Abiotic and biotic factors determine success or failure of individual organisms, populations and species. The early life stages are often the most vulnerable to heavy mortality due to environmental conditions. The deer ked (Lipoptena cervi Linnaeus, 1758) is an invasive insect ectoparasite of cervids that spends an important period of the life cycle outside host as immobile pupa. During winter, dark-coloured pupae drop off the host onto the snow, where they are exposed to environmental temperature variation and predation as long as the new snowfall provides shelter against these mortality factors. The other possible option is to passively sink into the snow, which is aided by morphology of pupae. Here, we experimentally studied passive snow sinking capacity of pupae of L. cervi. We show that pupae have a notable passive snow sinking capacity, which is the most likely explained by pupal morphology enabling solar energy absorption and pupal weight. The present results can be used when planning future studies and when evaluating possible predation risk and overall survival of this invasive ectoparasite species in changing environmental conditions., Sirpa Kaunisto, Hannu Ylönen, Raine Kortet., and Obsahuje bibliografii
Using a large sample of museum and newly collected specimens of the cryptic butterfly species Leptidea sinapis and L. reali, identified/confirmed based on genital characters, the patterns in their geographical distributions, historical changes in range and briefly also their habitat associations in Poland, were investigated. Leptidea sinapis occurs mainly in the lowland and upland parts of the country and is rarer than L. reali, which is widespread throughout Poland, including the mountains. In the first half of the 20th century, the range of L. sinapis included the whole of Poland, whereas currently it is confined to eastern and southern regions. Historical records of the distribution of L. reali are concentrated in southern and central Poland. Currently it is recorded from localities throughout Poland. Leptidea reali is recorded most frequently in meadows and shows no clear preference for a particular level of humidity, while L. sinapis is found mainly in woodland and xerothermic habitats. The two species are syntopic within the present range of L. sinapis, which is now a declining and local species, whereas L. reali is now common and widespread. and Konrad Sachanowicz, Agnieszka Wower, Jaroslaw Buszko.
In this study we analyzed the inter-specific relationships in assemblages of syrphids at a site in northern Italy in order to determine whether there are patterns in diurnal co-occurrence. We adopted a null model approach and calculated two co-occurrence metrics, the C-score and variance ratio (V-ratio), both for the total catch and of the morning (8:00–13:00) and afternoon (13:00–18:00) catches separately, and for males and females. We recorded discordant species richness, abundance and co-occurrence patterns in the samples collected. Higher species richness and abundance were recorded in the morning, when the assemblage had an aggregated structure, which agrees with previous findings on communities of invertebrate primary consumers. A segregated pattern of co-occurrence was recorded in the afternoon, when fewer species and individuals were collected. The pattern recorded is likely to be caused by a number of factors, such as a greater availability of food in the morning, prevalence of hot and dry conditions in the early afternoon, which are unfavourable for hoverflies, and possibly competition with other pollinators. Our results indicate that restricting community studies to a particular time of day will result in certain species and/or species interactions not being recorded., Manuela D´Amen ... [et al.]., and Obsahuje seznam literatury
Fleas infecting northern white-breasted hedgehogs, Erinaceus roumanicus (Barrett-Hamilton), collected from 2009-2011 in Budapest (Hungary) were studied. A total of 305 white-breasted hedgehogs were captured and 1,251 fleas were collected. The flea community comprised two species, the hedgehog flea Archaeopsylla erinacei (Bouche, 1835) and the dog flea Ctenocephalides canis (Curtis, 1826), although the latter was only found on three hedgehogs. Fleas were found on half of the host specimens (51%; n = 156) where their distribution was strongly aggregated. The sex ratio of A. erinacei was biased towards females and was correlated with host size. Interestingly, the sex ratio of fleas became more equal on heavier hosts. It had been expected that, under high competition, the sex ratio would be female biased because it is known that female ectoparasites dominate on poorer hosts. The body size of a random sample of 200 fleas (100 female and 100 male) was measured under a microscope. The analyses showed directional asymmetry in two features - the distance between the top of the head and the eye, and head length. In this two body traits the left side was significantly greater than right side in both sexes of A. erinacei. Our data shed light on the complex nature of the flea population infecting northern white-breasted hedgehogs in an urban area., Krzysztof Dudek, Gábor Földvári, Viktória Majláthová, Igor Majláth, Krisztina Rigó, Viktor Molnár, Mária Tóth, Łukasz Jankowiak, Piotr Tryjanowski., and Obsahuje bibliografii
1_Urbanisation is an important cause of species extinctions. Although urban water systems are also highly modified, studies on aquatic or semi-aquatic organisms are rare. The aim of this study is to identify the factors that determine species richness of Odonata in 22 Central European cities and along an urban-rural gradient within six of them. With 64 indigenous species in total and an average of 33 species per city, the species richness of Odonata in Central European cities is comparatively high. A generalised linear model indicates that species richness is positively related to city area. Additional predictors are climatic variables (temperature amplitude, sunshine duration and July temperature) and the year last studied. Since most cities are usually located in areas with naturally high habitat heterogeneity, we assume that cities should be naturally rich in dragonflies. The role of city area as a surrogate for habitat and structural richness most likely explains why it is strongly associated with Odonata species richness. The relationship between species richness and the climatic variables probably reflects that Odonata species richness in Central Europe is limited by warm and sunny conditions more than by availability of water. The temporal effect (the year last studied) on species richness is likely to be a consequence of the recent increase in Mediterranean species associated with global warming. Urbanisation clearly has an adverse effect on the species diversity of Odonata. Species richness increases along a gradient from the centre of a city to the rural area and is significantly highest in rural areas. This pattern probably reflects a gradient of increasing habitat quality from the centre of cities to rural areas. Moreover, the number of water bodies is generally very low in the city centres., 2_Based on our results, we make recommendations for increasing the abundance and number of species of dragonflies in cities., Christoph Willigalla, Thomas Farmann., and Obsahuje seznam literatury
We conducted a molecular phylogenetic analysis based on mitochondrial cytochrome oxidase subunit I and nuclear 28S rRNA gene sequences of species of Japanese elmids (23 species from 12 genera) and examined the hind-wings of 24 species in order to determine the incidence of hind-wing degeneration among species and the presence of dimorphic species with respect to hind-wing degeneration. Based on the molecular phylogenetic analysis, we determined that the previously separated winged and wingless species, Stenelmis vulgaris and S. miyamotoi, and Leptelmis gracilis and L. parallela, are two forms of the same species. Of the 24 species whose hind wings were studied, we found apterous (3 species of Zaitzeviaria), brachypterous (2 species of each of Optioservus and Paramacronychus) and dimorphic species (2 species as above) in separate clades of the phylogeny. These were the smallest or medium-sized species. Dimorphic species occurred in mid- to downstream areas and used reeds and wood as substrates. The percentage of species with hind-wing degeneration (wingless or dimorphic) was high among the species (29%) studied compared to the perceived percentage for temperate beetles (<10%). Thus, we found that the degeneration of hind wings has occurred repeatedly in these elmid species. However, we identified only ambiguous habitat and life history correlates of hind-wing degeneration, and the adaptive significance of hind-wing degeneration in these species of elmids remains unclear., Masakazu Hayashi, Simon D. Song, Teiji Sota., and Obsahuje seznam literatury