Generalist predators hunt a wide range of prey that possess various characteristics affecting the predators' hunting success (e.g., size, ability to detect the threat and defend against it, potential for escape). Therefore, it can be expected that the predator should flexibly react to different prey characteristics, hunting them in prey-specific ways. For a stalking predator a crucial prey feature is its ability to escape. In this study, the alternative prey-catching tactics of a dune-dwelling salticid Yllenus arenarius Menge 1868 were analyzed. Four naturally eaten prey taxa, two with a high ability to escape (Homoptera, Orthoptera) and two with a low ability to escape (Thysanoptera, larvae of Lepidoptera), were used. Numerous differences found between the tactics indicate that Y. arenarius can not only distinguish between different types of prey, but can also employ specific tactics to catch them. The tactics belong to a conditional strategy and are manifested in alternative: a) direction of approach, b) speed of approach, and c) other prey specific behaviors.

National parks are increasingly recognized as playing an important role in the development of nature-based tourism destinations that promote effective management of natural resources and socioeconomic development. The paper was designed to evaluate the tourism attractiveness and performance of national parks in Vietnam. The tourism performance of 30 Vietnamese national parks was evaluated using multiple criteria decision analysis with the stochastic multicriteria acceptability analysis (SMAA) and preference ranking organization method for enrichment evaluation (PROMETHEE) method; thirteen national park attributes were used to determine tourism attractiveness, measured by an exponential weighted acceptability index. It was found that the Phong Nha – Ke Bang, Cuc Phuong, and Ba Be National Parks were most attractive for more than 95% of all possible preference structures. In addition, 12 non-dominated national parks were identified, and for an average supporter of most non-dominated protected areas, the trail criterion appears to be the most important. A statistically significant correlation was found between tourism attractiveness and the number of tourists who visited national parks. Our findings offer potentially useful information for decision makers in developing effective tourism marketing and management strategies for national parks in Vietnam.

The hunting behavior of juvenile Ylleinis areucirius Menge 1868 in their first week after leaving sub-sand nests was studied. The spiders were tested with prey that can effectively escape (Homoptera) and prey that are not capable of efficient escape (Thysanoptera and larvae of Lepidoptera) in order to assess the complexity of young spiders' hunting tactics. Numerous differences were found in the mode of catching the prey, which indicate that the spiders possess a conditional hunting strategy. The strategy is expressed in: direction of approach, speed of approach, distance of attack and other prey-specific behaviors. The results strongly suggest the pre-programmed background of both the observed behaviors and sensitivity towards certain prey characteristics that enabled prey identification.

Abstract. From 2000 to 2006 a total of 52 CPUE samples of spider wasps (Hymenoptera: Pompilidae) were collected in the mosaic landscape of the Kampinos National Park (Poland), which is a UNESCO Biosphere Reserve. The hypothesis tested was that both pompilid species richness and abundance is positively associated with spatial heterogeneity. The patterns in spider wasp assemblages were identified using a Kohonen artificial neural network (i.e., self-organizing map). The highest numbers and greatest species richness of pompilids were recorded at sites in open habitats, especially those located on dry soils that are the preferred nesting sites of ground nesting (endogeic) spider wasps. However, pompilid distribution depended not only on the character of a sampling site, but also its location in a mosaic of habitats. The highest values of pompilid abundance and species richness were also recorded at sites surrounded by several different habitats. Both parameters were lower at sites in more homogenous areas, where there were fewer habitats within the flight ranges of spider wasps. A group of three "cultural species" (Agenioideus cinctellus, A. sericeus and Auplopus carbonarius) was identified that is significantly associated with wooden buildings. The results of this study are thus consistent with the concept that habitat heterogeneity enhances faunal diversity, as each type of habitat, including anthropogenic ones, potentially contributes to a wider range of available resources.

A long-term diet analysis of a polyphagous jumping spider Yllemis arenarius Menge 1868 (13 yr, « = 321 prey items) was carried out in Central Poland. Due to the spider's long life cycle two cohorts are present for the whole season and for one month three cohorts coexist, which allowed me to investigate whether coexisting spiders feed on similar or different prey. Diets of spiders from these three cohorts were found to differ in three aspects: prey taxa, prey diversity and prey size. Spiders from each cohort maintained a fairly constant ratio between prey size and their own size throughout the life cycle, which resulted in dietary separation between individuals from coexisting cohorts. Such mechanisms may reduce the intensity of competitive interactions between coexisting spiders.

In the Kampinos National Park (Poland), which is a UNESCO Biosphere Reserve, 47 caught per unit effort samples of Chrysididae were collected in 2000–2006. The aim of the study was to identify the factors promoting the diversity of this rarely studied group of parasitic wasps. A total of 722 specimens belonging to 37 species were recorded, including 18 threatened species and six others recently described as new to the Polish fauna. No chrysidids were recorded in forests, instead they were most abundant on fallow land (i.e. in open habitats), of which those located on dry soils were preferred over humid ones, just as by their endogeic (nesting in the ground) hosts. Many chrysidids that are parasites of hypergeic (nesting above the ground) species were significantly associated with old abandoned wooden buildings, where their hosts use holes in wood for nesting. In addition to the characteristics of the habitat sampled, its position in the land mosaic also determined the diversity of chrysidids. Their lowest abundance and species diversity were recorded in samples from different types of habitat, all located in a uniform environment (i.e. with few other habitats nearby), which limited the diversity of resources available within the flight ranges of chrysidids and their hosts. Our study, thus consistent with the concept that habitat heterogeneity enhances faunal diversity, brings important conclusions for the management of park landscapes: afforestation of open areas (both intentional and resulting from natural succession of plant communities) and removal of old abandoned wooden buildings may limit the land mosaicity and thus faunal diversity.

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