The creation of improved areas is one way of increasing the productivity of livestock on Cantabrian heathland (NW Spain), a habitat that is frequently located in less favourable mountainous areas where the development of sustainable husbandry is limited. The effect of this on the biodiversity of heathland is unclear and likely to depend on several factors, such as the grazing regime. In order to clarify this situation, the effects of type of vegetation, species of grazer and grazing regime on the composition of the ground-dwelling arthropod fauna of partially improved heathland were determined. The effects of grazing by cattle or sheep and two grazing regimes (cattle or sheep, or both of them together with goats) were studied in eight plots (two replicates per treatment). Each plot included two types of vegetation, gorse (Ulex gallii)-dominated shrubland and improved grassland (Lolium perenne-Trifolium repens). Arthropods were surveyed using pitfall traps. Overall, the composition of the arthropod fauna did not differ between plots grazed by different species of grazer or using different grazing regimes but was significantly associated with the type of vegetation. Most of the opilionids and several carabids clearly preferred shrubland, while lycosids and various carabids were mainly associated with grassland. While the species of grazer affected the faunal composition of grassland, grazing regime was more important in shrubland. Arthropod responses to the grazing treatments were determined by the grazing behaviour of the large herbivores and the habitat requirements of each arthropod taxon. The great structural heterogeneity of the vegetation and the more microhabitats in shrubland grazed by mixed flocks was mainly a result of the goats preferring to browse on the woody vegetation in these areas. The grazing by either sheep or cattle had less of an affect on the fauna of shrubland than grassland. and Rocío ROSA GARCÍA, Urcesino GARCÍA, Koldo OSORO, Rafael CELAYA.
Despite the importance of saprophagous macroarthropods as key facilitators of plant litter decomposition within ecosystems and their likely sensitivity to global climate change and land-use change, a lack of ecological data has precluded attempts to explain their distribution patterns in terms of traits. Using an extensive set of large-scale and long-term biological records, the distribution patterns of 33 woodlice (Crustacea: Oniscidea) species in Britain were characterised by their range size (area of occupancy) and aggregation (degree to which occupied squares are clustered across the range). Body size and seven ecological traits were examined as correlates of range size and fill, while controlling for phylogeny and recording intensity, and comparing fine and broad-scale measures of habitat heterogeneity. Species that used a greater diversity of habitats had larger range sizes. Broad categorisation of habitats (by dominant vegetation) alongside other traits was less accurate in predicting range size than fine-scale habitat (microsites where individuals were discovered) data. The latter explained 25% more variance than broad-scale habitat data, highlighting the value of coupling biological recording of species with data on micro-habitat. Habitat use is an important trait in explaining distribution patterns and we conclude that ensuring land cover heterogeneity will favour conservation of saprophagous macro-arthropod diversity., Bethan V. Purse ... [et al.]., and Obsahuje seznam lileratury
a1_Hesperomyces virescens is an ectoparasite of some Coccinellidae, which until the mid-1990s was relatively rarely only reported from warm regions in various parts of the world. Analysis of the host and distribution data of H. virescens recorded in the Western Palaearctic and North America reveals several trends in the occurrence and abundance of H. virescens: (1) it has recently been much more frequently recorded, (2) most of the recent records are for more northerly (colder) localities than the early records and (3) the recent records are mostly of a novel host, the invasive harlequin ladybird (Harmonia axyridis). While in North America H. virescens is almost exclusively found on H. axyridis, all European records of this association are very recent and still less numerous than records of Adalia bipunctata as a host. However, based on a relatively few published cases of the H. axyridis-H. virescens association in Europe and the case described in this paper, it is clear that the harlequin ladybird is currently the main host of this parasite. These changes in the abundance and geographical distribution of H. virescens are probably linked to some features of H. axyridis, such as its abundance, multivoltinism with overlapping generations, high level of promiscuity and overwintering in mass aggregations. The occurrence of these features in one species may make it especially suitable for H. virescens and other parasites that require close contact of host individuals for efficient transmission. Indeed, some of the data indicate that parasites other than H. virescens, like the podapolipid mite Coccipolipus hippodamiae and allantonematid nematodes of the genus Parasitylenchus may also heavily parasitize H. axyridis., a2_We hypothesize that the acquisition of H. axyridis as a host by H. virescens, C. hippodamiae and Parasitylenchus spp. may have further consequences for the abundance and distribution of these parasites, including the expansion of their ranges to other continents colonized by invasive populations of this ladybird and areas in Asia where H. axyridis is native., Piotr Ceryngier, Kamila Twardowska., and Seznam literatury
Heteroptera caught during day and night sampling at a height of 200 m above ground at Cardington, Bedfordshire, UK, during eight summers (1999, 2000, and 2002–2007) were compared to high-altitude catches made over the UK and North Sea from the 1930s to the 1950s. The height of these captures indicates that individuals were engaged in windborne migration over distances of at least several kilometres and probably tens of kilometres. This conclusion is generally supported by what is known of the species’ ecologies, which reflect the view that the level of dispersiveness is associated with the exploitation of temporary habitats or resources. The seasonal timing of the heteropteran migrations is interpreted in terms of the breeding/overwintering cycles of the species concerned., Don R. Reynolds, Bernard S. Nau, Jason W. Chapman., and Obsahuje seznam literatury
Seven polymorphic microsatellite loci were developed for the planthopper Hyalesthes obsoletus, vector of stolbur 16SrXII-A phytoplasma. The loci have di- or trinucleotide repeat motifs and are highly variable with 10 to 22 alleles per locus. Observed heterozygosity ranged from 0.278 to 0.950 for the 78 individuals genotyped. One locus is sex-linked. No linkage between loci was found. All loci amplified consistently among phylogeographic as well as host-plant related samples and proved highly informative for population genetic studies. and Miriam IMO, Julia LÜNEBURG, Thomas HANKELN, Alfred SEITZ, Jes JOHANNESEN.
The influence of host intrapatch spatial distribution on parasitoid host acceptance behavior was investigated with Trichogramma principium parasitizing eggs of grain moth, Sitotroga cerealella. Single females were placed in Petri dishes, each containing 60 host eggs arranged either as a compact patch or partitioned into 60 or 12 clusters each consisting of 1 or 5 eggs, respectively. Partitioned patches provoked parasitization more often than compact patches. The percentage of ovipositing females (i.e., females parasitizing at least one of 60 host eggs) increased with the number of clusters, while it was independent of the intercluster distance over intervals of 2.5-15 mm. The mean number of eggs parasitized by ovipositing females during 48 h was almost independent of the host egg spatial pattern. As a result, the rate of parasitization was higher when the hosts were sparsely distributed within a patch than when they were aggregated., Nataliya D. Voinovich, Taisiya Ya. Umarova, Sergey Ya. Reznik, and Lit
The use of species distribution models (SDMs) to predict the spatial occurrence and abundance of species in relation to environmental predictors has been debated in terms of species’ ecology and biogeography. The predictive power of these models is well recognized for vertebrates, but has not yet been tested for invertebrates. In this study, we aim to assess the use of SDMs for predicting local abundances of invertebrates at a macroscale level. A maximum entropy algorithm was used to build SDMs based on occurrence records of 61 species of butterflies and bioclimatic information with a 30 arc second resolution. Predictions of habitat suitability were correlated with butterfly abundance data derived from independently conducted field surveys in order to check for a relationship between the predictions of the model and local abundances. Even though the model accurately described the current distributions of the species in the study area at a macroscale, the observed occurrences of the species (i.e. presence/absence) recorded by the field surveys differed significantly from the model’s predictions for the corresponding grid cells. Moreover, there was no correlation between observed abundance and the model’s predictions for most species of butterflies. We conclude that the spatial abundance of butterflies cannot be predicted from environmental suitability modelled at a resolution as large as in this study. Using the finest scale bioclimatic information currently available (i.e. 30 arc seconds) it is not adequate to predict species abundances as structural and ecological factors as well as climatic patterns acting at a smaller scale are key determinants of the occurrence and abundance of invertebrates. Therefore, future studies have to account for the role of the resolution in environmental predictors when assessments of spatial abundances via SDMs will be conducted., Katharina J. Filz, Thomas Schmitt, Jan O. Engler., and Obsahuje seznam literatury
Species-level problems in the Aphis (Bursaphis) complex are reconsidered based on the partial sequences of the mitochondrial cox1 gene together with morphological and ecological data. This indicates that the American species A. oenotherae is a complex of four species (A. oenotherae, A. holoenotherae, A. costalis and A. neomexicana) and the taxonomic status of the species couples A. varians - A. manitobensis and A. epilobii - A. grossulariae require further clarification. Aphis sp. (USA: California, Oregon) of Blackman & Eastop (2006, p. 415) deserves the status of a species provided there is information on its host association and life cycle. Partial cox1 sequences might be misleading when used as standard DNA barcodes of aphid species of the subgenus Bursaphis. and Rimantas Rakauskas, Jurga Turčinavičienė, Jekaterina Bašilova.