Ixodes ricinus ticks were collected from dragging vegetation and from shot roe deer in the province of Trento and Belluno in northern Italy. Ticks were pooled for analyses and from 1060 pools of ticks collected in the province of Belluno and 12390 tick samples collected in Trentino, four proved positive by immunofluorescence microscopy using a tick-borne encephalitis (TBE)-specific antiserum. The identity of the virus isolates was determined by RT-PCR cycle sequencing and they were all found to be closely similar (> 98% nucleotide identity) to typical western European TBE complex viruses as found in Austria. The isolates from Trentino differed from the Neudorfl strain of western European TBE virus at eight nucleotide positions but as these nucleotide substitutions were all synonymous, there were no amino acid changes. These results imply that the virus isolates in Trentino have changed slightly from the typical European strains isolated in nearby Austria. The abundance of questing ticks and ticks feeding on roe deer was greater in TBE positive hunting districts than in hunting districts where TBE complex viruses were only probable or believed to be absent. In TBE positive and probable districts synchrony in the seasonal dynamics of larvae and nymphs of L. ricinus was observed. This study provides evidence to suggest that roe deer may have an important role to play in the maintenance of tick density and in the persistence of TBE virus.

Cases of Lyme disease and tick-borne encephalitis were recognized recently in the Province of Trento, Italian Alps. Assessment of areas of potential risk for these tick-borne diseases is carried out by a model based on classification and regression trees (CART), using both discrete and continuous variables. Data on Ixodes ricinus (L.) occurrence resulted from extensive sampling carried out by standard methods in 99 sites over an area of approximately 2,700 km2 in the Province of Trento. A series of environmental parameters were recorded from each site and population densities of roe deer, Capreolus capreolus (L.), were considered. The CART model discriminates 2 variables that appear to have the greatest effect on the mesoscale occurrence of ticks: altitude and geological substratum, with a drastic decrease of tick frequency above an altitude of approximately 1,100 m and on volcanic substrata. The model is effective in identifying the mesoscale areas at greater potential risk, with a relatively low sampling effort.

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The goal of the rapidly expanding field of conservation genetics is to combine genetic methods and theory to improve the management of species severely affected by human activities. Molecular biology and population genetics are the main components of this discipline, with the former yielding an impressive quantity of relevant data and the latter permitting detailed interpretations. Results can then be integrated with other conservation management tools to help define priorities for intervention (Frankham et al. 2002).Recently, the explosion in development of new analytical tools in population genetics (mainly based on Monte Carlo algorithms now treatable with desktop computers) and the possibility of analyzing a large number of genetic markers simultaneously (the genomic approach) have had two major consequences: the array of both statistical and technical methods potentially useful to conservation genetics has undergone a quantum leap, while a substantial gap has been created between the theoretical and applied sciences in this field.This gap was significantly narrowed at a recent workshop entitled "Population Genetics for Animal Conservation," where the splendid isolation of the conference site and evening software sessions encouraged lively discussion among the 18 invited speakers and 42 selected participants. (Abstracts available from http://web.unife.it/ progetti/genetica/pgac2003/pgac2003.htm, Center for Alpine Ecology, Trento, Italy).As underlined by Phil Morin, Mike Bruford, and several other speakers, conservation genetics urgently requires flexible statistical methods tailored to address specific questions. It emerged early in the workshop that the plethora of recent Bayesian methods based on multilocus genotypes is the answer to these needs (Eric Anderson). This step change will be realized through the implementation of new, fast, and efficient approximations based on summary statistics and modified rejection-sampling algorithms (Mark Beaumont, Laurent Excoffier), and understanding of complex population dynamics will be possible through the simultaneous estimation of important parameters such as effective population size and its rate of variation, admixture proportions, migration rates, and selection coefficients. Moreover, Bayesian methods are suitable for questions concerning individuals (e.g.,