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1.
Plant Dis ; 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35822892

RESUMEN

Whorled sunflower, Helianthus verticillatus Small, is an endangered (U.S. Fish and Wildlife Service 2014) perennial sunflower species indigenous to the southern United States (Matthews et al. 2002; Ellis et al. 2008). Helianthus verticillatus has a showy yellow floral display in the Fall that attracts a diversity of insect visitors (Strange et al. 2020). Its hardiness in the landscape and late-season blooming makes it a potential ornamental (Trigiano et al. 2021). In June 2021, anthracnose-like lesions were observed on mature leaves collected from potted H. verticillatus plants grown in the nursery compound at the University of Tennessee, Knoxville, TN, USA. Irregularly shaped leaf spots with 1‒2 mm tan centers were observed on mature leaves, which later expanded to 3‒5 mm, and became dark brown- to- black surrounded by chlorotic halos (Fig.1). Lesions from three infected leaves were excised from a single potted plant, trimmed to 1.5-cm squares with green borders, and surface-sterilized (Trigiano et al. 2018). Tissues were placed onto potato dextrose agar (PDA), amended with 100 mg/ml of each streptomycin sulfate and chlorotetracycline, and incubated at 21 °C in the dark until axenic cultures were obtained. Initially, appressed white- to- pale gray mycelia were formed that turned light pinkish-orange with age (Fig. 2A). Conidia (Fig. 2B-C) were single-celled, hyaline, and cylindrical- to- fusiform with acute ends, and were similar to Colletotrichum fioriniae (Damm et al. 2012). Conidia measured 8.9 ± 1.3 µm long and 3.3 ± 0.6 µm wide (N=40). Genomic DNA was isolated with a Phire Direct Plant PCR kit (Thermo FisherScientific, Waltham, MA). The partial beta-tubulin (TUB2) gene, chitin synthase 1 (CHS-1) gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, and the internal transcribed spacer (ITS) region of ribosomal DNA were amplified with primers T1/BT2B, CHS-354R/CHS-79F, GDF1/GDR1, and ITS1/ITS4, respectively and sequenced (Damm et al. 2012). The resulting sequences were submitted to GenBank (TUB2, ON036471; CHS-1, ON036472; GAPDH, ON036470; and ITS, ON008206). Consensus sequences had 100% identity with C. fioriniae type culture CBS 128517 accessions JQ949943 (TUB2), JQ948953 (CHS-1), JQ948622 (GAPDH), and MH865005 (ITS rDNA). Because H. verticillatus is endangered, and the scarcity of available plant material, Koch's postulates were performed using a detached leaf assay (Boggess et al. 2022). Six healthy leaves were surface-sterilized using the previously described protocol, longitudinally bisected, and placed on 1.5% water agar in three 15 × 100 mm petri dishes. Three half leaves were inoculated with sterile, 5 mm-diameter PDA plugs (controls). The remaining three leaves were inoculated with 5 mm-diameter PDA plugs of C. fioriniae and incubated as described previously. After ten days, necrotic lesions developed on leaves inoculated with C. fioriniae and were similar to the initially observed lesions on plants. Lesions did not develop on control leaves. Colletotrichum fioriniae was re-isolated from lesions using the previously described protocol. The disease does not appear to cause mortality of H. verticillatus and does not require control measures but does reduce the aesthetic value of the plant. To the best of our knowledge, this is the first report of C. fioriniae infecting H. verticillatus in the United States.

2.
J Nematol ; 54(1): 20220022, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35937923

RESUMEN

Soil is essential for the sustenance of life. Diverse soil organisms support several biological processes such as organic matter decomposition, mineralization, nutrient cycling, and controlling pests and diseases. Among multicellular soil organisms, nematodes are ubiquitous, functionally diverse, and abundant. Notably, agricultural practices have diverse impacts on plants, soils, and soil organisms. Tillage affects nematodes directly by altering pore size and disrupting the continuity of water films and indirectly by affecting the lower trophic groups such as bacteria and fungi. The primary goal of this study was to examine the effect of increasing levels of physical disturbance on nematode communities in an undisturbed forest ecosystem. The experiment included four treatments: control with no disturbance, surface litter removed with no litter and no vegetation, tilling the soil with a rototiller every 2 mon, and every 2 wk. Tillage significantly reduced the overall abundance and overall richness of nematode communities over time. Among nematode trophic groups, tillage significantly reduced the abundance and richness of bacterial feeders, predators, and omnivores over time. The abundance and richness of c-p 2, c-p 4, and c-p 5 class nematodes were significantly decreased by tillage. Unlike tillage, minimal disturbance such as removal of surface litter resulted in a significant decrease in the abundance of only three genera: Acrobeles, Aporcelaimellus, and Boleodorus. Nonmetric multidimensional scaling analysis revealed that nematodes of higher c-p classes such as Dorylaimida, Aporcelaimellus, Alaimus, Clarkus, and Tripyla were sensitive to physical disturbances. Bacterial feeders belonging to the c-p 2 class such as Tylocephalus, Acrobeles, Ceratoplectus, Plectus, and Pseudacrobeles were significantly reduced by tillage. Moreover, tillage significantly reduced the functional metabolic footprint of nematodes, which indicates decreased metabolic activity, reduced C inflow, and poorly structured soil food webs. Previous studies conducted in agricultural ecosystems determined that Clarkus, Filenchus, and Plectus were tolerant to tillage; however, they were found sensitive to tillage in our study. Overall, our study suggests that increasing levels of physical disturbance are detrimental to nematode community abundance and diversity that could affect soil ecosystem stability and sustainability.

3.
J Nematol ; 542022.
Artículo en Inglés | MEDLINE | ID: mdl-35386746

RESUMEN

The many decades during which the cultivation of Cannabis sativa (hemp) was strongly restricted by law resulted in little research on potential pathogenic nematodes of this increasingly important crop. The primary literature was searched for hemp-nematode papers, resulting in citations from 1890 through 2021. Reports were grouped into two categories: (i) nematodes as phytoparasites of hemp, and (ii) hemp and hemp products and extracts for managing nematode pests. Those genera with the most citations as phytoparasites were Meloidogyne (root-knot nematodes, 20 papers), Pratylenchus (lesion nematodes, 7) and Ditylenchus (stem nematodes, 7). Several Meloidogyne spp. were shown to reproduce on hemp and some field damage has been reported. Experiments with Heterodera humuli (hop cyst nematode) were contradictory. Twenty-three papers have been published on the effects of hemp and hemp products on plant-parasitic, animal-parasitic and microbivorous species. The effects of hemp tissue soil incorporation were studied in five papers; laboratory or glasshouse experiments with aqueous or ethanol extracts of hemp leaves accounted for most of the remainder. Many of these treatments had promising results but no evidence was found of large-scale implementation. The primary literature was also searched for chemistry of C. sativa roots. The most abundant chemicals were classified as phytosterols and triterpenoids. Cannabinoid concentration was frequently reported due to the interest in medicinal C. sativa. Literature on the impact of root-associated chemicals on plant parasitic nematodes was also searched; in cases where there were no reports, impacts on free-living or animal parasitic nematodes were discussed.

4.
J Nematol ; 532021.
Artículo en Inglés | MEDLINE | ID: mdl-34368772

RESUMEN

Beauveria bassiana is endophytic in many plant species and has been shown to protect host plants against insect pests and plant pathogens. However, less is known about its activity against plant-parasitic nematodes. In vitro and plant assays were conducted to determine the effect of B. bassiana 11-98 (Bb) on Meloidogyne incognita (root-knot nematode; RKN). Beauveria bassiana was confirmed as an endophyte in 'Rutgers' tomato and colonization patterns of Bb in 'Rutgers' (highly susceptible to RKN) were compared with those in 'Mountain Spring' (less susceptible to RKN). In greenhouse tests with 'Rutgers' at 30 and 60 days after treatment (DAT) with RKN and Bb, there were few differences in plant growth variables among treatments in repeated trials. However, RKN root galling and egg count/root system were enhanced in plants treated with Bb at 60 DAT. In an in vitro assay with egg masses from greenhouse tests, the percentages of hatched eggs, and mobile and immobile nematodes did not differ significantly for RKN and RKN+Bb treatments. The presence of viable Bb from roots was confirmed by collecting egg suspensions from root galls and plating them on selective medium. Colonies of Bb were verified on agar medium, but no parasitism of RKN eggs was observed. Research is needed to investigate factors responsible for increased galling by RKN in the presence of endophytic Bb in 'Rutgers' tomato.

5.
J Nematol ; 51: 1-17, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31088023

RESUMEN

Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm3. Results from data expressed per 100 g of soil indicated that overall richness was higher in forest than in NGL, DGL, urban, and agriculture ecosystems. The richness of all c-p guilds and of all trophic groups except herbivores was highest in forest ecosystems. In contrast, overall abundance was highest in DGL, agriculture and forest ecosystems. The abundance of c-p 1, c-p 2 and c-p 3 guilds and bacterivores, fungivores and herbivores was highest in disturbed ecosystems, while the abundance of c-p 4 and c-p 5 guilds and predators and omnivores was highest in relatively undisturbed ecosystems. Results from data expressed as nematodes per 100 cm3 of soil indicated that abundance followed a similar pattern, but richness often differed between the two methodologies. These meta-analyses strengthen the concept that human interventions adversely impact both richness and abundance using nematodes as soil health bioindicators.Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm3. Results from data expressed per 100 g of soil indicated that overall richness was higher in forest than in NGL, DGL, urban, and agriculture ecosystems. The richness of all c-p guilds and of all trophic groups except herbivores was highest in forest ecosystems. In contrast, overall abundance was highest in DGL, agriculture and forest ecosystems. The abundance of c-p 1, c-p 2 and c-p 3 guilds and bacterivores, fungivores and herbivores was highest in disturbed ecosystems, while the abundance of c-p 4 and c-p 5 guilds and predators and omnivores was highest in relatively undisturbed ecosystems. Results from data expressed as nematodes per 100 cm3 of soil indicated that abundance followed a similar pattern, but richness often differed between the two methodologies. These meta-analyses strengthen the concept that human interventions adversely impact both richness and abundance using nematodes as soil health bioindicators.

6.
J Gen Virol ; 99(10): 1418-1424, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30156527

RESUMEN

Analysis of transcriptome sequence data from eggs and second-stage juveniles (J2s) of sugar beet cyst nematode (SBCN, Heterodera schachtii) identified the full-length genome of a positive-sense single-stranded RNA virus, provisionally named sugar beet cyst nematode virus 1 (SBCNV1). The SBCNV1 sequence was detected in both eggs and J2s, indicating its possible vertical transmission. The 9503-nucleotide genome sequence contains a single long open reading frame, which was predicted to encode a polyprotein with conserved domains for picornaviral structural proteins proximal to its amino terminus and RNA helicase, cysteine proteinase and RNA-dependent RNA polymerase (RdRp) conserved domains proximal to its carboxyl terminus, hallmarks of viruses belonging to the order Picornavirales. Phylogenetic analysis of the predicted SBCNV1 RdRp amino acid sequence indicated that the SBCNV1 sequence is most closely related to members of the family Secoviridae, which includes genera of nematode-transmitted plant-infecting viruses. SBCNV1 represents the first fully sequenced viral genome from SBCN.


Asunto(s)
Beta vulgaris/parasitología , Picornaviridae/clasificación , Picornaviridae/aislamiento & purificación , Transcriptoma , Tylenchoidea/virología , Animales , Genoma Viral , Anotación de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , Picornaviridae/genética , ARN Polimerasa Dependiente del ARN/genética , Análisis de Secuencia de ADN , Análisis de Secuencia de ARN , Homología de Secuencia de Aminoácido , Tylenchoidea/genética , Tylenchoidea/crecimiento & desarrollo , Proteínas Virales/genética
7.
J Nematol ; 50(2): 133-146, 2018 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-30451434

RESUMEN

Stauratostoma shelleyi n. gen., n. sp. is described from the midgut and hindgut of nine species of the millipede family Xystodesmidae collected in the southern Appalachian regions of North Carolina, Tennessee and Alabama. Specimens of S. shelleyi were morphologically examined with differential interference contrast, phase contrast, and scanning electron microscopy. The head of S. shelleyi differs from other thelastomatid nematodes in having a head region mushroom-shaped in profile; cruciform stomatal opening formed from four flaps; greatly expanded labial disc; and eight-sectored annule-like column supporting the labial disc. Thirteen nematodes from various hosts were sequenced for 28S LSU rDNA and compared with other millipede-inhabiting nematodes. Stauratostoma shelleyi is the sister group to the few Thelastoma spp. that have been molecularly characterized using the D2-D3 expansion segments of the 28S LSU rDNA.

8.
J Nematol ; 48(3): 159-169, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27765989

RESUMEN

Twenty-four individuals of Narceus gordanus (Diplopoda: Spirobolidae) were collected in Ocala National Forest, FL, between November 2013 and July 2014. Each specimen was dissected to extract the intestine, which was removed and examined for parasitic nematodes. Coronostoma claireae n. sp. was collected from the hindgut and midgut of 10 specimens, and its morphology was examined with brightfield, differential interference contrast, phase contrast, and scanning electron microscopy. This species is separated from other Coronostoma spp. by the following characteristics: body length less than 3 mm; head sense organs pit-like; first annule long, extending past middle of corpus, width similar to that of second annule; basal bulb pyriform; eggs larger than 60 × 50 µm. This species is the first North American record for the genus Coronostoma, which is removed from Thelastomatoidea: Thelastomatidae and reassigned to Coronostomatidae on the basis of presumed apomorphies. A key is provided for known Coronostoma spp. The superfamily Coronostomatoidea is re-established for Coronostomatidae and Traklosiidae.

9.
Zootaxa ; 3754: 148-58, 2014 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-24869686

RESUMEN

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.


Asunto(s)
Artrópodos/clasificación , Animales , Región de los Apalaches , Artrópodos/anatomía & histología , Femenino , Masculino , Tennessee
10.
Zootaxa ; 4979(1): 232235, 2021 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-34186997

RESUMEN

A summary is presented of papers published on minor insect orders (MIO) in Zootaxa's first 20 years, as well as the number of new species described therein. The MIO orders currently covered by the editors and summarized here include Archaeognatha (Microcoryphia), Dermaptera, Embioptera, Siphonaptera, Zoraptera and Zygentoma, as well as the hexapod classes Protura and Diplura. Both fossil and extant taxa of these groups are included in the MIO purview. The MIO editors also have frequently served as interim editors for groups temporarily without a subject-matter editor, such as Carabidae, Blattodea and Mantodea; as a backup editor for Mecoptera; and as ad-hoc editors for papers written by the editors of a different taxonomic group or for papers without a single-taxon focus. In the period 2001‒2020, descriptions of 130 new species were published, compared with 816 species in all other journals. The greatest number of species were for Protura (49), while Zoraptera had the highest proportion of papers compared to all publications (50%).


Asunto(s)
Insectos/clasificación , Animales , Publicaciones Periódicas como Asunto , Filogenia
11.
J Nematol ; 42(2): 139-50, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22736850

RESUMEN

A new genus and species of cyst nematode, Vittatidera zeaphila, is described from Tennessee. The new genus is superficially similar to Cactodera but is distinguished from other cyst-forming taxa in having a persistent lateral field in females and cysts, persistent vulval lips covering a circumfenestrate vulva, and subventral gland nuclei of the female contained in a separate small lobe. Infective juveniles (J2) are distinguished from all previously described Cactodera spp. by the short stylet in the second-stage juvenile (14-17 µm); J2 of Cactodera spp. have stylets at least 18 µm long. The new species also is unusual in that the females produce large egg masses. Known hosts are corn and goosegrass. DNA analysis suggests that Vittatidera forms a separate group apart from other cyst-forming genera within Heteroderinae.

12.
Zootaxa ; 4861(4): zootaxa.4861.4.2, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-33311205

RESUMEN

Forty-four specimens of the millipede Narceus gordanus Chamberlin, 1943 (Spirobolida: Spirobolidae) were collected from Alachua, Citrus, Hernando, and Marion counties in peninsular Florida. Morphometric data were recorded for each. Nematodes were dissected from the intestine of each individual and sorted into morphotaxa. Heth pivari n. sp. (Oxyuridomorpha: Ransomnematoidea: Hethidae) was found in 33 (75%) of dissected N. gordanus and examined with brightfield, differential interference contrast, phase contrast and scanning electron microscopies. LSU rDNA sequences of representative males and females of H. pivari n. sp. were analyzed and compared to sequences of nematodes in the infraorder Rhigonematomorpha. Heth mauriesi, an introduced species, also was sequenced. Females of H. pivari n. sp. differ from those of other Heth spp. in having smooth, button-like somatic and cervical papillae and shallow, shield-like cervical collars. Males have slit-like or narrowed, rather than circular, stomal openings. Heth pivari n. sp. is the first species of this genus found in an indigenous millipede north of Mexico. Keys based on female cervical ornamentation are provided to differentiate the 52 known Heth spp.


Asunto(s)
Artrópodos , Nematodos , Animales , ADN Ribosómico , Femenino , Masculino , Nematodos/genética , Estados Unidos
13.
Insects ; 11(3)2020 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-32182866

RESUMEN

Protura are widespread, but their presence in the Arctic was first noted only ca. 70 years ago and is still little acknowledged. This work compiles taxonomic information on proturans in the Arctic regions and adds unpublished data from Northern Siberia. Currently, this fauna is represented by 23 species in two orders and 14 genera. The large cosmopolitan genus Eosentomon is represented by only four species, whereas Acerentomidae is much more diverse, with 19 species in 13 genera (eight Nipponentominae, five Acerentominae). Most of the Arctic species possess a larger number of setae than species living in temperate regions. Based on several unique characters, a new genus, Mastodonentomon, is erected for Nipponentomon macleani, and the species is re-described with the original description supplemented with new characters, including head chaetotaxy, seta length, and porotaxy. Proturan occurrence in the Arctic is limited to Beringia, but the majority of species have restricted distributions and none have been found in both the American Arctic and Siberia. This implies relict origins and high levels of proturan endemism in the Arctic. This emerging view on biogeographical history is, however, hampered by the limited extent of available data, which highlights the need for considerably greater survey efforts. A key to Arctic proturans is provided to facilitate further studies.

14.
PLoS One ; 15(11): e0241777, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33147264

RESUMEN

Decomposition of vertebrate remains is a dynamic process that creates localized soil enrichment zones. A growing body of literature has documented effects of vertebrate decomposition on soil pH, electrical conductivity, oxygen levels, nitrogen and carbon speciation, microbial biomass, and microbial successional patterns. However, relatively few studies have examined the microfaunal members of the soil food web that function as secondary consumers, specifically nematodes. Nematodes are often used as indicators of enrichment in other systems, and initial observations from vertebrate decomposition zones have indicated there is an effect on nematode communities. Our goal was to catalog decomposition-induced nematode succession and changes to alpha, beta, and functional diversity, and identify potential indicator taxa associated with decomposition progression. Six adult beaver (Castor canadensis) carcasses were allowed to decompose in a forest ecosystem for one year. During this period soil temperature, moisture, and electrical conductivity were monitored. Soils samples were taken at two depths in order to assess nematode community dynamics: 30-cm cores and 1-cm interface samples. Nematode abundance, alpha, beta, and functional diversity all responded to soil enrichment at the onset of active decay, and impacts persisted through skeletonization. After one year, nematode abundances and alpha diversity had recovered to original levels, however both community membership and functional diversity remained significantly altered. We identified seven indicator taxa that marked major transitions in decomposition progression. Enrichment of Rhabditidae (B1) and Diplogasteridae (B1) coupled with depletion in Filenchus (F2) characterized active and advanced decay prior to skeletonization in both cores and interface soils. Enrichment of Acrobeloides (B2), Aphelenchoides (F2), Tylencholaimidae (F4) and Seinura (P2) occurred during a narrow period in mid-skeletonization (day 153). Our study has revealed soil nematode successional patterns during vertebrate decomposition and has identified organisms that may function as indicator taxa for certain periods during decomposition.


Asunto(s)
Nematodos/fisiología , Suelo/parasitología , Animales , Biodiversidad , Bosques , Nematodos/crecimiento & desarrollo , Roedores/fisiología , Suelo/química , Temperatura
15.
Environ Entomol ; 48(3): 592-602, 2019 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-31006819

RESUMEN

Cellulose and lignin decomposition is crucial for efficient nutrient cycling, yet few studies have been performed regarding the effects of soil fauna on cellulose and lignin decomposition. This study was conducted to better understand the effects of soil fauna on lignin and cellulose decomposition in the Changbai Mountain. Litterbags of two different mesh sizes were used to examine cellulose and lignin decomposition of 11 species of plant litter in the four vegetation zones of the Changbai Mountain North Slope over a 24-mo period. Cellulose and lignin clearly declined over time for all 11 species of plant litter. Cellulose decomposition rate faster than the rate of lignin decomposition in the majority of plant species. Soil fauna could promote the decomposition of cellulose and lignin. The abundance and richness of soil fauna in coniferous broad-leaved mixed forests were greater than in coniferous forest, Betula ermanii Cham. (Fagales: Betulaceae) forest, and alpine tundra. Soil fauna had a greater effect on Abies nephrolepis Maxim. (Pinales: Pinaceae) cellulose and lignin, whereas contribution rates were relatively lower in the Fraxinus mandshurica Rupr. (Contortae: Oleaceae) and Acer mono Maxim. (Sapindales: Aceraceae) litterbags at the end of the experiment. Litter quality was negatively correlated with the soil faunal contribution to litter decomposition directly. Overall, the findings of this study have implications for the effects of soil fauna on cellulose and lignin decomposition in the alpine ecosystem, and also can provide experimental evidence that soil faunal contribution is affected by soil faunal communities and litter quality.


Asunto(s)
Lignina , Suelo , Animales , Celulosa , China , Ecosistema , Hojas de la Planta
16.
Zookeys ; (742): 1-12, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29670427

RESUMEN

European species of Eosentomon are examined. A taxonomic key to identification of 61 Eosentomon species is provided based on body chaetotaxy, shape, and position of sensilla on the foretarsus and shape of sensilla on the maxillary palps. Biogeographically, 13 of the known European Eosentomon species are known only from their type localities.

17.
PLoS One ; 13(12): e0208845, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30540836

RESUMEN

Decomposing vertebrates, including humans, result in pronounced changes in surrounding soil biogeochemistry, particularly nitrogen (N) and carbon (C) availability, and alter soil micro- and macrofauna. However, the impacts of subsurface human decomposition, where oxygen becomes limited and microbial biomass is generally lower, are far less understood. The goals of this study were to evaluate the impact of human decomposition in a multi-individual, shallow (~70 cm depth) grave on soil biogeochemistry and soil microbial and nematode communities. Three individuals were interred and allowed to decay for four years. Soils were collected from two depths (0‒5 and 30‒35 cm) along linear transects radiating from the grave as well as from within and below (85‒90 cm depth) the grave during excavation to assess how decomposition affects soil properties. Along radiating surface transects, several extracellular enzymes rates and nematode richness increased with increasing distance from the grave, and likely reflect physical site disruption due to grave excavation and infill. There was no evidence of carcass-sourced C and N lateral migration from the grave, at least at 30‒35 cm depth. Within the grave, soils exhibited significant N-enrichment (e.g., ammonium, dissolved organic N), elevated electrical conductivity, and elevated respiration rates with depth. Soil biogeochemistry within the grave, particularly in the middle (30‒35 cm) and base (70‒75 cm depth), was significantly altered by human decomposition. Mean microbial gene abundances changed with depth in the grave, demonstrating increased microbial presence in response to ongoing decomposition. Human-associated Bacteroides were only detected at the base of the grave where anoxic conditions prevailed. Nematode community abundance and richness were reduced at 70‒75 cm and not detectable below 85‒90 cm. Further, we identified certain Plectus spp. as potential indicators of enrichment due to decomposition. Here we demonstrate that human decomposition influences soil biogeochemistry, microbes, and microfauna up to four years after burial.


Asunto(s)
Nematodos/fisiología , Microbiología del Suelo , Suelo , Animales , Humanos
18.
Zootaxa ; 4162(3): 451-78, 2016 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-27615985

RESUMEN

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.


Asunto(s)
Artrópodos/anatomía & histología , Artrópodos/clasificación , Animales , Femenino , Masculino , Especificidad de la Especie , Tennessee
19.
Zootaxa ; 3918(3): 301-38, 2015 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-25781097

RESUMEN

Species of Hypogastruridae and Onychiuridae described by D. L. Wray were reexamined and redescribed where necessary from type material and other specimens. Mitchellania hermosa is redescribed and transferred to Ceratophysella. Hypogastrura ireneae is redescribed and H. gravesi is validated with additional material. Hypogastrura gami is synonymized with H. humi and H. utahensis is synonymized with H. promatro. A lectotype is designated for Schoettella (Knowltonella) idahoensis. Achorutes magnoliana is confirmed as a synonym of Schoettella glasgowi. Xenylla carolinensis is synonymized with Xenyllodes armatus Axelson (Odontellidae). Onychiurus mai is transferred to the genus Leeonychiurus and becomes L. mai, and O. magninus is transferred to Heteraphorura and becomes H. magnina. Additional details are given for Onychiurus wilchi.


Asunto(s)
Artrópodos/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Artrópodos/anatomía & histología , Artrópodos/crecimiento & desarrollo , Tamaño Corporal , Ecosistema , Femenino , Masculino , Tamaño de los Órganos
20.
Zootaxa ; 4006(3): 521-39, 2015 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-26623781

RESUMEN

The arthropod class Pauropoda was not recognized from China until 1988, but currently 36 known species are now recorded from 27 sites in 18 provinces. This paper contains descriptions of three new species of Decapauropus Remy, 1931: D. biclavula sp. n., D. annulcordatus sp. n. and D. tribulosus sp. n. from Jiangsu, Hunan, Jiangxi and Guangxi Provinces, respectively. These three new species bring the known pauropod fauna of China to 39 species in 11 genera and four families. In addition, Dasongius (Sun & Guo, 2010) nom. nov. is proposed to replace the invalid junior homonym of Songius Sun & Guo, 2010.


Asunto(s)
Artrópodos/clasificación , Animales , China , Femenino , Masculino
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