Využitie repelentov na ochranu proti kukuričiarovi koreňovému (Diabrotica virgifera virgifera LeConte, 1868)

The aim of the study was to find the level of repellent effect of two chemical substances (DEET and 2-Undecanone) and two essential oils (from Allium sativum and Eucalyptus oil) on the Western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, 1868 in field conditions. Repellents were used in the area of 5 x 4 meters with four replications. They were applied as a solution of 700 μl chemical/essential oil in one litter of water. TWEEN 80 was used as a surfactant. After 24 and 48 hours, the repellent effect was checked by visual observation. After 24 hours, yellow sticky traps were installed in each plot and checked after the next 24 hours for the detection of the WCR adult beetles. The experiment was carried out during two years (2019 and 2020) in a maize field in Mojmírovce (48.199284°N, 18.038637°E), Slovakia. The results showed significant repellent effect of chemicals DEET and 2-Undecanone on WCR adults. After 48 hours the number of beetles per plant was significantly higher compared to the control for both DEET and 2-Undecamone. This was confirmed by yellow sticky traps in 2020, but not in 2019, probably due to the lower catching of WCR adults. The results indicate that repellent substances can influence the number of the WCR adults in maize fields.Cieľom práce bolo zistiť hladinu repelentného účinku dvoch chemických látok DEET, 2-Undecanone a esenciálnych olejov z Allium sativum a eukalyptového oleja na kukurici siatej proti kukuričiarovi koreňovému (WCR), Diabrotica virgiera virgifera LeConte, 1868 v poľných podmienkach. Repelenty boli použité na ploche 5 x 4 metre so štyrmi opakovaniami. Aplikovali sa ako roztok 700 μl chemického/esenciálneho oleja v jednom diely vody. Ako rozpúšťadlo sa použil TWEEN 80. Po 24 a 48 hodinách sa repelentný účinok skontroloval vizuálnym pozorovaním. Po 48 hodinách sa na detekciu výskytu dospelých chrobákov použili žlté lapače. Pokus sa uskutočnil v dvoch termínoch na kukuričnom poli v Mojmírovciach (48.199284°N, 18.038637°E) na Slovensku. Naše výsledky ukázali, že preukazný účinok chemikálií DEET a 2-Undekanone na imága kukuričiara koreňového. Po 48 hodinách bol počet imág v obidvoch prípadoch preukazne nižší ako v kontrolnom variante. Toto sa potvrdilo pri použití žltých lepových lapačov v roku 2020, ale nie v roku 2019 pravdepodobne z dôvodu nižšieho počtu nachytaných imág. Výsledky naznačujú, že repelentné látky môžu ovplyvniť početnosť imág kukuričiara koreňového na kukuričnom poli

THE INFLUENCE OF ULTRAVIOLET LIGHT ON PATHOGENICITY OF ENTOMOPATHOGENIC FUNGUS BEAUVERIA BASSIANA (BALSAMO) VUILLEMIN TO THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS HBN. (LEPIDOPTERA: CRAMBIDAE)

The influence of different doses of ultraviolet (UV) light on the pathogenicity of entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin to the European corn borer, Ostrinia nubilalis Hbn., and radial growth of fungus was studied in laboratory conditions. The suspensions of B. bassiana isolate SK99 were exposed to UV light. Four different doses of UV light were used in the experiment. The distance between exposed suspensions and UV light source was 0.3 m. Exposure duration was 15, 30, 45 and 60 minutes (as A, B, C and D variants). Control variant SK99 and obtained variants SK99A, SK99B, SK99C and SK99D were cultivated 21 days on Sabourard-dextrose agar. The larvae of O. nubilalis were infected with dry powder consisted of mycelia and spores from fungus cultures. During 10 days, the mortality of infected larvae was evaluated. It was ascertained that UV light exposition significantly influenced the mortality effect of B. bassiana isolates to O. nubilalis larvae. Variant SK99C showed the highest level of infectivity. Radial growth of UV variants was slower with rising time of exposure. The best ability to grow possessed non-irradiated isolate SK99 and the worse variant SK99D. The difference between these two variants was significant

BIOLOGICKÉ VLASTNOSTI SLOVENSKÝCH IZOLÁTOV ENTOMOPATOGÉNNEJ HUBY PANDORA NEOAPHIDIS (REMAUDIÈRE ET HENNEBERT) HUMBER (ZYGOMYCETES, ENTOMOPHTHORALES)

Intraspecific variability of biological characteristics within entomopathogenic fungus Pandora neoaphidis was evaluated. Fifteen isolates of the fungus were obtained from 5 aphid species in Slovakia. Size of conidia, conidial germination, virulence, radial growth, and biomass production were evaluated. Conidial size varied considerably with exception of isolates originating from the same host population. Conidial germination was observed on all the surfaces tested and it was greatest at saturated humidity. Virulence, daily rate of radial growth and biomass production varied depending on isolates. Isolates obtained from the same host colonies during fungal epizootics shoved also significant differences in the characteristics, what may suggest that epizootics in aphid populations are caused by associations of strains and not by prevalence of a single virulent strain.V práci sa hodnotila vnútrodruhová variabilita biologických vlastností entomopatogénnej huby Pandora neoaphidis. Hodnotilo sa 15 izolátov získaných z 5 druhov vošiek. Posudzovali sa nasledovné vlastnosti: veľkosť a klíčivosť konídií, virulencia, radiálny rast a produkcia biomasy izolátov. Zistili sa preukazné rozdiely vo veľkosti konídií, s výnimkou izolátov získaných z vošiek pochádzajúcich z rovnakých populácií. Konídie klíčili na všetkých hodnotených povrchoch, najvyššia klíčivosť bola pri 100% relatívnej vlhkosti. Virulencia izolátov, denná rýchlosť rastu a produkcia biomasy varírovala v závislosti od izolátu. Izoláty, ktoré boli získané z rovnakých kolónií vošiek počas epizoócií patogéna preukázali tiež významné rozdiely v hodnotených vlastnostiach. Toto poukazuje na skutočnosť, že epizoócie v populáciách vošiek sú vyvolávané asociáciou viacerých a nie prevalenciou jedného virulentného kmeňa patogéna

BIOLOGICAL CHARACTERISTICS OF SLOVAK ISOLATES OF ENTOMOPATHOGENIC FUNGUS PANDORA NEOAPHIDIS (REMAUDIÈRE ET HENNEBERT) HUMBER (ZYGOMYCETES, ENTOMOPHTHORALES)

Intraspecific variability of biological characteristics within entomopathogenic fungus Pandora neoaphidis was evaluated. Fifteen isolates of the fungus were obtained from 5 aphid species in Slovakia. Size of conidia, conidial germination, virulence, radial growth, and biomass production were evaluated. Conidial size varied considerably with exception of isolates originating from the same host population. Conidial germination was observed on all the surfaces tested and it was greatest at saturated humidity. Virulence, daily rate of radial growth and biomass production varied depending on isolates. Isolates obtained from the same host colonies during fungal epizootics shoved also significant differences in the characteristics, what may suggest that epizootics in aphid populations are caused by associations of strains and not by prevalence of a single virulent strain

First records of Melanagromyza cuscutae Hering, 1958 (Diptera: Agromyzidae) from Slovakia and its new host plant

The occurrence of Melanagromyza cuscutae Hering was observed in the agroecosystems of Slovakia. These findings were the first records of the species in Slovakia. Four dodder species were recorded at Slovakian cropland during the study. From those, Cuscuta europaea, C. lupuliformis and C. campestris served as hosts for M. cuscutae. There was no infestation of C. epitkymum. Larvae fed within flower heads of C. europaea and C. lupuliformis but within the stems of C. campestris, where gall formation occurred. C. campestris was recorded as a host of M. cuscutae for the first time

The laboratory estimation of essential oils as biological methods against black cherry aphids M. cerasi

Received: March 19th, 2023 ; Accepted: September 21st, 2023 ; Published: October 20th, 2023 ; Correspondence: [email protected]' essential oils play a considerable role in the plant integrated protection systems against harmful insects. Therefore the aim of our study was to find the potential repellency and toxicity effects of essential oils (EOs) from Allium sativum L., Ocimum basilicum L., Lavandula angustifolia Mill, Eucalyptus globulus, Labill and Curcuma longa L., and two chemical substances DEET (N, N-diethyl-3-methylbenzamide) and 2-Undecanone on the black cherry aphids Myzus cerasi. Repellent peculiarities were evaluated at five different concentrations: 0.3%, 0.6%, 0.9%, 1.2% and 1.5%, with 4 replications at the interim of 15 and 30 minutes for an olfactometer test and mortality was evaluated after 2, 6 and 24 hours for insecticidal activity test. The repellent index was most influenced by the concentration of essential oil; the percentage of influence was 64%. At the same time, the highest repellency index 95% was achieved at a concentration of 1.5% when using essential oils of A. sativum and E. globulus, as well as when using 2-Undecanone within 30 minutes of waiting. A contact toxicity (mortality) test in Petri dishes showed efficacy for all tested oils and chemicals after a 6-hour treatment period. The lowest concentration that ensured 100% insect mortality was 0.9% when using E. globulus essential oil. The lowest lethal concentration (LC50) value of 0.00240 mL/10 mL was obtained with O. basilicum oil and the lowest LC98 value of 0.28209 mL/10 mL was obtained with E. globulus oil after a 6-hour treatment period

Vývin kukuričiara koreňového Diabrotica virgifera virgifera v pôde

Monitoring of developmental stages of the Western corn rootworm (WCR) (Diabrotica virgifera virgifera) is an important aspect of its control. In the experiment there were analysed randomly selected plants of maize on six localities in western Slovakia, in the years 2008-2010 a 2014-2015. The aim of the study was to identify exact time of the emergence of the WCR adults in the consequence of different years and different localities and to find the best date for their eradication. The most of the WCR individuals at the northern locality were observed on 29 June and the first adults were found on 07 June, during colder year 2006. The development started about nine days earlier in the next year in southern Slovakia, because of extremely hot weather. The population of pest increased slower in 2008 than in previous years, and the highest appearance was monitored up-to 02 July. The first adults were monitored on 27 June in the years 2009-2010 as well as 2014-2015. Generally, the highest numbers of the first instar larvae were observed on 22 June at the locality Čiližská Radvaň. The second instar larvae and the most of adults was found on 20 June in Sokolce. On 29 June it was monitored the largest amount of the third instar larvae at the locality Čiližská Radvaň. The differences in the time of the emergence of adults depended on the year. Based on the monitoring in Slovakia, it can be expected the third instar larvae from second decade of June and the first adults in the last decade of June and in the first decade of July.Monitorovanie vývinových štádií kukuričiara koreňového je dôležitým aspektom jeho regulácie. V experimente boli analyzované náhodne vybrané rastliny kukurice na šiestich vybraných lokalitách Západného Slovenska, v rokoch 2008-2010 a 2014-2015. Cieľom tejto štúdie bolo určiť presný čas výskytu dospelých jedincov kukuričiara koreňového (Diabrotica virgifera virgifera) v dôsledku vplyvu ročníka a rôznych lokalít a nájsť najlepší dátum pre ich reguláciu. Počas chladnejšieho roku 2006 bolo v severnejšej lokalite najviac jedincov detekovaných 29. júna, a prvé imágo bolo pozorované 7. júla. O rok neskôr sa vývin na juhu Západného Slovenska vplyvom extrémne teplého počasia uskutočnil o 9 dní skôr. Nárast populácie škodcu bol v roku 2008 menší ako v predchádzajúcich rokoch, a maximálny počet imág bol zaznamenaný až 2. júla. Prvé imága v rokoch 2009-2010 a taktiež 2014-2015 boli pozorované 27. júna. Všeobecne, najvyšší počet lariev prvého instaru bol pozorovaný 22. júna v Čiližskej Radvani. Druhý instar lariev a najviac imág bolo sledovaných 20. júna v Sokolciach. Dňa 29. júna bolo monitorované najväčšie množstvo lariev tretieho instaru na lokalite Čiližská Radvaň. Rozdielnosť v čase výskytu imág ovplyvňoval ročník. Na základe monitoringu môžeme na Slovensku očakávať larvy tretieho instaru od druhej dekády júna, a prvé imága v poslednej dekáde júna a v prvej dekáde júla

A Design and Development of a Universal Power Supply for Laptops in Contemporary Motor Vehicles

Táto práca sa zaoberá návrhom a zhotovením napájacieho zdroja s nastaviteľným výstupným napätím v rozsahu 15 až 30 V, ktorého hlavnou časťou je DC/DC menič, pracujúci v topológii buck-boost. Práca sa venuje výberu vhodného riadiaceho obvodu DC/DC meniča a výpočtu potrebných hodnôt externých súčiastok. Navrhnutý menič je vybavený ochranou voči prepätiu, reverznej polarite vstupného napätia a ochranou voči skratu. Menič je doplnený mikrokontrolérom, displejom a rotačným enkodérom, ktoré umožňujú jednoduché ovládanie zariadenia. V závere sa práca venuje porovnaniu dosiahnutých parametrov v simulácii a v praxi.This thesis deals with design of DC power supply with adjustable output voltage in range of 15 to 30 V, working in buck-boost topology. Thesis explains selection of buck-boost controller integrated circuit and calculation of values of external components. Designed converter is supplied with overvoltage, overcurrent, and reverse voltage protection circuit. Final circuit is equipped with microcontroller, display, and rotary encoder, which make it easily operable. Further, there are compared parameters of the device achieved in simulation and in practice.

Construction design of one purpose face milling machine

V úvodných kapitolách opisuje bakalárska práca široké spektrum možností pri výbere komponentov vo fáze návrhu CNC stroja, či už z hobby alebo profesionálnej oblasti. Následne uvádza 3 koncepčné varianty kinematického usporiadania a niekoľko relevantných kritérií, na základe ktorých bude zvolený ten najvhodnejší. S využitím nadobudnutých poznatkov je v praktickej časti popísaný výber jednotlivých súčastí stroja, doplnený základnými technickými výpočtami.In introduction chapters of the bachelor's thesis there is described a wide range of options for components selection in the design phase of a CNC machine, from a hobby or a professional field. Subsequently, there are introduced 3 conceptual variants of the kinematic arrangement and several relevant criteria, on the basis of which the most suitable one will be chosen. By using the acquired knowledge, in the practical part there is described the process of machine´s individual parts selection, supplemented by the basic technical calculations.