Cereal pests among nest parasites – the story of barley thrips, Limothrips denticornis Haliday (Thysanoptera: Thripidae)

Barley thrips, Limothrips denticornis, Haliday, 1836 (Thysanoptera: Thripidae), a grass-dwelling Holarctic species represents a model example to study transport mechanisms of Thysanoptera into nests. In samples from more than 1,500 nests, barley thrips were recorded in nests of 20 vertebrate species, both birds and mammals. Applying appropriate statistics (nonparametric methods) clear clustering among nest materials and a strong relationship between presence of thrips and grass as the nest material was found. Occurrence of thrips was not associated with nest size, location or height. To validate our statistical analyses 15 wooden boxes were installed and equipped with sticky traps to record the whole year migration dynamics. Barley thrips infiltrate nests by various ways (e. g. dwelling on bark, landing from atmosphere), however most of them (88%) invade passively on nest material (grass) in spring (1st summer nesting) and autumn (winter nest building)

Dehydrogenase activity in topsoil at windthrow plots in Tatra National Park

The aim of the study was to compare the effect of windthrow treatments established after the windstorm in 2004 on the activity of enzyme dehydrogenase (DHA) in forest topsoils. We also focused on the effect of the recent windthrow (May 2014) on the DHA in topsoil. Soil samples were collected in July 2014 from four sites in the Tatra National Park: EXT - tree trunks and wood debris extracted after the windstorm in 2004, NEX - area left for self-regeneration after the windstorm in 2004, REX - tree trunks and wood debris extracted after the windstorm (May 2014), REN - Norway spruce stand set as a control plot. We measured pH, dry weight %, soil organic matter (SOM), carbon content in microbial biomass (Cblo) and DHA. Dehydrogenase activity at studied plots was the lowest at the EXT plot and the highest values were measured at the REN plot. DHA at NEX was similar to REN suggesting comparable ecological conditions at these plots comparing to EXT. Carbon content in microbial biomass at plots reflected intensity of dehydrogenase activity in sequence EXT < REX < NEX < REN

Determination of Organic Fractions and Enzymatic Activity in Forest Spruce Soil of Tatra National Park

The formation and quality of soil organic matter (SOM) highly depends on the input of organic material and microbial enzymatic activities. Soil extractions with specific nonpolar and polar extractives can be used to identify qualitative changes in SOM. The aim of this paper was to understand the correlations among microbial enzymatic activity and specific organic fractions in acidic spruce forest soil. Klason lignin (KL), acid soluble lignin (ASL), holocellulose (HC), SOM content, and potential enzymatic activity (FDA and phosphatase) was measured and analyzed. We sampled Dystric Cambisol of forest spruce stands (Picea abies) in Tatra National Park (Slovakia). The SOM fractions were determined gravimetrically based on their extractivity in nonpolar (dichloromethane (DME)) and polar (acetone (AE), ethanol (EE), water (WE)) solvents Total extractives content was 0.079% and nonpolar extractives 0.036%. The mean amount of polar extractives tented to increase in the order EE<AE<WE. The total lignin content was determined to be 1.079% and HC 0.774%. FDA negatively correlated with KL (r=-0.873 p<0.05) and DME (r=-0.913 p<0.05). Phosphatase positively correlated with WE (r=0.972 p<0.01) and KL (r=0.957 p<0.01)

Unraveling the Significance of Draglines: Female Sexual Signalization in the Nursery-Web Spider, <i>Pisaura mirabilis</i>

Chemical signals used by animals to attract the opposite sex are well known in insects, but heavily understudied in spiders. We investigated the role of chemical signals in female draglines in a gift-giving spider, Pisaura mirabilis, using combined data from behavioral tests and high-performance liquid chromatography (HPLC). We also investigated whether the quality of sexual signalization is influenced by crucial factors, such as female spider ontogeny, nutritional status, and mating status. We found that draglines of adult (versus subadult) and hungry (versus fed) females stimulated male motivation to produce nuptial gift, and highly sexually excited males invested more silk in gift production than less sexually excited males. Unexpectedly, chemical signals of eggsac-carrying females were similarly sexually attractive to draglines of adult females not carrying eggsac. HPLC identified significant chemical differences in female draglines, but these differences did not always correspond to male behavior. The integration of behavioral and chemical approaches is required to better understand animal behavior in future research

Composition of microbial PLFAs and correlations with topsoil characteristics in the rare active travertine spring-fed fen

We studied soil PLFAs composition and specific soil properties among transect of small-scale fen in Stankovany, Slovakia. The aim of this study was to determine potential differences in the microbial community structure of the fen transect and reveal correlations among PLFAs and specific soil characteristics. PCA analyses of 43 PLFAs showed a separation of the samples along the axis largely influenced by i14:0, 16:1ω5, br17:0, 10Me16:0, cy17:0, cy17:1, br18:0 and 10Me17:0. We measured a high correlation of sample scores and distance from fen edge (Kendall’s test τ = 0.857, P < 0.01). Kendall’s test showed a negative correlation of PLFAs content (mol%) and distance from the fen border for Gram (+) bacteria, Actinomycetes, mid-chain branched saturated PLFAs and total PLFAs. The redundancy analysis of the PLFA data set for the eight samples using PLFAs as species and 21 environmental variables identified soil properties significantly associated with the PLFA variables, as tested by Monte Carlo permutation showing most significant environmental variables including dichlormethan extractables, water extractables, Klason lignin, acid-soluble lignin, holocellulose, total extractables, organic matter content, total PLFA amount, bacterial PLFA and total nitrogen negatively correlated to axis 1 and dry weight and carbonate carbon positively correlated to axis 1. The amounts of Klason lignin, acid-soluble lignin, holocellulose total extractables, total PLFA, bacterial PLFA and total nitrogen were significantly correlated positively to the distance from fen border while moisture and total carbonate carbon were correlated negatively

Changes in Diversity and Structure of Thrips (Thysanoptera) Assemblages in the Spruce Forest Stands of High Tatra Mts. after a Windthrow Calamity

Strong winds, fire, and subsequent forest management impact arthropod communities. We monitored the diversity and changes in the community structure of forest thrips assemblages in the context of secondary succession and anthropogenic impact. There were eight study plots that were affected to varying degrees by the mentioned disturbances that were selected in the Central European spruce (Picea abies (L.) Karst.) forests in Slovakia. The soil photoeclectors were used to obtain thrips in the study plots during two vegetation seasons. The thrips assemblages and their attributes were analyzed by non-metric multidimensional scaling (NMDS). The significant changes in community structure, composition, stratification, species richness, and diversity of thrips assemblages that were caused by natural- (wind) and human-induced disturbance (forestry and fire) were observed in our research. Our analyses revealed a clear relationship between different thrips assemblages and impacted environment. Moreover, our results indicate that silvicolous thrips species may be useful for indicating changes and disturbances in forest ecological systems