Search results for "mites"
showing 10 items of 108 documents
Terrestrial plants and marine algae from the Late Jurassic lithographic limestone of the Causse Méjean (Lozère, southern France)
2016
International audience; A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Méjean, Lozère (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a f…
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift
2016
Abstract Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a…
Novel mutations in the voltage-gated sodium channel of pyrethroid-resistant Varroa destructor populations from the Southeastern USA
2016
The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here,…
The Odorant-Binding Proteins of the Spider Mite Tetranychus urticae
2021
Spider mites are one of the major agricultural pests, feeding on a large variety of plants. As a contribution to understanding chemical communication in these arthropods, we have characterized a recently discovered class of odorant-binding proteins (OBPs) in Tetranychus urticae. As in other species of Chelicerata, the four OBPs of T. urticae contain six conserved cysteines paired in a pattern (C1–C6, C2–C3, C4–C5) differing from that of insect counterparts (C1–C3, C2–C5, C4–C6). Proteomic analysis uncovered a second family of OBPs, including twelve members that are likely to be unique to T. urticae. A three-dimensional model of TurtOBP1, built on the recent X-ray structure of Varroa destruc…
Assessing the effect of emergent vegetation in a surface-flow constructed wetland on eutrophication reversion and biodiversity enhancement
2018
Abstract A free water-surface constructed wetland (F4-unit) was created in a Mediterranean protected site to treat eutrophic inflows to the Albufera de Valencia lagoon, and enhance biodiversity. In 2013, the F4-unit was divided into three subunits and planted with different compositions of emergent macrophytes (Phragmites australis, Iris pseudacorus, and a mixture of several macrophytes: F4-Reed, F4-Iris and F4-Mixed subunits). Two nine-month periods were monitored after planting, and water quality variables were measured in the inflows and outflows. Waterfowl occupation and plankton biomass were analyzed to evaluate their role in eutrophication reversion. The low removal efficiencies relat…
Species specificity of trail pheromones of fungus-growing termites from northern Vietnam
2001
Trail-following pheromones were studied in four fungus-growing termites from northern Vietnam: Macrotermes annandalei, M. barneyi, Odontotermes hainanensis and O. maesodensis. From bioassays, we suggest that trail pheromones of these species are composed of a common or anony-mous signal, as well as species-specific signals. The anonymous signal has been identified by GC-MS as (Z)-dodec-3-en-1-ol for each species from extracts of sternal glands and from solid phase microextraction of the surface of their sternal gland. This compound is secreted in much higher quantities (up to 1.4 ng/worker) than dodecatrienol, another anonymous signal of trail-following in termites. (Z)-dodec-3-en-1-ol is a…
INHIBITION OF THE FUNGAL PATHOGEN METARHIZIUM ANISOPLIAE IN THE ALIMENTARY TRACTS OF FIVE TERMITE (ISOPTERA) SPECIES
2010
We previously showed that in the subterranean termite Reticulitermes flavipes conidia of Metarhizium anisopliae did not germinate in the alimentary tract of living termites and the antifungal activity remained for 2 d post mortem in the gut. We have confirmed that this mechanism is common throughout the termite phylogeny by extending our observations to 5 additional species, from 5 different families. Grooming and ingestion of microorganisms from the cuticle ofnestmate was found to be consistent in all the species and none of the conidia found in the alimentary tracts germinated.
The phylogeny of termites (Dictyoptera : Isoptera) based on mitochondrial and nuclear markers : implications for the evolution of the worker and pseu…
2008
A phylogenetic hypothesis of termite relationships was inferred from DNA sequence data. Seven gene fragments (12S rDNA, 16S rDNA, 18S rDNA, 28S rDNA, cytochrome oxidase I, cytochrome oxidase II and cytochrome b) were sequenced for 40 termite exemplars, representing all termite families and 14 outgroups. Termites were found to be monophyletic with Mastotermes darwiniensis (Mastotermitidae) as sister group to the remainder of the termites. In this remainder, the family Kalotermitidae was sister group to other families. The families Kalotermitidae, Hodotermitidae and Termitidae were retrieved as monophyletic whereas the Termopsidae and Rhinotermitidae appeared paraphyletic. All of these result…
Tomato trichomes are deadly hurdles limiting the establishment of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae)
2021
[EN] Amblyseius swirskii is a predatory mite widely used for the control of very important pest species, such as whiteflies and thrips, in organic farming and conventional agriculture. However, this species cannot establish on tomato crops, probably due to the toxic effects of plant trichomes and their exudates. We evaluated tomato plants for effects on: a) A. swirskii preference mediated by plant volatiles, b) A. swirskii development, predation capacity and reproductive performance, c) the dispersal and survival of mites as affected by stem trichomes, and d) mite survival as a function of secondary metabolites secreted by tomato trichomes. The results showed that A. swirskii mites which ga…
Population asynchrony alone does not explain stability in species‐rich soil animal assemblages: The stabilizing role of forest age on oribatid mite c…
2020
The importance of microbial and plant communities in the control of the diversity and structure of soil animal communities has been clarified over the last decade. Previous research focused on abiotic factors, niche separation and spatial patterns. Significant gaps still exist in our knowledge of the factors that control the stability of these communities over time. We analysed a 9-year dataset from the national Long-term Ecological Research Network of Latvia. We focused on 117 oribatid species from three Scots pine forests of different age (40, 65 and150 years) and structure. For each forest type, 100 samples were collected each year, providing very high replication and long time series fo…