El género Uralichas Delgado, 1892 (Trilobita, Lichaida) en el Ordovícico de la Península Ibérica

Se revisan los trilobites Lichaida procedentes de los materiales lutíticos de las «Capas con Tristani» del Macizo Hespérico, encontrados en 20 localidades de la zona Centroibérica de edad comprendida entre el Llanvirn Inferior y el Dobrotiviense (Llandeilo) Superior. Todos los hallazgos corresponden al género Uralichas DELGADO, 1892, que se encuentra representado por dos formas: U. gutierrezi n. sp. (Llanvirn Inferior de los Montes de Toledo-Villuercas), y U. hispanicus (VERNEUIL y BARRANDE, 1856), conocido en materiales más modernos (Llanvirn Superior-Dobrotiviense Superior) del área ibero-armoricana. Esta segunda especie es la más moderna del género, y al mismo tiempo representa el trilobites más grande conocido (66 cm. de longitud). Igualmente, se ha podido demostrar la prioridad nomenclatural de U. hispanicus (VERNEUIL y BARRANDE,, 1856), sobre U. ribeiroi DELGADO, 1892; y la revisión de los representantes del género en el SO de Europa ha aportado otra posible nueva especie [U. heberti (ROUAULT, 1849) sensu RACHEBOEUF, 1969]. El material tipo del auténtico U.? heberti corresponde a un lichaido indeterminable, que proponemos restringir al único ejemplar figurado por ROUAULT.

Factors driving the abundance of ixodes ricinus ticks and the prevalence of zoonotic I. ricinus-borne pathogens in natural foci

Environmental factors may drive tick ecology and therefore tick-borne pathogen (TBP) epidemiology, which determines the risk to animals and humans of becoming infected by TBPs. For this reason, the aim of this study was to analyze the influence of environmental factors on the abundance of immature-stage Ixodes ricinus ticks and on the prevalence of two zoonotic I. ricinus-borne pathogens in natural foci of endemicity. I. ricinus abundance was measured at nine sites in the northern Iberian Peninsula by dragging the vegetation with a cotton flannelette, and ungulate abundance was measured by means of dung counts. In addition to ungulate abundance, data on variables related to spatial location, climate, and soil were gathered from the study sites. I. ricinus adults, nymphs, and larvae were collected from the vegetation, and a representative subsample of I. ricinus nymphs from each study site was analyzed by PCR for the detection of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum DNA. Mean prevalences of these pathogens were 4.0% ± 1.8% and 20.5% ± 3.7%, respectively. Statistical analyses confirmed the influence of spatial factors, climate, and ungulate abundance on I. ricinus larva abundance, while nymph abundance was related only to climate. Interestingly, cattle abundance rather than deer abundance was the main driver of B. burgdorferi sensu lato and A. phagocytophilum prevalence in I. ricinus nymphs in the study sites, where both domestic and wild ungulates coexist. The increasing abundance of cattle seems to increase the risk of other hosts becoming infected by A. phagocytophilum, while reducing the risk of being infected by B. burgdorferi sensu lato. Controlling ticks in cattle in areas where they coexist with wild ungulates would be more effective for TBP control than reducing ungulate abundance.