Search results for "SYSTEMATICS"
showing 10 items of 6702 documents
Spatiotemporal Structure of Host‐Pathogen Interactions in a Metapopulation
2009
International audience; The ecological and evolutionary dynamics of species are influenced by spatiotemporal variation in population size. Unfortunately, we are usually limited in our ability to investigate the numerical dynamics of natural populations across large spatial scales and over long periods of time. Here we combine mechanistic and statistical approaches to reconstruct continuous-time infection dynamics of an obligate fungal pathogen on the basis of discrete-time occurrence data. The pathogen, Podosphaera plantaginis, infects its host plant, Plantago lanceolata, in a metapopulation setting where the presence of the pathogen has been recorded annually for 6 years in similar to 4,00…
Chemistry of defensive secretions in nymphs and adults of fire bug , Pyrrhocoris apterus L.(Heteroptera, Pyrrhocoridae)
1992
International audience; The defensive secretions from the nymphs and the adults of both sexes in P. apterus were chemically investigated. Forty components were identified from the nymphal posterior dorsoabdominal glands and 35 from the adult metathoracic glands of both sexes. Within the 43 identified chemicals, we found 23 aldehydes, five saturated hydrocarbons, five alcohols, three ketones, three lactones, two terpenes, one phenol and one ester. Thirteen of these compounds had never been reported within the Heteroptera. Whereas eight components are specific to the nymphs, methyl pentenal, (E)-2-hexenol, and heptadecanal are the only adult-specific components. The biological role of all the…
Megaphylogenetic Specimen-level Approaches to the <I>Carex</I> (Cyperaceae) Phylogeny Using ITS, ETS, and <I>matK</I> Sequenc…
2016
Abstract We present the first large-scale phylogenetic hypothesis for the genus Carex based on 996 of the 1983 accepted species (50.23%). We used a supermatrix approach using three DNA regions: ETS, ITS and matK. Every concatenated sequence was derived from a single specimen. The topology of our phylogenetic reconstruction largely agreed with previous studies. We also gained new insights into the early divergence structure of the two largest clades, core Carex and Vignea clades, challenging some previous evolutionary hypotheses about inflorescence structure. Most sections were recovered as non-monophyletic. Homoplasy of characters traditionally selected as relevant for classification, histo…
A large-scale, higher-level, molecular phylogenetic study of the insect order Lepidoptera (moths and butterflies).
2013
Background Higher-level relationships within the Lepidoptera, and particularly within the species-rich subclade Ditrysia, are generally not well understood, although recent studies have yielded progress. We present the most comprehensive molecular analysis of lepidopteran phylogeny to date, focusing on relationships among superfamilies. Methodology / Principal Findings 483 taxa spanning 115 of 124 families were sampled for 19 protein-coding nuclear genes, from which maximum likelihood tree estimates and bootstrap percentages were obtained using GARLI. Assessment of heuristic search effectiveness showed that better trees and higher bootstrap percentages probably remain to be discovered even …
The concept of genus within the family Phytoseiidae (Acari: Parasitiformes): historical review and phylogenetic analyses of the genus Neoseiulus Hugh…
2012
Systematic studies on the family Phytoseiidae were first conducted at the beginning of the 20th century but increased greatly after the Second World War. Various classifications have been proposed based on different characters such as: dorsal, ventral, and leg chaetotaxy; the shape of ventrianal and sternal shields; the shape of the insemination apparatus (spermatheca) and spermatodactylus; the number of teeth on the movable digit of chelicera; and dorsal and ventral adenotaxy. The genus concepts developed over the last five decades can be divided into two main categories or hypotheses. The first, supported mainly by Chant and McMurtry, focuses on dorsal and ventral chaetotaxy, and the gene…
The DNA barcoding of Mediterranean combtooth blennies suggests the paraphyly of some taxa (Perciformes, Blenniidae)
2019
A dataset including novel and publicly available mtDNA COI sequences of 14 Mediterranean combtooth blenny species belonging to nine genera was assembled in order to provide a reference dataset for DNA barcoding studies. Some inconsistencies in the current taxonomy of some genera were observed. In particular, the monophyly of the genera Parablennius and Salaria is not supported by the present dataset and the absence of reciprocal monophyly between the morphospecies Salaria basilisca and S. pavo questions their status and stresses the need of a revision of the genus Salaria.
New taxa of Orthoptera (Insecta Tettigoniidae Phaneropterinae) from Madagascar.
2017
The author reports the results of a study on Orthoptera collected in Madagascar and preserved in two European Natural History museums. He describes Symmetroraggea depravata n. sp., Parapyrrhicia longipodex n. sp., Madagascarantia bartolozzii n. gen. n. sp., Mimoscudderia spinicercata n. sp. In addition, he lists new records or unknown taxonomical characters of Xenodus nobilis Carl, 1914 and Parapyrrhicia virilis Carl, 1914.
New Reptile Hosts for Helminth Parasites in a Mediterranean Region
2020
ABSTRACT Parasitic helminths are an almost universal feature of vertebrate animals, but reptiles are among the hosts with the most depauperate parasite communities. Biological traits of reptiles ar...
Nest Insulating Capacity during Incubation and after Fledging are Related
2016
Most birds build nests to hold eggs and nestlings. An important property of nests is their ability to keep eggs and nestlings at an optimum temperature. This is usually measured as the insulating capacity (IC); nests with a higher IC will keep their content warm for longer. The usual protocol to estimate IC involves collecting nests after fledging of the young. However, nest properties change throughout the nesting period, potentially affecting IC. Therefore, a relevant question is whether the nest IC, measured after fledging, actually reflects its IC during incubation and early nestling development, when it is most crucial. In April 2015, we collected 18 Great Tit ( Parus major) nests 3-4…
The role of partial incubation and egg repositioning within the clutch in hatching asynchrony and subsequent effects on breeding success
2019
The main mechanism to achieve hatching asynchrony (HA) for incubating birds is to start heating the eggs before clutch completion. This might be achieved through partial incubation and/or early incubation. Even in the absence of incubation behaviour during the laying phase, clutches still experience a certain degree of asynchrony. Recent studies have shown that eggs located in the centre of the nest receive more heat than peripheral ones during incubation. As eggs receiving more heat would develop faster, we hypothesized that HA should be shorter in nests where eggs were moved homogeneously along the centre–periphery space during incubation than in those nests where eggs repeatedly remained…