Is a combination of different natural substances suitable for slug (Arion spp.) control?

In a laboratory study we investigated the contact and barrier efficacy of different natural substances (wood ash, sawdust, hydrated lime, and diatomaceous earth) against slugs of the genus Arion, an important agricultural pest. Natural substances were tested individually and in combination with each other. The experiment was carried out in plastic petri dishes and in glass insectaria. Moistened tampons and fresh leaves of lettuce were placed into both experimental arenas. The slugs were starved for 48 hours prior to the experiment. Six categories of behaviour were identified for slugs in the presence of the natural substances: (1) slug survived the experiment, (2) slug died during the experiment, (3) slug crossed the barrier, (4) slug did not cross the barrier, (5) slug fed on the lettuce, and (6) slug did not feed on the lettuce. The effect of different treatments (natural substances) was significant. The results of our study have shown that hydrated lime had the best contact efficacy on slugs (the mortality of slugs was 100%), both individually and in combination with other substances. The treatments with hydrated lime also proved to be the most efficient barrier preventing slugs from feeding on lettuce. Hydrated lime shows great potential in Arion control in our investigation; however, further research is needed to investigate the practical value (how to avoid the problem when the substance becomes wet), safety and economics of hydrated lime used in this way

The Role of Volatile Substances Emitted by Cultivated Plant\u27s Roots in Indirect Defense Against Soil Herbivores

Plants in nature have developed many defense mechanisms to defend themselves against attacks by harmful organisms; these mechanisms are indirect and direct. When attacked by a harmful organism, many plant species release volatile substances that attract natural enemies of herbivores. Volatile substances have an important role in the tritrophic system consisting of a plant, a herbivore, and its natural enemy. They function as a kind of chemical signal (semiochemical) which directly influences both harmful pests and their natural enemy. Some of these substances appear on damaged as well as undamaged plants, while other substances are released in the case of mechanic damage or feeding of a particular herbivore species. Volatile substances may repel a herbivore. Harmful pests have an important role in attracting natural enemies, as they also emit chemical signals that function as kairomones for natural enemies. In order to increase our knowledge in the field of indirect plant defense we studied chemosensation of four entomopathogenic nematode species (Steinernema, Heterorhabditis) to compounds released by insect (wireworms and grubs) damaged and undamaged potato and carrot roots, and mechanically damaged maize roots. The aim of our research was (1) to study the effect of different EPN foraging strategies (ambush, intermediate, or cruise) toward the tested volatile compounds, (2) to determine whether chemotaxis is species-specific, and (3) to assess whether the volatile compounds from damaged and undamaged roots have any behavioral effects on the EPNs studied, and (4) if volatile compounds are a part of an indirect plant defense. Our results indicate that all of the tested EPN species exhibited attraction (or repulsion) to volatiles, irrespective of their foraging strategy, and suggest that responses to distinct volatile cues are a species-specific characteristic. These results expand our knowledge of volatile compounds as cues, which may be used by EPNs to find hosts and for other aspects of navigation in soil

The effect of different entomopathogens on white grubs (Coleoptera: Scarabaeidae) in an organic hay-producing grassland

In 2011, a field block trial examined the biological control of white grubs of June beetle (Amphimallon solstitialis), margined vine chafer (Anomala dubia) and garden chafer (Phyllopertha horticola) on a permanent cut grassland in Gotenica (SE Slovenia). The efficacy of Beauveria brongniartii, Beauveria bassiana, Bacillus thuringiensis var. kurstaki and Heterorhabditis bacteriophora in the form of water suspension and infested grain was tested against a control treatment. The initial number of white grubs (April 12; 39 white grubs/m2) was reduced with all tested entomopathogens up until the third evaluation (May 26; 32 white grubs/m2). However, the studied treatments were not sufficient to reduce the white grub population in the soils below the economical threshold (20 individuals/m2). The average number of white grubs was affected mostly by the treatment where the active ingredient was B. thuringiensis var. kurstaki. With one application in April, only the abundance of overwintered white grubs was reduced. To decrease the summer generation of white grubs, an application of biological agents is also required at a later time. The 8% higher dry matter yield at the first cut (June 10) compared to the second cut (September 6) provided evidence for the prior statement

INVESTIGATION OF FORMS OF ENGINEERING CONTRACTS, CONCLUDED ON THE WORLD MARKET

This article shows the results of analysis of the forms of engineering contracts presented on the world market. EPC and EPCM contracts are singled out as the most suitable for use in the construction of oil and gas facilities due to their specific features. In the article the analysis of the selected forms is carried out with the definition of key features and differences between them, as well as the modeling of the processes that arise when these contracts are executed

Slovenski esej: kronološki uvid terminoloških rešitev

The essay is a specific genre which is beneficial for the study of literature in those areas of research literature that cannot be dealt which solely through scientific discussion. This article presents solutions for the terminological variability pertaining to the essay in Slovenian literary studies, namely, by presenting a chronological overview of published discussions that have appeared in book form – from Esej in Literarni leksikon to Miran Štuhec’s Slovenska esejistika v drugi polovici dvajsetega stoletja

DEFINITION OF THE FIELDS OF THE BEST PRACTICES OF EPC (M)-PROJECT MANAGEMENT ON THE BASIS OF THE ANALYSIS OF THE WORLD MARKET

This article presents the results obtained within the framework of the dissertation research, after the analysis of the materials of the leading foreign institutes regarding the best application/implementation of the EPC (M)-projects. Based on the results, 15 most significant areas of EPC-projects management in the world market were identified, the strengthening of which leads to significant improvement of indicators in a certain direction and implementation of the project as a whole

DEFINITION OF THE FIELDS OF THE BEST PRACTICES OF EPC (M)-PROJECT MANAGEMENT ON THE BASIS OF THE ANALYSIS OF THE WORLD MARKET

This article presents the results obtained within the framework of the dissertation research, after the analysis of the materials of the leading foreign institutes regarding the best application/implementation of the EPC (M)-projects. Based on the results, 15 most significant areas of EPC-projects management in the world market were identified, the strengthening of which leads to significant improvement of indicators in a certain direction and implementation of the project as a whole

Seasonal dynamics of three lepidopteran stored grain pests in Slovenia

In the period 2004-2006 seasonal dynamics of Mediterranean flour moth (Ephestia kuehniella), Indianmeal moth (Plodia interpunctella) and Angoumois grain moth (Sitotroga cerealella) was studied in the mills and grain warehouses in central Slovenia. For this purpose pheromone traps were used from April until December, and the males of all three lepidopteran pests were counted in two week intervals. The three insect pests under investigation developed two peaks in capture per year that might represent two distinct generations per year. In the maize open air storage Ephestia kuehniella was the most numerous, while Plodia interpunctella was more frequent in the closed storage in mills and warehouses, Sitotroga cerealella was slightly less common in these latter closed warehouses. Keywords: Monitoring, Lepidoptera, Stored grain pest, Pheromones, Sloveni