Although Carabidae is among the best-studied families of beetles in Europe from the faunistic point of view, there is still a lack of available information on the ecological requirements of the particular carabid species. The habitat preferences that determine the distribution of species are largely influenced by habitat structure and microclimate. In addition to other factors, these habitat parameters are influenced by the nature of the vegetation. Therefore, our study investigated the influence of tree species on carabid beetle communities. We conducted the research at 9 stands in the Borova Hora Arboretum (Zvolen, Central Slovakia). Each studied site represents a monoculture of one of nine tree species. At each site, some soil and leaf litter attributes (pH, conductivity, and content of H, C, N and P) were evaluated. Ground beetles were collected by pitfall trapping during the vegetation periods in 2008–2011. In total, 3012 individuals of 29 species were obtained. Significant differences in the total dynamic activity and species richness of the carabid beetle communities among the compared forest stands were revealed. The results of the research confirmed statistically significant relationships among 1) the soil conductivity and both the richness and Shannon diversity of the ground beetle communities, 2) the litter and soil N content and richness, the Shannon diversity and the species composition of the ground beetle communities. The Shannon diversity and richness were negatively related to the soil conductivity and positively related with the N content. Our research showed that dominant tree species indirectly influence diversity and composition of carabid communities via the soil properties.

Influence of tree species and soil properties on ground beetle (Coleoptera: Carabidae) communities

Morphological variability is the result of interaction between genetic diversity of the population and environmental selection. Despite the large number of studies of morphological variability of ground beetles, there is very little research dedicated to influence of environmental factors on it. This article discusses the influence of natural and anthropogenic factors on the variability of Bembidion minimum (Fabricius, 1792). B. minimum is a West Palearctic species which is distributed in North Africa, Europe, Western Asia. It is a macropterous species that lives in humid biotopes along the shores of seas, rivers and standing water bodies. 410 specimens were collected from 12 ecosystems differing by plant cover, degree of litter development, mechanical composition of the soil, mineralization and acidity of soil solution, type and intensity of anthropogenic impact. 13 linear characteristics, one angular characteristic, density of elytra puncturing and contrast of spots on the beetles’ elytra were measured. Additionally 6 morphometric indices were calculated. More than a third of the variability of imagoes in the studied populations was found to be determined by the general body size. Sexual dimorphism was observed on all linear parameters and most morphometric indices. Females do not differ from males in the back angles of the prothorax. Natural and anthropogenic factors to a greater or lesser degree were shown to affect the morphological variability of B. minimum: soil acidity and mineralization have the greatest impact. The soil acidity causes significant variability of most linear parameters; mineralization – body length, head length, prothorax length and width, elytra width. Plant cover and mechanical composition of the soil have a slight impact on imago morphology. The type and structure of vegetation significantly affect head width, prothorax length and width, and the mechanical composition of the soil – body length and head length. Degree of litter development does not cause significant changes in the linear dimensions of beetles. With thickening of the litter the posterior spots on the elytra become brighter, they have sharper contours, and density of elytra puncturing also changes. The mean value of the back angles is affected by the herb layer of meadow vegetation, soil mineralization and acidity. The variability of morphometric indexes under the influence of natural factors was found to be lower than variability of linear characteristics. The recreational load and cattle grazing cause similar changes in linear measurements and morphometric indexes of B. minimum. With escalation of these factors, the body length, length and width of elytra of both females and males decrease. Assessing the natural morphological variability of populations in ecosystems whose environmental factors are within extreme and sub-extreme values for a given population is a promising direction of research in modern ecology.

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Morphological variability of Bembidion minimum (Coleoptera, Carabidae) populations under the influence of natural and anthropogenic factors

Rearing tiger beetles in the laboratory [Cicindelidae, for ecological and behavioural studies]

The impact of salinity on a saline water insect: Contrasting survival and energy budget

Abstract This article discusses the effect of soil salinity on the variability of Bembidion (Notaphus) varium (Oliver, 1795). The authors of the article collected imagoes of this species in five ecosystems that differed in soil salinity; 13 linear characteristics, one angular characteristic and 6 morphometric indices were measured. Significant changes in six linear parameters of B. varium (body length, head length and width, width of prothorax between front angles, maximum width of prothorax and elytra width) and two morphometric indices are observed in the considered ecosystems. Soil salinity probably has the most impact on the variability of these characteristics. However, the influence of other important natural and anthropogenic factors is not ruled out. Significant differences between the sexes are observed for all linear parameters: females of B. varium are larger than males. There are no differences between males and females in morphometric indices. The head width, prothorax length and width, elytra length and width depend on the body length of B. varium individuals. The morphological variability of B. varium under the influence of other environmental factors needs further research.

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Morphological variability of Bembidion varium (Coleoptera, Carabidae) in gradient of soil salinity

Effective rearing methods are needed to recover the federally endangered Salt Creek tiger beetle, Cicindela (Ellipsoptera) nevadica lincolniana Casey, a subspecies that occurs exclusively in saline wetlands and seeps along Little Salt Creek in Lancaster County, Nebraska. Experiments were initiated to determine soil type and salinity concentrations appropriate for stimulating female oviposition in laboratory settings to produce larvae and/or adults for reintroduction to native habitats. In 2013, there were highly significant differences between native soil and a sand/loess soil mixture, but no differences between two salinity levels, 0.354 M and 0.5 M. In 2014, using only a sand/loess soil mixture, there were again no differences between the test salinity levels. A sand/loess soil mixture of either 0.354 M or 0.5 M salinity was determined to be optimum for egg production.

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Determining Optimum Soil Type and Salinity for Rearing the Federally Endangered Salt Creek Tiger Beetle, Cicindela (Ellipsoptera) nevadica lincolniana Casey (Coleoptera: Carabidae: Cicindelinae)

Aimee M. Johns

Papers

Determining Optimum Soil Type and Salinity for Rearing the Federally Endangered Salt Creek Tiger Beetle, Cicindela (Ellipsoptera) nevadica lincolniana Casey (Coleoptera: Carabidae: Cicindelinae)