be acceptable.

  1. Stanislaw Smreczynskis legacy and the Department of Zoology of the Jagiellonian University of Krakow (Poland).

    PubMed

    Jaglarz, Mariusz K

    2008-01-01

    This article covers the origin and development of scientific interest in insect and amphibian developmental biology at the Department of Systematic Zoology and Zoogeography of the Jagiellonian University. The greater part of this historical account is devoted to Professor Stanislaw Smreczynski (1899-1975), the founding father of the Department, and comments on his biography and research achievements in the field of animal experimental embryology. A particular emphasis is on Smreczynski's contributions to contemporary understanding of early embryonic development of amphibians and insects as well as his expertise in Pleistocene and extant weevils (Curculionidae). A concise survey of developmental phenomena studied by some of Smreczynski's co-workers and followers is also presented, including the early embryogenesis of entognathans as well as germ cell determination and gonad formation in Drosophila virilis conducted by Jura; analysis of oogenesis in Collembola carried out by Krzysztofowicz; investigations of insects and tradigrades by Weglarska, and finally research into various aspects of ovary structure in diverse insect taxa by the Bilinski group.

  2. Gene Family Evolution Reflects Adaptation to Soil Environmental Stressors in the Genome of the Collembolan Orchesella cincta

    PubMed Central

    Faddeeva-Vakhrusheva, Anna; Derks, Martijn F. L.; Anvar, Seyed Yahya; Agamennone, Valeria; Suring, Wouter; Smit, Sandra; van Straalen, Nico M.; Roelofs, Dick

    2016-01-01

    Collembola (springtails) are detritivorous hexapods that inhabit the soil and its litter layer. The ecology of the springtail Orchesella cincta is extensively studied in the context of adaptation to anthropogenically disturbed areas. Here, we present a draft genome of an O. cincta reference strain with an estimated size of 286.8 Mbp, containing 20,249 genes. In total, 446 gene families are expanded and 1,169 gene families evolved specific to this lineage. Besides these gene families involved in general biological processes, we observe gene clusters participating in xenobiotic biotransformation. Furthermore, we identified 253 cases of horizontal gene transfer (HGT). Although the largest percentage of them originated from bacteria (37.5%), we observe an unusually high percentage (30.4%) of such genes of fungal origin. The majority of foreign genes are involved in carbohydrate metabolism and cellulose degradation. Moreover, some foreign genes (e.g., bacillopeptidases) expanded after HGT. We hypothesize that horizontally transferred genes could be advantageous for food processing in a soil environment that is full of decaying organic material. Finally, we identified several lineage-specific genes, expanded gene families, and horizontally transferred genes, associated with altered gene expression as a consequence of genetic adaptation to metal stress. This suggests that these genome features may be preadaptations allowing natural selection to act on. In conclusion, this genome study provides a solid foundation for further analysis of evolutionary mechanisms of adaptation to environmental stressors. PMID:27289101

  3. Effects of inter-row management intensity on wild bee, plant and soil biota diversity in vineyards

    NASA Astrophysics Data System (ADS)

    Kratschmer, Sophie; Pachinger, Bärbel; Winter, Silvia; Zaller, Johann G.; Buchholz, Jacob; Querner, Pascal; Strauß, Peter; Bauer, Thomas; Stiper, Katrin

    2016-04-01

    Vineyards may provide a range of essential ecosystem services, which interact with a diverse community of above- and belowground organisms. Intensive soil management like frequent tilling has resulted in the degradation of habitat quality with consequences on biodiversity and ecosystem services. This study is part of the European BiodivERsA project "VineDivers - Biodiversity-based ecosystem services in vineyards". We study the effects of different soil management intensities on above- and below-ground biodiversity (plants, insect pollinators, and soil biota), their interactions and the consequences for ecosystem services. We investigated 16 vineyards in Austria assessing the diversity of (1) wild bees using a semi-quantitative transect method, (2) earthworms by hand sorting, (3) Collembola (springtails) via pitfall trapping and soil coring, (4) plants by relevés and (5) litter decomposition (tea bag method). Management intensity differed in tillage frequency from intermediate intensity resulting in temporary vegetation cover to no tillage in permanent vegetation cover systems. First results show opposed relationships between the biodiversity of selected species groups and management intensity. We will discuss possible explanations and evaluate ecological interactions between wild bee, plant and soil biota diversity.

  4. Invertebrates associated with a horizontal-flow, subsurface constructed wetland in a northern climate.

    PubMed

    Giordano, Rosanna; Weber, Everett; Darby, Brian J; Soto-Adames, Felipe N; Murray, Robert E; Drizo, Aleksandra

    2014-04-01

    Wetlands function as buffers between terrestrial and aquatic ecosystems, filtering pollutants generated by human activity. Constructed wetlands were developed to mimic the physical and biological filtering functions of natural systems for the treatment of human and animal waste under controlled conditions. Previous studies on the effect of constructed wetlands on native invertebrate populations have concentrated almost exclusively on mosquitoes. Here, we present the first study investigating the relationship between vegetation cover and aeration regime, and the diversity and abundance of nematodes and springtails (Collembola) in a constructed wetland designed to treat dairy farm wastewater in northwestern Vermont. We investigated four treatment cells differing in aeration regime and vegetation cover, but equally overlaid by a layer of compost to provide insulation. Analysis showed that nematodes were most abundant in the nonplanted and nonaerated cells, and that bacterivorous nematodes dominated the community in all cells. Springtails were found to be most numerous in the planted and nonaerated cells. We hypothesize that the vegetation provided differing environmental niches that supported a more diverse system of bacteria and fungi, as well as offering protection from predators and inclement weather. Nematodes were likely imported with the original compost material, while springtails migrated into the cells either via air, water, or direct locomotion. PMID:24534015

  5. Effects of water addition on soil arthropods and soil characteristics in a precipitation-limited environment

    NASA Astrophysics Data System (ADS)

    Chikoski, Jennifer M.; Ferguson, Steven H.; Meyer, Lense

    2006-09-01

    We investigated the effect of water addition and season on soil arthropod abundance and soil characteristics (%C, %N, C:N, moisture, pH). The experimental design consisted of 24 groups of five boxes distributed within a small aspen stand in Saskatchewan, Canada. The boxes depressed the soil to create a habitat with suitable microclimate for soil arthropods, and by overturning boxes we counted soil arthropods during weekly surveys from April to September 1999. Soil samples were collected at two-month intervals and water was added once per week to half of the plots. Of the eleven recognizable taxonomic units identified, only mites (Acari) and springtails (Collembola) responded to water addition by increasing abundance, whereas ants decreased in abundance with water addition. During summer, springtail numbers increased with water addition, whereas pH was a stronger determinant of mite abundance. In autumn, springtails were positively correlated with water and negatively correlated with mites, whereas mite abundance was negatively correlated with increasing C:N ratio, positively correlated to water addition, and negatively correlated with springtail abundance. Although both mite and springtail numbers decreased in autumn with a decrease in soil moisture, mites became more abundant than springtails suggesting a predator-prey (mite-springtail) relationship. Water had a significant effect on both springtails and mites in summer and autumn supporting the assertion that prairie soil communities are water limited.

  6. [Effects of different afforestation types on soil faunal diversity in Horqin Sand Land].

    PubMed

    Liu, Ren-Tao; Zhao, Ha-Lin; Zhao, Xue-Yong

    2012-04-01

    In order to deeply understand the effects of afforestation on the soil faunal diversity in mobile sand land, an investigation was conducted on the community structure of soil animals in the mobile sand land and its adjacent about 30 years old forest land and shrub land in Hrqin Sand Land. Afforestation on the mobile sand land had remarkable effects on the soil properties, especially the soil environment in shrub land, in which, the soil water content, pH, and nutrient contents were improved. In the three lands investigated, a total of 485 individuals belonging to 11 soil animal groups were collected, among which, Acarina and Collembola were the dominant groups, Corrodentia was the common group, and the others were of rare groups. From the mobile sand land to shrub land to forest land, the soil faunal density decreased, group richness and Shannon index increased, and evenness declined, but no significant differences were observed in these indices among these three lands. It was suggested that afforestation on mobile sand land could improve the soil environment and enhance soil faunal diversity, but there was a limitation to take 30 years old plantations as test objects to investigate the effects of afforestation on soil faunal diversity in mobile sand land.

  7. Gene Family Evolution Reflects Adaptation to Soil Environmental Stressors in the Genome of the Collembolan Orchesella cincta.

    PubMed

    Faddeeva-Vakhrusheva, Anna; Derks, Martijn F L; Anvar, Seyed Yahya; Agamennone, Valeria; Suring, Wouter; Smit, Sandra; van Straalen, Nico M; Roelofs, Dick

    2016-01-01

    Collembola (springtails) are detritivorous hexapods that inhabit the soil and its litter layer. The ecology of the springtail Orchesella cincta is extensively studied in the context of adaptation to anthropogenically disturbed areas. Here, we present a draft genome of an O. cincta reference strain with an estimated size of 286.8 Mbp, containing 20,249 genes. In total, 446 gene families are expanded and 1,169 gene families evolved specific to this lineage. Besides these gene families involved in general biological processes, we observe gene clusters participating in xenobiotic biotransformation. Furthermore, we identified 253 cases of horizontal gene transfer (HGT). Although the largest percentage of them originated from bacteria (37.5%), we observe an unusually high percentage (30.4%) of such genes of fungal origin. The majority of foreign genes are involved in carbohydrate metabolism and cellulose degradation. Moreover, some foreign genes (e.g., bacillopeptidases) expanded after HGT. We hypothesize that horizontally transferred genes could be advantageous for food processing in a soil environment that is full of decaying organic material. Finally, we identified several lineage-specific genes, expanded gene families, and horizontally transferred genes, associated with altered gene expression as a consequence of genetic adaptation to metal stress. This suggests that these genome features may be preadaptations allowing natural selection to act on. In conclusion, this genome study provides a solid foundation for further analysis of evolutionary mechanisms of adaptation to environmental stressors. PMID:27289101

  8. [Dynamics of soil arthropod community structure and its responses to forest fragmentation during the decomposition of Castanopsis eyrei leaf litter].

    PubMed

    Luo, Yuan-Yuan; Yuan, Jin-Feng; Shen, Guo-Chun; Zhao, Gu-Feng; Yu, Ming-Jian

    2011-05-01

    Five evergreen broad-leaved forests (one continuous forest and four fragmented forests) in the mountain areas in the juncture of Zhejiang, Fujian, and Jiangxi Provinces, East China were selected as test objects to study the dynamics of soil arthropod community structure and its responses to forest fragmentation during the decomposition of dominant tree species Castanopsis eyrei leaf litter. A total of 899 soil arthropods were collected, belonging to 9 classes and 25 orders. Lepidoptera was the dominant taxon, accounting for 10% of the individual, while Hymenoptera, Collembola, Diptera, Prostigmata, and Geophilomorpha were the common taxa. The decomposition rate of C. eyrei leaf litter was the highest in August and lower in April-June and December, which was in accordance with the seasonal dynamics of the taxa number and individual number of soil arthropods. Meanwhile, the taxa number, individual number, and species diversity of soil arthropods differed between continuous forest and fragmented forests, suggesting that both area effect and edge effect affected the dynamics of soil arthropod community structure during the decomposition of C. eyrei leaf litter.

  9. Abundance and Diversity of Soil Arthropods in the Olive Grove Ecosystem

    PubMed Central

    Gonçalves, Maria Fátima; Pereira, José Alberto

    2012-01-01

    Arthropods are part of important functional groups in soil food webs. Recognizing these arthropods and understanding their function in the ecosystem as well as when they are active is essential to understanding their roles. In the present work, the abundance and diversity of soil arthropods is examined in olive groves in the northeast region of Portugal during the spring. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta, and Arachnida. Captures were numerically dominated by Collembola within Entognatha, representing 70.9% of total captures. Arachnida and Insecta classes represented about 20.4 and 9.0%, respectively. Among the predatory arthropods, the most representative groups were Araneae and Opiliones from Arachnida, and Formicidae, Carabidae, and Staphylinidae from Insecta. From the Formicidae family, Tetramorium semilaeve (Andre 1883), Tapinoma nigerrimum (Nylander 1856), and Crematogaster scutellaris (Olivier 1792) were the most representative ant species. Arthropods demonstrated preference during the day, with 74% of the total individuals recovered in this period, although richness and similarity were analogous during the day and night. PMID:22943295

  10. Headwater riparian invertebrate communities associated with red alder and conifer wood and leaf litter in southeastern Alaska

    USGS Publications Warehouse

    LeSage, C.M.; Merritt, R.W.; Wipfli, M.S.

    2005-01-01

    We examined how management of young upland forests in southeastern Alaska affect riparian invertebrate taxa richness, density, and biomass, in turn, potentially influencing food abundance for fish and wildlife. Southeastern Alaska forests are dominated by coniferous trees including Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), with mixed stands of red cedar (Thuja plicata Donn.). Red alder (Alnus rubra Bong.) is hypothesized to influence the productivity of young-growth conifer forests and through forest management may provide increased riparian invertebrate abundance. To compare and contrast invertebrate densities between coniferous and alder riparian habitats, leaf litter and wood debris (early and late decay classes) samples were collected along eleven headwater streams on Prince of Wales Island, Alaska, during the summers of 2000 and 2001. Members of Acarina and Collembola were the most abundant taxa collected in leaf litter with alder litter having significantly higher mean taxa richness than conifer litter. Members of Acarina were the most abundant group collected on wood debris and alder wood had significantly higher mean taxa richness and biomass than conifer wood. Alder wood debris in more advanced decay stages had the highest mean taxa richness and biomass, compared to other wood types, while conifer late decay wood debris had the highest densities of invertebrates. The inclusion of alder in young-growth conifer forests can benefit forest ecosystems by enhancing taxa richness and biomass of riparian forest invertebrates. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  11. Structural mouthpart interaction evolved already in the earliest lineages of insects.

    PubMed

    Blanke, Alexander; Rühr, Peter T; Mokso, Rajmund; Villanueva, Pablo; Wilde, Fabian; Stampanoni, Marco; Uesugi, Kentaro; Machida, Ryuichiro; Misof, Bernhard

    2015-08-01

    In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting-chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages--Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting-chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed.

  12. Sex-determining mechanisms in insects based on imprinting and elimination of chromosomes.

    PubMed

    Sánchez, L

    2014-01-01

    As a rule, the sex of an individual is fixed at fertilization, and the chromosomal constitution of the zygote is a direct consequence of the chromosomal constitution of the gametes. However, there are cases in which the chromosomal differences determining sex are brought about by elimination or inactivation of chromosomes in the embryo. In Sciaridae insects, all zygotes start with the XXX constitution; the loss of either 1 or 2 X chromosomes determines whether the zygote becomes XX (female) or X0 (male). In Cecydomyiidae and Collembola insects, all zygotes start with the XXXX constitution. If the embryo does not eliminate any X chromosome, this remains XXXX and develops as female, whereas if 2 X chromosomes are eliminated, the embryo becomes XX0 and develops as a male. In the coccids (scale insects), the chromosomal differences between the sexes result from either the elimination or the heterochromatinization (inactivation) of half of the chromosomes giving rise to haploid males and diploid females. The chromosomes that are eliminated or inactivated are those inherited from the father. Therefore, in the formation of the sex-determining chromosomal signal in those insects, a marking ('imprinting') process must occur in one of the parents, which determines that the chromosomes to be eliminated or inactivated are of paternal origin. In this article, the sex determination mechanism of these insects and the associated imprinting process are reviewed.

  13. [Decomposition of Schima superba leaf litter and dynamics change of soil meso-micro arthropods community structure in evergreen broad-leaved forest fragments].

    PubMed

    Luo, Yuan-Yuan; Yuan, Jin-Feng; Shen, Guo-Chun; Zhao, Gu-Feng; Yu, Ming-Jian

    2010-02-01

    Taking four evergreen broad-leaved forest fragments within the adjacent mountainous region of Zhejiang, Fujian, and Jiangxi provinces as study objects, and the continuous forest in Gutianshan National Natural Reserve as the control, an investigation was made by litter bag method from June 2004 to April 2006, aimed to understand the community structure and its dynamics change of soil meso-micro arthropods during the decomposition of Schima superba leaf litter. A total of 1050 soil meso-micro arthropods belonging to 8 classes and 23 orders were collected, among which, Lepidoptera, Hymenoptera, Collembola and Diptera were the dominant taxa. The impact of habitat fragmentation on the community composition of soil arthropods was mainly manifested in the differences of rare taxa, and the dominance of different taxa at different decomposition stages of S. superba leaf litter varied with the functions of the taxa in litter decomposition. After two-year decomposition, the mass loss of S. superba leaf litter was 60%-70%, and the species diversity indices of soil arthropods showed certain changes, being different between forest fragments and continuous forest.

  14. Food and growth parameters of juvenile chinook in the central Columbia River

    SciTech Connect

    Becker, C.D.

    1994-10-01

    Juvenile chinook, salmon (Oncorhynchus tshawytscha) in the Hanford area of the free-flowing central Columbia River, Washington consume almost entirely adult and larval stages of aquatic insects. The diet is dominated by midges (Diptera: Chironomidae). By numbers, adult midges provided 64 and 58% of the diet and larval midges 17 and 18% of the diet, in 1968 and 1969, respectively. The families Hydropsychidae (Trichoptera), Notonectidae (Hemiptera) and Hypogastruridae (Collembola) are of minor numerical importance with a combined utilization of 7% in 1968 and 15% in 1969. Distinctive features of food and feeding activity of juvenile chinook at Hanford are fourfold: (1) the fish utilize relatively few insect groups, predominantly Chironomidae; (2) they depend largely upon autochthonous river organisms; (3) they visually select living prey drifting, floating or swimming in the water; and (4) they are apparently habitat opportunists to a large extent. Analyses were made of variations in diet and numbers of insects consumed between six sampling stations distributed along a 38 km section of the river. Data are provided on feeding intensity, fish lengths, length-weight relationships, and coefficients of condition. Seasonal changes in river temperature and discharge, as well as variations in regulated flow levels are environmental features influencing feeding, growth, and emigration of fish in the Hanford environs.

  15. Seed dressing pesticides on springtails in two ecotoxicological laboratory tests.

    PubMed

    Alves, Paulo Roger L; Cardoso, Elke J B N; Martines, Alexandre M; Sousa, José Paulo; Pasini, Amarildo

    2014-07-01

    Terrestrial ecotoxicological tests are powerful tools for assessing the ecological risks that pesticides pose to soil invertebrates, but they are rarely used to evaluate seed dressing pesticides. This study investigated the effects of seed dressing pesticides on survival and reproduction of Folsomia candida (Collembola), using standardized ecotoxicological tests (after ISO guidelines with few adaptations for tropical conditions). Commercial formulations of five seed dressing pesticides were tested individually in Tropical Artificial Soil (TAS): the insecticides imidacloprid, fipronil, thiametoxam, and the fungicides captan and carboxin+thiram. Thiametoxam, captan, and carboxin+thiram were only lethal to F. candida at the highest concentration tested (1000mg of active ingredient kg(-1) of dry soil). Imidacloprid and fipronil were lethal at lower concentrations (100 and 10mg a.i. kg(-1) soil d.w, respectively), however, these concentrations were much higher than those predicted (PEC) for soil. Imidacloprid and fipronil were the most toxic pesticides in both tests, reducing significantly collembolan reproduction (EC20=0.02 and 0.12mga.i.kg(-1) soil d.w, respectively). Further studies under more realistic conditions are needed, since imidacloprid and fipronil reduced collembolan reproduction at concentrations below or close to their respective PECs.

  16. Generalisation within specialization: inter-individual diet variation in the only specialized salamander in the world.

    PubMed

    Costa, Andrea; Salvidio, Sebastiano; Posillico, Mario; Matteucci, Giorgio; De Cinti, Bruno; Romano, Antonio

    2015-08-21

    Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

  17. A Comparison of the Pitfall Trap, Winkler Extractor and Berlese Funnel for Sampling Ground-Dwelling Arthropods in Tropical Montane Cloud Forests

    PubMed Central

    Sabu, Thomas K.; Shiju, Raj T.; Vinod, KV.; Nithya, S.

    2011-01-01

    Little is known about the ground-dwelling arthropod diversity in tropical montane cloud forests (TMCF). Due to unique habitat conditions in TMCFs with continuously wet substrates and a waterlogged forest floor along with the innate biases of the pitfall trap, Berlese funnel and Winkler extractor are certain to make it difficult to choose the most appropriate method to sample the ground-dwelling arthropods in TMCFs. Among the three methods, the Winkler extractor was the most efficient method for quantitative data and pitfall trapping for qualitative data for most groups. Inclusion of floatation method as a complementary method along with the Winkler extractor would enable a comprehensive quantitative survey of ground-dwelling arthropods. Pitfall trapping is essential for both quantitative and qualitative sampling of Diplopoda, Opiliones, Orthoptera, and Diptera. The Winkler extractor was the best quantitative method for Psocoptera, Araneae, Isopoda, and Formicidae; and the Berlese funnel was best for Collembola and Chilopoda. For larval forms of different insect orders and the Acari, all the three methods were equally effective. PMID:21529148

  18. The monitoring of insects to maintain biodiversity in Ogawa Fores Reserve.

    PubMed

    Makino, S; Goto, H; Inoue, T; Sueyoshi, M; Okabe, K; Hasegawa, M; Hamaguchi, K; Ctanaka, H; Okochi, I

    2006-09-01

    The results of a biodiversity monitoring program conducted in the Ogawa Forest Reserve and its vicinity, situated in a cool temperate region of Japan, identified three different patterns for species richness. Forests of the region are characterized by a mosaic of secondary deciduous stands of various ages scattered among plantations of conifers. The three different types of change in species richness observed in response to the stand age are as follows: Type I (butterflies, tube-renting bees and wasps, hoverflies, fruit flies, and longicorn beetles), the species diversity was highest in open areas, just after clear-cutting, decreasing with the stand age; Type II (mushrooms and mites associated with them), older stands showed greater diversity than younger stands; and, Type III (moths, oribatid mites, collembolas, carabid beetles, and ants), the number of species did not change greatly with the stand age, though ordination analysis revealed that there was variation in species compositions. These results indicate that combinations of stands of different ages, or heterogeneously arranged stands, can contribute to the maintenance of insect biodiversity at the landscape level.

  19. Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods.

    PubMed

    Teets, Nicholas M; Denlinger, David L

    2014-01-01

    Abiotic stress is one of the primary constraints limiting the range and success of arthropods, and nowhere is this more apparent than Antarctica. Antarctic arthropods have evolved a suite of adaptations to cope with extremes in temperature and water availability. Here, we review the current state of knowledge regarding the environmental physiology of terrestrial arthropods in Antarctica. To survive low temperatures, mites and Collembola are freeze-intolerant and rely on deep supercooling, in some cases supercooling below -30°C. Also, some of these microarthropods are capable of cryoprotective dehydration to extend their supercooling capacity and reduce the risk of freezing. In contrast, the two best-studied Antarctic insects, the midges Belgica antarctica and Eretmoptera murphyi, are freeze-tolerant year-round and rely on both seasonal and rapid cold-hardening to cope with decreases in temperature. A common theme among Antarctic arthropods is extreme tolerance of dehydration; some accomplish this by cuticular mechanisms to minimize water loss across their cuticle, while a majority have highly permeable cuticles but tolerate upwards of 50-70% loss of body water. Molecular studies of Antarctic arthropod stress physiology are still in their infancy, but several recent studies are beginning to shed light on the underlying mechanisms that govern extreme stress tolerance. Some common themes that are emerging include the importance of cuticular and cytoskeletal rearrangements, heat shock proteins, metabolic restructuring and cell recycling pathways as key mediators of cold and water stress in the Antarctic.

  20. Primary assembly of soil communities: disentangling the effect of dispersal and local environment.

    PubMed

    Ingimarsdóttir, María; Caruso, Tancredi; Ripa, Jörgen; Magnúsdóttir, Olöf Birna; Migliorini, Massimo; Hedlund, Katarina

    2012-11-01

    It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

  1. Abundance and diversity of soil arthropods in the olive grove ecosystem.

    PubMed

    Gonçalves, Maria Fátima; Pereira, José Alberto

    2012-01-01

    Arthropods are part of important functional groups in soil food webs. Recognizing these arthropods and understanding their function in the ecosystem as well as when they are active is essential to understanding their roles. In the present work, the abundance and diversity of soil arthropods is examined in olive groves in the northeast region of Portugal during the spring. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta, and Arachnida. Captures were numerically dominated by Collembola within Entognatha, representing 70.9% of total captures. Arachnida and Insecta classes represented about 20.4 and 9.0%, respectively. Among the predatory arthropods, the most representative groups were Araneae and Opiliones from Arachnida, and Formicidae, Carabidae, and Staphylinidae from Insecta. From the Formicidae family, Tetramorium semilaeve (Andre 1883), Tapinoma nigerrimum (Nylander 1856), and Crematogaster scutellaris (Olivier 1792) were the most representative ant species. Arthropods demonstrated preference during the day, with 74% of the total individuals recovered in this period, although richness and similarity were analogous during the day and night.

  2. The diversity and abundance of small arthropods in onion, Allium cepa, seed crops, and their potential role in pollination.

    PubMed

    Walker, M K; Howlett, B G; Wallace, A R; McCallum, J A; Teulon, D A J

    2011-01-01

    Onion, Allium cepa L. (Asparagales: Amaryllidaceae), crop fields grown for seed production require arthropod pollination for adequate seed yield. Although many arthropod species visit A. cepa flowers, for most there is little information on their role as pollinators. Small flower visiting arthropods (body width < 3 mm) in particular are rarely assessed. A survey of eight flowering commercial A. cepa seed fields in the North and South Islands of New Zealand using window traps revealed that small arthropods were highly abundant among all except one field. Insects belonging to the orders Diptera and Thysanoptera were the most abundant and Hymenoptera, Collembola, Psocoptera, Hemiptera, and Coleoptera were also present. To test whether small arthropods might contribute to pollination, seed sets from umbels caged within 3 mm diameter mesh cages were compared with similarly caged, hand-pollinated umbels and uncaged umbels. Caged umbels that were not hand-pollinated set significantly fewer seeds (average eight seeds/umbel, n = 10) than caged hand-pollinated umbels (average 146 seeds/umbel) and uncaged umbels (average 481 seeds/umbel). Moreover, sticky traps placed on umbels within cages captured similar numbers of small arthropods as sticky traps placed on uncaged umbels, suggesting cages did not inhibit the movement of small arthropods to umbels. Therefore, despite the high abundance of small arthropods within fields, evidence to support their role as significant pollinators of commercial A. cepa seed crops was not found.

  3. The meaning of predatory specialization as illustrated by Aelurillus m-nigrum, an ant-eating jumping spider (Araneae: Salticidae) from Azerbaijan.

    PubMed

    Huseynov, Elchin F; Jackson, Robert R; Cross, Fiona R

    2008-03-01

    The distinctions between a predator's diet, its prey-choice behaviour and its preference are illustrated in a study of Aelurillus m-nigrum Kulczyn'ski, a salticid spider from Azerbaijan. The natural diet of A. m-nigrum was determined from records of individuals feeding in the field (N=58). Ten arthropod orders were represented. Nine were from the class Insecta (Coleoptera, Collembola, Diptera, Heteroptera, Homoptera, Hymenoptera, Lepidoptera, Orthoptera, Psocoptera) and one from the class Arachnida (Araneae). Of 50 insects among the prey, 21 (42%) were Hymenoptera, with ants (family Formicidae) alone accounting for 31% of all prey records. Although the majority (69%) of the natural prey were not ants, results from prey-choice testing in the laboratory implied that A. m-nigrum preferred ants as prey. However, this preference was evident only when the testing environment included sand and a small stone. Our findings illustrate the importance of not conflating the concept of a predator's preference with the concept of a predator's natural diet and illustrate that physical features of a predator's habitat may be an important factor in influencing how strongly preference is expressed. PMID:18178038

  4. Invertebrates associated with a horizontal-flow, subsurface constructed wetland in a northern climate.

    PubMed

    Giordano, Rosanna; Weber, Everett; Darby, Brian J; Soto-Adames, Felipe N; Murray, Robert E; Drizo, Aleksandra

    2014-04-01

    Wetlands function as buffers between terrestrial and aquatic ecosystems, filtering pollutants generated by human activity. Constructed wetlands were developed to mimic the physical and biological filtering functions of natural systems for the treatment of human and animal waste under controlled conditions. Previous studies on the effect of constructed wetlands on native invertebrate populations have concentrated almost exclusively on mosquitoes. Here, we present the first study investigating the relationship between vegetation cover and aeration regime, and the diversity and abundance of nematodes and springtails (Collembola) in a constructed wetland designed to treat dairy farm wastewater in northwestern Vermont. We investigated four treatment cells differing in aeration regime and vegetation cover, but equally overlaid by a layer of compost to provide insulation. Analysis showed that nematodes were most abundant in the nonplanted and nonaerated cells, and that bacterivorous nematodes dominated the community in all cells. Springtails were found to be most numerous in the planted and nonaerated cells. We hypothesize that the vegetation provided differing environmental niches that supported a more diverse system of bacteria and fungi, as well as offering protection from predators and inclement weather. Nematodes were likely imported with the original compost material, while springtails migrated into the cells either via air, water, or direct locomotion.

  5. Role of Autochthonous Filamentous Fungi in Bioremediation of a Soil Historically Contaminated with Aromatic Hydrocarbons

    PubMed Central

    D'Annibale, A.; Rosetto, F.; Leonardi, V.; Federici, F.; Petruccioli, M.

    2006-01-01

    Nine fungal strains isolated from an aged and heavily contaminated soil were identified and screened to assess their degradative potential. Among them, Allescheriella sp. strain DABAC 1, Stachybotrys sp. strain DABAC 3, and Phlebia sp. strain DABAC 9 were selected for remediation trials on the basis of Poly R-478 decolorization associated with lignin-modifying enzyme (LME) production. These autochthonous fungi were tested for the abilities to grow under nonsterile conditions and to degrade various aromatic hydrocarbons in the same contaminated soil. After 30 days, fungal colonization was clearly visible and was confirmed by ergosterol determination. In spite of subalkaline pH conditions and the presence of heavy metals, the autochthonous fungi produced laccase and Mn and lignin peroxidases. No LME activities were detected in control microcosms. All of the isolates led to a marked removal of naphthalene, dichloroaniline isomers, o-hydroxybiphenyl, and 1,1′-binaphthalene. Stachybotrys sp. strain DABAC 3 was the most effective isolate due to its ability to partially deplete the predominant contaminants 9,10-anthracenedione and 7H-benz[DE]anthracen-7-one. A release of chloride ions was observed in soil treated with either Allescheriella sp. strain DABAC 1 or Stachybotrys sp. strain DABAC 3, suggesting the occurrence of oxidative dehalogenation. The autochthonous fungi led to a significant decrease in soil toxicity, as assessed by both the Lepidium sativum L. germination test and the Collembola mortality test. PMID:16391021

  6. Bioavailability of chemical pollutants in contaminated soils and pitfalls of chemical analyses in hazard assessment.

    PubMed

    Vasseur, P; Bonnard, M; Palais, F; Eom, I C; Morel, J L

    2008-10-01

    Decision-making for remediation of industrial wastelands are still based on the concentrations of pollutants of concern measured in soils. In this work, two soils polluted by polycyclic aromatic hydrocarbons (PAHs) and metals were investigated for their toxicity on earthworms (Eisenia fetida), collembolae (Folsomia candida), and higher plants (Brassica chinensis, Lactucca sativa and Avena sativa) in order to study the relationships between chemical contamination and biological effects. Although the level of contamination by PAHs was elevated and commensurate in the two soils, their toxicity profile was quite different. Soil A affected survival and reproduction of invertebrates and growth of higher plants. Surprisingly, soil B, heavily contaminated by metals in addition to PAHs, was devoid of toxicity. Our results indicate that toxicity cannot simply be extrapolated from pollutant concentrations in a complex matrix in which bioavailability of pollutants may be reduced by ageing. Moreover, the use of toxicity data obtained from spiked soils characterized by readily bioavailable pollutants can also be called into question for such extrapolations. Predicting biological effects therefore requires biological tools to avoid any erroneous conclusions that can be drawn from sole extrapolation of analytical results.

  7. Effects on weed and invertebrate abundance and diversity of herbicide management in genetically modified herbicide-tolerant winter-sown oilseed rape.

    PubMed

    Bohan, David A; Boffey, Caroline W H; Brooks, David R; Clark, Suzanne J; Dewar, Alan M; Firbank, Les G; Haughton, Alison J; Hawes, Cathy; Heard, Matthew S; May, Mike J; Osborne, Juliet L; Perry, Joe N; Rothery, Peter; Roy, David B; Scott, Rod J; Squire, Geoff R; Woiwod, Ian P; Champion, Gillian T

    2005-03-01

    We evaluated the effects of the herbicide management associated with genetically modified herbicide-tolerant (GMHT) winter oilseed rape (WOSR) on weed and invertebrate abundance and diversity by testing the null hypotheses that there is no difference between the effects of herbicide management of GMHT WOSR and that of comparable conventional varieties. For total weeds, there were few treatment differences between GMHT and conventional cropping, but large and opposite treatment effects were observed for dicots and monocots. In the GMHT treatment, there were fewer dicots and monocots than in conventional crops. At harvest, dicot biomass and seed rain in the GMHT treatment were one-third of that in the conventional, while monocot biomass was threefold greater and monocot seed rain almost fivefold greater in the GMHT treatment than in the conventional. These differential effects persisted into the following two years of the rotation. Bees and Butterflies that forage and select for dicot weeds were less abundant in GMHT WORS management in July. Year totals for Collembola were greater under GMHT management. There were few other treatment effects on invertebrates, despite the marked effects of herbicide management on the weeds. PMID:15799941

  8. Structural mouthpart interaction evolved already in the earliest lineages of insects.

    PubMed

    Blanke, Alexander; Rühr, Peter T; Mokso, Rajmund; Villanueva, Pablo; Wilde, Fabian; Stampanoni, Marco; Uesugi, Kentaro; Machida, Ryuichiro; Misof, Bernhard

    2015-08-01

    In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting-chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages--Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting-chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed. PMID:26203002

  9. Seed dressing pesticides on springtails in two ecotoxicological laboratory tests.

    PubMed

    Alves, Paulo Roger L; Cardoso, Elke J B N; Martines, Alexandre M; Sousa, José Paulo; Pasini, Amarildo

    2014-07-01

    Terrestrial ecotoxicological tests are powerful tools for assessing the ecological risks that pesticides pose to soil invertebrates, but they are rarely used to evaluate seed dressing pesticides. This study investigated the effects of seed dressing pesticides on survival and reproduction of Folsomia candida (Collembola), using standardized ecotoxicological tests (after ISO guidelines with few adaptations for tropical conditions). Commercial formulations of five seed dressing pesticides were tested individually in Tropical Artificial Soil (TAS): the insecticides imidacloprid, fipronil, thiametoxam, and the fungicides captan and carboxin+thiram. Thiametoxam, captan, and carboxin+thiram were only lethal to F. candida at the highest concentration tested (1000mg of active ingredient kg(-1) of dry soil). Imidacloprid and fipronil were lethal at lower concentrations (100 and 10mg a.i. kg(-1) soil d.w, respectively), however, these concentrations were much higher than those predicted (PEC) for soil. Imidacloprid and fipronil were the most toxic pesticides in both tests, reducing significantly collembolan reproduction (EC20=0.02 and 0.12mga.i.kg(-1) soil d.w, respectively). Further studies under more realistic conditions are needed, since imidacloprid and fipronil reduced collembolan reproduction at concentrations below or close to their respective PECs. PMID:24785712

  10. An automated image analysis system to measure and count organisms in laboratory microcosms.

    PubMed

    Mallard, François; Le Bourlot, Vincent; Tully, Thomas

    2013-01-01

    1. Because of recent technological improvements in the way computer and digital camera perform, the potential use of imaging for contributing to the study of communities, populations or individuals in laboratory microcosms has risen enormously. However its limited use is due to difficulties in the automation of image analysis. 2. We present an accurate and flexible method of image analysis for detecting, counting and measuring moving particles on a fixed but heterogeneous substrate. This method has been specifically designed to follow individuals, or entire populations, in experimental laboratory microcosms. It can be used in other applications. 3. The method consists in comparing multiple pictures of the same experimental microcosm in order to generate an image of the fixed background. This background is then used to extract, measure and count the moving organisms, leaving out the fixed background and the motionless or dead individuals. 4. We provide different examples (springtails, ants, nematodes, daphnia) to show that this non intrusive method is efficient at detecting organisms under a wide variety of conditions even on faintly contrasted and heterogeneous substrates. 5. The repeatability and reliability of this method has been assessed using experimental populations of the Collembola Folsomia candida. 6. We present an ImageJ plugin to automate the analysis of digital pictures of laboratory microcosms. The plugin automates the successive steps of the analysis and recursively analyses multiple sets of images, rapidly producing measurements from a large number of replicated microcosms. PMID:23734199

  11. Wetting resistance at its topographical limit: the benefit of mushroom and serif T structures.

    PubMed

    Hensel, René; Helbig, Ralf; Aland, Sebastian; Braun, Hans-Georg; Voigt, Axel; Neinhuis, Christoph; Werner, Carsten

    2013-01-29

    Springtails (Collembola) are wingless arthropods adapted to cutaneous respiration in temporarily rain-flooded habitats. They immediately form a plastron, protecting them against suffocation upon immersion into water and even low-surface-tension liquids such as alkanes. Recent experimental studies revealed a high-pressure resistance of such plastrons against collapse. In this work, skin sections of Orthonychiurus stachianus are studied by transmission electron microscopy. The micrographs reveal cavity side-wall profiles with characteristic overhangs. These were fitted by polynomials to allow access for analytical and numerical calculations of the breakthrough pressure, that is, the barrier against plastron collapse. Furthermore, model profiles with well-defined geometries were used to set the obtained results into context and to develop a general design principle for the most robust surface structures. Our results indicate the decisive role of the sectional profile of overhanging structures to form a robust heterogeneous wetting state for low-surface-tension liquids that enables the omniphobicity. Furthermore, the design principles of mushroom and serif T structures pave the way for omniphobic surfaces with a high-pressure resistance irrespective of solid surface chemistry. PMID:23278566

  12. Bacterial and eukaryotic biodiversity patterns in terrestrial and aquatic habitats in the Sør Rondane Mountains, Dronning Maud Land, East Antarctica.

    PubMed

    Obbels, Dagmar; Verleyen, Elie; Mano, Marie-José; Namsaraev, Zorigto; Sweetlove, Maxime; Tytgat, Bjorn; Fernandez-Carazo, Rafael; De Wever, Aaike; D'hondt, Sofie; Ertz, Damien; Elster, Josef; Sabbe, Koen; Willems, Anne; Wilmotte, Annick; Vyverman, Wim

    2016-06-01

    The bacterial and microeukaryotic biodiversity were studied using pyrosequencing analysis on a 454 GS FLX+ platform of partial SSU rRNA genes in terrestrial and aquatic habitats of the Sør Rondane Mountains, including soils, on mosses, endolithic communities, cryoconite holes and supraglacial and subglacial meltwater lenses. This inventory was complemented with Denaturing Gradient Gel Electrophoresis targeting Chlorophyta and Cyanobacteria. OTUs belonging to the Rotifera, Chlorophyta, Tardigrada, Ciliophora, Cercozoa, Fungi, Bryophyta, Bacillariophyta, Collembola and Nematoda were present with a relative abundance of at least 0.1% in the eukaryotic communities. Cyanobacteria, Proteobacteria, Bacteroidetes, Acidobacteria, FBP and Actinobacteria were the most abundant bacterial phyla. Multivariate analyses of the pyrosequencing data revealed a general lack of differentiation of both eukaryotes and prokaryotes according to habitat type. However, the bacterial community structure in the aquatic habitats was dominated by the filamentous cyanobacteria Leptolyngbya and appeared to be significantly different compared with those in dry soils, on mosses, and in endolithic habitats. A striking feature in all datasets was the detection of a relatively large amount of sequences new to science, which underscores the need for additional biodiversity assessments in Antarctic inland locations. PMID:26936447

  13. The effect of latitudinal gradient on the species diversity of Chinese litter-dwelling thrips

    PubMed Central

    Wang, Jun; Tong, Xiaoli; Wu, Donghui

    2014-01-01

    Abstract To understand the global distribution patterns of litter-dwelling thrips, a total 150 leaf litter samples were collected from 6 natural reserves located in three climatic regions, temperate, subtropical and tropical. The results showed the relative abundance of Thysanoptera was over 3.0% in 4 natural reserves from subtropical and tropical zone, and reached 5.9% in one tropical reserve, only less than Acarina and Collembola. In contrast it was only 0.3% in the warm temperate natural reserves, and no thrips were collected in a mid temperate reserve. The order on the average species numbers per plot of litter thrips was tropic > subtropics > temperate (n=25, p<0.05). Mean density of litter thrips per plots in the tropics and subtropics was significantly higher than that in the temperate region (n=25, p<0.05), but the average density was not significantly different between tropical and subtropical zones (n=25, p>0.05). The diversity of litter thrips in the tropics and subtropics was much higher than that in the temperate area based on comparsions of Shannon-Wiener diversity index (H’), Pielou eveness index (J), and Simpson dominance index (D). All of these results indicated that litter-dwelling thrips lived mainly in tropical and subtropical regions; meanwhile, species number and relative abundance increased with decreasing latitude. PMID:25061351

  14. Generalisation within specialization: inter-individual diet variation in the only specialized salamander in the world

    PubMed Central

    Costa, Andrea; Salvidio, Sebastiano; Posillico, Mario; Matteucci, Giorgio; De Cinti, Bruno; Romano, Antonio

    2015-01-01

    Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration. PMID:26292804

  15. [Environmental activity of earthworms (Lumbricus terrestris L.) and the spatial organization of soil communities].

    PubMed

    Tiunov, A V; Kuznetsova, N A

    2000-01-01

    The effect of feeding and burrowing activities of anecic earthworms (Lumbricus terrestris) on abiotic characteristics of the soil, biomass and activity of soil microorganisms, and the spatial distribution of Collembola and Lumbricidae species was studied in a Iinden forest near Moscow. The results showed that organic carbon content, nitrogen content, pH, and microbial biomass and basal respiration are considerably higher around L. terrestris burrows than in the surrounding soil. The total density of springtails near the burrows was 1.6-1.7 as high as at the control sites. The most pronounced preference for earthworm burrows was observed in the species dominating in the soils of undisturbed deciduous forests (Isotomiella minor and Isotoma notabilis). The number and biomass of epigeic and endogeic earthworms also increased significantly in the zone of L. terrestris burrows. However, some springtail (Isotoma viridis, Protaphorura cf. nemorata, Lepidocyrtus lignorum) and earthworm species (Aporrectodea rosea) did not accumulate near L. terrestris burrows and even avoided them. Thus, L. terrestris activities create a mosaic of soil microhabitats, which provides for the coexistence of different microcommunities of soil organisms.

  16. Generalisation within specialization: inter-individual diet variation in the only specialized salamander in the world.

    PubMed

    Costa, Andrea; Salvidio, Sebastiano; Posillico, Mario; Matteucci, Giorgio; De Cinti, Bruno; Romano, Antonio

    2015-01-01

    Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration. PMID:26292804

  17. [Environmental activity of earthworms (Lumbricus terrestris L.) and the spatial organization of soil communities].

    PubMed

    Tiunov, A V; Kuznetsova, N A

    2000-01-01

    The effect of feeding and burrowing activities of anecic earthworms (Lumbricus terrestris) on abiotic characteristics of the soil, biomass and activity of soil microorganisms, and the spatial distribution of Collembola and Lumbricidae species was studied in a Iinden forest near Moscow. The results showed that organic carbon content, nitrogen content, pH, and microbial biomass and basal respiration are considerably higher around L. terrestris burrows than in the surrounding soil. The total density of springtails near the burrows was 1.6-1.7 as high as at the control sites. The most pronounced preference for earthworm burrows was observed in the species dominating in the soils of undisturbed deciduous forests (Isotomiella minor and Isotoma notabilis). The number and biomass of epigeic and endogeic earthworms also increased significantly in the zone of L. terrestris burrows. However, some springtail (Isotoma viridis, Protaphorura cf. nemorata, Lepidocyrtus lignorum) and earthworm species (Aporrectodea rosea) did not accumulate near L. terrestris burrows and even avoided them. Thus, L. terrestris activities create a mosaic of soil microhabitats, which provides for the coexistence of different microcommunities of soil organisms. PMID:11042967

  18. Structural mouthpart interaction evolved already in the earliest lineages of insects

    PubMed Central

    Blanke, Alexander; Rühr, Peter T.; Mokso, Rajmund; Villanueva, Pablo; Wilde, Fabian; Stampanoni, Marco; Uesugi, Kentaro; Machida, Ryuichiro; Misof, Bernhard

    2015-01-01

    In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting–chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages—Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting–chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed. PMID:26203002

  19. Using a toxicokinetics approach to explain the effect of soil pH on cadmium bioavailability to Folsomia candida.

    PubMed

    Ardestani, Masoud M; van Gestel, Cornelis A M

    2013-09-01

    The aim of this study was to improve our understanding of metal bioavailability in soil by linking the biotic ligand approach with toxicokinetics modelling. We determined cadmium bioaccumulation kinetics in Folsomia candida (Collembola) as a function of soil pH. Animals were exposed for 21 days to LUFA 2.2 soil at 5 or 20 μg Cd g(-1) dry soil followed by 21 days elimination in clean soil. Internal cadmium concentrations were modelled using a first-order one-compartment model, relating uptake rate constants (k1) to total soil, water or 0.01 M CaCl2 extractable and porewater concentrations. Based on total soil concentrations, k1 was independent of soil pH while it strongly increased with increasing pH based on porewater concentrations explaining the reduced competition of H(+) ions making cadmium more bioavailable in pore water at high pH. This shows that the principles of biotic ligand modelling are applicable to predict cadmium accumulation kinetics in soil-living invertebrates.

  20. Humus characteristics and seasonal changes of soil arthropod communities in a natural sessile oak (Quercus petraea L.) stand and adjacent Austrian pine (Pinus nigra Arnold) plantation.

    PubMed

    Cakir, Meric; Makineci, Ender

    2013-11-01

    In order to assess the effects of conversion of natural stands into plantations, soil invertebrate micro- and macroarthropod communities were evaluated for their abundance and richness in a sessile oak (SO; Quercus petraea L.) stand and adjacent Austrian pine (AP; Pinus nigra Arnold) plantation. Sites were sampled four times a year in 3-month intervals from May 2009 to February 2010. Humus characteristics such as total mass; carbon, lignin, and cellulose contents; and C/N ratio were significantly different between SO and AP. Statistically significant differences were detected on soil pH, carbon and nitrogen contents, and electrical conductivity between the two sites. The number of microarthropods was higher in AP than in the SO site. The annual mean abundance values of microarthropods in a square meter were 67,763 in AP and 50,542 in SO, and the annual mean abundance values of macroarthropods were 921 m(-2) in AP and 427 m(-2) in SO. Among the soil microarthropods, Acari and Collembola were the dominant groups. Shannon's diversity index was more affected by evenness than species number despite the species diversity (H') of soil arthropods being generally higher in the SO stand. The abundance of microarthropods showed clear seasonal trends depending upon the humidity of the soil.

  1. How does litter cover, litter diversity and fauna affect sediment discharge and runoff?

    NASA Astrophysics Data System (ADS)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2013-04-01

    Litter cover plays a major role in soil erosion processes. It is known that litter cover reduces erosivity of raindrops, decreases sediment discharge and lowers runoff volume compared to bare ground. However, in the context of biodiversity, the composition of litter cover, its effect on sediment discharge and runoff volume and their influence on soil erosion have not yet been analyzed in detail. Focusing on initial soil erosion (splash), our experimental design is designated to get a better understanding of these mechanisms. The experiments were carried out within the DFG research unit "Biodiversity and Ecosystem Functioning (BEF)-China" in subtropical China. The "New Integrated Litter Experiment (NILEx)" used as platform combining different subprojects of BEF-China dealing with "decomposition and nutrient cycling", "mechanisms of soil erosion" and "functional effects of herbivores, predators and saproxylics" in one experiment. In NILEx, 96 40cm x 40cm runoff plots on two hill slopes inside a castanea molissima forest plantation have been installed and filled with seven different types of litter cover. 16 one-species plots, 24 two-species plots, 4 four-species plots and 4 bare ground plots have been set up, each replicated once. We prepared 48 Plots with traps (Renner solution) for soil macrofauna (diplopods and collembola), so half of the plots were kept free from fauna while the other half was accessible for fauna. Rainfall was generated artificially by using a rainfall simulator with a continuous and stable intensity of 60 mm/h. Our experiments included two runs of 20 minutes duration each, both conducted at two different time steps (summer 2012 and autumn 2012). Runoff volume and sediment discharge were measured every 5 minutes during one rainfall run. Litter coverage and litter mass were recorded at the beginning (summer 2012) and at the end of the experiment (autumn 2012). Our results show that sediment discharge as well as runoff volume decreases

  2. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China.

    PubMed

    Cui, Yang; Wang, Silong; Yan, Shaokui

    2016-01-01

    Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors) relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA) showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA), were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007). In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences and distribution

  3. Comparative assessment of fungal augmentation treatments of a fine-textured and historically oil-contaminated soil.

    PubMed

    Covino, Stefano; Stella, Tatiana; D'Annibale, Alessandro; Lladó, Salvador; Baldrian, Petr; Čvančarová, Monika; Cajthaml, Tomas; Petruccioli, Maurizio

    2016-10-01

    The removal of aged hydrophobic contaminants from fine-textured soils is a challenging issue in remediation. The objective of this study was to compare the efficacy of augmentation treatments to that of biostimulation in terms of total aliphatic hydrocarbon (TAH) and toxicity removal from a historically contaminated clay soil and to assess their impact on the resident microbial community. To this aim, Pleurotus ostreatus, Botryosphaeria rhodina and a combination of both were used as the inoculants while the addition of a sterilized lignocellulose mixture to soil (1:5, w/w) was used as a biostimulation approach. As opposed to the non-amended control soil, where no changes in TAH concentration and residual toxicity were observed after 60days, the activation of specialized bacteria was found in the biostimulated microcosms resulting in significant TAH removal (79.8%). The bacterial community structure in B. rhodina-augmented microcosms did not differ from the biostimulated microcosms due to the inability of the fungus to be retained within the resident microbiota. Best TAH removals were observed in microcosms inoculated with P. ostreatus alone (Po) and in binary consortium with B. rhodina (BC) (86.8 and 88.2%, respectively). In these microcosms, contaminant degradation exceeded their bioavailability thresholds determined by sequential supercritical CO2 extraction. Illumina metabarcoding of 16S rRNA gene showed that the augmentation with Po and BC led to lower relative abundances of Gram(+) taxa, Actinobacteria in particular, than those in biostimulated microcosms. Best detoxification, with respect to the non-amended incubation control, was found in Po microcosms where a drop in collembola mortality (from 90 to 22%) occurred. At the end of incubation, in both Po and BC, the relative abundances of P. ostreatus sequences were higher than 60% thus showing the suitability of this fungus in bioaugmentation-based remediation applications. PMID:27220102

  4. Survival of rapidly fluctuating natural low winter temperatures by High Arctic soil invertebrates.

    PubMed

    Convey, Peter; Abbandonato, Holly; Bergan, Frode; Beumer, Larissa Teresa; Biersma, Elisabeth Machteld; Bråthen, Vegard Sandøy; D'Imperio, Ludovica; Jensen, Christina Kjellerup; Nilsen, Solveig; Paquin, Karolina; Stenkewitz, Ute; Svoen, Mildrid Elvik; Winkler, Judith; Müller, Eike; Coulson, Stephen James

    2015-12-01

    The extreme polar environment creates challenges for its resident invertebrate communities and the stress tolerance of some of these animals has been examined over many years. However, although it is well appreciated that standard air temperature records often fail to describe accurately conditions experienced at microhabitat level, few studies have explicitly set out to link field conditions experienced by natural multispecies communities with the more detailed laboratory ecophysiological studies of a small number of 'representative' species. This is particularly the case during winter, when snow cover may insulate terrestrial habitats from extreme air temperature fluctuations. Further, climate projections suggest large changes in precipitation will occur in the polar regions, with the greatest changes expected during the winter period and, hence, implications for the insulation of overwintering microhabitats. To assess survival of natural High Arctic soil invertebrate communities contained in soil and vegetation cores to natural winter temperature variations, the overwintering temperatures they experienced were manipulated by deploying cores in locations with varying snow accumulation: No Snow, Shallow Snow (30 cm) and Deep Snow (120 cm). Air temperatures during the winter period fluctuated frequently between +3 and -24 °C, and the No Snow soil temperatures reflected this variation closely, with the extreme minimum being slightly lower. Under 30 cm of snow, soil temperatures varied less and did not decrease below -12 °C. Those under deep snow were even more stable and did not decline below -2 °C. Despite these striking differences in winter thermal regimes, there were no clear differences in survival of the invertebrate fauna between treatments, including oribatid, prostigmatid and mesostigmatid mites, Araneae, Collembola, Nematocera larvae or Coleoptera. This indicates widespread tolerance, previously undocumented for the Araneae, Nematocera or Coleoptera, of

  5. Ecology of beach wrack in northern New England with special reference to Orchestia platensis*1

    NASA Astrophysics Data System (ADS)

    Behbehani, Manaf I.; Croker, Robert A.

    1982-12-01

    The northern New England beach wrack community with special reference to the cosmopolitan amphipod crustacean, Orchestia platensis, was examined at estuarine and open coastal habitats. Beach wrack was dominated by the plant genera Ascophyllum, Zostera, Spartina and Chondrus, and was most abundant during spring and late summer. Animal community numbers, biomass and frequency in fresh to moderately decomposed wrack were dominated by O. platensis throughout the year at all habitats; oligochaetes and Collembola were also important. The abundance of O. platensis showed high spatial and temporal variability, with low abundance generally associated with decreased amounts of wrack during colder months. An exception was the winter presence of the species at one estuarine habitat, in patchy aggregations within gravel-cobble refuges. The abundance of O. platensis averaged 1280 (0.04 m 2) -1, with a maximum of 7040 (0.04 m 2) -1. The life cycle of O. platensis is bivoltine, with summer-hatched young reaching maturity within 1 month. Laboratory studies indicate females with up to 4 broods (30 days) -1, averaging 18 eggs brood -1. Orchestia platensis is omnivorous, eating fresh plant tissue, live oligochaetes, Limulus eggs and diatom 'fuzz'. The rate of laboratory consumption of algae and Zostera was 0.05 mg plant mg -1 wet body weight day -1. Presumptive predators of O. platensis are juvenile green crab, Carcinus maenus, and the earwig. Anisolabis maritima. The mobility, aggregation and aggressiveness of O. platensis assist the species in establishing and maintaining populations in the rigorous wrack habitat. The general competitive superiority of O. platensis over its congener, O. gammarella, and the co-occurrence of these species on both eastern and western Atlantic shores is discussed.

  6. Spatially structured environmental filtering of collembolan traits in late successional salt marsh vegetation.

    PubMed

    Widenfalk, Lina A; Bengtsson, Jan; Berggren, Åsa; Zwiggelaar, Krista; Spijkman, Evelien; Huyer-Brugman, Florrie; Berg, Matty P

    2015-10-01

    Both the environment and the spatial configuration of habitat patches are important factors that shape community composition and affect species diversity patterns. Species have traits that allow them to respond to their environment. Our current knowledge on environment to species traits relationships is limited in spite of its potential importance for understanding community assembly and ecosystem function. The aim of our study was to examine the relative roles of environmental and spatial variables for the small-scale variation in Collembola (springtail) communities in a Dutch salt marsh. We used a trait-based approach in combination with spatial statistics and variance partitioning, between environmental and spatial variables, to examine the important ecological factors that drive community composition. Turnover of trait diversity across space was lower than for species diversity. Most of the variation in community composition was explained by small-scale spatial variation in topography, on a scale of 4-6 m, most likely because it determines the effect of inundation, which restricts where habitat generalists can persist. There were only small pure spatial effects on species and trait diversity, indicating that biotic interactions or dispersal limitation probably were less important for structuring the community at this scale. Our results suggest that for springtails, life form (i.e. whether they live in the soil or litter or on the surface/in vegetation) is an important and useful trait to understand community assembly. Hence, using traits in addition to species identity when analysing environment-organism relationships results in a better understanding of the factors affecting community composition. PMID:26001605

  7. Toxicodynamics of copper and cadmium in Folsomia candida exposed to simulated soil solutions.

    PubMed

    Ardestani, Masoud M; van Gestel, Cornelis A M

    2013-12-01

    To improve our understanding of metal bioavailability to soil-living invertebrates, the effect of porewater composition on the toxicodynamics of copper and cadmium in Folsomia candida (Collembola) was investigated. Assuming that porewater is the main exposure route, F. candida was exposed to simulated soil solutions of different composition. Toxicity of copper was slightly lower in a calcium-only solution than in a multication solution. With increasing copper concentrations from 0.005 mM to 1.37 mM, internal copper concentrations similarly increased in both exposure solutions, suggesting that a single cation nutrient solution is suitable for testing F. candida. In the second experiment, animals were exposed for 7 d to copper and cadmium in simplified soil solutions with different calcium (0.2 mM, 0.8 mM, 3.2 mM, 12.8 mM) and pH (5.0, 6.0, 7.0) levels. The median lethal concentration (LC50) values decreased with time in both the calcium and pH series. A hormetic-type effect was observed for copper in the second test, as well as in the calcium-only solution in the first experiment. Because of stronger hormesis, LC50s for copper were higher at lower calcium concentrations. For cadmium, LC50 values were higher at higher calcium concentrations, suggesting competition of calcium with the free cadmium ion. Toxicity of cadmium increased with decreasing pH, while copper was more toxic at intermediate pH. The results show that a toxicodynamics approach can help to improve the interpretation of metal toxicity to soil invertebrates, taking into account soil solution properties. PMID:23955663

  8. Soil invertebrate community change over fuel-contaminated sites on a subantarctic island: An ecological field-based line of evidence for site risk assessment.

    PubMed

    Wasley, Jane; Mooney, Thomas J; King, Catherine K

    2016-04-01

    A number of fuel spills, of both recent and historic origins, have occurred on World Heritage-listed subantarctic Macquarie Island. Sites contaminated by mainly diesel fuels are undergoing remediation by the Australian Antarctic Division. The risks posed by these sites are being managed using a "weight of evidence" approach, for which this study provides a preliminary line of evidence for the ecological assessment component of this site management decision framework. This knowledge is pertinent, given the absence of environmental guidelines for fuel contaminants in subantarctic ecosystems. We provide a field-based, site-specific ecological risk assessment for soil invertebrate communities across the fuel spill sites, before the commencement of in situ remediation activities. Springtails (Collembola) were the most abundant taxa. Springtail community patterns showed only limited correlations with the level of fuel contamination at the soil surface, even when elevated levels occurred in the substratum layers. Of the environmental variables measured, community patterns were most strongly correlated with vegetation cover. We identify a suite of 6 species that contribute most to the community dynamics across these sites. A subset of these we propose as useful candidates for future development of single-species toxicity tests: Folsomotoma punctata, Cryptopygus caecus, Cryptopygus antarcticus and Parisotoma insularis. Findings from this study advance our understanding of soil invertebrate community dynamics within these contaminated sites, directly contributing to the improved management and restoration of the sites. Not only does this study provide an important line of evidence for the island's ecological risk assessment for fuel contaminants, it also enhances our understanding of the potential impact of fuels at other subantarctic islands. PMID:26202610

  9. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China

    PubMed Central

    Cui, Yang; Wang, Silong; Yan, Shaokui

    2016-01-01

    Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors) relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA) showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA), were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007). In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences and distribution

  10. Survival of rapidly fluctuating natural low winter temperatures by High Arctic soil invertebrates.

    PubMed

    Convey, Peter; Abbandonato, Holly; Bergan, Frode; Beumer, Larissa Teresa; Biersma, Elisabeth Machteld; Bråthen, Vegard Sandøy; D'Imperio, Ludovica; Jensen, Christina Kjellerup; Nilsen, Solveig; Paquin, Karolina; Stenkewitz, Ute; Svoen, Mildrid Elvik; Winkler, Judith; Müller, Eike; Coulson, Stephen James

    2015-12-01

    The extreme polar environment creates challenges for its resident invertebrate communities and the stress tolerance of some of these animals has been examined over many years. However, although it is well appreciated that standard air temperature records often fail to describe accurately conditions experienced at microhabitat level, few studies have explicitly set out to link field conditions experienced by natural multispecies communities with the more detailed laboratory ecophysiological studies of a small number of 'representative' species. This is particularly the case during winter, when snow cover may insulate terrestrial habitats from extreme air temperature fluctuations. Further, climate projections suggest large changes in precipitation will occur in the polar regions, with the greatest changes expected during the winter period and, hence, implications for the insulation of overwintering microhabitats. To assess survival of natural High Arctic soil invertebrate communities contained in soil and vegetation cores to natural winter temperature variations, the overwintering temperatures they experienced were manipulated by deploying cores in locations with varying snow accumulation: No Snow, Shallow Snow (30 cm) and Deep Snow (120 cm). Air temperatures during the winter period fluctuated frequently between +3 and -24 °C, and the No Snow soil temperatures reflected this variation closely, with the extreme minimum being slightly lower. Under 30 cm of snow, soil temperatures varied less and did not decrease below -12 °C. Those under deep snow were even more stable and did not decline below -2 °C. Despite these striking differences in winter thermal regimes, there were no clear differences in survival of the invertebrate fauna between treatments, including oribatid, prostigmatid and mesostigmatid mites, Araneae, Collembola, Nematocera larvae or Coleoptera. This indicates widespread tolerance, previously undocumented for the Araneae, Nematocera or Coleoptera, of

  11. Maximizing collection and minimizing risk: does vacuum suction sampling increase the likelihood for misinterpretation of food web connections?

    PubMed

    Chapman, Eric G; Romero, Susan A; Harwood, James D

    2010-11-01

    Molecular tools that characterize the structure of complex food webs and identify trophic connectedness in the field have become widely adopted in recent years. However, characterizing the intensity of predator-prey interactions can be prone to error. Maximizing collection success of small, fast-moving predators with vacuum suction samplers has the potential to increase the likelihood of prey DNA detection either through surface-level contamination with damaged prey or direct consumption within the sampling device. In this study, we used PCR to test the hypothesis that vacuum suction sampling will not cause an erroneous increase in the detection of 'predation', thereby incorrectly assigning trophic linkages when evaluating food web structure. We utilized general (1) Aphidoidea and (2) Collembola primers to measure the predation rates of Glenognatha foxi (Araneae: Tetragnathidae) on these prey collected by hand versus those sampled with a vacuum suction device. With both primer pairs, there was no significant increase in predators screening positive for prey DNA when sampled by vacuum suction versus those predators collected, in parallel, by hand. These results clearly validate the application of vacuum suction sampling during molecular gut-content analysis of predator-prey feeding linkages in the field. Furthermore, we found no evidence that predation was occurring inside the suction sampler because specimens collected were never observed to be feeding nor did they screen positive at greater frequencies than hand-collected individuals. Therefore, it can be concluded that the use of vacuum suction sampling devices (in this case a Modified CDC Backpack Aspirator Model 1412) is suitable for molecular gut-content analysis.

  12. Making sense of soil ecotoxicology

    USGS Publications Warehouse

    Beyer, W.N.; Linder, G.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John=

    1995-01-01

    Conclusion: Van de Westeringh likened the accumulation of litter in pesticide-treated orchards to the development of a mor. At Palmerton, although Strojan recorded reductions of all litter arthropod taxa he sampled, the reductions were especially severe for oribatid mites, millipedes, and centipedes, and were relatively minor for other mites and Collembola. We may view the accumulation of 02 litter at contaminated sites not simply as a reduction in the rate of decomposition, but as a shift toward a mor. The sites studied by Tyler et al. were already naturally mors; thus, the metal contamination did not change the kind of litter development, but thickened the 02 horizon. We suggest that a general way of describing the changes reported at various contaminated sites is a shift from the macrotrophic system to the microtrophic or mesotrophic systems. We suggest this should be considered more than a change in the soil ecosystem, but damage to it, because the soil is likely to be less productive. The organic matter may still decompose, but the beneficial effects of the larger soil organisms are absent. We suggest that the accumulation of organic matter in contaminated orchards and turf grass may be more a result of reduced incorporation of organic matter into mineral soil rather than of a reduced rate of decomposition. The microtrophic and mesotrophic systems may carry out the decomposition process when macrotrophic organisms are eliminated, and the rate of decomposition per area may return to normal, but soil quality may deteriorate nonetheless. This loss of soil quality is a logical basis for protecting populations of earthworms and other large soil organisms. We suggest that a measure of the importance of the macrotrophic organisms relative to all decomposers could be used to estimate damage to a soil ecosystem from environmental contaminants

  13. Density and community structure of soil- and bark-dwelling microarthropods along an altitudinal gradient in a tropical montane rainforest

    PubMed Central

    Illig, Jens; Norton, Roy A.; Scheu, Stefan

    2010-01-01

    Microarthropod communities in the soil and on the bark of trees were investigated along an elevation gradient (1,850, 2,000, 2,150, 2,300 m) in a tropical montane rain forest in southern Ecuador. We hypothesised that the density of microarthropods declines with depth in soil and increases with increasing altitude mainly due to the availability of resources, i.e. organic matter. In addition, we expected bark and soil communities to differ strongly, since the bark of trees is more exposed to harsher factors. In contrast to our hypothesis, the density of major microarthropod groups (Collembola, Oribatida, Gamasina, Uropodina) was generally low and decreased with altitude. However, as we predicted the density of each of the groups decreased with soil depth. Density of microarthropods on tree bark was lower than in soil. Overall, 43 species of oribatid mites were found, with the most abundant higher taxa being Poronota, pycnonotic Apheredermata, Mixonomata and Eupheredermata. The oribatid mite community on bark did not differ significantly from that in soil. The number of oribatid mite species declined with altitude (24, 23, 17 and 13 species at 1,850, 2,000, 2,150 and 2,300 m, respectively). Rarefaction curves indicate that overall about 50 oribatid mite species are to be expected along the studied altitudinal gradient. Results of this study indicate (1) that microarthropods may be limited by the quality of resources at high altitudes and by the amount of resources at deeper soil layers, and (2) that the bark of trees and the soil are habitats of similar quality for oribatid mites. Electronic supplementary material The online version of this article (doi:10.1007/s10493-010-9348-x) contains supplementary material, which is available to authorized users. PMID:20229099

  14. Impact of land use practices on faunal abundance, nutrient dynamics and biochemical properties of desert pedoecosystem.

    PubMed

    Tripathi, G; Sharma, B M

    2005-11-01

    Increased dependence of resource-poor rural communities on soils of low inherent fertility are the major problem of desert agroecosystem. Agrisilviculture practices may help to conserve the soil biota for maintaining essential soil properties and processes in harsh climate. Therefore, the impacts of different land use systems on faunal density, nutrient dynamics and biochemical properties of soil were studied in agrisilviculture system of Indian desert. The selected fields had trees (Zizyphus mauritiana, Prosopis cineraria, Acacia nilotica) and crops (Cuminum cyminum, Brassica nigra, Triticum aestivum) in different combinations. Populations of Acari, Myriapoda, Coleoptera, Collembola, other soil arthropods and total soil fauna showed significant changes with respect to different land use practices and tree species, indicating a strong relation between above and below ground biodiversity. The Coleoptera exhibited greatest association with all agrisilviculture fields. The Z. mauritiana system indicated highest facilitative effects (RTE value) on all groups of soil fauna. Soil temperature, moisture, organic carbon, nitrate- and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were greater under tree than that of tree plus cropping system. It showed accumulation of nitrate-nitrogen in tree field and more utilization by crops in cultivated lands. Positive and significant correlation among organic carbon, nitrate- and ammonical-nitrogen, phosphorus, soil respiration and dehydrogenase activity clearly reflects increase in soil nutrients with the increase in microbial and other biotic activity. P. cineraria field was the best pedoecosystem, while C. cyminum was the best winter crop for cultivation in desert agroforestry system for soil biological health and soil sustainability. The increase in organic carbon, soil nutrients and microbial activity is associated with the increase in soil faunal population which reflect role of soil fauna

  15. Diversified forest ecosystems can grow on industrial waste residues: evidence from a multiproxy approach

    NASA Astrophysics Data System (ADS)

    Cortet, Jerome; Schwartz, Christophe; Echevarria, Guillaume; Nahmani, Johanne; Masfaraud, Jean-François; Ouvrard, Stéphanie; Sirguey, Catherine; Watteau, Francoise; Morel, Jean Louis

    2010-05-01

    Smelter activities in the Lorraine region (North-East France) have lead to the creation of flotation ponds that were used to eliminate wastes, mainly slag. After industrial decline, some of these flotation ponds were colonized by vegetation and evolved to forest ecosystems. One of these old flotation ponds, situated in Pompey, close to Nancy (North-East France), was studied by collecting information on several physico-chemical and biological indicators. The main objective was to understand the biological functioning of this system, whose soil can be classified as a pure Technosol, characterised by a very complex stratified profile created by successive slag deposits. Soil is characterized by its apparent heterogeneity, but also its high agronomic fertility and particularly high metal contents. Holorganic horizons can vary from one to several centimetres. Macrofauna is characterized by a very low abundance of earthworms and a dominance of millipedes. Furthermore, whereas earthworms do accumulate metals, this is not the case for millipedes. Mesofauna is typical of a temperate forest system, dominated by Collembola. Soil organo-mineral associations showed a high proportion of faecal pellets from Oribatid mites, Isopods and Diplopods. Furthermore, Mn, which is highly associated to metals (especially Zn and Pb) seems to play an important role in organo-mineral associations, including bacteria. An organic fraction is also directly associated to Calcium, Pb and Cu. Vegetation presents a high diversity, with more than 70 species, with very low metal transfer to plants. Results from soil respirometry are typical from temperate forest ecosystems. All this information has been combined to propose a model for the biochemical functioning of a such Technosol.

  16. Soil microcosm for testing the effects of chemical pollutants on soil fauna communities and trophic structure

    SciTech Connect

    Parmelee, R.W. . Dept. of Entomology); Wentsel, R.S.; Phillips, C.T.; Checkai, R.T. ); Simini, M. )

    1993-08-01

    A microcosm technique is presented that uses community and trophic-level analysis of soil nematodes and microarthropods to determine the effects of chemicals on soil systems. Forest soil was treated with either copper, p-nitrophenol, or trinitrotoluene. Nematodes were sorted into bacterivore, fungivore, herbivore, and omnivore-predator trophic groups, and a hatchling category. Microarthropods were sorted to the acarine suborders Prostigmata, Mesostigmata, and Oribatida; the insectan order Collembola; and a miscellaneous group. Omnivore-predator nematodes and meso-stigmatid and oribatid mites were the groups most sensitive to copper and were significantly reduced at levels as low as 100 [mu]g g[sup [minus]1] copper. Total nematode and microarthropod numbers declined above 200 [mu]g g[sup [minus]1] copper. Trophic structure analysis suggested that high sensitivity of nematode predators to intermediate levels of copper reduced predation on herbivore nematodes and resulted in greater numbers of nematodes compared to controls. p-Nitrophenol was very toxic to the nematode community, and all trophic groups were significantly reduced above 20 [mu]g g[sup [minus]1]. However, there was no effect of p-nitrophenol on microarthropods. Trinitrotoluene had no significant negative effect on total abundance of either groups of soil fauna, but oribatids were significantly reduced at 200 [mu]g g[sup [minus]1]. The results demonstrated that soil nematodes and microarthropods were sensitive indicators of environmental contaminants and that trophic-structure and community analysis has the potential to detect more subtle indirect effects of chemicals on soil food-web structure. The authors conclude that microcosms with field communities of soil microfauna offer high resolution of the ecotoxicological effects of chemicals in complex soil systems.

  17. Preliminary study of the refaunation of alkaline shale coal surface mine spoil by soil arthropods

    SciTech Connect

    Cross, E.A.; Wilman, J.M.

    1982-12-01

    Soil sampling stations were laid out on (largely) untopsoiled shale surface mine spoil in 1979. Stations were located on spoil graded in 1978-1979, in ungraded spoil cast in 1972 and aerially seeded in 1973, and in adjacent off-mine woods and an old field. Additional stations were added in 1982 on spoil graded only 3.5 weeks - 3 months prior to sampling. Stations were located to include important variables typical of the mine. Of 17 classes-orders of arthropods recovered from all sites, only Acari (78-99% of total individuals) and Collembola (2-12%) were consistently widespread and numerous, and only Acari were important in the youngest spoils. A total of 69 mite families - superfamilies - were identified during the course of the study. Low-moderate mite populations were found in bare shale spoil graded only 3.5 weeks - 3 months prior to sampling, these distributed among 4 families. Samples from 1978-79 spoil contained 13 families 3-7 months after grading and 2 years later were comparable to off-mine sites both in numbers of individuals and number of families. Spoil from 1973 was comparable to off-mine sites in these 2 respects when first sampled. Earliest pioneer species were 3 (presumably) microherbivores, these remaining dominant for several years. Predatory mites appeared early and were well established less than a year after grading. Saprovores were absent or relatively scarce in the 2 youngest spoils, but well established in the 1973 spoil at first sampling.

  18. Effects of future rainfall patterns on density and diversity of predatory mites (Gamasida) in characteristic agricultural soils of the Pannonian area

    NASA Astrophysics Data System (ADS)

    Wissuwa, Janet; Berthold, Helene; Bruckner, Alexander; Zaller, Johann; Hösch, Johannes; Baumgarten, Andreas

    2013-04-01

    Regional climate change scenarios for the end of this century predict fewer but heavier rainfalls and longer lasting droughts during the vegetation period without substantial changes in the total annual amount of rainfall for Eastern Austria (Pannonian region). In a multidisciplinary study, the consequences of future precipitation patterns on agroecosystem processes and functions in one of the most productive agricultural areas of Austria are tested at the AGES Lysimeter station. The lysimeter station comprises the three main soil types of the pannonian agricultural area (calcaric phaeozem, gleyic phaeozem, calcic chernozem) together covering about 80% of the agricultural area. Lysimeters are a valuable tool to study the effects of climate change on the complete soil ecosystem interacting with plants. Precipitation rates are modified according to the predicted 2050 scenario in comparison to the current precipitation patterns. The abundance and diversity of soil arthropods (Collembola, Gamasida, Oribatida) is monitored for three years. Five randomly taken soil samples per lysimeter (ø 5 cm, 10 cm depth) are pooled for arthropod extraction. Here we will present first year results for Gamasida. As one of the dominant acarine predators Gamasida play a crucial role in soil food webs contributing to nutrient cycling. Preliminary results indicate a stronger influence of soil type than rainfall patterns on mite density. Gamasida density decreased in the order calcaric phaeozem > calcic chernozem > gleyic phaeozem for every sampling date. No difference between current and predicted rainfall was found in May, where the different irrigation measures were launched, and July. Mite density tended to be higher for current rainfall in September.

  19. Field trials to evaluate effects of continuously planted transgenic insect-resistant cottons on soil invertebrates.

    PubMed

    Li, Xiaogang; Liu, Biao; Wang, Xingxiang; Han, Zhengmin; Cui, Jinjie; Luo, Junyu

    2012-03-01

    Impacts on soil invertebrates are an important aspect of environmental risk assessment and post-release monitoring of transgenic insect-resistant plants. The purpose of this study was to research and survey the effects of transgenic insect-resistant cottons that had been planted over 10 years on the abundance and community structure of soil invertebrates under field conditions. During 3 consecutive years (2006-2008), eight common taxa (orders) of soil invertebrates belonging to the phylum Arthropoda were investigated in two different transgenic cotton fields and one non-transgenic cotton field (control). Each year, soil samples were taken at four different growth stages of cotton (seedling, budding, boll forming and boll opening). Animals were extracted from the samples using the improved Tullgren method, counted and determined to the order level. The diversity of the soil fauna communities in the different fields was compared using the Simpson's, Shannon's diversity indices and evenness index. The results showed a significant sampling time variation in the abundance of soil invertebrates monitored in the different fields. However, no difference in soil invertebrate abundance was found between the transgenic cotton fields and the control field. Both sampling time and cotton treatment had a significant effect on the Simpson's, Shannon's diversity indices and evenness index. They were higher in the transgenic fields than the control field at the growth stages of cotton. Long-term cultivation of transgenic insect-resistant cottons had no significant effect on the abundance of soil invertebrates. Collembola, Acarina and Araneae could act as the indicators of soil invertebrate in this region to monitor the environmental impacts of transgenic plants in the future.

  20. A complete insect from the Late Devonian period.

    PubMed

    Garrouste, Romain; Clément, Gaël; Nel, Patricia; Engel, Michael S; Grandcolas, Philippe; D'Haese, Cyrille; Lagebro, Linda; Denayer, Julien; Gueriau, Pierre; Lafaite, Patrick; Olive, Sébastien; Prestianni, Cyrille; Nel, André

    2012-08-01

    After terrestrialization, the diversification of arthropods and vertebrates is thought to have occurred in two distinct phases, the first between the Silurian and the Frasnian stages (Late Devonian period) (425-385 million years (Myr) ago), and the second characterized by the emergence of numerous new major taxa, during the Late Carboniferous period (after 345 Myr ago). These two diversification periods bracket the depauperate vertebrate Romer's gap (360-345 Myr ago) and arthropod gap (385-325 Myr ago), which could be due to preservational artefact. Although a recent molecular dating has given an age of 390 Myr for the Holometabola, the record of hexapods during the Early-Middle Devonian (411.5-391 Myr ago, Pragian to Givetian stages) is exceptionally sparse and based on fragmentary remains, which hinders the timing of this diversification. Indeed, although Devonian Archaeognatha are problematic, the Pragian of Scotland has given some Collembola and the incomplete insect Rhyniognatha, with its diagnostic dicondylic, metapterygotan mandibles. The oldest, definitively winged insects are from the Serpukhovian stage (latest Early Carboniferous period). Here we report the first complete Late Devonian insect, which was probably a terrestrial species. Its 'orthopteroid' mandibles are of an omnivorous type, clearly not modified for a solely carnivorous diet. This discovery narrows the 45-Myr gap in the fossil record of Hexapoda, and demonstrates further a first Devonian phase of diversification for the Hexapoda, as in vertebrates, and suggests that the Pterygota diversified before and during Romer's gap.

  1. An evolutionary analysis of flightin reveals a conserved motif unique and widespread in Pancrustacea.

    PubMed

    Soto-Adames, Felipe N; Alvarez-Ortiz, Pedro; Vigoreaux, Jim O

    2014-01-01

    Flightin is a thick filament protein that in Drosophila melanogaster is uniquely expressed in the asynchronous, indirect flight muscles (IFM). Flightin is required for the structure and function of the IFM and is indispensable for flight in Drosophila. Given the importance of flight acquisition in the evolutionary history of insects, here we study the phylogeny and distribution of flightin. Flightin was identified in 69 species of hexapods in classes Collembola (springtails), Protura, Diplura, and insect orders Thysanura (silverfish), Dictyoptera (roaches), Orthoptera (grasshoppers), Pthiraptera (lice), Hemiptera (true bugs), Coleoptera (beetles), Neuroptera (green lacewing), Hymenoptera (bees, ants, and wasps), Lepidoptera (moths), and Diptera (flies and mosquitoes). Flightin was also found in 14 species of crustaceans in orders Anostraca (water flea), Cladocera (brine shrimp), Isopoda (pill bugs), Amphipoda (scuds, sideswimmers), and Decapoda (lobsters, crabs, and shrimps). Flightin was not identified in representatives of chelicerates, myriapods, or any species outside Pancrustacea (Tetraconata, sensu Dohle). Alignment of amino acid sequences revealed a conserved region of 52 amino acids, referred herein as WYR, that is bound by strictly conserved tryptophan (W) and arginine (R) and an intervening sequence with a high content of tyrosines (Y). This motif has no homologs in GenBank or PROSITE and is unique to flightin and paraflightin, a putative flightin paralog identified in decapods. A third motif of unclear affinities to pancrustacean WYR was observed in chelicerates. Phylogenetic analysis of amino acid sequences of the conserved motif suggests that paraflightin originated before the divergence of amphipods, isopods, and decapods. We conclude that flightin originated de novo in the ancestor of Pancrustacea > 500 MYA, well before the divergence of insects (~400 MYA) and the origin of flight (~325 MYA), and that its IFM-specific function in Drosophila is a more

  2. Influence of crop management practices on bean foliage arthropods.

    PubMed

    Pereira, J L; Picanço, M C; Pereira, E J G; Silva, A A; Jakelaitis, A; Pereira, R R; Xavier, V M

    2010-12-01

    Crop management practices can affect the population of phytophagous pest species and beneficial arthropods with consequences for integrated pest management. In this study, we determined the effect of no-tillage and crop residue management on the arthropod community associated with the canopy of common beans (Phaseolus vulgaris L.). Abundance and species composition of herbivorous, detritivorous, predaceous and parasitoid arthropods were recorded during the growing seasons of 2003 and 2004 in Coimbra County, Minas Gerais State, Brazil. Arthropod diversity and guild composition were similar among crop management systems, but their abundance was higher under no-tillage relative to conventional cultivation and where residues from the preceding crop were maintained in the field. Thirty-four arthropod species were recorded, and those most representative of the impact of the crop management practices were Hypogastrura springtails, Empoasca kraemeri and Circulifer leafhoppers, and Solenopsis ants. The infestation levels of major insect-pests, especially leafhoppers (Hemiptera: Cicadellidae), was on average seven-fold lower under no-tillage with retention of crop residues relative to the conventional system with removal of residues, whereas the abundance of predatory ants (Hymenoptera: Formicidae) and springtails (Collembola: Hypogastruridae) were, respectively, about seven- and 15-fold higher in that treatment. Importantly, a significant trophic interaction among crop residues, detritivores, predators and herbivores was observed. Plots managed with no-tillage and retention of crop residues had the highest bean yield, while those with conventional cultivation and removal of the crop residues yielded significantly less beans. This research shows that cropping systems that include zero tillage and crop residue retention can reduce infestation by foliar insect-pests and increase abundance of predators and detritivores, thus having direct consequences for insect pest management.

  3. Complex responses to invasive grass litter by ground arthropods in a Mediterranean scrub ecosystem.

    PubMed

    Wolkovich, Elizabeth Mary; Bolger, Douglas T; Holway, David A

    2009-10-01

    Plant invasions have tremendous potential to alter food webs by changing basal resources. Recent studies document how plant invasions may contribute to increased arthropod abundances in detritus-based food webs. An obvious mechanism for this phenomenon-a bottom-up effect resulting from elevated levels of detritus from the invasive plant litter-has not been explicitly studied. We examined the effects of an annual grass invasion on ground arthropod assemblages in the coastal sage scrub (CSS) of southern California. Bottom-up food web theory predicts that the addition of detritus would increase generalist-feeding arthropods at all trophic levels; accordingly, we expected increases in fungi, Collembola, and common predators such as mites and spiders. For the common ant taxa, habitat alteration may also be important for predicting responses. Thus we expected that Forelius mccooki and Pheidole vistana, the most common ant species, would decline because of changes in soil temperature (F. mccooki) and habitat structure (P. vistana) associated with litter. We studied trends observationally and conducted a 3-year experiment in which we manipulated litter quantity. In contrast to other published studies, most detritus-based arthropod taxa declined in areas of high grass invasion, and, within trophic levels, responses often varied idiosyncratically. For the two most common taxa, a native ant (F. mccooki), and predatory mites in the Anystidae, we experimentally linked declines in abundance to increased levels of invasive grass litter. Such declines, especially those exhibited by the most common ant taxa, could have cascading effects on the CSS ecosystem, where ants are numerically dominant and thus may have broad influences on food web and ecosystem properties. Our results highlight that accurately predicting arthropod responses to invasive plant litter requires careful consideration of the structural and food resources provided by detritus to each particular food web.

  4. Dynamics of the leaf-litter arthropod fauna following fire in a neotropical woodland savanna.

    PubMed

    Vasconcelos, Heraldo L; Pacheco, Renata; Silva, Raphael C; Vasconcelos, Pedro B; Lopes, Cauê T; Costa, Alan N; Bruna, Emilio M

    2009-11-09

    Fire is an important agent of disturbance in tropical savannas, but relatively few studies have analyzed how soil-and-litter dwelling arthropods respond to fire disturbance despite the critical role these organisms play in nutrient cycling and other biogeochemical processes. Following the incursion of a fire into a woodland savanna ecological reserve in Central Brazil, we monitored the dynamics of litter-arthropod populations for nearly two years in one burned and one unburned area of the reserve. We also performed a reciprocal transplant experiment to determine the effects of fire and litter type on the dynamics of litter colonization by arthropods. Overall arthropod abundance, the abundance of individual taxa, the richness of taxonomic groups, and the species richness of individual taxa (Formiciade) were lower in the burned site. However, both the ordinal-level composition of the litter arthropod fauna and the species-level composition of the litter ant fauna were not dramatically different in the burned and unburned sites. There is evidence that seasonality of rainfall interacts with fire, as differences in arthropod abundance and diversity were more pronounced in the dry than in the wet season. For many taxa the differences in abundance between burned and unburned sites were maintained even when controlling for litter availability and quality. In contrast, differences in abundance for Collembola, Formicidae, and Thysanoptera were only detected in the unmanipulated samples, which had a lower amount of litter in the burned than in the unburned site throughout most of our study period. Together these results suggest that arthropod density declines in fire-disturbed areas as a result of direct mortality, diminished resources (i.e., reduced litter cover) and less favorable microclimate (i.e., increased litter desiccation due to reduction in tree cover). Although these effects were transitory, there is evidence that the increasingly prevalent fire return interval of

  5. A soil microcosm to test the effects of pollutants on soil nematode and microarthropod communities

    SciTech Connect

    Parmelee, R.W.; Wentsel, R.S.; Checkai, R.T.; Phillips, C.T.; Bohlen, P.J.

    1995-12-31

    Previous studies have demonstrated that microcosms with field collected soil nematode and microarthropod communities are suitable model systems to detect effects of toxins on soil food web structure and function. The authors investigated the toxicity of copper, cadmium, malathion, and Aroclor 1254 to nematodes (total, bacterivores, fungivores, herbivores, omnivore-predators, hatchlings) and microarthropods (Prostigmata, Mesostigmata, Oribatida, Collembola, other arthropods). Nematodes were sensitive indicators of copper application, and total numbers were reduced at 100 {micro}g g{sup {minus}1}. Fungivore, bacterivore and omnivore-predators were the most susceptible trophic groups. Cadmium had no effects on either nematode or microarthropod communities. Microarthropods were more sensitive to malathion than nematodes, and total microarthropod abundance was lower than controls at 320 {micro}g g{sup {minus}1}. Prostigmatid mites and other arthropods were the most affected groups. Only the herbivore nematode trophic group was affected by malathion, and numbers did not decline until 1,280 {micro}g g{sup {minus}1}. Aroclor 1254 also had a greater negative impact on microarthropods than on nematodes. Total microarthropod abundance declined at 2,500 {micro}g g{sup {minus}1}, while there was no effect on nematodes. Prostigmatid and oribatid mites were the most susceptible groups to PCB application. Strong differential sensitivity between nematode and microarthropod communities indicates that both groups need to be examined to fully evaluate the impact of chemicals on soil systems. The authors conclude that microcosms with field-collected communities of soil microfauna offer high resolution of the ecotoxicological effects of chemicals in complex soil systems.

  6. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China.

    PubMed

    Cui, Yang; Wang, Silong; Yan, Shaokui

    2016-01-01

    Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors) relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA) showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA), were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007). In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences and distribution

  7. Arthropods associated with the crown of Mauritia flexuosa (Arecaceae) palm trees in three different environments from Brazilian Cerrado.

    PubMed

    Gurgel-Gonçalves, Rodrigo; Palma, Alexandre R T; Motta, Paulo C; Bar, Maria E; Cuba, Cesar A C

    2006-01-01

    Canopy arthropods, mainly from palm trees, are little known in the Brazilian Cerrado. In order to describe the arthropod community structure associated with the crown of Mauritia flexuosa (Arecaceae), we sampled 150 palm trees in six "veredas" of the Federal District, Brazil, in wild, rural and periurban areas in the rainy season. The arthropods within abandoned bird nests, mammal refuges, leaves and organic matter were manually collected, preserved in ethanol 70% and separated by order, family, morphospecies and feeding guilds. Stem height and diameter of the palm crowns were measured and leaves and bird nests were counted. We collected 3,862 arthropods, from 15 orders, 45 families and 135 morphospecies. The most abundant orders were Coleoptera (28.6%), Blattodea (21.8%), Collembola (11.4%) and Hemiptera (10.2%). The families Blaberidae, Entomobryidae, Reduviidae, Oniscidae, Staphylinidae, Carabidae and Formicidae, represented 82.1% of all individuals collected. The majority of morphospecies was not abundant, 71 (52.6%) were represented by less than 1 individual/tree. Coleopterans accounted for the highest number of morphospecies (43.7%) followed by Araneae (20.0%). The analysis of the arthropod feeding guilds showed prevalence of predatory/hematophagous ones (36.0%). Arthropod richness and abundance presented smaller values for periurban environment. The number of bird nests presented positive correlation with abundance and richness; this was not found when considering the measurements of the palm trees. The importance of M. flexuosa for the maintenance of the arthropod fauna of the "veredas" in Cerrado biome is discussed.

  8. Sweeping beauty: is grassland arthropod community composition effectively estimated by sweep netting?

    PubMed Central

    Spafford, Ryan D; Lortie, Christopher J

    2013-01-01

    Arthropods are critical ecosystem components due to their high diversity and sensitivity to perturbation. Furthermore, due to their ease of capture they are often the focus of environmental health surveys. There is much debate regarding the best sampling method to use in these surveys. Sweep netting and pan trapping are two sampling methods commonly used in agricultural arthropod surveys, but have not been contrasted in natural grassland systems at the community level. The purpose of this study was to determine whether sweep netting was effective at estimating arthropod diversity at the community level in grasslands or if supplemental pan trapping was needed. Arthropods were collected from grassland sites in Montana, USA, in the summer of 2011. The following three standardized evaluation criteria (consistency, reliability, and precision) were developed to assess the efficacy of sweep netting and pan trapping, based on analyses of variations in arthropod abundances, species richness, evenness, capture frequency, and community composition. Neither sampling method was sufficient in any criteria to be used alone for community-level arthropod surveys. On a taxa-specific basis, however, sweep netting was consistent, reliable, and precise for Thysanoptera, infrequently collected (i.e., rare) insects, and Arachnida, whereas pan trapping was consistent, reliable, and precise for Collembola and bees, which is especially significant given current threats to the latter's populations worldwide. Species-level identifications increase the detected dissimilarity between sweep netting and pan trapping. We recommend that community-level arthropod surveys use both sampling methods concurrently, at least in grasslands, but likely in most nonagricultural systems. Target surveys, such as monitoring bee communities in fragmented grassland habitat or where detailed information on behavior of the target arthropod groups is available can in some instances employ singular methods. As a

  9. Assessing environmental conditions of Antarctic footpaths to support management decisions.

    PubMed

    Tejedo, Pablo; Benayas, Javier; Cajiao, Daniela; Albertos, Belén; Lara, Francisco; Pertierra, Luis R; Andrés-Abellán, Manuela; Wic, Consuelo; Luciáñez, Maria José; Enríquez, Natalia; Justel, Ana; Reck, Günther K

    2016-07-15

    Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over a decade and is a marked route that is clearly visible. The second one was created more recently. Several physical and biological indicators were measured in order to assess the environmental conditions for both paths. Some physical variables related to human impact were lower for the first path (e.g. soil penetration resistance and secondary treads), while other biochemical and microbiological variables were higher for the second path (e.g. β-glucosidase and phosphatase activities, soil respiration). Moss communities located along the new path were also more diverse and sensitive to trampling. Soil biota (Collembola) was also more abundant and richer. These data indicate that the decision to adopt the second path did not lead to the reduction of environmental impacts as this path runs over a more vulnerable area with more outstanding biological features (e.g. microbiota activity, flora and soil fauna diversity). In addition, the adoption of a new route effectively doubles the human footprint on the island. We propose using only the original path that is less vulnerable to the impacts of trampling. Finally from this process, we identify several key issues that may be taken into account when carrying out impact assessment and environmental management decision-making in the

  10. Toxicodynamics of copper and cadmium in Folsomia candida exposed to simulated soil solutions.

    PubMed

    Ardestani, Masoud M; van Gestel, Cornelis A M

    2013-12-01

    To improve our understanding of metal bioavailability to soil-living invertebrates, the effect of porewater composition on the toxicodynamics of copper and cadmium in Folsomia candida (Collembola) was investigated. Assuming that porewater is the main exposure route, F. candida was exposed to simulated soil solutions of different composition. Toxicity of copper was slightly lower in a calcium-only solution than in a multication solution. With increasing copper concentrations from 0.005 mM to 1.37 mM, internal copper concentrations similarly increased in both exposure solutions, suggesting that a single cation nutrient solution is suitable for testing F. candida. In the second experiment, animals were exposed for 7 d to copper and cadmium in simplified soil solutions with different calcium (0.2 mM, 0.8 mM, 3.2 mM, 12.8 mM) and pH (5.0, 6.0, 7.0) levels. The median lethal concentration (LC50) values decreased with time in both the calcium and pH series. A hormetic-type effect was observed for copper in the second test, as well as in the calcium-only solution in the first experiment. Because of stronger hormesis, LC50s for copper were higher at lower calcium concentrations. For cadmium, LC50 values were higher at higher calcium concentrations, suggesting competition of calcium with the free cadmium ion. Toxicity of cadmium increased with decreasing pH, while copper was more toxic at intermediate pH. The results show that a toxicodynamics approach can help to improve the interpretation of metal toxicity to soil invertebrates, taking into account soil solution properties.

  11. General relationships between abiotic soil properties and soil biota across spatial scales and different land-use types.

    PubMed

    Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W; Wolters, Volkmar; Schrumpf, Marion

    2012-01-01

    Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider

  12. Changes in herbivore control in arable fields by detrital subsidies depend on predator species and vary in space.

    PubMed

    von Berg, Karsten; Thies, Carsten; Tscharntke, Teja; Scheu, Stefan

    2010-08-01

    Prey from the decomposer subsystem may help sustain predator populations in arable fields. Adding organic residues to agricultural systems may therefore enhance pest control. We investigated whether resource addition (maize mulch) strengthens aboveground trophic cascades in winter wheat fields. Evaluating the flux of the maize-borne carbon into the food web after 9 months via stable isotope analysis allowed differentiating between prey in predator diets originating from the above- and belowground subsystems. Furthermore, we recorded aphid populations in predator-reduced and control plots of no-mulch and mulch addition treatments. All analyzed soil dwelling species incorporated maize-borne carbon. In contrast, only 2 out of 13 aboveground predator species incorporated maize carbon, suggesting that these 2 predators forage on prey from the above- and belowground systems. Supporting this conclusion, densities of these two predator species were increased in the mulch addition fields. Nitrogen isotope signatures suggested that these generalist predators in part fed on Collembola thereby benefiting indirectly from detrital resources. Increased density of these two predator species was associated by increased aphid control but the identity of predators responsible for aphid control varied in space. One of the three wheat fields studied even lacked aphid control despite of mulch-mediated increased density of generalist predators. The results suggest that detrital subsidies quickly enter belowground food webs but only a few aboveground predator species include prey out of the decomposer system into their diet. Variation in the identity of predator species benefiting from detrital resources between sites suggest that, depending on locality, different predator species are subsidised by prey out of the decomposer system and that these predators contribute to aphid control. Therefore, by engineering the decomposer subsystem via detrital subsidies, biological control by

  13. Automated Discovery of Food Webs from Ecological Data Using Logic-Based Machine Learning

    PubMed Central

    Bohan, David A.; Caron-Lormier, Geoffrey; Muggleton, Stephen; Raybould, Alan; Tamaddoni-Nezhad, Alireza

    2011-01-01

    Networks of trophic links (food webs) are used to describe and understand mechanistic routes for translocation of energy (biomass) between species. However, a relatively low proportion of ecosystems have been studied using food web approaches due to difficulties in making observations on large numbers of species. In this paper we demonstrate that Machine Learning of food webs, using a logic-based approach called A/ILP, can generate plausible and testable food webs from field sample data. Our example data come from a national-scale Vortis suction sampling of invertebrates from arable fields in Great Britain. We found that 45 invertebrate species or taxa, representing approximately 25% of the sample and about 74% of the invertebrate individuals included in the learning, were hypothesized to be linked. As might be expected, detritivore Collembola were consistently the most important prey. Generalist and omnivorous carabid beetles were hypothesized to be the dominant predators of the system. We were, however, surprised by the importance of carabid larvae suggested by the machine learning as predators of a wide variety of prey. High probability links were hypothesized for widespread, potentially destabilizing, intra-guild predation; predictions that could be experimentally tested. Many of the high probability links in the model have already been observed or suggested for this system, supporting our contention that A/ILP learning can produce plausible food webs from sample data, independent of our preconceptions about “who eats whom.” Well-characterised links in the literature correspond with links ascribed with high probability through A/ILP. We believe that this very general Machine Learning approach has great power and could be used to extend and test our current theories of agricultural ecosystem dynamics and function. In particular, we believe it could be used to support the development of a wider theory of ecosystem responses to environmental change. PMID

  14. Molecular evolution of the crustacean hyperglycemic hormone family in ecdysozoans

    PubMed Central

    2010-01-01

    Background Crustacean Hyperglycemic Hormone (CHH) family peptides are neurohormones known to regulate several important functions in decapod crustaceans such as ionic and energetic metabolism, molting and reproduction. The structural conservation of these peptides, together with the variety of functions they display, led us to investigate their evolutionary history. CHH family peptides exist in insects (Ion Transport Peptides) and may be present in all ecdysozoans as well. In order to extend the evolutionary study to the entire family, CHH family peptides were thus searched in taxa outside decapods, where they have been, to date, poorly investigated. Results CHH family peptides were characterized by molecular cloning in a branchiopod crustacean, Daphnia magna, and in a collembolan, Folsomia candida. Genes encoding such peptides were also rebuilt in silico from genomic sequences of another branchiopod, a chelicerate and two nematodes. These sequences were included in updated datasets to build phylogenies of the CHH family in pancrustaceans. These phylogenies suggest that peptides found in Branchiopoda and Collembola are more closely related to insect ITPs than to crustacean CHHs. Datasets were also used to support a phylogenetic hypothesis about pancrustacean relationships, which, in addition to gene structures, allowed us to propose two evolutionary scenarios of this multigenic family in ecdysozoans. Conclusions Evolutionary scenarios suggest that CHH family genes of ecdysozoans originate from an ancestral two-exon gene, and genes of arthropods from a three-exon one. In malacostracans, the evolution of the CHH family has involved several duplication, insertion or deletion events, leading to neuropeptides with a wide variety of functions, as observed in decapods. This family could thus constitute a promising model to investigate the links between gene duplications and functional divergence. PMID:20184761

  15. General Relationships between Abiotic Soil Properties and Soil Biota across Spatial Scales and Different Land-Use Types

    PubMed Central

    Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M.; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W.; Wolters, Volkmar; Schrumpf, Marion

    2012-01-01

    Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider

  16. Arthropod community structure on bark of koa (Acacia koa) and ʻōhiʻā (Metrosideros polymorpha) at Hakalau Forest National Wildlife Refuge, Hawaiʻi Island, Hawaiʻi

    USGS Publications Warehouse

    Peck, Robert W.; Banko, Paul C.; Stelmach, Matt

    2014-01-01

    The arthropod community associated with tree bark contains a wide variety of taxa but is poorly described, particularly in Hawaiʽi. Our overall goals were to evaluate the abundance of arthropods available to foraging birds and how variation in bark substrates may contribute to arthropod distributions in native forests. Our study aimed to identify this fauna on the dominant canopy-forming trees koa (Acacia koa) and ʽōhiʽa (Metrosideros polymorpha) within wet montane forest at Hakalau Forest National Wildlife Refuge, Hawaiʽi Island. At two sites roughly similar in elevation and habitat structure, we deployed three trap types designed to intercept arthropods moving along bark within tree canopies: a bole trap based on a pre-existing design and two traps specially designed for this study. Bole traps were placed on koa and ʽōhiʽa while branch traps were established on large and small branches of ʽōhiʽa. In total, 15 arthropod orders were identified, with Collembola most abundant (number/trap-day) generally followed by Isopoda and Araneae. Differences in abundance were found in some instances, but overall, few differences were detected between tree species or sites. Relative abundances of arthropod groups were also generally similar between trees and sites and among different parts of ʽōhiʽa. These results indicate that bark-dwelling arthropod communities are similar on koa and ʽōhiʽa, and birds should not develop strong preferences for gleaning arthropods from the bark of either species of tree based on prey availability.

  17. Effects of Essential Oils from Eucalyptus globulus Leaves on Soil Organisms Involved in Leaf Degradation

    PubMed Central

    Natal-da-Luz, Tiago; Sousa, José Paulo; Gonçalves, Maria José; Salgueiro, Lígia; Canhoto, Cristina

    2013-01-01

    The replacement of native Portuguese forests by Eucalyptus globulus is often associated with deleterious effects on terrestrial and aquatic communities. Several studies have suggested that such a phenomenon is linked with the leaf essential oils released into the environment during the Eucalyptus leaf degradation process. However, to date, the way these compounds affect leaf degradation in terrestrial systems i.e. by direct toxic effects to soil invertebrates or indirectly by affecting food of soil fauna, is still unknown. In order to explore this question, the effect of essential oils extracted from E. globulus leaves on terrestrial systems was investigated. Fungal growth tests with species known as leaf colonizers (Mucor hiemalis, Alternaria alternata, Penicillium sp., Penicillium glabrum and Fusarium roseum) were performed to evaluate the antifungal effect of essential oils. In addition, a reproduction test with the collembolans Folsomia candida was done using a gradient of eucalyptus essential oils in artificial soil. The influence of essential oils on feeding behaviour of F. candida and the isopods Porcellio dilatatus was also investigated through food avoidance and consumption tests. Eucalyptus essential oils were lethal at concentrations between 2.5–20 µL/mL and inhibited growth of all fungal species between 1.25–5 µL/mL. The collembolan reproduction EC50 value was 35.0 (28.6–41.2) mg/kg and both collembola and isopods preferred leaves without oils. Results suggested that the effect of essential oils in leaf processing is related to direct toxic effects on fungi and soil fauna and to indirect effects on the quality and availability of food to soil invertebrates. PMID:23577212

  18. Ecotoxicological assessment of biosolids by microcosms.

    PubMed

    Groth, Vitor Avelar; Carvalho-Pereira, Ticiana; da Silva, Eduardo Mendes; Niemeyer, Júlia Carina

    2016-10-01

    Biosolids have been applied as soil amendments to improve and maintain the soil fertility and faster plant growth. In spite of its beneficial use, the potential risks of land disposal should be analyzed, considering potential ecological receptors in soil and water. This work describes the use of an early warning laboratory microcosm system to evaluate the integrated ecotoxicological potential of two biosolids: BIO-1 and BIO-2 (18 and 28 months after landfarming, respectively), from an effluent treatment station in a petrochemical and industrial district. The endpoints related to habitat function were: a) germination, growth and biomass of Phaseolus vulgaris; b) survival, biomass and number of cocoons of Eisenia andrei (Oligochaeta) and; c) reproduction of Folsomia candida (Collembola). The retention function was evaluated by testing the leachates using the tropical cladoceran Latonopsis australis (Cladocera) in a 48-h acute toxicity test, and growth of the aquatic plant Lemna minor in a 7-d chronic test. Tropical artificial soil (TAS) and a natural soil (NS) from the region were used as control soils. Results showed no chronic toxicity of BIO-1 and BIO-2 to the soil organisms tested, but acute toxicity of BIO-1 in the leachate for 50% of L. australis, and chronic toxicity of both biosolid leachates to L. minor (inhibition of growth rate), indicating potential risks to aquatic ecosystems. The results confirmed the ability of this microcosm system as a rapid tool to assess biosolid toxicity over time and its potential for hazardous waste characterization in environmental risk assessment, in a screening phase. PMID:27448314

  19. Impact of land use practices on faunal abundance, nutrient dynamics and biochemical properties of desert pedoecosystem.

    PubMed

    Tripathi, G; Sharma, B M

    2005-11-01

    Increased dependence of resource-poor rural communities on soils of low inherent fertility are the major problem of desert agroecosystem. Agrisilviculture practices may help to conserve the soil biota for maintaining essential soil properties and processes in harsh climate. Therefore, the impacts of different land use systems on faunal density, nutrient dynamics and biochemical properties of soil were studied in agrisilviculture system of Indian desert. The selected fields had trees (Zizyphus mauritiana, Prosopis cineraria, Acacia nilotica) and crops (Cuminum cyminum, Brassica nigra, Triticum aestivum) in different combinations. Populations of Acari, Myriapoda, Coleoptera, Collembola, other soil arthropods and total soil fauna showed significant changes with respect to different land use practices and tree species, indicating a strong relation between above and below ground biodiversity. The Coleoptera exhibited greatest association with all agrisilviculture fields. The Z. mauritiana system indicated highest facilitative effects (RTE value) on all groups of soil fauna. Soil temperature, moisture, organic carbon, nitrate- and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were greater under tree than that of tree plus cropping system. It showed accumulation of nitrate-nitrogen in tree field and more utilization by crops in cultivated lands. Positive and significant correlation among organic carbon, nitrate- and ammonical-nitrogen, phosphorus, soil respiration and dehydrogenase activity clearly reflects increase in soil nutrients with the increase in microbial and other biotic activity. P. cineraria field was the best pedoecosystem, while C. cyminum was the best winter crop for cultivation in desert agroforestry system for soil biological health and soil sustainability. The increase in organic carbon, soil nutrients and microbial activity is associated with the increase in soil faunal population which reflect role of soil fauna

  20. Effects of an Ecosystem Engineer on Belowground Movement of Microarthropods

    PubMed Central

    Cameron, Erin K.; Proctor, Heather C.; Bayne, Erin M.

    2013-01-01

    Ecosystem engineers affect other species by changing physical environments. Such changes may influence movement of organisms, particularly belowground where soil permeability can restrict dispersal. We investigated whether earthworms, iconic ecosystem engineers, influence microarthropod movement. Our experiment tested whether movement is affected by tunnels (i.e., burrows), earthworm excreta (mucus, castings), or earthworms themselves. Earthworm burrows form tunnel networks that may facilitate movement. This effect may be enhanced by excreta, which could provide resources for microarthropods moving along the network. Earthworms may also promote movement via phoresy. Conversely, negative effects could occur if earthworms alter predator-prey relationships or change competitive interactions between microarthropods. We used microcosms consisting of a box connecting a “source” container in which microarthropods were present and a “destination” container filled with autoclaved soil. Treatments were set up within the boxes, which also contained autoclaved soil, as follows: 1) control with no burrows; 2) artificial burrows with no excreta; 3) abandoned burrows with excreta but no earthworms; and 4) earthworms (Lumbricus rubellus) present in burrows. Half of the replicates were sampled once after eight days, while the other half were sampled repeatedly to examine movement over time. Rather than performing classical pairwise comparisons to test our hypotheses, we used AICc to assess support for three competing models (presence of tunnels, excreta, and earthworms). More individuals of Collembola, Mesostigmata, and all microarthropods together dispersed when tunnels were present. Models that included excreta and earthworms were less well supported. Total numbers of dispersing Oribatida and Prostigmata+Astigmata were not well explained by any models tested. Further research is needed to examine the impact of soil structure and ecosystem engineering on movement

  1. Assessing environmental conditions of Antarctic footpaths to support management decisions.

    PubMed

    Tejedo, Pablo; Benayas, Javier; Cajiao, Daniela; Albertos, Belén; Lara, Francisco; Pertierra, Luis R; Andrés-Abellán, Manuela; Wic, Consuelo; Luciáñez, Maria José; Enríquez, Natalia; Justel, Ana; Reck, Günther K

    2016-07-15

    Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over a decade and is a marked route that is clearly visible. The second one was created more recently. Several physical and biological indicators were measured in order to assess the environmental conditions for both paths. Some physical variables related to human impact were lower for the first path (e.g. soil penetration resistance and secondary treads), while other biochemical and microbiological variables were higher for the second path (e.g. β-glucosidase and phosphatase activities, soil respiration). Moss communities located along the new path were also more diverse and sensitive to trampling. Soil biota (Collembola) was also more abundant and richer. These data indicate that the decision to adopt the second path did not lead to the reduction of environmental impacts as this path runs over a more vulnerable area with more outstanding biological features (e.g. microbiota activity, flora and soil fauna diversity). In addition, the adoption of a new route effectively doubles the human footprint on the island. We propose using only the original path that is less vulnerable to the impacts of trampling. Finally from this process, we identify several key issues that may be taken into account when carrying out impact assessment and environmental management decision-making in the

  2. Future rainfall patterns will reduce arthropod abundance in model arable agroecosystems with different soil types

    NASA Astrophysics Data System (ADS)

    Zaller, Johann; Simmer, Laura; Tabi Tataw, James; Formayer, Herbert; Hösch, Johannes; Baumgarten, Andreas

    2013-04-01

    Climate change scenarios for eastern Austria predict a seasonal shift in precipitation patterns with fewer but heavier rainfall events and longer drought periods during the growing season and more precipitation during winter. This is expected to alter arthropods living in natural and agricultural ecosystems with consequences for several ecosystem functions and services. In order to better understand the effects of future rainfall patterns on aboveground arthropods inhabiting an agroecosystem, we conducted an experiment where we simulated rainfall patterns in model arable systems with three different soil types. Experiments were conducted in winter wheat cultivated in a lysimeter facility near Vienna, Austria, where three different soil types (calcaric phaeozem, calcic chernozem and gleyic phaeozem) were subjected to long-term current vs. predicted rainfall patterns according to regionalized climate change projections for 2071-2100. Aboveground arthropods were assessed by suction sampling in April, May and June 2012. We found significant differences in mean total arthropod abundances between the sampling dates with 20 ± 2 m-2, 90 ± 20 m-2 and 289 ± 54 m-2 in April, May and June, respectively. Across all three sampling dates, future rainfall patterns significantly reduced the abundance of Araneae (-43%), Auchenorrhyncha (-39%), Coleoptera (-48%), Carabidae (-41%), Chrysomelidae (-64%), Collembola (-58%), Diptera (-75%) and Neuroptera (-73%). Generally, different soil types had no effect on the abundance of arthropods. The diversity of arthropod communities was unaffected by rainfall patterns or soil types. Correlation analyses of arthropod abundances with crop biomass, weed density and abundance suggest that rainfall effects indirectly affected arthropods via changes on crops and weeds. In conclusion, these results show that future rainfall patterns will have detrimental effects on the abundance of a variety of aboveground arthropods in winter wheat with potential

  3. Effects of pesticides on soil invertebrates in laboratory studies: a review and analysis using species sensitivity distributions.

    PubMed

    Frampton, Geoff K; Jansch, Stephan; Scott-Fordsmand, Janeck J; Römbke, Jörg; Van den Brink, Paul J

    2006-09-01

    Species sensitivity distributions (SSD) and 5% hazardous concentrations (HC5) are distribution-based approaches for assessing environmental risks of pollutants. These methods have potential for application in pesticide risk assessments, but their applicability for assessing pesticide risks to soil invertebrate communities has not been evaluated. Using data obtained in a systematic review, the present study investigates the relevance of SSD and HC5 for predicting pesticide risks to soil invertebrates. Altogether, 1950 laboratory toxicity data were obtained, representing 250 pesticides and 67 invertebrate taxa. The majority (96%) of pesticides have toxicity data for fewer than five species. Based on a minimum of five species, the best available endpoint data (acute mortality median lethal concentration) enabled SSD and HC5 to be calculated for 11 pesticides (atrazine, carbendazim, chlorpyrifos, copper compounds, diazinon, dimethoate, gamma-hexachlorocyclohexane, lambda-cyhalothrin, parathion, pentachlorophenol, and propoxur). Arthropods and oligochaetes exhibit pronounced differences in their sensitivity to most of these pesticides. The standard test earthworm species, Eisenia fetida sensu lato, is the species that is least sensitive to insecticides based on acute mortality, whereas the standard Collembola test species, Folsomia candida, is among the most sensitive species for a broad range of toxic modes of action (biocide, fungicide, herbicide, and insecticide). These findings suggest that soil arthropods should be tested routinely in regulatory risk assessments. In addition, the data indicate that the uncertainty factor for earthworm acute mortality tests (i.e., 10) does not fully cover the range of earthworm species sensitivities and that acute mortality tests would not provide the most sensitive risk estimate for earthworms in the majority (95%) of cases.

  4. Transcriptomics reveals extensive inducible biotransformation in the soil-dwelling invertebrate Folsomia candida exposed to phenanthrene

    PubMed Central

    Nota, Benjamin; Bosse, Mirte; Ylstra, Bauke; van Straalen, Nico M; Roelofs, Dick

    2009-01-01

    Background Polycyclic aromatic hydrocarbons are common pollutants in soil, have negative effects on soil ecosystems, and are potentially carcinogenic. The Springtail (Collembola) Folsomia candida is often used as an indicator species for soil toxicity. Here we report a toxicogenomic study that translates the ecological effects of the polycyclic aromatic hydrocarbon phenanthrene in soil to the early transcriptomic responses in Folsomia candida. Results Microarrays were used to examine two different exposure concentrations of phenanthrene, namely the EC10 (24.95 mg kg-1 soil) and EC50 (45.80 mg kg-1 soil) on reproduction of this springtail, which evoked 405 and 251 differentially expressed transcripts, respectively. Fifty transcripts were differential in response to either concentration. Many transcripts encoding xenobiotic detoxification and biotransformation enzymes (phases I, II, and III) were upregulated in response to either concentration. Furthermore, indications of general and oxidative stress were found in response to phenanthrene. Chitin metabolism appeared to be disrupted particularly at the low concentration, and protein translation appeared suppressed at the high concentration of phenanthrene; most likely in order to reallocate energy budgets for the detoxification process. Finally, an immune response was evoked especially in response to the high effect concentration, which was also described in a previous transcriptomic study using the same effect concentration (EC50) of cadmium. Conclusion Our study provides new insights in the molecular mode of action of the important polluting class of polycyclic aromatic hydrocarbons in soil animals. Furthermore, we present a fast, sensitive, and specific soil toxicity test which enhances traditional tests and may help to improve current environmental risk assessments and monitoring of potentially polluted sites. PMID:19457238

  5. BiodivERsA project VineDivers: Analysing interlinkages between soil biota and biodiversity-based ecosystem services in vineyards across Europe

    NASA Astrophysics Data System (ADS)

    Zaller, Johann G.; Winter, Silvia; Strauss, Peter; Querner, Pascal; Kriechbaum, Monika; Pachinger, Bärbel; Gómez, José A.; Campos, Mercedes; Landa, Blanca; Popescu, Daniela; Comsa, Maria; Iliescu, Maria; Tomoiaga, Liliana; Bunea, Claudiu-Ioan; Hoble, Adela; Marghitas, Liviu; Rusu, Teodor; Lora, Ángel; Guzmán, Gema; Bergmann, Holger

    2015-04-01

    Essential ecosystem services provided by viticultural landscapes result from diverse communities of above- and belowground organisms and their interactions. For centuries traditional viticulture was part of a multifunctional agricultural system including low-input grasslands and fruit trees resulting in a high functional biodiversity. However, in the last decades intensification and mechanisation of vineyard management caused a separation of production and conservation areas. As a result of management intensification including frequent tilling and/or use of pesticides several ecosystem services are affected leading to high rates of soil erosion, degradation of soil structure and fertility, contamination of groundwater and high levels of agricultural inputs. In this transdisciplinary BiodivERsA project we will examine to what extent differently intensive managed vineyards affect the activity and diversity of soil biota (e.g. earthworms, collembola, soil microorganisms) and how this feed back on aboveground biodiversity (e.g. weeds, pollinators). We will also investigate ecosystem services associated with soil faunal activity and biodiversity such as soil structure, the formation of stable soil aggregates, water infiltration, soil erosion as well as grape quality. These effects will become increasingly important as more extreme precipitation events are predicted with climate change. The socio-economic part of the project will investigate the role of diversely structured, species-rich viticultural landscapes as a cultural heritage providing aesthetic values for human well-being and recreation. The project objectives will be analysed at plot, field (vineyard) and landscape scales in vineyards located in Spain, France, Romania and Austria. A detailed engagement and dissemination plan for stakeholder at the different governance levels will accompany scientific research and will contribute to the implementation of best-practice recommendations for policy and farmers.

  6. Dynamics of the Leaf-Litter Arthropod Fauna Following Fire in a Neotropical Woodland Savanna

    PubMed Central

    Vasconcelos, Heraldo L.; Pacheco, Renata; Silva, Raphael C.; Vasconcelos, Pedro B.; Lopes, Cauê T.; Costa, Alan N.; Bruna, Emilio M.

    2009-01-01

    Fire is an important agent of disturbance in tropical savannas, but relatively few studies have analyzed how soil-and-litter dwelling arthropods respond to fire disturbance despite the critical role these organisms play in nutrient cycling and other biogeochemical processes. Following the incursion of a fire into a woodland savanna ecological reserve in Central Brazil, we monitored the dynamics of litter-arthropod populations for nearly two years in one burned and one unburned area of the reserve. We also performed a reciprocal transplant experiment to determine the effects of fire and litter type on the dynamics of litter colonization by arthropods. Overall arthropod abundance, the abundance of individual taxa, the richness of taxonomic groups, and the species richness of individual taxa (Formiciade) were lower in the burned site. However, both the ordinal-level composition of the litter arthropod fauna and the species-level composition of the litter ant fauna were not dramatically different in the burned and unburned sites. There is evidence that seasonality of rainfall interacts with fire, as differences in arthropod abundance and diversity were more pronounced in the dry than in the wet season. For many taxa the differences in abundance between burned and unburned sites were maintained even when controlling for litter availability and quality. In contrast, differences in abundance for Collembola, Formicidae, and Thysanoptera were only detected in the unmanipulated samples, which had a lower amount of litter in the burned than in the unburned site throughout most of our study period. Together these results suggest that arthropod density declines in fire-disturbed areas as a result of direct mortality, diminished resources (i.e., reduced litter cover) and less favorable microclimate (i.e., increased litter desiccation due to reduction in tree cover). Although these effects were transitory, there is evidence that the increasingly prevalent fire return interval of

  7. Gluing the 'unwettable': soil-dwelling harvestmen use viscoelastic fluids for capturing springtails.

    PubMed

    Wolff, Jonas O; Schönhofer, Axel L; Schaber, Clemens F; Gorb, Stanislav N

    2014-10-01

    Gluing can be a highly efficient mechanism of prey capture, as it should require less complex sensory-muscular feedback. Whereas it is well known in insects, this mechanism is much less studied in arachnids, except spiders. Soil-dwelling harvestmen (Opiliones, Nemastomatidae) bear drumstick-like glandular hairs (clavate setae) at their pedipalps, which were previously hypothesized to be sticky and used in prey capture. However, clear evidence for this was lacking to date. Using high-speed videography, we found that the harvestman Mitostoma chrysomelas was able to capture fast-moving springtails (Collembola) just by a slight touch of the pedipalp. Adhesion of single clavate setae increased proportionally with pull-off velocity, from 1 μN at 1 μm s(-1) up to 7 μN at 1 mm s(-1), which corresponds to the typical weight of springtails. Stretched glue droplets exhibited characteristics of a viscoelastic fluid forming beads-on-a-string morphology over time, similar to spider capture threads and the sticky tentacles of carnivorous plants. These analogies indicate that viscoelasticity is a highly efficient mechanism for prey capture, as it holds stronger the faster the struggling prey moves. Cryo-scanning electron microscopy of snap-frozen harvestmen with glued springtails revealed that the gluey secretions have a high affinity to wet the microstructured cuticle of collembolans, which was previously reported to be barely wettable for both polar and non-polar liquids. Glue droplets can be contaminated with the detached scaly setae of collembolans, which may represent a counter-adaptation against entrapment by the glue, similar to the scaly surfaces of Lepidoptera and Trichoptera (Insecta) facilitating escape from spider webs. PMID:25274325

  8. Patch size matters more than dispersal distance in a mainland-island metacommunity.

    PubMed

    Aström, Jens; Bengtsson, Jan

    2011-11-01

    Micro-arthropods in moss patches have been used as a model system to investigate the effects of habitat destruction and fragmentation on population viability and ecosystem functioning. Previous assessments of the sensitivity to fragmentation and the effectiveness of mitigating landscape structures have to some extent been contradictory, one possible reason being a lack of knowledge of the realised dispersal distances of the species involved. We investigated the dispersal capabilities of oribatid mites (Acari: Oribatida) and springtails (Collembola) in an experimentally fragmented system consisting of bryophytes on a bare rock surface. We used defaunated patches that were recolonized from populated patches nearby as well as from a mainland surrounding the experimental arena, during 10 weeks in summer. We measured within-mainland, mainland-to-island, and island-to-island dispersal, and found that: (1) Oribatid mites were severely dispersal limited within the time frame of the experiment, even at isolation distances of only 5 cm; (2) springtails did not show any dispersal limitation over distances as far as 300 cm; (3) despite the observed dispersal limitation, the mainland had a relatively large influence on microarthropod occurrence, even at 300 cm distance; and (4) the dispersal rates were high enough for both species sorting and-in the case of collembolans-mass effects processes to occur. Our results indicate that fragmentation can strongly influence species occurrence and abundance in natural systems that are limited by dispersal. They also show that the presence of a distant mainland can override the influence of nearby habitat patches on local diversity and abundance. PMID:21625982

  9. Invertebrate pathogenicity and toxin-producing potential of strains of Bacillus thuringiensis endemic to Antarctica.

    PubMed

    Prabhakar, A; Bishop, A H

    2011-06-01

    Several strains of Bacillus thuringiensis were previously isolated from soil in Antarctica and appeared to have physiological adaptations to this cold, nutrient-poor environment. In spite of this they could produce abnormally large, parasporal crystals under laboratory conditions. Here, they have been further characterised for toxin genes and invertebrate pathogenicity. All of the strains were positive in PCR assays for the cry1Aa and cry2 genes. This was confirmed by sequence analysis and the parasporal crystals of all strains contained polypeptides of about 130kDa. This potential for lepidopteran toxicity was borne out in bioassays of purified δ-endotoxins against larvae of Pieris brassicae: the LD(50) values of B2408 (288μg) were comparable to that of the reference strain, HD-12 (201μg). There was no activity against the nematode Caenorhabditis elegans in spite of the fact that all strains appeared to possess the cry6 gene. PCR screening for genes encoding other nematode-toxic classes of toxins (Cry5, 4 and 21) was negative. B. thuringiensis has never previously been shown to be toxic to Collembola (springtails) but the purified δ-endotoxins of one of the Antarctic strains showed some activity against Folsomia candida and Seira domestica (224μg and 238μg, respectively). It seems unlikely that the level of toxicity demonstrated against springtails would support a pathogenic life-style in nature. All of the strains were positive for genes encoding Bacillus cereus-type enterotoxins. In the absence of higher insects and mammals the ecological value of retaining the toxic capability demonstrated here is uncertain. PMID:21457716

  10. An evolutionary analysis of flightin reveals a conserved motif unique and widespread in Pancrustacea.

    PubMed

    Soto-Adames, Felipe N; Alvarez-Ortiz, Pedro; Vigoreaux, Jim O

    2014-01-01

    Flightin is a thick filament protein that in Drosophila melanogaster is uniquely expressed in the asynchronous, indirect flight muscles (IFM). Flightin is required for the structure and function of the IFM and is indispensable for flight in Drosophila. Given the importance of flight acquisition in the evolutionary history of insects, here we study the phylogeny and distribution of flightin. Flightin was identified in 69 species of hexapods in classes Collembola (springtails), Protura, Diplura, and insect orders Thysanura (silverfish), Dictyoptera (roaches), Orthoptera (grasshoppers), Pthiraptera (lice), Hemiptera (true bugs), Coleoptera (beetles), Neuroptera (green lacewing), Hymenoptera (bees, ants, and wasps), Lepidoptera (moths), and Diptera (flies and mosquitoes). Flightin was also found in 14 species of crustaceans in orders Anostraca (water flea), Cladocera (brine shrimp), Isopoda (pill bugs), Amphipoda (scuds, sideswimmers), and Decapoda (lobsters, crabs, and shrimps). Flightin was not identified in representatives of chelicerates, myriapods, or any species outside Pancrustacea (Tetraconata, sensu Dohle). Alignment of amino acid sequences revealed a conserved region of 52 amino acids, referred herein as WYR, that is bound by strictly conserved tryptophan (W) and arginine (R) and an intervening sequence with a high content of tyrosines (Y). This motif has no homologs in GenBank or PROSITE and is unique to flightin and paraflightin, a putative flightin paralog identified in decapods. A third motif of unclear affinities to pancrustacean WYR was observed in chelicerates. Phylogenetic analysis of amino acid sequences of the conserved motif suggests that paraflightin originated before the divergence of amphipods, isopods, and decapods. We conclude that flightin originated de novo in the ancestor of Pancrustacea > 500 MYA, well before the divergence of insects (~400 MYA) and the origin of flight (~325 MYA), and that its IFM-specific function in Drosophila is a more

  11. Oxidative stress biomarkers and metallothionein in Folsomia candida--responses to Cu and Cd.

    PubMed

    Maria, Vera L; Ribeiro, Maria João; Amorim, Mónica J B

    2014-08-01

    Folsomia candida (Collembola) is a standard soil ecotoxicological species; effect assessment includes survival and reproduction as endpoints. In the present study, and for the first time, a range of oxidative stress biomarkers measurement was optimized and validated. The antioxidant capacity was measured by the activities of catalase (CAT), glutathione reductase (GR), glutathione-s-transferase (GST) and content of total glutathione (TG). The oxidative damage in the lipid membranes was estimated by lipid peroxidation (LPO) and metallothionein (MT) levels. The exposure included the essential and non-essential metals Cu and Cd, in LUFA 2.2 natural standard soil, using a series of sampling times along a 10 days period (0, 2, 4, 6 and 10 days). Exposure concentrations were selected based on their reproduction EC50 values, 60 and 1000 mg/kg soil DW, for Cd and Cu respectively. The protocols were optimized and results show that oxidative stress biomarkers can be successfully used in F. candida, this being highly relevant as complementary information to the mechanistic level. The selected sampling times gave a good indication of the markers dynamic and can be reduced/adapted in future testing. Results showed that both metals caused an increase in the MT levels after 6 days but Cd acted as a stronger oxidant agent compared to Cu, i.e. causing higher damage. In sum, Cd mobilized/activated more antioxidant enzymes, but the increased activities were not enough to prevent LPO. This study confirms that the oxidative stress caused by Cd is higher despite the use of same reproduction EC50 indicating that toxicity seems more reversible for Cu than for Cd. Among others, GST and MT would be a good selection of biomarkers for Cd effect. PMID:24949815

  12. Comparative assessment of fungal augmentation treatments of a fine-textured and historically oil-contaminated soil.

    PubMed

    Covino, Stefano; Stella, Tatiana; D'Annibale, Alessandro; Lladó, Salvador; Baldrian, Petr; Čvančarová, Monika; Cajthaml, Tomas; Petruccioli, Maurizio

    2016-10-01

    The removal of aged hydrophobic contaminants from fine-textured soils is a challenging issue in remediation. The objective of this study was to compare the efficacy of augmentation treatments to that of biostimulation in terms of total aliphatic hydrocarbon (TAH) and toxicity removal from a historically contaminated clay soil and to assess their impact on the resident microbial community. To this aim, Pleurotus ostreatus, Botryosphaeria rhodina and a combination of both were used as the inoculants while the addition of a sterilized lignocellulose mixture to soil (1:5, w/w) was used as a biostimulation approach. As opposed to the non-amended control soil, where no changes in TAH concentration and residual toxicity were observed after 60days, the activation of specialized bacteria was found in the biostimulated microcosms resulting in significant TAH removal (79.8%). The bacterial community structure in B. rhodina-augmented microcosms did not differ from the biostimulated microcosms due to the inability of the fungus to be retained within the resident microbiota. Best TAH removals were observed in microcosms inoculated with P. ostreatus alone (Po) and in binary consortium with B. rhodina (BC) (86.8 and 88.2%, respectively). In these microcosms, contaminant degradation exceeded their bioavailability thresholds determined by sequential supercritical CO2 extraction. Illumina metabarcoding of 16S rRNA gene showed that the augmentation with Po and BC led to lower relative abundances of Gram(+) taxa, Actinobacteria in particular, than those in biostimulated microcosms. Best detoxification, with respect to the non-amended incubation control, was found in Po microcosms where a drop in collembola mortality (from 90 to 22%) occurred. At the end of incubation, in both Po and BC, the relative abundances of P. ostreatus sequences were higher than 60% thus showing the suitability of this fungus in bioaugmentation-based remediation applications.

  13. [Litter decomposition and soil faunal diversity of two understory plant debris in the alpine timberline ecotone of western Sichuan in a snow cover season].

    PubMed

    He, Run-lian; Chen, Ya-mei; Deng, Chang-chun; Yan, Wan-qin; Zhang, Jian; Liu, Yang

    2015-03-01

    In order to understand the relationship between litter decomposition and soil fauna diversity during snow cover season, litterbags with plant debris of Actinothuidium hookeri, Cystopteris montana, two representative understory plants in the alpine timberline ecotone, and their mixed litter were incubated in the dark coniferous forest, timberline and alpine meadow, respectively. After a snow cover season, the mass loss and soil fauna in litterbags were investigated. After decomposition with a snow cover season, alpine meadow showed the highest mass loss of plant debris in comparison with coniferous forest and timberline, and the mass loss of A. hookeri was more significant. The mixture of two plants debris accelerated the mass loss, especially in the timberline. A total of 968 soil invertebrates, which belonged to 5 classes, 10 orders and 35 families, were captured in litterbags. Acarina and Collembola were the dominant groups in plant debris. The numbers of individuals and groups of soil faunal communities in litter of timberline were higher than those of alpine meadow and dark coniferous forest. Canonical correspondence analysis (CCA) indicated that the groups of soil animals were related closely with the average temperature, and endemic species such as Isoptera and Geophilomorpha were observed only in coniferous forest, while Hemiptera and Psocoptera only in.the alpine meadow. The diversity of soil faunal community was more affected by plant debris varieties in the timberline than in the coniferous forest and alpine meadow. Multiple regression analysis indicated that the average temperature and snow depth explained 30.8% of the variation of litter mass loss rate, soil animals explained 8.3%, and altogether explained 34.1%. Snow was one of the most critical factors impacting the decomposition of A. hookeri and C. montana debris in the alpine timberline ecotone.

  14. Soil invertebrate community change over fuel-contaminated sites on a subantarctic island: An ecological field-based line of evidence for site risk assessment.

    PubMed

    Wasley, Jane; Mooney, Thomas J; King, Catherine K

    2016-04-01

    A number of fuel spills, of both recent and historic origins, have occurred on World Heritage-listed subantarctic Macquarie Island. Sites contaminated by mainly diesel fuels are undergoing remediation by the Australian Antarctic Division. The risks posed by these sites are being managed using a "weight of evidence" approach, for which this study provides a preliminary line of evidence for the ecological assessment component of this site management decision framework. This knowledge is pertinent, given the absence of environmental guidelines for fuel contaminants in subantarctic ecosystems. We provide a field-based, site-specific ecological risk assessment for soil invertebrate communities across the fuel spill sites, before the commencement of in situ remediation activities. Springtails (Collembola) were the most abundant taxa. Springtail community patterns showed only limited correlations with the level of fuel contamination at the soil surface, even when elevated levels occurred in the substratum layers. Of the environmental variables measured, community patterns were most strongly correlated with vegetation cover. We identify a suite of 6 species that contribute most to the community dynamics across these sites. A subset of these we propose as useful candidates for future development of single-species toxicity tests: Folsomotoma punctata, Cryptopygus caecus, Cryptopygus antarcticus and Parisotoma insularis. Findings from this study advance our understanding of soil invertebrate community dynamics within these contaminated sites, directly contributing to the improved management and restoration of the sites. Not only does this study provide an important line of evidence for the island's ecological risk assessment for fuel contaminants, it also enhances our understanding of the potential impact of fuels at other subantarctic islands.

  15. [Analysis of soil respiration and influence factors in wheat farmland under conservation tillage in southwest hilly region].

    PubMed

    Zhang, Sai; Zhang, Xiao-Yu; Wang, Long-Chang; Luo, Hai-Xiu; Zhou, Hang-Fei; Ma, Zhong-Lian; Zhang, Cui-Wei

    2013-07-01

    In order to investigate the effect of conservation tillage on soil respiration in dry cropping farmland in southwest purple hilly region, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei, Chongqing. The respiration and the hydrothermal and biotic factors of soil were measured and analyzed during the growth period of wheat in the triple intercropping system of wheat/maize/soybean. There were four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching) and RS (ridge tillage + straw mulching), which were all in triplicates. The results indicated that the soil respiration rate changed in the range of 1.100-2.508 micromol x (m2 x s)(-1) during the reproductive growth stage of wheat. There were significant differences in soil respiration rate among different treatments, which could be ranked as RS > R > TS > T. The soil temperature in the 10cm layer was ranked as T > R > TS > RS. The relationship between soil respiration and soil temperature fitted well with an exponential function, in which the Q10 values were 1.25, 1.20, 1.31 and 1.26, respectively. The soil moisture in the 5cm layer was ranked as TS > RS > T > R. The best fitting model between soil moisture and soil respiration was a parabolic curve, indicating the presence of soil moisture with the strongest soil respiration. The response threshold of wheat to soil moisture was 14.80%-17.47% during the reproductive stage. The dominant groups of soil animals were Collembola and Acarina, which were correlated with soil respiration to some extent. The correlation was high in the treatments T and R, ranged from 0.669-0.921, whereas there was no remarkable correlation in the other treatments. PMID:24028018

  16. [Analysis of soil respiration and influence factors in wheat farmland under conservation tillage in southwest hilly region].

    PubMed

    Zhang, Sai; Zhang, Xiao-Yu; Wang, Long-Chang; Luo, Hai-Xiu; Zhou, Hang-Fei; Ma, Zhong-Lian; Zhang, Cui-Wei

    2013-07-01

    In order to investigate the effect of conservation tillage on soil respiration in dry cropping farmland in southwest purple hilly region, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei, Chongqing. The respiration and the hydrothermal and biotic factors of soil were measured and analyzed during the growth period of wheat in the triple intercropping system of wheat/maize/soybean. There were four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching) and RS (ridge tillage + straw mulching), which were all in triplicates. The results indicated that the soil respiration rate changed in the range of 1.100-2.508 micromol x (m2 x s)(-1) during the reproductive growth stage of wheat. There were significant differences in soil respiration rate among different treatments, which could be ranked as RS > R > TS > T. The soil temperature in the 10cm layer was ranked as T > R > TS > RS. The relationship between soil respiration and soil temperature fitted well with an exponential function, in which the Q10 values were 1.25, 1.20, 1.31 and 1.26, respectively. The soil moisture in the 5cm layer was ranked as TS > RS > T > R. The best fitting model between soil moisture and soil respiration was a parabolic curve, indicating the presence of soil moisture with the strongest soil respiration. The response threshold of wheat to soil moisture was 14.80%-17.47% during the reproductive stage. The dominant groups of soil animals were Collembola and Acarina, which were correlated with soil respiration to some extent. The correlation was high in the treatments T and R, ranged from 0.669-0.921, whereas there was no remarkable correlation in the other treatments.

  17. Influence of Ca and pH on the uptake and effects of Cd in Folsomia candida exposed to simplified soil solutions.

    PubMed

    Ardestani, Masoud M; Ortiz, Maria Diez; van Gestel, Cornelis A M

    2013-08-01

    The present study sought to quantify the components of a biotic ligand model (BLM) for the effects of Cd on Folsomia candida (Collembola). Assuming that soil porewater is the main route of exposure and to exclude the effects of soil particles on metal availability, animals were exposed for 7 d to different Cd concentrations between 0.1 mM and 100 mM in simplified soil solutions at different Ca concentrations (0.2 mM, 0.8 mM, 3.2 mM, and 12.8 mM) or at different pH (5.0, 6.0, and 7.0). Higher Ca concentrations decreased the toxicity of Cd (adult survival) in test solutions, whereas toxicity was slightly lower at pH 7 and 6 than at pH 5, suggesting a mitigating effect of Ca and to a lesser extent pH on Cd toxicity to F. candida. Internal Cd concentrations in the animals increased with increasing exposure level but were significantly reduced by increasing Ca concentrations and were not significantly affected by pH. By using Langmuir isotherms, binding constants for Cd, Ca, and protons and the fraction of binding sites occupied by Cd were calculated and used to predict effects of Cd on survival. Predicted toxicity showed a good agreement with measured responses when Ca and pH were used as separate factors or combined together. The present study shows indications of protective effects of Ca but less of protons on the toxicity and uptake of Cd in F. candida on exposure to simplified soil solutions, which can be described using the principles of a biotic ligand model.

  18. Sweeping beauty: is grassland arthropod community composition effectively estimated by sweep netting?

    PubMed

    Spafford, Ryan D; Lortie, Christopher J

    2013-09-01

    Arthropods are critical ecosystem components due to their high diversity and sensitivity to perturbation. Furthermore, due to their ease of capture they are often the focus of environmental health surveys. There is much debate regarding the best sampling method to use in these surveys. Sweep netting and pan trapping are two sampling methods commonly used in agricultural arthropod surveys, but have not been contrasted in natural grassland systems at the community level. The purpose of this study was to determine whether sweep netting was effective at estimating arthropod diversity at the community level in grasslands or if supplemental pan trapping was needed. Arthropods were collected from grassland sites in Montana, USA, in the summer of 2011. The following three standardized evaluation criteria (consistency, reliability, and precision) were developed to assess the efficacy of sweep netting and pan trapping, based on analyses of variations in arthropod abundances, species richness, evenness, capture frequency, and community composition. Neither sampling method was sufficient in any criteria to be used alone for community-level arthropod surveys. On a taxa-specific basis, however, sweep netting was consistent, reliable, and precise for Thysanoptera, infrequently collected (i.e., rare) insects, and Arachnida, whereas pan trapping was consistent, reliable, and precise for Collembola and bees, which is especially significant given current threats to the latter's populations worldwide. Species-level identifications increase the detected dissimilarity between sweep netting and pan trapping. We recommend that community-level arthropod surveys use both sampling methods concurrently, at least in grasslands, but likely in most nonagricultural systems. Target surveys, such as monitoring bee communities in fragmented grassland habitat or where detailed information on behavior of the target arthropod groups is available can in some instances employ singular methods. As a

  19. Feeding bionomics of juvenile chinook salmon relative to thermal discharges in the central Columbia River

    SciTech Connect

    Becker, C.D.

    1994-10-01

    Juvenile chinook salmon (Oncorhynchus tshawytscha) in the Hanford environs of the central Columbia River, Washington consumed almost entirely adult and larval stages of aquatic insects. The food organisms were dominated by midges (Diptera: Tendipedidae); by numbers, adult midges provided 64 and 58% of the diet and larval midges 17 and 18% of the diet, in 1968 and 1969, respectively. The families Hydropsychidae (Trichoptera), Notonectidae (Hemiptera) and Hypogastruridae (Collembola) were of secondary importance. Small fry fed almost exclusively on the small tendipedids. Over 95% of all food organisms originated within the river ecosystem. The distinctive features of food and feeding activity were fourfold: first, relatively few insect groups were utilized; second, the fish depended on drifting, floating, or swimming organisms; third, they visually selected living prey moving in or on the water; and fourth, they were habitat opportunists to a high degree. The 1969 data, were studied to reveal possible thermal effects of heated discharges from plutonium production reactors at Hanford on food and growth parameters. All data were characterized by considerable variation between and within stations. No discernable effects between coldwater and warmwater stations were revealed by analyses of: (1) groups of food organisms utilized, (2) food and feeding activity, (3) numbers of insects consumed, (4) seasonal increases in fish length, (5) fish length-weight relationships, (6) fish coefficients of condition, and (7) stomach biomass. The lack of detectable thermal effects was apparently due to the fact that the main effluent plumes discharge in midstream and the effluents are well mixed before reaching inshore feeding areas. The transient nature of fish groups at each station, influenced by changes in regulated river flows, and the availability of food organisms in the river drift were ecological factors affecting critical thermal evaluation in situ.

  20. Abrupt vegetation transitions characterise long-term Amazonian peatland development

    NASA Astrophysics Data System (ADS)

    Roucoux, K. H.; Baker, T. R.; Gosling, W. D.; Honorio Coronado, E.; Jones, T. D.; Lahteenoja, O.; Lawson, I. T.

    2012-04-01

    Recent investigations of wetlands in western Amazonia have revealed the presence of extensive peatlands with peat deposits of up to 8 m-thick developing under a variety of vegetation types (Lähteenoja et al. 2012). Estimated to cover 150,000 km2 (Schulman et al. 1999), these peatlands make a valuable contribution to landscape and biological diversity and represent globally important carbon stores. In order to understand the processes leading to peat formation, and the sensitivity of these environments to future climatic change, it is necessary to understand their long-term history. The extent to which peatland vegetation changes over time, the stability of particular communities, the controls on transitions between vegetation types and how these factors relate to the accumulation of organic matter are not yet known. We report the first attempt to establish the long-term (millennial scale) vegetation history of a recently-described peatland site: Quistococha, a palm swamp, or aguajal, close to Iquitos in northern Peru. The vegetation is dominated by Mauritia flexuosa and Mauritiella armata and occupies a basin which is thought to be an abandoned channel of the River Amazon. We obtained a 4 m-long peat sequence from the deepest part of the basin. AMS-radiocarbon dating yielded a maximum age of 2,212 cal yr BP for the base of the peat, giving an average accumulation rate of 18 cm per century. Below the peat are 2 m of uniform, largely inorganic pale grey clays of lacustrine origin, which are underlain by an unknown thickness of inorganic sandy-silty clay of fluvial origin. Pollen analysis, carried out at c. 88-year intervals, shows the last 2,212 years to be characterised by the development of at least four distinct vegetation communities, with peat accumulating throughout. The main phases were: (1) Formation of Cyperaceae (sedge) fen coincident with peat initiation; (2) A short-lived phase of local Mauritia/Mauritiella development; (3) Development of mixed wet

  1. New systematic assignments in Gonyleptoidea (Arachnida, Opiliones, Laniatores)

    PubMed Central

    Pinto-da-Rocha, Ricardo; Benedetti, Alípio Rezende; de Vasconcelos, Eduardo Gomes; Hara, Marcos Ryotaro

    2012-01-01

    , 1913, syn. n. and Paragonyleptes simoni Roewer, 1930, syn. n.; Gonyleptes pustulatus Sørensen, 1884 = Gonyleptes guttatus Roewer, 1917, syn. n.; Haversia defensa (Butler, 1876) = Sadocus vallentini Hogg, 1913, syn. n.; Liogonyleptoides minensis (Piza, 1946) = Currala bahiensis Soares, 1972, syn. n.; Megapachylus grandis Roewer, 1913 = Metapachyloides almeidai Soares & Soares, 1946, syn. n.; Mischonyx cuspidatus (Roewer, 1913) = Gonazula gibbosa Roewer, 1930 syn. n.; Mischonyx scaber (Kirby, 1819) = Xundarava holacantha Mello-Leitão, 1927, syn. n.; Parampheres tibialis Roewer, 1917 = Metapachyloides rugosus Roewer, 1917, syn. n.; Parapachyloides uncinatus (Sørensen, 1879) = Goyazella armata Mello-Leitão, 1931, syn. n.; Pseudopucrolia mutica (Perty, 1833) = Meteusarcus armatus Roewer, 1913, syn. n. The following new combinations are proposed: Acrographinotus ornatus (Roewer, 1929), comb. n. (ex Unduavius); Gonyleptellus bimaculatus (Sørensen, 1884),comb. n. (ex Gonyleptes);Gonyleptes perlatus (Mello-Leitão, 1935), comb. n. (exMoojenia);Mischonyx scaber (Kirby, 1819), comb. n. (ex Gonyleptes); and Neopachyloides peruvianus (Roewer, 1956), comb. n. (ex Ceropachylus). The following species of Gonyleptidae, Gonyleptinae are revalidated: Gonyleptes atrus Mello-Leitão, 1923 and Gonyleptes curvicornis (Roewer, 1913). PMID:22707905

  2. Food-web structure and trophodynamics of mesopelagic-suprabenthic bathyal macrofauna of the Algerian Basin based on stable isotopes of carbon and nitrogen

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Cartes, J. E.; Rumolo, P.; Sprovieri, M.

    2009-09-01

    (the hyperiid Phrosina semilunata) to -19.9‰ (the decapod Pasiphaea multidentata), while δ 15N values ranged from 3.9‰ ( P. semilunata) to 7.5‰ ( P. multidentata). Among zooplankton, more enriched δ 15N values were found among carnivores (e.g. the fish Cyclothone spp. and Pasiphaea multidentata) preying on copepods, hyperiids, euphausiids and small fish. The lowest δ 15N values were found for hyperiids that feed on the mucus nets of salps (e.g. Vibilia armata). After contrasting isotope analysis with dietary data, we conclude there were two trophic levels among zooplankton/micronekton. Strong correlation between the mean annual δ 15N and δ 13C values was found for zooplankton ( R2=0.7), but not for suprabenthos, which suggests a single source of carbon for plankton. We found a general seasonal trend for δ 13C enrichment from late autumn (November) to late winter-spring (February-April) for both suprabenthos and zooplankton. The δ 13C enrichment in February-April was correlated in zooplankton with higher surface chlorophyll a concentration 1 month before sampling. As evidenced by δ 13C-δ 15N correlations, the response of zooplankton to the peak of surface primary production was almost immediate (an increase of δ 13C-δ 15N correlations in February), and stronger than for suprabenthos. The response among suprabenthos was weak, with slight increase in δ 13C-δ 15N relationships in April-June.

  3. Phylogenetic analysis of mitochondrial protein coding genes confirms the reciprocal paraphyly of Hexapoda and Crustacea

    PubMed Central

    Carapelli, Antonio; Liò, Pietro; Nardi, Francesco; van der Wath, Elizabeth; Frati, Francesco

    2007-01-01

    Background The phylogeny of Arthropoda is still a matter of harsh debate among systematists, and significant disagreement exists between morphological and molecular studies. In particular, while the taxon joining hexapods and crustaceans (the Pancrustacea) is now widely accepted among zoologists, the relationships among its basal lineages, and particularly the supposed reciprocal paraphyly of Crustacea and Hexapoda, continues to represent a challenge. Several genes, as well as different molecular markers, have been used to tackle this problem in molecular phylogenetic studies, with the mitochondrial DNA being one of the molecules of choice. In this study, we have assembled the largest data set available so far for Pancrustacea, consisting of 100 complete (or almost complete) sequences of mitochondrial genomes. After removal of unalignable sequence regions and highly rearranged genomes, we used nucleotide and inferred amino acid sequences of the 13 protein coding genes to reconstruct the phylogenetic relationships among major lineages of Pancrustacea. The analysis was performed with Bayesian inference, and for the amino acid sequences a new, Pancrustacea-specific, matrix of amino acid replacement was developed and used in this study. Results Two largely congruent trees were obtained from the analysis of nucleotide and amino acid datasets. In particular, the best tree obtained based on the new matrix of amino acid replacement (MtPan) was preferred over those obtained using previously available matrices (MtArt and MtRev) because of its higher likelihood score. The most remarkable result is the reciprocal paraphyly of Hexapoda and Crustacea, with some lineages of crustaceans (namely the Malacostraca, Cephalocarida and, possibly, the Branchiopoda) being more closely related to the Insecta s.s. (Ectognatha) than two orders of basal hexapods, Collembola and Diplura. Our results confirm that the mitochondrial genome, unlike analyses based on morphological data or nuclear

  4. Wood source and pyrolysis temperature interact to control PyOM degradation rates

    NASA Astrophysics Data System (ADS)

    Bird, J. A.; Hatton, P. J.; Filley, T. R.; Chatterjee, S.; Auclerc, A.; Gormley, M.; Dastmalchi, K.; Stark, R. E.; Nadelhoffer, K. J.

    2015-12-01

    Surprisingly little is known about how shifts in tree species composition and increased forest fire frequency and intensity will affect one of the most stable pools of soil organic matter, i.e. the pyrogenic organic matter (PyOM or char). In a previous study, we showed that wood source and pyrolysis temperature interact to control PyOM structure and potential reactivity for two tree species common in high-latitude forests, jack pine (JP) and red maple (RM). Here, we investigate whether these differences affect PyOM turnover by examining the fates of 13C/15N-enriched JP wood and PyOM pyrolyzed at 300 (JP300) and 450 °C (JP450) and RM pyrolyzed at 450 °C (RM450). The substrates were applied 1-3 cm below the O/A interface of a well-drained Spodosol in a long-term forest fire study located at the University of Michigan Biological Station (Pellston, MI, USA). 13C-CO2effluxes from the first 996 days of decay showed a significant wood source by pyrolysis temperature interaction on PyOM field mineralisation rates, with RM450 mineralising twice faster than JP450 during the first 90 days. Increasing pyrolysis temperature substantially decreased field mineralization rates during the first 996 days, with mineralisation rates 24 and 80 times slower for JP300 and JP450 compared with JP wood. After 1 year, (i) bacterial groups were large sinks for PyOM-derived C as pyrolysis temperature increased and as substrate use efficiency decreased; (ii) potential phenol oxidase and net peroxidase activities were unaffected by the PyOM addition, although net peroxidase activities measured tended to lesser for soils amended with JP450 and RM450; and (iii) Collembola detritivores appeared less likely to be found for soils amended with JP450 and RM450. PyOM-derived C and N recoveries did not differ after 1 year; we will present 3-y recovery data. Our results suggest that the composition of angiosperms (e.g. RM) and gymnosperms (e.g. JP) in high-latitude forests is an underappreciated but

  5. Cinque Terre National Park vineyards: soil microarthropod community and biodiversity

    NASA Astrophysics Data System (ADS)

    Simoni, Sauro; Nannelli, Roberto; Castagnoli, Marisa; Perrone, Matteo; Corino, Lorenzo; Guidi, Silvia; Goggioli, Donatella; Tarchi, Franca; Gagnarli, Elena

    2015-04-01

    The study was part of the LABTER (Laboratory for the sustainability of the viticulture in the 5 Terre Park), a project aiming at gathering knowledge on quality of viticulture and stability of soils in the 5 Terre National Park, territory protected by UNESCO, by means of a multidisciplinary approach. The Cinque Terre is a particular area on Italy's coast, with terraced hillsides mainly devoted to viticulture and quite homogeneously managed. The relationship between biodiversity and soil processes is primarily defined by dynamics and interactions in the soil community food webs. The abundance and structure of microarthropod communities are highly respondent to different soil 'status' and quality. The aims were to study soil microartropods' community of terraced vineyards and to evaluate microarthropod distribution at different altitudes and distance from the seaside. The experimental design was set with five samplings in five different areas of the Park, at different altitudes, between 50 and 400 meters above the sea level, and at different distance from the sea. All the microarthtropods were counted, identified and classified up to Order level, at least. On the whole, by considering all the microarthropods collected (6,739 specimens), mite community represented the most numerous group (56.6%), followed by Collembola (35.2%). Within mite groups, Oribatids were the most numerous with the higher number of species, about 40, followed by Prostigmata, Mesostigmata and Astigmata. The ANOVA analysis showed that the density of microarthropods was affected by sampling time (F4,111= 7.27; P=.000) and sampling location (F4,111= 7.01; P=.000). On the whole, the highest densities were registered at the end of Summer and the beginning of Autumn. As regards the sampling location, oribatid mites (F4,111= 3.38; P=.012) and springtails (F4,111= 6.30; P=.000) were the groups more affected by sampling sites. The biological soil quality was also defined through the determination of the

  6. [Community traits of soil fauna in forestlands converted from cultivated lands in limestone red soil region of Ruichang, Jiangxi Province of China].

    PubMed

    Li, Tao; Liu, Yuan-Qiug; Guo, Sheng-Mao; Ke, Guo-Qing; Zhang, Zhao; Xiao, Xu-Bao; Liu, Wu

    2012-04-01

    This paper studied the variations of the community composition and individuals' number of soil fauna in limestone red soil region of Ruichang, Jiangxi Province after six years of converting cultivated lands into forestlands. Three converted forestlands, including the lands of mixed multiple-species forest, bamboo-broadleaved forest, and tree-seedling integration, were selected as test objects, with cultivated lands as the comparison. A total of 34 orders, 17 classes, and 6 phyla of soil fauna were observed in the converted forestlands. The dominant group was Nematoda, accounting for 86.7% of the total, whereas Acarina, Enchytraeidae, and Collembola were the common groups. In the cultivated lands, soil fauna had 21 orders, 10 classes, and 5 phyla. The dominant group was also Nematoda, accounting 86.7% of the total, and Acarina and Enchytraeidae were the common groups. In the converted forestlands, the group number of rare species was greater than that in the cultivated lands (30 vs. 18), and, except in winter, the group number and average density were significantly higher than those in the cultivated lands (P < 0.05). The vertical distribution of soil fauna in the soil profiles showed an obvious surface accumulation, which was more apparent in converted forestlands than in cultivated lands, and the individuals' number had significant differences between the surface (0-5 cm) layer and the 5-10 cm and 10-15 cm layers (P < 0.01) for both the converted forestlands and the cultivated lands. The group number of soil fauna in the converted forestlands had a seasonal variation ranked in the order of summer > autumn > spring > winter, and there was a significant difference between summer-autumn and spring-winter. The average density of the soil fauna also had a seasonal variation but ranked as autumn > summer > spring > winter, and the differences among the seasons were significant (P < 0.05). The biodiversity index of soil fauna was significantly higher in converted

  7. Implementation of a Shallow Groundwater Temperature Manipulation: Linking Hydrogeology, Biogeochemistry, and Aquatic Ecology

    NASA Astrophysics Data System (ADS)

    Wilson, K. P.; Williams, D. D.

    2004-05-01

    shows no difference between seasons but higher densities at -20cm then at all other depths. The most common meiofaunal taxa include Harpacticoida, Nematoda, Ostracoda, Chironomidae, Collembola, and Hydracarina. Plecoptera and Hymenoptera larvae are also found on occasion above -60 cm.

  8. Handling and Use of Oxygen by Pancrustaceans: Conserved Patterns and the Evolution of Respiratory Structures.

    PubMed

    Harrison, Jon F

    2015-11-01

    accepted phylogenies, invaginations of cuticle to form lungs or tracheae occurred independently multiple times across the Arthropoda and Pancrustacea in association with the evolution of terrestriality. However, the timing and number of such events in the evolution of tracheal systems remain controversial. Despite molecular phylogenies that place the origin of the hexapods before the appearance of land plants in the Ordovician, terrestrial fossils of Collembola, Archaeognatha, and Zygentoma in the Silurian and Devonian, and the lack of fossil evidence for older aquatic hexapods, suggest that the tracheated hexapods likely evolved from Remipedia-like ancestors on land.

  9. The use of acute and chronic bioassays to determine the ecological risk and bioremediation efficiency of oil-polluted soils.

    PubMed

    van Gestel, C A; van der Waarde, J J; Derksen, J G; van der Hoek, E E; Veul, M F; Bouwens, S; Rusch, B; Kronenburg, R; Stokman, G N

    2001-07-01

    To compare the effectiveness of acute and chronic bioassays for the ecological risk assessment of polluted soils, soil samples from a site with an historical mineral oil contamination (< 50-3,300 mg oil/kg dry soil) at the Petroleum Harbour in Amsterdam, The Netherlands, were screened for ecological effects using acute and chronic bioassays. A two-step 0.001 M Ca(NO3)2 extraction at a final solution-to-soil ratio of 1:1 was used to prepare extracts for the acute bioassays. Acute bioassays (< or = 5 d) applied to the 0.001 M Ca(NO3)2 extracts from the polluted and reference soils included growth tests with bacteria (Bacillus sp.), algae (Raphidocelis subcapitata), and plants (Lactuca sativa), immobility tests with nematodes (Plectus acuminatus), springtails (Folsomia candida), and cladocerans (Daphnia magna), and the Microtox test (Vibrio fischeri). Chronic bioassays (four weeks) performed on the same soil samples included tests with L. sativa, F. candida, and earthworms (Eisenia fetida) and the bait-lamina test (substrate consumption). The acute bioassays on Microtox showed a response that corresponded with the level of oil pollution. All other acute bioassays did not show such a consistent response, probably because pollutant levels were too low to cause acute effects. All chronic bioassays showed sublethal responses according to the contaminant levels (oil and in some soils also metals). This shows that chronic bioassays on soil samples are more sensitive in assessing the toxicity of mineral oil contamination in soil than acute bioassays on soil extracts. A pilot scale bioremediation study on soils taken from the two most polluted sites and a control site showed a rapid decline of oil concentrations to reach a stable level within eight weeks. Acute bioassays applied to the soils, using Microtox, algae, and D. magna, and chronic bioassays, using plants, Collembola, earthworms, and bait-lamina consumption, in all cases showed a rapid reduction of toxicity, which

  10. Effects of Winter Climate Change on Plant and Soil Ecology of Cryoturbated Non-Sorted Circles Tundra

    NASA Astrophysics Data System (ADS)

    Monteux, S.; Krab, E. J.; Rönnefarth, J.; Becher, M.; Blume-Werry, G.; Kreyling, J.; Keuper, F.; Klaminder, J.; Kobayashi, M.; Lundin, E. J.; Milbau, A.; Teuber, L. M.; Weedon, J.; Dorrepaal, E.

    2014-12-01

    Cryoturbation is the movement of soil particles through repeated freeze-thaw events, resulting in the burial of large amounts of soil organic carbon (SOC). Non-sorted circles are a common type of cryoturbated ground in arctic and alpine areas underlain by permafrost. They appear as sparsely vegetated areas surrounded by denser tundra vegetation. Climate change in arctic environments will likely increase winter precipitation in large parts of the Arctic in Europe, Asia and America, resulting in deeper snow cover. Snow is a good thermal insulator and modifications in freezing intensity and freeze-thaw cycles are therefore likely, which could affect the burial of organic matter. Moreover, vegetation, soil fauna and soil microbial communities, which are important drivers of SOC dynamics, may be impacted directly by the altered winter conditions and indirectly by reduced cryoturbation. We aimed to investigate this, and therefore subjected non-sorted circles in North-Swedish subarctic alpine tundra to two years of increased thermal insulation in winter and spring, using snow fences or fibre cloth (Figure 1). Both snow fences and fibre cloth manipulations increased surface soil temperatures, especially daily minimum temperatures, and strongly reduced freeze-thaw frequency. We compared the impacts of these manipulations on plant performance, soil chemistry, soil fauna and soil microbial communities between the centre of the circles and the dense tundra heath just outside. Directly after snowmelt, the extra winter insulation decreased plant leaf damage, both in the centre and in adjacent tundra, but responses differed between species. We will further present the responses of plant phenology and growth, soil pH and dissolved organic carbon content, soil fauna activity, Collembola community composition and body size distribution, as well as fungal and bacterial diversity profiles and functional groups abundance. We expect that winter warming due to increased snow cover and

  11. Biochar and biological carbon cycling in temperate soils

    NASA Astrophysics Data System (ADS)

    McCormack, S. A.; Vanbergen, A. J.; Bardgett, R. D.; Hopkins, D. W.; Ostle, N.

    2012-04-01

    Production of biochar, the recalcitrant residue formed by pyrolysis of plant matter, is suggested as a means of increasing storage of stable carbon (C) in the soil (1). Biochar has also been shown to act as a soil conditioner, increasing the productivity of certain crops by reducing nutrient leaching and improving soil water-holding capacity. However, the response of soil carbon pools to biochar addition is not yet well understood. Studies have shown that biochar has highly variable effects on microbial C cycling and thus on soil C storage (2,3,4). This discrepancy may be partially explained by the response of soil invertebrates, which occupy higher trophic levels and regulate microbial activity. This research aims to understand the role of soil invertebrates (i.e. Collembola and nematode worms) in biochar-mediated changes to soil C dynamics across a range of plant-soil communities. An open-air, pot-based mesocosm experiment was established in May, 2011 at the Centre for Ecology and Hydrology, Edinburgh. Three treatments were included in a fully-factorial design: biochar (presence [2 % w/w] or absence), soil type (arable sandy, arable sandy loam, grassland sandy loam), and vegetation type (Hordeum vulgare, Lolium perenne, unvegetated). Monitored parameters include: invertebrate and microbial species composition, soil C fluxes (CO2 and trace gas evolution, leachate C content, primary productivity and soil C content), and soil conditions (pH, moisture content and water-holding capacity). Preliminary results indicate that biochar-induced changes to soil invertebrate communities and processes are affected by pre-existing soil characteristics, and that soil texture in particular may be an important determinant of soil response to biochar addition. 1. Lehmann, 2007. A handful of carbon. Nature 447, 143-144. 2. Liang et al., 2010. Black carbon affects the cycling of non-black carbon in soil. Organic Geochemistry 41, 206-213. 3. Van Zwieten et al., 2010. Influence of

  12. A revision of the Axylus group of Agraeciini (Orthoptera: Tettigoniidae: Conocephalinae) and of some other species formerly included in Nicsara or Anthracites Revision of the Indo-Australian Conocephalinae, Part 3.

    PubMed

    Ingrisch, Sigfrid

    2015-01-01

    . sudirman sp. nov., E. ternate sp. nov., E. variata sp. nov.; 51 species in Heminicsara: H. albatros sp. nov., H. albipuncta sp. nov., H. albogeniculata Naskrecki & Ingrisch sp. nov., H. alticola sp. nov., H. ammea sp. nov., H. anggi sp. nov., H. bilobata sp. nov., H. cingima sp. nov., H. comprima sp. nov., H. coriformis sp. nov., H. corneli sp. nov., H. cyclops sp. nov., H. despecta Naskrecki & Ingrisch sp. nov., H. dilatata sp. nov., H. dividata sp. nov., H. dobo sp. nov., H. elongata Naskrecki & Ingrisch sp. nov., H. furcata sp. nov., H. gibba sp. nov., H. gugusu Naskrecki & Ingrisch sp. nov., H. illugi sp. nov., H. jacobii Karny, 1912, H. jayawijaya sp. nov., H. kelila sp. nov., H. kolombangara sp. nov., H. lamas Naskrecki & Ingrisch sp. nov., H. longiloba sp. nov., H. lord sp. nov., H. malu sp. nov., H. mamberamo sp. nov., H. manus sp. nov., H. montana sp. nov., H. nigra sp. nov., H. nomoensis sp. nov., H. obiensis sp. nov., H. ohu sp. nov., H. pak sp. nov., H. parallela Naskrecki & Ingrisch sp. nov., H. pinniger sp. nov., H. popoman sp. nov., H. rugosa sp. nov., H. scutula sp. nov., H. sica sp. nov., H. sinewit sp. nov., H. siwi sp. nov., H. stylata sp. nov., H. tabtab sp. nov., H. truncata Naskrecki & Ingrisch sp. nov., H. tumulus sp. nov., H. umasani sp. nov., H. wanuma sp. nov., H. zugi sp. nov.; and three species in Sulasara: S. armata sp. nov., S. renschi sp. nov., S. tambu sp. nov. PMID:26624732

  13. The Strepsiptera problem: phylogeny of the holometabolous insect orders inferred from 18S and 28S ribosomal DNA sequences and morphology.

    PubMed

    Whiting, M F; Carpenter, J C; Wheeler, Q D; Wheeler, W C

    1997-03-01

    Phylogenetic relationships among the holometabolous insect orders were inferred from cladistic analysis of nucleotide sequences of 18S ribosomal DNA (rDNA) (85 exemplars) and 28S rDNA (52 exemplars) and morphological characters. Exemplar outgroup taxa were Collembola (1 sequence), Archaeognatha (1), Ephemerida (1), Odonata (2), Plecoptera (2), Blattodea (1), Mantodea (1), Dermaptera (1), Orthoptera (1), Phasmatodea (1), Embioptera (1), Psocoptera (1), Phthiraptera (1), Hemiptera (4), and Thysanoptera (1). Exemplar ingroup taxa were Coleoptera: Archostemata (1), Adephaga (2), and Polyphaga (7); Megaloptera (1); Raphidioptera (1); Neuroptera (sensu stricto = Planipennia): Mantispoidea (2), Hemerobioidea (2), and Myrmeleontoidea (2); Hymenoptera: Symphyta (4) and Apocrita (19); Trichoptera: Hydropsychoidea (1) and Limnephiloidea (2); Lepidoptera: Ditrysia (3); Siphonaptera: Pulicoidea (1) and Ceratophylloidea (2); Mecoptera: Meropeidae (1), Boreidae (1), Panorpidae (1), and Bittacidae (2); Diptera: Nematocera (1), Brachycera (2), and Cyclorrhapha (1); and Strepsiptera: Corioxenidae (1), Myrmecolacidae (1), Elenchidae (1), and Stylopidae (3). We analyzed approximately 1 kilobase of 18S rDNA, starting 398 nucleotides downstream of the 5' end, and approximately 400 bp of 28S rDNA in expansion segment D3. Multiple alignment of the 18S and 28S sequences resulted in 1,116 nucleotide positions with 24 insert regions and 398 positions with 14 insert regions, respectively. All Strepsiptera and Neuroptera have large insert regions in 18S and 28S. The secondary structure of 18S insert 23 is composed of long stems that are GC rich in the basal Strepsiptera and AT rich in the more derived Strepsiptera. A matrix of 176 morphological characters was analyzed for holometabolous orders. Incongruence length difference tests indicate that the 28S + morphological data sets are incongruent but that 28S + 18S, 18S + morphology, and 28S + 18S + morphology fail to reject the hypothesis of