Potentialités de développement deTetranychus urticae Koch (Tetranychidae, Acari ) sur quelques hôtes sauvages et cultivés

Pour mieux comprendre les mécanismes de pullulation de T. urticae sur Citrus, nous avons étudié en laboratoire, à différentes températures et hôtes alimentaires, ses paramètres biologiques. Les résultats acquis, témoignent d'une faible fécondité des individus élevés sur Citrus. La longévité du tétranyque est plus courte lorsqu'il est nourri sur plantes sauvages. Le développement est plus rapide chez les individus élevés sur plantes herbacées et plus particulièrement sur morelle (Solanum nigrum). Le transfert de l'acarien, récolté initialement sur mauvaises herbes, sur des feuilles d'agrumes se traduit par une baisse notoire de ses potentialités reproductives. A travers ses résultats synthétiques nous avons tenté de consolider les acquis obtenus lors du suivi des populations en verger.Developmental time of Tetranychus urticae Koch (Tetranychidae, Acari ) on spontaneous weed and CitrusExtensive data on the developmental time of Tetranychus urticae Koch in relation to temperature and food resources were described. At most temperatures, the order of relative influence on the life history of the mite was diet. Solanum nigrum, spontaneous weed in orchards, is responsible for a high potential population increase. However, the mite either feeding or transfered from weeds on Citrus leaves (oranges, clementines) showed moderate reproductive capacities. The obtained results consolided the survey ofmite population in orchards

Estudio coste efectividad del proceso diagnóstico de la trombosis venosa profunda desde la atención primaria

Analizar el coste-efectividad de la aplicación de algoritmos diagnósticos en pacientes con sospecha de un primer episodio de trombosis venosa profunda (TVP) en la atención primaria, en comparación con la derivación sistemática a centros especializados. Estudio observacional, transversal y analítico. Pacientes seleccionados en urgencias hospitalarias derivados desde la atención primaria para completar estudio y diagnóstico. Se reclutó a 138 candidatos con clínica compatible con un primer episodio de TVP; 22 fueron excluidos (sin informe de derivación, clínica de más de 30 días, anticoagulados y TVP previa), incluyéndose finalmente a 116 pacientes, un 61% mujeres, de 71 años edad media. Variables de las escalas de probabilidad clínica de Wells y Oudega, dímero-D (portátil y hospitalario), ecografía-Doppler y costes directos generados por los 3 circuitos analizados: derivación sistemática de todos los pacientes, derivación según escala de Oudega o de Wells. En el 18,9% se confirmó el diagnóstico de TVP. Las 2 escalas de probabilidad clínica presentaron una sensibilidad del 100% (IC del 95%: 85,1-100) y una especificidad alrededor del 40%. Con la aplicación de las escalas, se hubiesen podido evitar con total seguridad un tercio de las derivaciones a urgencias hospitalarias (p < 0,001) y se hubieran podido disminuir los costes del proceso diagnóstico en 8.620 € según Oudega y 9.741 € según Wells, por cada 100 pacientes atendidos. La aplicación de algoritmos diagnósticos en las sospechas de TVP permitiría al médico de atención primaria una orientación más resolutiva y coste-efectiva del proceso diagnóstico

Circonstances des pullulations de Tetranychus urticae Koch (Tetranychidae, Acari) en verger d'agrumes

T. urticae est l'un des gros ravageurs actuellement recens&eacute;s sur diverses cultures et plantes spontan&eacute;es. Le travail, centr&eacute; autour d'observations conduites en verger d'agrumes, pr&eacute;sente la gen&egrave;se des pullulations du t&eacute;tranyque. Les facteurs climatiques, le r&ocirc;le des mauvaises herbes dans l'approvisionnement des arbres en individus sont analys&eacute;s. Il ressort de l'agencement de l'ensemble des observations conduites, l'importance d&eacute;cisive des interactions qui s'exercent entre cl&eacute;mentinier et strate herbac&eacute;e. Le suivi des populations de T. urticae &agrave; des fins de phytoprotection doit n&eacute;cessairement tenir compte de la charge en individus de ces composantes du syst&egrave;me verger.Swarminr circumBtances of Tetranychus urticae Koch (Tetranychidae, Acan) in Citrus orchardsTetranychus urticae Koch is one of the most important, actually recorder, pest on various crops and spontaneous plants. Based on observation done in Citrus orchards, this work present the genesis of the mite swarming in nature. The effect of climatic factors and weds on Citrus trees infestation were analyzed. The interaction between clementine trees and herbaceous stratum was determined in this infestation. Thesurvey of the Twospotted spider mite pullulation on weeds should be considered in any control programme

Sequence analysis of the ribosomal Internal Transcribed Spacers region in spider mites (Prostigmata: Tetranychidae) occurring in citrus orchards in Eastern Spain: use for species discrimination

Tetranychus urticae is a polyphagous mite which is an important pest of citrus worldwide. This mite can be found feeding on many plant species occurring in the citrus agrosystem moving from weeds to trees. Because field samples consist of a mixture of different Tetranychidae species, as a first step necessary to further implement population characterization of T. urticae, species-discriminating criteria based on molecular techniques are needed. In this study, the nucleotide variation of the Internal Transcribed Spacers (ITS) 1 and 2 and the intergenic 5.8S fragment of nuclear ribosomal DNA of T. urticae, T. turkestani, T. evansi, T. ludeni and P. citri, have been determined. Results demostrate that for these species, the rDNA ITS2 regions are much more conserved than the corresponding rDNA ITS1. The high homogeneity of the ITS2 sequence observed among the specimens of T. urticae obtained from the same eco-region makes this DNA-sequience an excellent tool for species discrimination. ITS sequences differentiate not only species but also specimens from different geographical origin. Furthemore, PCR-RFLP analysis of the ITS2 proved adequate for a quick screening of high numbers of field sample

Sequence analysis of the ribosomal internal transcribed spacers region in spider mites (Prostigmata: Tetranychidae) occurring in citrus orchards in Eastern Spain: use for species discrimination

Correspondence to Mónica Hurtado Ruiz, Departament de Ciències Agràries i del Medi Natural, Universitat Jaume I, Campus del Riu Sec, E-12071-Castelló de la Plana, Spain. Email: [email protected] Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699International audienceTetranychus urticae is a polyphagous mite which is an important pest of citrus worldwide. This mite can be found feeding on many plant species occurring in the citrus agrosystem moving from weeds to trees. Because field samples consist of a mixture of different Tetranychidae species, as a first step necessary to further implement population characterisation of T. urticae, species-discriminating criteria based on molecular techniques are needed. In this study, the nucleotide variation of the internal transcribed spacers (ITS) 1 and 2 and the intergenic 5.8S fragment of nuclear rDNA of T. urticae, Tetranychus turkestani, Tetranychus evansi, Tetranychus ludeni and Panonychus citri have been determined. Results demonstrate that for these species, the rDNA ITS2 regions are much more conserved than the corresponding rDNA ITS1. The high homogeneity of the ITS2 sequence observed among the specimens of T. urticae obtained from the same ecoregion makes this DNA sequence an excellent tool for species discrimination. ITS sequences differentiate not only species but also specimens from different geographical origin. Furthermore, polymerase chain reaction–restriction fragment length polymorphism analysis of the ITS2 proved adequate for a quick screening of high numbers of field sample