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The springtail cuticle as a blueprint for omniphobic surfacesHensel, René, Neinhuis, Christoph, Werner, Carsten 11 December 2015 (has links) (PDF)
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 oilrepellent 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.
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Springtail diversity in the Cape floristic regionJanion, Charlene, Scheepers, Charlene 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Understanding the distribution, abundance and diversity of species and the mechanisms
causing these patterns has been the interest of ecologists and taxonomists for decades. The
exceptionally high plant diversity in the Fynbos biome has been well studied. Whilst early
arguments suggested that the high plant diversity is not reflected in the arthropod diversity
and that insect species richness is low compared to other comparable areas, these
observations might have been hampered by the taxonomic impediment. Despite global
recognition of the significance of this below-ground component of diversity for ecosystem
functioning, soil is one of the most poorly studied habitats of terrestrial ecosystems.
Although knowledge is increasing for epigaeic groups, other significant groups such as the
Collembola remain especially poorly understood. This thesis starts addressing this serious
gap in knowledge concerning the below-ground component of biodiversity in the Fynbos
biome and the effects of landscape transformation thereon. As part of the work,
considerable attention was given to resolving the taxonomic impediment for the springtail
fauna of the Fynbos biome using modern morphological and DNA barcoding methods, while
also examining the correlates of soil animal diversity in the biome, by using Collembola
(springtails) as exemplars. First, using a combination of published records of Collembola
from South Africa, various sampling methods and DNA barcoding, a species list is compiled
for the Western Cape. Currently 213 species are known to exist from the Western Cape. A
high level of cryptic diversity was also found in several genera, together with several
potential species radiations in the Ectonura, Seira, Parisotoma and Cryptopygus. A start is a
made at addressing the lack of taxonomic knowledge by describing five new species. Two
Ectonura Cassagnau 1980 species are described from Betty’s Bay and Grootvadersbosch
respectively and a key to the Neanurinae of South Africa is provided. The first record of the
genus Triacanthella Schäffer, 1897 is described from a cave in Table Mountain, while two
new species of Delamarephorura are described and the genera Spicatella Thibaud 2002 and
Delamarephorura Weiner & Najt 1999 are synonymized. Although fire is thought to be the
main form of decomposition in the Fynbos biome, recent work has shown that biological
decomposition may be more important than previously thought. I examine the resilience of
Collembola after a large-scale fire in Jonkershoek Nature Reserve using quantitative
sampling which is temporally replicated. The resilience of invertebrate fauna in the fynbos is
not well understood, thus I investigate the diversity of Collembola before and after a major
fire. Results show Collembola species richness and abundance recovered surprisingly quickly after the fire. On a larger scale, litterbags were deployed at six sites across the Western Cape
using different litter types. Here, a total of 113 morphospecies species was found. Local
richness was found to be highest in Kogelberg (32 species), while the turnover between sites
was also high. Thus, the degradation of local habitat patches will be as much of a threat to
Collembola as to the endemic plants in this region. / AFRIKAANSE OPSOMMING: Begrip van die verspreiding, spesierykheid en verskeidenheid van spesies en die meganismes
wat hierdie patrone veroorsaak is al die belangstelling van ekoloë en taksonome vir dekades.
Die buitengewoon hoë plant diversiteit in die Fynbos-bioom is goed bestudeer. Terwyl vroeë
argumente voorstel dat die hoë plantdiversiteit nie weerspieël word in die geleedpotige
diversiteit nie en dat insekspesierykheid laag is in vergelyking met ander gebiede, kon
hierdie waarnemings nie gemaak word nie as gevolg van taksonomiese hindernisse. Ten
spyte van die wêreldwye erkenning van die belangrikheid van hierdie ondergrondse
komponent van diversiteit vir die funksionering van die ekosisteem, is die grond een van die
swakste bestudeerde habitatte van terrestriële ekosisteme. Alhoewel kennis vermeerder vir
bogrondse groepe, word ander belangrike groepe soos die Collembola swak verstaan.
Hierdie tesis begin hierdie ernstige leemte in kennis aanspreek, met betrekking tot die
ondergrondse komponent van biodiversiteit in die Fynbos bioom en die gevolge van die
landskap transformasie daarop. As deel van die werk, is heelwat aandag gegee aan die
oplossing van die taksonomiese hindernis vir die springstert fauna van die fynbos bioom met
behulp van moderne morfologiese en DNA metodes, terwyl dit ook die ooreenkomste van
grond diere diversiteit ondersoek in die bioom, deur gebruik te maak van Collembola
(springsterte) as voorbeelde. Eerste, met behulp van 'n kombinasie van gepubliseerde
rekords van Collembola van Suid-Afrika, verskillende kolleksie metodes en DNA metodes is 'n
spesielys saamgestel vir die Wes-Kaap. Tans is 213 spesies bekend vir die Wes-Kaap. 'n Hoë
vlak van kriptiese diversiteit is ook gevind in verskeie genera, saam met verskeie potensiële
spesies radiasies in die Ectonura, Seira, Parisotoma en Cryptopygus. 'n Begin is gemaak op
die aanspreek van die gebrek van taksonomiese kennis deur vyf nuwe spesies te beskryf.
Twee Ectonura Cassagnau 1980 spesies van Bettiesbaai en Grootvadersbosch is beskryf en 'n
sleutel tot die Neanurinae van Suid-Afrika word verskaf. Die eerste rekord van die genus
Triacanthella Schaffer, 1897 word beskryf van 'n grot in Tafelberg, terwyl twee nuwe spesies
van Delamarephorura beskryf word en die genera Spicatella Thibaud 2002 en Delamarephorura Weiner & Najt 1999 gesinomiseer word. Hoewel vuur beskou word as die
belangrikste vorm van ontbinding in die Fynbos bioom, het onlangse werk getoon dat die
biologiese ontbinding belangriker mag wees as wat voorheen vermoed was. Ek ondersoek
die veerkragtigheid van Collembola na 'n groot skaal vuur in Jonkershoek Natuurreservaat
met behulp van kwantitatiewe steekproefneming wat tydelik herhaal. Die veerkragtigheid
van ongewerwelde fauna in die fynbos word nie goed verstaan nie, dus het ek ondersoek
ingestel na die diversiteit van Collembola voor en na 'n groot vuur. Resultate toon dat
Collembola se spesierykheid en hoveelheid verbasend vinnig herstel na die vuur. Op 'n
groter skaal, is kolleksies by ses plekke regoor die Wes-Kaap gebruik en verskillende
blaarafval word vergelyk. Hier word 'n totaal van 113 morfologiese spesies gevind. Daar is
gevind dat die hoogste aantal spesies in Kogelberg is (32 spesies), terwyl die omset tussen
plekke baie hoog was. So sal die agteruitgang van plaaslike habitatte net soveel van 'n
bedreiging inhou vir Collembola as vir die endemiese plante in hierdie streek.
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Mesofaunal recolonisation of degraded soilsWilliams, Jennifer January 2013 (has links)
The degradation of soil quality due to anthropogenic causes is globally important, both in terms of ecosystem services and ecological biodiversity. Soil quality reduction is stated to be detrimental for population densities and species diversity of soil invertebrates, including the mesofauna (Acari and Collembola). Within the soil food web, mesofauna occupy several trophic levels and as such facilitate nutrient turnover, fulfilling vital ecosystem functions and services. Understanding soil invertebrate population dynamics not only during degradation, but equally upon ecosystem restoration, is vital to identify possible losses or benefits to healthy ecosystem functioning. Prior to this investigation the Highfield site, Rothamsted Research, had been divided and maintained as grassland, arable cropping or bare fallow for 50 years. The latter resulted in a soil that had low soil organic matter levels, poor structure, low bacterial biomass and virtually no invertebrate population. Investigations into the invertebrate population changes, within both the experimental plots and surrounding land, upon alteration of the existing management strategies was completed over a two year period. Changes to mesofaunal populations were detected across all treatments following conversion. Generally, new fallow and arable management strategies produced low density fluctuating populations affected by the physical disturbance of ploughing and lack of soil organic matter as a basal food resource. Grassland management produced increased species diversity and abundance within a more stable soil food web. Each of the new management strategies developed towards its equivalent management strategy within the control treatments. Although it was apparent that the mesofaunal populations were re-establishing under more favourable environmental conditions, there was no definitive conclusion as to the source of the population increases. An attempt to identify the physical mode of invertebrate movement was completed, utilising a prototype mesocosm to act as a physical barrier, this showed promise for future use in such studies.
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FEEDING BEHAVIOUR OF FOLSOMIA CANDIDA AS INFLUENCED BY DIET-SWITCHING IN THE PRESENCE OF LIVE MAIZE ROOTSEerpina, Ramesh 30 October 2013 (has links)
ABSTRACT
Collembola are known to feed on soil fungi, mycorrhizae and plant derived products. A recent study revealed that one species of Collembola, Protaphorura fimata, completely switched from decomposer to herbivore when live roots were present. The current study investigated the occurrence of diet-switching in Folsomia candida Willem. from plant detritus to live by examining its dietary preferences using stable isotope techniques. They were offering with live maize roots (C4 plant) in C3 soil, along with 15N enriched ryegrass litter and. Results demonstrated the presence of a partial diet-switch from detritus to live maize roots. Additional tests suggested that the diet-switch towards maize roots was a response to both improved food quality and greater food availability. The presence of live roots improved the body growth of F. candida and the incorporation of C from live roots into Collembola tissue suggesting
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Interação de plantas de trevo vermelho inoculadas com rizóbios com ácaros e colêmbolos edáficos / Interaction of red clover plants inoculated with rhizobia with edaphic mites and springtailsBassani, Victor Lucas January 2015 (has links)
A mesofauna edáfica, compreendendo ácaros e colêmbolos, é sensível a alterações no solo, sendo considerada um indicador de qualidade, uma vez que realiza a fragmentação de matéria orgânica, controle populacional de determinados grupos da biota do solo e ingestão de microrganismos. A colonização de plantas por micro-organismos, como a de leguminosas por rizobios, pode levar a mudanças na rizosfera vegetal e influenciar a mesofauna. Este estudo teve por objetivo avaliar o efeito da inoculação de plantas de trevo vermelho com rizóbios sobre os ácaros e colêmbolos edáficos e avaliar se colêmbolos alimentados com rizóbios poderiam inocular plantas hospedeiras. Para isso, plantas de trevo vermelho, inoculadas com as estirpes SEMIA 2081, SEMIA 2082 e SEMIA 222, e plantas controle sem inoculação foram plantadas em tubos-armadilha e inseridas em campo. A seguir, a mesofauna atraída foi extraída e identificada. Outro experimento em laboratório utilizou plantas de trevo vermelho que foram colocadas em contato com colêmbolos da família Hypogastruridae e dos gêneros Proisotoma, Onychiurus e Orthonychiurus, os quais haviam sido alimentados com um substrato impregnado com o rizóbio da estirpe SEMIA 2081 As plantas inoculadas com as três estirpes de rizóbios atrairam ácaros edáficos mas não colêmbolos, quando comparadas com as plantas que não foram inoculadas nem receberam fonte de nitrogênio. Considerando os números totais de ácaros e colêmbolos, somente as plantas inoculadas com a estirpe SEMIA 222 apresentaram atratividade quando comparadas ao controle sem inoculação e sem fonte de nitrogênio. A atratividade de ácaros e colêmbolos observada no tratamento controle com nitrogênio foi similar aos tratamentos inoculados. No experimento de laboratório, os colêmbolos vivos e o macerado de colêmbolos da família Hypogastruridae, e gêneros Proisotoma e Orthonychiurus foram capazes de transferir os rizóbios que receberam pela alimentação às plantas, formando nódulos radiculares. As plantas que receberam o macerado de colêmbolos da família Hypogastruridae apresentaram maior número de nódulos comparadas às plantas que receberam os mesmos colêmbolos vivos. / The soil mesofauna comprising mites and springtails, is sensitive to changes in soil, and it is considered a quality indicator since it performs fragmentation of organic matter, population control of certain soil biota groups and ingestion of microorganisms. The plants colonized by microorganisms, such as legumes by rhizobia can lead to changes in plant rhizosphere and influence mesofauna. This study aimed to evaluate the effect of inoculation of red clover plants with rhizobia on edaphic mites and springtails and assess if springtails fed with rhizobia could inoculate host plants. For this, red clover plants inoculated with strains SEMIA 2081, SEMIA 2082 and SEMIA 222, and control plants without inoculation were planted in trap-tubes and inserted on field. Then, the attracted mesofauna was submitted to extraction and identification. Another laboratory experiment used red clover plants put in contact with springtails. These springtails of Hypogastruridae family and Proisotoma, Onychiurus and Orthonychiurus genera, had been fed with a substrate impregnated with rhizobia strain SEMIA 2081. Plants inoculated with three Rhizobia strains attracted edaphic mites, but not Collembola, when compared to uninoculated plants with no nitrogen source Considering the total numbers of mites and springtails, only plants inoculated with SEMIA 222 strain showed attractiveness when compared to the control without inoculation and no nitrogen source. The attractiveness of mites and springtails observed in the control treatment with nitrogen was similar to the inoculated treatments. In the laboratory experiment, the living springtails and the macerate of springtails of Hypogastruridae family, and Proisotoma and Orthonychiurus genera were able to transfer the rhizobia that they received by feeding to the plants, forming root nodules. The plants that received the macerate of springtails of the Hypogastruridae family had a higher number of nodules compared to the plants that received the same living springtails.
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Interação de plantas de trevo vermelho inoculadas com rizóbios com ácaros e colêmbolos edáficos / Interaction of red clover plants inoculated with rhizobia with edaphic mites and springtailsBassani, Victor Lucas January 2015 (has links)
A mesofauna edáfica, compreendendo ácaros e colêmbolos, é sensível a alterações no solo, sendo considerada um indicador de qualidade, uma vez que realiza a fragmentação de matéria orgânica, controle populacional de determinados grupos da biota do solo e ingestão de microrganismos. A colonização de plantas por micro-organismos, como a de leguminosas por rizobios, pode levar a mudanças na rizosfera vegetal e influenciar a mesofauna. Este estudo teve por objetivo avaliar o efeito da inoculação de plantas de trevo vermelho com rizóbios sobre os ácaros e colêmbolos edáficos e avaliar se colêmbolos alimentados com rizóbios poderiam inocular plantas hospedeiras. Para isso, plantas de trevo vermelho, inoculadas com as estirpes SEMIA 2081, SEMIA 2082 e SEMIA 222, e plantas controle sem inoculação foram plantadas em tubos-armadilha e inseridas em campo. A seguir, a mesofauna atraída foi extraída e identificada. Outro experimento em laboratório utilizou plantas de trevo vermelho que foram colocadas em contato com colêmbolos da família Hypogastruridae e dos gêneros Proisotoma, Onychiurus e Orthonychiurus, os quais haviam sido alimentados com um substrato impregnado com o rizóbio da estirpe SEMIA 2081 As plantas inoculadas com as três estirpes de rizóbios atrairam ácaros edáficos mas não colêmbolos, quando comparadas com as plantas que não foram inoculadas nem receberam fonte de nitrogênio. Considerando os números totais de ácaros e colêmbolos, somente as plantas inoculadas com a estirpe SEMIA 222 apresentaram atratividade quando comparadas ao controle sem inoculação e sem fonte de nitrogênio. A atratividade de ácaros e colêmbolos observada no tratamento controle com nitrogênio foi similar aos tratamentos inoculados. No experimento de laboratório, os colêmbolos vivos e o macerado de colêmbolos da família Hypogastruridae, e gêneros Proisotoma e Orthonychiurus foram capazes de transferir os rizóbios que receberam pela alimentação às plantas, formando nódulos radiculares. As plantas que receberam o macerado de colêmbolos da família Hypogastruridae apresentaram maior número de nódulos comparadas às plantas que receberam os mesmos colêmbolos vivos. / The soil mesofauna comprising mites and springtails, is sensitive to changes in soil, and it is considered a quality indicator since it performs fragmentation of organic matter, population control of certain soil biota groups and ingestion of microorganisms. The plants colonized by microorganisms, such as legumes by rhizobia can lead to changes in plant rhizosphere and influence mesofauna. This study aimed to evaluate the effect of inoculation of red clover plants with rhizobia on edaphic mites and springtails and assess if springtails fed with rhizobia could inoculate host plants. For this, red clover plants inoculated with strains SEMIA 2081, SEMIA 2082 and SEMIA 222, and control plants without inoculation were planted in trap-tubes and inserted on field. Then, the attracted mesofauna was submitted to extraction and identification. Another laboratory experiment used red clover plants put in contact with springtails. These springtails of Hypogastruridae family and Proisotoma, Onychiurus and Orthonychiurus genera, had been fed with a substrate impregnated with rhizobia strain SEMIA 2081. Plants inoculated with three Rhizobia strains attracted edaphic mites, but not Collembola, when compared to uninoculated plants with no nitrogen source Considering the total numbers of mites and springtails, only plants inoculated with SEMIA 222 strain showed attractiveness when compared to the control without inoculation and no nitrogen source. The attractiveness of mites and springtails observed in the control treatment with nitrogen was similar to the inoculated treatments. In the laboratory experiment, the living springtails and the macerate of springtails of Hypogastruridae family, and Proisotoma and Orthonychiurus genera were able to transfer the rhizobia that they received by feeding to the plants, forming root nodules. The plants that received the macerate of springtails of the Hypogastruridae family had a higher number of nodules compared to the plants that received the same living springtails.
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Distribuição da fauna de colêmbolos cavernícolas em matriz de minério de ferro no Quadrilátero Ferrífero, Minas Gerais, sudeste do BrasilMachado, Thais Gomes 29 April 2016 (has links)
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Previous issue date: 2016-04-29 / Vale S. A. / In general, cave species have changes in their morphology and physiology as way of adaptation to the environment and are classified as troglobites; eutroglophiles; subtroglophiles and trogloxenes. Compared to epigean ecosystem, the cave ecosystem has low species diversity, dependence of nutrients from the external environment, humidity and stable temperature in the year, therefore, this environment is strongly influenced by external environmental changes, such as mining, deforestation, urbanization, etc. This study examines the distribution of troglobite species of Collembola caves in different lithologies in areas of mining interest. Located in Minas Gerais, the Quadrilátero Ferrífero represents one of the main metallogenetic provinces of Brazil. We examined the biological material deposited in the Reference Collection in the Paraíba Soil Fauna in the Universidade Estadual da Paraíba. Held up the organization of a database with records of occurrence and geographical distribution of species, for the geo-referencing of all wells. We performed the analysis of 1.589 specimens, divided into 16 families, 59 genera and 131 species. Of these, 13 were considered possible troglobites. The species Pararrhopalites sp4, Pararrhopalites sp7, Pseudosinella sp4, Trogolaphysa sp6, Troglobius ferroicus e Troglobius sp2 were confirmed troglobite. Arrhopalites sp2 and Arrhopalites sp3 can be the same specie and is believed that Pseudosinella sp4 move around on MSS and Trogolaphysa sp6 may be experiencing a vicarious process. Human activities and the use of natural resources in this environment entails degradation and local or regional extinction of species. The cave environment acts as excellent places for ecological studies and frequently have endemic species, so it is extremely important to preserve this environment and your fauna. / Em geral, espécies cavernícolas possuem alterações em sua morfologia e fisiologia como forma de adaptação ao ambiente e podem ser classificadas como troglóbias, eutroglófilas, subtroglófilas e trogloxenas. Quando comparados a ecossistemas epígeos, ecossistemas cavernícolas possuem baixa diversidade de espécies, dependência de nutrientes provenientes do meio externo e condições de umidade e temperatura estáveis ao longo do ano. Desta forma, este ambiente é fortemente influenciado por alterações ambientais externas, como a mineração, desmatamento, urbanização, entre outras. O presente estudo tem como objetivo avaliar a distribuição das espécies troglóbias de Collembola em cavernas inseridas em diferentes litologias em áreas de significativo interesse minerário. Localizado em Minas Gerais, o Quadrilátero Ferrífero representa uma das principais províncias metalogenéticas do Brasil. Analisamos o material biológico depositado na Coleção de Referência em Fauna de Solo da Paraíba da Universidade Estadual da Paraíba. Foi realizada a organização de um banco de dados com os registros da ocorrência e a distribuição geográfica das espécies, para o georreferenciamento de todas as cavidades. Foram analisados 1.589 espécimes, divididos em 16 famílias, 59 gêneros e 131 espécies. Destas, 13 foram consideradas possivelmente troglóbias. As espécies Pararrhopalites sp4, Pararrhopalites sp7, Pseudosinella sp4, Trogolaphysa sp6, Troglobius ferroicus e Troglobius sp2 foram consideradas troglóbias. Arrhopalites sp2 e Arrhopalites sp3 podem ser a mesma espécie. Acredita-se que Pseudosinella sp4 locomove-se pelo MSS e Trogolaphysa sp6 pode estar passando por um processo vicariante. As atividades antrópicas e o uso dos recursos naturais nestes ambientes acarretam degradação e extinção local ou regional das espécies. O ambiente cavernícola funciona como locais excelentes para estudos ecológicos e frequentemente abrigam espécies endêmicas, portanto é de fundamental importância à conservação deste ambiente e consequentemente de sua fauna.
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Nutrient resources and stoichiometry affect the ecology of above- and belowground invertebrate consumersJonas, Jayne January 1900 (has links)
Doctor of Philosophy / Department of Biology / Anthony Joern / Aboveground and belowground food webs are linked by plants, but their reciprocal influences are seldom studied. Because phosphorus (P) is the primary nutrient associated with arbuscular mycorrhizal (AM) symbiosis, and evidence suggests it may be more limiting than nitrogen (N) for some insect herbivores, assessing carbon (C):N:P stoichiometry will enhance my ability to discern trophic interactions. The objective of this research was to investigate functional linkages between aboveground and belowground invertebrate populations and communities and to identify potential mechanisms regulating these interactions using a C:N:P stoichiometric framework. Specifically, I examine (1) long-term grasshopper community responses to three large-scale drivers of grassland ecosystem dynamics, (2) food selection by the mixed-feeding grasshopper Melanoplus bivittatus, (3) the mechanisms for nutrient regulation by M. bivittatus, (4) food selection by fungivorous Collembola, and (5) the effects of C:N:P on invertebrate community composition and aboveground-belowground food web linkages. In my analysis of grasshopper community responses to fire, bison grazing, and weather over 25 years, I found that all three drivers affected grasshopper community dynamics, most likely acting indirectly through effects on plant community structure, composition and nutritional quality. In a field study, the diet of M. bivittatus was dominated by forbs with grasses constituting only a minor fraction of their diet under ambient soil conditions, but grass consumption approximately doubled as a result of changes in grass C:N:P. M. bivittatus was found to rely primarily on selective consumption of foods with varying nutritional quality, rather than compensatory feeding or altering post-ingestive processes, to maintain C:N homeostasis in a laboratory experiment. In a soil-based mesocosm study, I show that Collembola feed on both saprophytic and AM fungi, in some cases exhibiting a slight preference for AM fungi. In the final study, although I did not find the expected indirect relationship between soil Collembola and aboveground herbivory as mediated through host plant quality, there were significant effects of root C:N and AM colonization on Collembola density and of plant C:N on aboveground herbivory. Overall, this research shows that host plant C:N:P stoichiometry can influence both above- and belowground invertebrate population, community, and food web dynamics.
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Interação de plantas de trevo vermelho inoculadas com rizóbios com ácaros e colêmbolos edáficos / Interaction of red clover plants inoculated with rhizobia with edaphic mites and springtailsBassani, Victor Lucas January 2015 (has links)
A mesofauna edáfica, compreendendo ácaros e colêmbolos, é sensível a alterações no solo, sendo considerada um indicador de qualidade, uma vez que realiza a fragmentação de matéria orgânica, controle populacional de determinados grupos da biota do solo e ingestão de microrganismos. A colonização de plantas por micro-organismos, como a de leguminosas por rizobios, pode levar a mudanças na rizosfera vegetal e influenciar a mesofauna. Este estudo teve por objetivo avaliar o efeito da inoculação de plantas de trevo vermelho com rizóbios sobre os ácaros e colêmbolos edáficos e avaliar se colêmbolos alimentados com rizóbios poderiam inocular plantas hospedeiras. Para isso, plantas de trevo vermelho, inoculadas com as estirpes SEMIA 2081, SEMIA 2082 e SEMIA 222, e plantas controle sem inoculação foram plantadas em tubos-armadilha e inseridas em campo. A seguir, a mesofauna atraída foi extraída e identificada. Outro experimento em laboratório utilizou plantas de trevo vermelho que foram colocadas em contato com colêmbolos da família Hypogastruridae e dos gêneros Proisotoma, Onychiurus e Orthonychiurus, os quais haviam sido alimentados com um substrato impregnado com o rizóbio da estirpe SEMIA 2081 As plantas inoculadas com as três estirpes de rizóbios atrairam ácaros edáficos mas não colêmbolos, quando comparadas com as plantas que não foram inoculadas nem receberam fonte de nitrogênio. Considerando os números totais de ácaros e colêmbolos, somente as plantas inoculadas com a estirpe SEMIA 222 apresentaram atratividade quando comparadas ao controle sem inoculação e sem fonte de nitrogênio. A atratividade de ácaros e colêmbolos observada no tratamento controle com nitrogênio foi similar aos tratamentos inoculados. No experimento de laboratório, os colêmbolos vivos e o macerado de colêmbolos da família Hypogastruridae, e gêneros Proisotoma e Orthonychiurus foram capazes de transferir os rizóbios que receberam pela alimentação às plantas, formando nódulos radiculares. As plantas que receberam o macerado de colêmbolos da família Hypogastruridae apresentaram maior número de nódulos comparadas às plantas que receberam os mesmos colêmbolos vivos. / The soil mesofauna comprising mites and springtails, is sensitive to changes in soil, and it is considered a quality indicator since it performs fragmentation of organic matter, population control of certain soil biota groups and ingestion of microorganisms. The plants colonized by microorganisms, such as legumes by rhizobia can lead to changes in plant rhizosphere and influence mesofauna. This study aimed to evaluate the effect of inoculation of red clover plants with rhizobia on edaphic mites and springtails and assess if springtails fed with rhizobia could inoculate host plants. For this, red clover plants inoculated with strains SEMIA 2081, SEMIA 2082 and SEMIA 222, and control plants without inoculation were planted in trap-tubes and inserted on field. Then, the attracted mesofauna was submitted to extraction and identification. Another laboratory experiment used red clover plants put in contact with springtails. These springtails of Hypogastruridae family and Proisotoma, Onychiurus and Orthonychiurus genera, had been fed with a substrate impregnated with rhizobia strain SEMIA 2081. Plants inoculated with three Rhizobia strains attracted edaphic mites, but not Collembola, when compared to uninoculated plants with no nitrogen source Considering the total numbers of mites and springtails, only plants inoculated with SEMIA 222 strain showed attractiveness when compared to the control without inoculation and no nitrogen source. The attractiveness of mites and springtails observed in the control treatment with nitrogen was similar to the inoculated treatments. In the laboratory experiment, the living springtails and the macerate of springtails of Hypogastruridae family, and Proisotoma and Orthonychiurus genera were able to transfer the rhizobia that they received by feeding to the plants, forming root nodules. The plants that received the macerate of springtails of the Hypogastruridae family had a higher number of nodules compared to the plants that received the same living springtails.
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The springtail cuticle as a blueprint for omniphobic surfacesHensel, René, Neinhuis, Christoph, Werner, Carsten 11 December 2015 (has links)
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 oilrepellent 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.
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