Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Más filtros











Intervalo de año de publicación
1.
J Parasitol ; 110(4): 375-385, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39155055

RESUMEN

With the intensity and frequency of wildfires increasing rapidly, the need to study the ecological effects of these wildfires is also growing. An understudied aspect of fire ecology is the effect fires have on parasite-host interactions, including ectoparasites that might be pathogen vectors. Although some studies have examined the impacts of fire on ticks, studies on other ectoparasites, including pathogen vectors, are rare. To help address this knowledge gap, we examined the abiotic and biotic factors that predict the likelihood and extent of parasitism of deer mice (Peromyscus maniculatus) by fleas within a landscape of unburned and recovering burned (>9 yr postfire) mixed conifer forests. We sampled 227 individual deer mice across 27 sites within the Jemez Mountains of northern New Mexico in 2022 and quantified measures of parasitism by fleas (primarily Aetheca wagneri). These sites were distributed in both unburned areas (n = 15) and recovering burned areas (n = 12), with the latter derived from 2 large fires, the Las Conchas fire (2011) and the Thompson Ridge fire (2013). Using these data, we tested for differences in prevalence, mean abundance, and mean intensity of fleas on deer mice, focusing on the predictive importance of host sex and fire history. We also created generalized linear mixed-effects models to investigate the best host and environmental predictors of parasitism by fleas. Approximately a decade postfire, we found minimal evidence to suggest that fire history influenced either the presence or intensity of fleas on deer mice. Rather, at the current forest-regeneration stage, the extent of parasitism by fleas was best predicted by measures of host sex, body condition, and the trapline's ability to accumulate water, as measured through topography. As host body condition increased, the probability of males being parasitized increased, whereas the opposite pattern was seen for females. Male mice also had significantly greater flea loads. Among potential abiotic predictors, the topographic wetness index or compound topographic index (a proxy for soil moisture) was positively related to flea intensity, suggesting larger flea populations in burrows with higher relative humidity. In summary, although fire may potentially have short-term impacts on the likelihood and extent of host parasitism by fleas, in this recovering study system, host characteristics and topographic wetness index are the primary predictors of parasitism by fleas.


Asunto(s)
Infestaciones por Pulgas , Bosques , Peromyscus , Enfermedades de los Roedores , Siphonaptera , Animales , Peromyscus/parasitología , Femenino , Masculino , Infestaciones por Pulgas/veterinaria , Infestaciones por Pulgas/parasitología , Infestaciones por Pulgas/epidemiología , Siphonaptera/fisiología , Siphonaptera/clasificación , Enfermedades de los Roedores/parasitología , Enfermedades de los Roedores/epidemiología , New Mexico/epidemiología , Incendios Forestales , Interacciones Huésped-Parásitos , Incendios , Tracheophyta/parasitología
2.
Curr Biol ; 31(9): R419-R420, 2021 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-33974863

RESUMEN

Fettig and Audley introduce the bark beetles-a large and diverse group of insects of which some are commonly recognized as important disturbance agents in conifer forests.


Asunto(s)
Corteza de la Planta/parasitología , Tracheophyta/parasitología , Gorgojos/fisiología , Gorgojos/patogenicidad , Animales , Femenino , Bosques
3.
Commun Biol ; 3(1): 708, 2020 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-33239710

RESUMEN

Many plant genera in the tropical West Pacific are survivors from the paleo-rainforests of Gondwana. For example, the oldest fossils of the Malesian and Australasian conifer Agathis (Araucariaceae) come from the early Paleocene and possibly latest Cretaceous of Patagonia, Argentina (West Gondwana). However, it is unknown whether dependent ecological guilds or lineages of associated insects and fungi persisted on Gondwanan host plants like Agathis through time and space. We report insect-feeding and fungal damage on Patagonian Agathis fossils from four latest Cretaceous to middle Eocene floras spanning ca. 18 Myr and compare it with damage on extant Agathis. Very similar damage was found on fossil and modern Agathis, including blotch mines representing the first known Cretaceous-Paleogene boundary crossing leaf-mine association, external foliage feeding, galls, possible armored scale insect (Diaspididae) covers, and a rust fungus (Pucciniales). The similar suite of damage, unique to fossil and extant Agathis, suggests persistence of ecological guilds and possibly the component communities associated with Agathis since the late Mesozoic, implying host tracking of the genus across major plate movements that led to survival at great distances. The living associations, mostly made by still-unknown culprits, point to previously unrecognized biodiversity and evolutionary history in threatened rainforest ecosystems.


Asunto(s)
Evolución Biológica , Fósiles , Tracheophyta , Animales , Argentina , Asia Sudoriental , Australia , Biodiversidad , Hongos/patogenicidad , Hongos/fisiología , Insectos/fisiología , Bosque Lluvioso , Tracheophyta/microbiología , Tracheophyta/parasitología , Tracheophyta/fisiología
4.
Sci Rep ; 9(1): 17916, 2019 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-31784622

RESUMEN

Hadrosaurian dinosaurs were abundant in the Late Cretaceous of North America, but their habitats remain poorly understood. Cretaceous amber is also relatively abundant, yet it is seldom found in direct stratigraphic association with dinosaur remains. Here we describe an unusually large amber specimen attached to a Prosaurolophus jaw, which reveals details of the contemporaneous paleoforest and entomofauna. Fourier-transform Infrared spectroscopy and stable isotope composition (H and C) suggest the amber formed from resins exuded by cupressaceous conifers occupying a coastal plain. An aphid within the amber belongs to Cretamyzidae, a Cretaceous family suggested to bark-feed on conifers. Distinct tooth row impressions on the amber match the hadrosaur's alveolar bone ridges, providing some insight into the taphonomic processes that brought these remains together.


Asunto(s)
Ámbar/química , Biodiversidad , Dinosaurios/anatomía & histología , Fósiles , Animales , Áfidos/patogenicidad , Dinosaurios/fisiología , Maxilares/anatomía & histología , Paleontología/métodos , Tracheophyta/parasitología
5.
Antonie Van Leeuwenhoek ; 112(10): 1501-1521, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31140027

RESUMEN

Fungi under the order Ophiostomatales (Ascomycota) are known to associate with various species of bark beetles (Coleoptera: Curculionidae: Scolytinae). In addition this group of fungi contains many taxa that can impart blue-stain on sapwood and some are important tree pathogens. A recent survey that focussed on the diversity of the Ophiostomatales in the forest ecosystems of the Czech Republic and Poland uncovered four putative new species. Phylogenetic analyses of four gene regions (ITS1-5.8S-ITS2 region, ß-tubulin, calmodulin, and translation elongation factor 1-α) indicated that these four species are members of the genus Ophiostoma. All four newly described species can be distinguished from each other and from closely related species based on DNA sequence comparisons, morphological characters, growth rates, and their insect associations. Based on this study four new taxa can be circumscribed and the following names are provided: Ophiostoma pityokteinis sp. nov., Ophiostoma rufum sp. nov., Ophiostoma solheimii sp. nov., and Ophiostoma taphrorychi sp. nov. O. rufum sp. nov. is a member of the Ophiostoma piceae species complex, while O. pityokteinis sp. nov. resides in a discrete lineage within Ophiostoma s. stricto. O. taphrorychi sp. nov. together with O. distortum formed a well-supported clade in Ophiostoma s. stricto close to O. pityokteinis sp. nov. O. solheimii sp. nov. groups within a currently undefined lineage A, which also includes Ophiostoma grandicarpum and Ophiostoma microsporum. This study highlights the need for more intensive surveys that should include additional countries of Central Europe, insect vectors and host tree species in order to elucidate Ophiostoma species diversity in this region.


Asunto(s)
Ophiostoma/clasificación , Ophiostoma/aislamiento & purificación , Filogenia , Gorgojos/microbiología , Animales , Calmodulina/genética , República Checa , ADN Espaciador Ribosómico/genética , Técnicas de Tipificación Micológica , Ophiostoma/genética , Ophiostoma/fisiología , Factor 1 de Elongación Peptídica/genética , Polonia , ARN Ribosómico 5.8S/genética , Análisis de Secuencia de ADN , Tracheophyta/parasitología , Tubulina (Proteína)/genética , Gorgojos/crecimiento & desarrollo , Madera/parasitología
6.
Tree Physiol ; 39(4): 590-605, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30597102

RESUMEN

Synchrony between host budburst and insect emergence greatly influences the time window for insect development and survival. A few alterations of bud phenology have been reported under defoliation without clear consensus regarding the direction of effects, i.e., advance or delay. Here, we compared budburst phenology between conifers in defoliation and control treatments, and measured carbon allocation as a potential mechanistic explanation of changes in phenology. In a 2-year greenhouse experiment, saplings of balsam fir, black spruce and white spruce of two different provenances (north and south) were subjected to either control (no larvae) or natural defoliation treatment (larvae added) by spruce budworm. Bud and instar phenology, primary and secondary growth, defoliation and non-structural carbohydrates were studied during the growing season. No differences were observed in bud phenology during the first year of defoliation. After 1 year of defoliation, bud phenology advanced by 6-7 days in black spruce and balsam fir and by 3.5 days in white spruce compared with the control. Because of this earlier bud break, apical and shoot growth exceeded 50% of its final length before mature instar defoliation occurred, which decreased the overall level of damage. A sugar-mediated response, via earlier starch breakdown, and higher sugar availability to buds explains the advanced budburst in defoliated saplings. The advanced phenological response to defoliation was consistent across the conifer species and provenances except for one species × provenance combination. Allocation of carbon to buds and shoots growth at the expense of wood growth in the stem and reserve accumulation represents a shift in the physiological resources priorities to ensure tree survival. This advancement in bud phenology could be considered as a physiological response to defoliation based on carbohydrate needs for primary growth, rather than a resistance trait to spruce budworm.


Asunto(s)
Abies/fisiología , Interacciones Huésped-Parásitos , Mariposas Nocturnas/fisiología , Picea/fisiología , Enfermedades de las Plantas/parasitología , Tracheophyta/fisiología , Abies/parasitología , Animales , Carbono/metabolismo , Larva , Fenotipo , Picea/parasitología , Hojas de la Planta/parasitología , Hojas de la Planta/fisiología , Estaciones del Año , Almidón/metabolismo , Estrés Fisiológico , Tracheophyta/parasitología , Árboles
7.
Glob Chang Biol ; 25(3): 869-884, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30570807

RESUMEN

Future changes in climate are widely anticipated to increase fire frequency, particularly in boreal forests where extreme warming is expected to occur. Feedbacks between vegetation and fire may modify the direct effects of warming on fire activity and shape ecological responses to changing fire frequency. We investigate these interactions using extensive field data from the Boreal Shield of Saskatchewan, Canada, a region where >40% of the forest has burned in the past 30 years. We use geospatial and field data to assess the resistance and resilience of eight common vegetation states to frequent fire by quantifying the occurrence of short-interval fires and their effect on recovery to a similar vegetation state. These empirical relationships are combined with data from published literature to parameterize a spatially explicit, state-and-transition simulation model of fire and forest succession. We use this model to ask if and how: (a) feedbacks between vegetation and wildfire may modify fire activity on the landscape, and (b) more frequent fire may affect landscape forest composition and age structure. Both field and GIS data suggest the probability of fire is low in the initial decades after fire, supporting the hypothesis that fuel accumulation may exert a negative feedback on fire frequency. Field observations of pre- and postfire composition indicate that switches in forest state are more likely in conifer stands that burn at a young age, supporting the hypothesis that resilience is lower in immature stands. Stands dominated by deciduous trees or jack pine were generally resilient to fire, while mixed conifer and well-drained spruce forests were less resilient. However, simulation modeling suggests increased fire activity may result in large changes in forest age structure and composition, despite the feedbacks between vegetation-fire likely to occur with increased fire activity.


Asunto(s)
Taiga , Tracheophyta/parasitología , Incendios Forestales , Cambio Climático , Monitoreo del Ambiente , Modelos Teóricos , Saskatchewan , Especificidad de la Especie , Factores de Tiempo , Tracheophyta/clasificación , Tracheophyta/crecimiento & desarrollo
8.
Mol Phylogenet Evol ; 123: 35-43, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29378247

RESUMEN

Mitogenomes are useful markers for phylogenetic studies across a range of taxonomic levels. Here, we focus on mitogenome variation across the tortricid moth genus Choristoneura and particularly the spruce budworm (Choristoneura fumiferana) species complex, a notorious pest group of North American conifer forests. Phylogenetic relationships of Tortricidae, representing two subfamilies, four tribes and nine genera, were analyzed using 21 mitogenomes. These included six newly-sequenced mitogenomes for species in the spruce budworm complex plus three additional Choristoneura species and 12 previously published mitogenomes from other tortricids and one from the Cossidae. We evaluated the phylogenetic informativeness of the mitogenomes and reconstructed a time-calibrated tree with fossil and secondary calibrations. We found that tortricid mitogenomes had conserved protein and ribosomal regions, and analysis of all protein-coding plus ribosomal genes together provided an efficient marker at any taxonomic rank. The time-calibrated phylogeny showed evolutionary convergence of conifer feeding within Choristoneura, with two independent lineages, the Nearctic spruce budworm complex and the Palearctic species Choristoneura murinana, both shifting onto conifers about 11 million years ago from angiosperms. These two host-plant shifts both occurred after the formation of boreal forest in the late Miocene. Haplotype diversification within the spruce budworm complex occurred in the last 4 million years, and is probably linked to the initial cooling cycles of the Northern Hemisphere in the Pliocene.


Asunto(s)
Herbivoria/fisiología , Mariposas Nocturnas/fisiología , Taiga , Tracheophyta/parasitología , Animales , Secuencia de Bases , Calibración , ADN Mitocondrial/genética , Genoma Mitocondrial , Mariposas Nocturnas/genética , Filogenia , Factores de Tiempo
9.
Nat Commun ; 8(1): 556, 2017 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-28916787

RESUMEN

Beetles are the most diverse group of macroscopic organisms since the mid-Mesozoic. Much of beetle speciosity is attributable to myriad life habits, particularly diverse-feeding strategies involving interactions with plant substrates, such as wood. However, the life habits and early evolution of wood-boring beetles remain shrouded in mystery from a limited fossil record. Here we report new material from the upper Permian (Changhsingian Stage, ca. 254-252 million-years ago) of China documenting a microcosm of ecological associations involving a polyphagan wood-borer consuming cambial and wood tissues of the conifer Ningxiaites specialis. This earliest evidence for a component community of several trophically interacting taxa is frozen in time by exceptional preservation. The combination of an entry tunnel through bark, a cambium mother gallery, and up to 11 eggs placed in lateral niches-from which emerge multi-instar larval tunnels that consume cambium, wood and bark-is ecologically convergent with Early Cretaceous bark-beetle borings 120 million-years later.Numerous gaps remain in our knowledge of how groups of organisms interacted in ancient ecosystems. Here, Feng and colleagues describe a late Permian fossil wood-boring beetle microcosm, with the oldest known example of complex tunnel geometry, host tissue response, and the presence of fungi within.


Asunto(s)
Escarabajos/fisiología , Tracheophyta/parasitología , Madera/parasitología , Animales , China , Escarabajos/crecimiento & desarrollo , Ecosistema , Conducta Alimentaria , Larva/crecimiento & desarrollo , Larva/fisiología
10.
Plant Physiol ; 175(2): 641-651, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28794260

RESUMEN

Acetophenones are phenolic compounds involved in the resistance of white spruce (Picea glauca) against spruce budworm (Choristoneura fumiferiana), a major forest pest in North America. The acetophenones pungenol and piceol commonly accumulate in spruce foliage in the form of the corresponding glycosides, pungenin and picein. These glycosides appear to be inactive against the insect but can be cleaved by a spruce ß-glucosidase, PgßGLU-1, which releases the active aglycons. The reverse glycosylation reaction was hypothesized to involve a family 1 UDP-sugar dependent glycosyltransferase (UGT) to facilitate acetophenone accumulation in the plant. Metabolite and transcriptome profiling over a developmental time course of white spruce bud burst and shoot growth revealed two UGTs, PgUGT5 and PgUGT5b, that glycosylate pungenol. Recombinant PgUGT5b enzyme produced mostly pungenin, while PgUGT5 produced mostly isopungenin. Both UGTs also were active in vitro on select flavonoids. However, the context of transcript and metabolite accumulation did not support a biological role in flavonoid metabolism but correlated with the formation of pungenin in growing shoots. Transcript levels of PgUGT5b were higher than those of PgUGT5 in needles across different genotypes of white spruce. These results support a role of PgUGT5b in the biosynthesis of the glycosylated acetophenone pungenin in white spruce.


Asunto(s)
Acetofenonas/metabolismo , Glicosiltransferasas/metabolismo , Insectos/fisiología , Enfermedades de las Plantas/inmunología , Inmunidad de la Planta , Tracheophyta/enzimología , Animales , Glucósidos/metabolismo , Glicósidos/metabolismo , Glicosiltransferasas/genética , Enfermedades de las Plantas/parasitología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tracheophyta/genética , Tracheophyta/inmunología , Tracheophyta/parasitología , Azúcares de Uridina Difosfato/metabolismo
11.
J Chem Ecol ; 43(2): 172-179, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28032268

RESUMEN

Woodwasps in Sirex and related genera are well-represented in North American conifer forests, but the chemical ecology of native woodwasps is limited to a few studies demonstrating their attraction to volatile host tree compounds, primarily monoterpene hydrocarbons and monoterpene alcohols. Thus, we systematically investigated woodwasp-host chemical interactions in California's Sierra Nevada and West Virginia's Allegheny Mountains. We first tested common conifer monoterpene hydrocarbons and found that (-)-α-pinene, (+)-3-carene, and (-)-ß-pinene were the three most attractive compounds. Based on these results and those of earlier studies, we further tested three monoterpene hydrocarbons and four monoterpene alcohols along with ethanol in California: monoterpene hydrocarbons caught 72.3% of all woodwasps. Among monoterpene hydrocarbons, (+)-3-carene was the most attractive followed by (-)-ß-pinene and (-)-α-pinene. Among alcohols, ethanol was the most attractive, catching 41.4% of woodwasps trapped. Subsequent tests were done with fewer selected compounds, including ethanol, 3-carene, and ethanol plus (-)-α-pinene in both Sierra Nevada and Allegheny Mountains. In both locations, ethanol plus (-)-α-pinene caught more woodwasps than other treatments. We discussed the implications of these results for understanding the chemical ecology of native woodwasps and invasive Sirex noctilio in North America. In California, 749 woodwasps were caught, representing five species: Sirex areolatus Cresson, Sirex behrensii Cresson, Sirex cyaneus Fabricius, Sirex longicauda Middlekauff, and Urocerus californicus Norton. In West Virginia 411 woodwasps were caught representing four species: Sirex edwardsii Brullé, Tremex columba Linnaeus, Sirex nigricornis F., and Urocerus cressoni Norton.


Asunto(s)
Etanol , Control de Insectos/métodos , Monoterpenos , Tracheophyta/parasitología , Avispas/fisiología , Animales , Conducta Animal/efectos de los fármacos , Monoterpenos Bicíclicos , California , Etanol/análisis , Etanol/farmacología , Interacciones Huésped-Parásitos , Monoterpenos/análisis , Monoterpenos/farmacología , Feromonas/análisis , Feromonas/metabolismo , Feromonas/farmacología , Tracheophyta/crecimiento & desarrollo , Tracheophyta/metabolismo , West Virginia
12.
J Eukaryot Microbiol ; 64(3): 322-335, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27613221

RESUMEN

The genus Tetrahymena (Ciliophora, Oligohymenophorea) probably represents the best studied ciliate genus. At present, more than forty species have been described. All are colorless, i.e. they do not harbor symbiotic algae, and as aerobes they need at least microaerobic habitats. Here, we present the morphological and molecular description of the first green representative, Tetrahymena utriculariae n. sp., living in symbiosis with endosymbiotic algae identified as Micractinium sp. (Chlorophyta). The full life cycle of the ciliate species is documented, including trophonts and theronts, conjugating cells, resting cysts and dividers. This species has been discovered in an exotic habitat, namely in traps of the carnivorous aquatic plant Utricularia reflexa (originating from Okavango Delta, Botswana). Green ciliates live as commensals of the plant in this anoxic habitat. Ciliates are bacterivorous, however, symbiosis with algae is needed to satisfy cell metabolism but also to gain oxygen from symbionts. When ciliates are cultivated outside their natural habitat under aerobic conditions and fed with saturating bacterial food, they gradually become aposymbiotic. Based on phylogenetic analyses of 18S rRNA and mitochondrial cox1 genes T. utriculariae forms a sister group to Tetrahymena thermophila.


Asunto(s)
Chlorophyta/parasitología , Cilióforos/clasificación , Oligohimenóforos/clasificación , Filogenia , Plantas/parasitología , Simbiosis/fisiología , Tetrahymena/clasificación , Animales , Secuencia de Bases , Cilióforos/metabolismo , Cilióforos/fisiología , ADN Protozoario , Ecología , Ecosistema , Estadios del Ciclo de Vida , Mitocondrias/genética , Oxígeno/metabolismo , ARN Ribosómico 18S/genética , Tetrahymena/citología , Tetrahymena/aislamiento & purificación , Tetrahymena/metabolismo , Tetrahymena thermophila/clasificación , Tetrahymena thermophila/genética , Tracheophyta/parasitología
13.
Sci Rep ; 6: 20123, 2016 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-26838797

RESUMEN

The mountains of southwest China are one of the hot spots of biodiversity in the world. However, the high-altitude fauna that inhabit these mountains remain a mystery. In this study, the species diversity of the aphids of the genus Cinara from the high-altitude coniferous forests was first assessed, and then the processes and the mechanisms of speciation were discussed. Three hundreds and four aphid samples that contained 3040 individuals were collected during fourteen field surveys. The molecular clusters derived from the DNA barcodes were used to explore the species diversity. Notably, the aphid alpha-diversity was high, with as many as 94 candidate species, and furthermore, 86.2% of the species collected had not been previously recorded. The centers of aphid species richness corresponded to the distributional pattern of the diversity of the host conifer plant species. The divergence time revealed that following the uplift of the Qinghai-Tibetan Plateau during the Pleistocene, the changes in the climate, ecology and host habitats were likely the most important factors that drove the rapid process of evolutionary radiation in the aphids. Our findings revealed the high species diversity of the aphids with DNA barcoding.


Asunto(s)
Áfidos/clasificación , Áfidos/genética , Código de Barras del ADN Taxonómico/métodos , Tracheophyta/parasitología , Animales , Biodiversidad , Evolución Biológica , China , Clima , Filogenia , Análisis de Secuencia de ADN
14.
PLoS One ; 11(1): e0147107, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26790149

RESUMEN

The evolutionary history, divergence times and phylogenetic relationships of Uleiella chilensis (Ustilaginomycotina, smut fungi) associated with Araucaria araucana were analysed. DNA sequences from multiple gene regions and morphology were analysed and compared to other members of the Basidiomycota to determine the phylogenetic placement of smut fungi on gymnosperms. Divergence time estimates indicate that the majority of smut fungal orders diversified during the Triassic-Jurassic period. However, the origin and relationships of several orders remain uncertain. The most recent common ancestor between Uleiella chilensis and Violaceomyces palustris has been dated to the Lower Cretaceous. Comparisons of divergence time estimates between smut fungi and host plants lead to the hypothesis that the early Ustilaginomycotina had a saprobic lifestyle. As there are only two extant species of Araucaria in South America, each hosting a unique Uleiella species, we suggest that either coevolution or a host shift followed by allopatric speciation are the most likely explanations for the current geographic restriction of Uleiella and its low diversity. Phylogenetic and age estimation analyses, ecology, the unusual life-cycle and the peculiar combination of septal and haustorial characteristics support Uleiella chilensis as a distinct lineage among the Ustilaginomycotina. Here, we describe a new ustilaginomycetous order, the Uleiellales to accommodate Uleiella. Within the Ustilaginomycetes, Uleiellales are sister taxon to the Violaceomycetales.


Asunto(s)
Evolución Biológica , Parásitos/patogenicidad , Tracheophyta/parasitología , Ustilaginales/patogenicidad , Animales , ADN de Hongos/genética , Filogenia , América del Sur
15.
PLoS One ; 10(10): e0139634, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26441311

RESUMEN

Host plant interactions are likely key drivers of evolutionary processes involved in the diversification of phytophagous insects. Granivory has received substantial attention for its crucial role in shaping the interaction between plants and their seed parasites, but fine-scale mechanisms explaining the role of host plant reproductive biology on specialization of seed parasites remain poorly described. In a comparative approach using plant histological techniques, we tested the hypotheses that different seed parasite species synchronize their life cycles to specific stages in seed development, and that the stage they target depends on major differences in seed development programs. In a pinaceous system, seed storage products are initiated before ovule fertilization and the wasps target the ovule's nucellus during megagametogenesis, a stage at which larvae may benefit from the by-products derived from both secreting cells and dying nucellar cells. In a cupressaceous system, oviposition activity peaks later, during embryogenesis, and the wasps target the ovule's megagametophyte where larvae may benefit from cell disintegration during embryogenesis. Our cytohistological approach shows for the first time how, despite divergent oviposition targets, different parasite species share a common strategy that consists of first competing for nutrients with developing plant structures, and then consuming these developed structures to complete their development. Our results support the prediction that seed developmental program is an axis for specialization in seed parasites, and that it could be an important parameter in models of their ecological and taxonomic divergence. This study provides the basis for further investigating the possibility of the link between plant ontogeny and pre-dispersal seed parasitism.


Asunto(s)
Evolución Biológica , Interacciones Huésped-Parásitos , Estadios del Ciclo de Vida/fisiología , Semillas/parasitología , Tracheophyta/parasitología , Animales , Oviposición/fisiología , Simbiosis , Avispas
16.
Pesqui. vet. bras ; 34(10): 942-946, out. 2014. tab
Artículo en Portugués | LILACS | ID: lil-730537

RESUMEN

Para investigar o potencial anti-helmíntico do extrato hidroalcóolico da raiz de Tarenaya spinosa, como alternativa no controle do nematóide gastrintestinal Haemonchus contortus de ovinos, foram realizados testes in vitro com Artemia salina, em seguida, sobre coproculturas contendo ovos do helminto, avaliando a ação ovicida e larvicida do extrato. Após os testes preliminares, foi realizado o teste in vivo em 20 ovinos machos os quais foram divididos em quatro tratamentos Grupo 1: ivermectina 1%; Grupo 2: sem tratamento; Grupo 3: extrato hidroalcóolico de T. spinosa 150μg/mL; Grupo 4: extrato hidroalcóolico de T. spinosa 300μg/mL, amostras de fezes e de sangue foram coletadas para exames parasitológicos e hematológicos. No teste in vitro, a toxicidade frente a A. salina foi de 150μg/mL, obteve-se eficiência de 81,53% sobre ovos e larvas do H. contortus. No teste in vivo, a avaliação da eficácia dos tratamentos foi realizada pelo teste de redução na contagem de ovos fecais (RCOF), os grupos tratados com Ivermectina e T. spinosa a 150μg/mL e 300μg/mL obtiveram os melhores resultados, reduzindo o OPG após 28 dias em 40,6, 41 e 40,2% respectivamente, revelando assim seu potencial fitoterápico para fins de controle de nematódeos gastrintestinais em ovinos.


To investigate the anthelmintic potential of hydroalcoholic extract of the root of Tarenaya spinosa, as an alternative in the control of gastrointestinal nematode Haemonchus contortus in sheep, in vitro tests were performed with Artemia salina then on stool cultures containing helminth eggs, assessing ovicidal and larvicidal action of the extract. After preliminary tests, the in vivo test was performed in 20 male sheep were divided into four treatments: Group 1 Ivermectin 1 %, Group 2: untreated; Group 3: hydroalcoholic extract of T. spinosa 150μg/mL; Group 4: hydroalcoholic extract T. spinosa 300μg/mL, stool samples and blood were collected for parasitological and haematological tests. In in vitro tests, toxicity against A. salina was 150μg/mL, there was obtained 81.53% efficiency against eggs and larvae of H. contortus. In vivo test, evaluating the effectiveness of treatments was performed by reduction test in faecal egg count (RCOF), the groups treated with Ivermectin and T. spinosa the 150μg/mL and 300μg/mL obtained the best results, reducing OPG after 28 days in 40.6, 41 and 42.6% respectively, thus revealing its herbal potential for control of gastrointestinal nematodes in sheep.


Asunto(s)
Animales , Haemonchus , Larvicidas , Ovinos/parasitología , Tracheophyta/parasitología , Haemonchus/patogenicidad , Insecticidas
18.
Zootaxa ; 3778: 1, 3-157, 2014 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-24871621

RESUMEN

The Tenuipalpidae associated with the Casuarinaceae are reviewed, including one new genus, Palpipalpus gen. nov., twelve new species, and seven redescriptions. Two new generic records for Australia are established, Pentamerismus and Philippipalpus. The new species are: Chaudhripalpus costacola Beard and Seeman sp. nov., Crossipalpus gersoni Beard and Seeman sp. nov., Crossipalpus raveni Beard and Seeman sp. nov., Magdalenapalpus caperatus Beard and Seeman sp. nov., Magdalenapalpus forsteri Seeman and Beard sp. nov., Pentamerismus sititoris Beard and Seeman sp. nov., Pentamerismus hicklingorum Seeman and Beard sp. nov., Pentamerismus wardo Seeman and Beard sp. nov., Palpipalpus hesperius Beard and Seeman sp. nov. gen. nov., Philippipalpus flumaquercus Beard and Seeman sp. nov., Philippipalpus belah Beard and Seeman sp. nov., and Philippipalpus nigraquercus Seeman and Beard sp. nov.  Meyeraepalpus delfinadae Smiley et al., is reinstated based on new material and an analysis of its phylogenetic relationships. Crossipalpus muellerianae Smiley et al., Crossipalpus verticillatae Smiley et al., and Tegopalpus conicus Womersley are redescribed and rediagnosed from the original type specimens and newly collected material; and Chaudhripalpus creelae (Smiley et al.), Magdalenapalpus strandtmanni (Smiley et al.) and Philippipalpus agohoi Corpuz-Raros are redescribed and rediagnosed from type material only. All flat mite species were host-specific. Up to three species of flat mite were collected from a single she-oak species. Leg setation and ontogeny are reviewed for the taxa studied. A key to Tenuipalpidae from Casuarinaceae is provided. A phylogeny of the subfamily Tegopalpinae found the following relationships: Meyeraepalpus (Australopalpus, Crossipalpus, Palpipalpus (Magdalenapalpus (Philippipalpus (Chaudhripalpus + Tegopalpus)))). Our preliminary analysis of the Tegopalpinae suggested the group is monophyletic and its sister group is Phytoptipalpus.


Asunto(s)
Ácaros/clasificación , Tracheophyta/parasitología , Animales , Australia , Femenino , Especificidad del Huésped , Larva , Masculino , Ácaros/anatomía & histología , Ácaros/genética , Filogenia
19.
Exp Appl Acarol ; 63(4): 497-520, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24711065

RESUMEN

Eriophyoid species belonging to the genus Trisetacus are economically important as pests of conifers. A narrow host specialization to conifers and some unique morphological characteristics have made these mites interesting subjects for scientific inquiry. In this study, we assessed morphological and genetic variation of seven Trisetacus species originating from six coniferous hosts in Poland by morphometric analysis and molecular sequencing of the mitochondrial cytochrome oxidase subunit I gene and the nuclear D2 region of 28S rDNA. The results confirmed the monophyly of the genus Trisetacus as well as the monophyly of five of the seven species studied. Both DNA sequences were effective in discriminating between six of the seven species tested. Host-dependent genetic and morphological variation in T. silvestris and T. relocatus, and habitat-dependent genetic and morphological variation in T. juniperinus were detected, suggesting the existence of races or even distinct species within these Trisetacus taxa. This is the first molecular phylogenetic analysis of the Trisetacus species. The findings presented here will stimulate further investigations on the evolutionary relationships of Trisetacus as well as the entire Phytoptidae family.


Asunto(s)
Ácaros y Garrapatas/genética , Variación Genética/genética , Filogenia , Tracheophyta/parasitología , Ácaros y Garrapatas/ultraestructura , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN/química , ADN/genética , Análisis Discriminante , Complejo IV de Transporte de Electrones/química , Complejo IV de Transporte de Electrones/genética , Femenino , Microscopía de Contraste de Fase , Datos de Secuencia Molecular , Polonia , Reacción en Cadena de la Polimerasa , ARN Ribosómico 28S/química , ARN Ribosómico 28S/genética , Alineación de Secuencia , Análisis de Secuencia de ADN
20.
Zootaxa ; 3741: 538-50, 2013 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-25113005

RESUMEN

The genus Hemistola Warren, 1893 in Taiwan is reviewed. Seven species are confirmed, with descriptions of three new species provided: H. piceacola sp. nov., H. fui sp. nov. and H. taiwanensis sp. nov. The immature stages and unusual conifer-feeding behavior of H. piceacola on Taiwan spruce (Picea morrisonicola) are reported. The distribution of H. tenuilinea (Alphéraky, 1897) is discussed and this species is omitted from the Taiwanese fauna.


Asunto(s)
Mariposas Nocturnas/clasificación , Picea/parasitología , Tracheophyta/parasitología , Animales , Conducta Alimentaria , Femenino , Genitales/anatomía & histología , Larva , Masculino , Mariposas Nocturnas/anatomía & histología , Taiwán
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA