The white-clawed crayfish is endemic to western and southern Europe and its populations have decreased over recent decades. Spanish populations are generally poorly represented in scientific reports and are usually studied only with a single molecular marker. Here, we use two mitochondrial markers (cytochrome oxidase subunit I and rDNA 16S genes) to examine levels and patterns of genetic structure across the range of the species' distribution in Spain. Data reveal the existence of two main genetic groups of white-clawed crayfish in Spain with the Ebro basin as a possible contact zone. Processes occurred in historical and recent times, such as genetic drift and translocations, contribute greatly to this genetic structure. Levels of genetic variability and genetic structure of Spanish populations together with demographic inferences suggest that the species established in the Iberian Peninsula, at least since the Late Pleistocene. Knowing the true origin of the Spanish populations is crucial when deciding upon the management policies that should be followed. Given the lack of any clear evidence against its indigenous status, we propose that current protection and conservation measures should be maintained. From a management point of view, we suggest that Spanish population should be considered as a single evolutionary significant unit (ESU) with two management units (MUs) corresponding with the genetic clusters detected in the present study.
Key-words:Austropotamobius italicus was once widely distributed throughout most of the country's limestone basins in Spain. But its populations have shown a very strong decline over the last thirty years, due to different factors. Thus, the species now enjoys protection under regional, national and international legislation. Therefore, knowledge of the levels and patterns of distribution of genetic diversity in crayfish populations is critical when making conservation management decisions. In the present work, the current genetic structure of Spanish populations of white-clawed crayfish, A. italicus, was analyzed. Eleven Spanish populations and an Italian sample were studied through an 1184 bp-lentgh sequence of cytochrome oxidase subunit I mitochondrial gene. Data analysis revealed the existence of eight haplotypes in the Iberian Peninsula, the highest diversity reported to date in Spanish crayfish. Also a substantial genetic differentiation among populations was found, with a clear geographic pattern. The genetic variability found in these populations is similar to, and even higher, than that reported in previous studies on other Spanish and European populations of A. italicus. Thus, given the current risk status of the species across its range, this variability in certain populations offers some hope for the species from a management point of view.
RÉSUMÉ
La variabilité de l'ADN mitochondrial des populations espagnoles d' A. italicus déduite de l'analyse d'une région COI
Mots-clés :Austropotamobius italicus, mtDNA, Austropotamobius italicus était autrefois largement distribué dans la plupart des régions des bassins calcaires en Espagne. Mais ces populations ont montré une baisse très forte au cours des trente dernières années, en raison de différents facteurs. Ainsi, l'espèce bénéficie aujourd'hui d'une protection législative régionale, nationale et internationale. Par conséquent, la connaissance des niveaux et des schémas de distribution de la diversité des ressources génétiques dans les populations d'écrevisses est essentielle pour prendre des décisions de bioconservation. Dans le présent travail, la structure génétique actuelle des populations espagnoles de l'écrevisse à pattes blanches, A. italicus, a été analysée. Onze populations
The tephritid Bactrocera oleae (Gmelin) is a harmful pest of olive crops that cause important agricultural and economic losses in the Mediterranean area where 90% of the world olive trees are cultivated. The knowledge of the genetic diversity in insect pest species populations is critical for decisions concerning appropriate control management strategies. In the present work, the genetic variability within and among 7 populations ‐five from Spain, one from Italy and one from Tunisia‐, was assessed by sequencing 1151 bp of the COI gene. A total of 21 haplotypes were observed. The intraspecific diversity was high, particularly in the Spanish populations (haplotype and nucleotide diversity 0.84 and 0.00137, respectively). However, the genetic differentiation among the populations was low in the case of Spanish ones (Fst between 0 and 0.041), and higher –and statistically significant– when comparing with the Italian and Tunisian samples. The haplotypes distribution and the PCoA analysis show three clear groups of populations: Spanish, Italian and Tunisian. The results might indicate the length of time elapsed since B. oleae became established in the Mediterranean region, the large effective sizes expected of its populations and the high gene flow among Iberian populations. The information could be relevant for integrated control programmes coordination.
Abstract:The European Union (EU) is facing the recent arrival of the bacterium Xylella fastidiosa. Its fast spread has caused great alarm because of the economic impact it implies for the agroeconomy of European countries. Among its insect vectors, Philaenus spumarius has been demonstrated to transmit the bacterium from infected to uninfected trees in the EU, where different measures have been established to control it. One of the proposals to manage this vector is the augmentation of natural enemy populations. However, the identification of candidate predator species is essential if such a management system is to be introduced. The present paper describes a set of species-specific primers designed to detect the presence of P. spumarius DNA in soil arthropod fauna generalist predators' gut which can reveal candidate species for the pest's biological control. Such primers have been proven to be a useful and reliable taxonomic tool for P. spumarius identification at any life stage, i.e., nymphs. This rapid and accurate identification is essential for control strategies designed to avoid the spread of the pest and consequently the considerable economic losses it causes in crops.
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