Andrej Gubka

First record of Entomophaga maimaiga (Entomophthorales: Entomophthoraceae) in Slovakia

The entomopathogenic fungus Entomophaga maimaiga was found for the first time in Slovakia in 2013. Late instar larvae of gypsy moth, Lymantria dispar, from two sites with different population densities were dissected to evaluate the presence of pathogens. The presence of conidia and resting spores of E. maimaiga in gypsy moth cadavers was confirmed from both sites.

Attraction of ambrosia beetles to ethanol baited traps in a Slovakian oak forest

The attractiveness of ultra high release ethanol lures to ambrosia beetles in Slovakian oak forests was tested from 2010 to 2012. A total of 24,705 specimens were captured during this three year period with Xyleborinus saxesenii (Ratzeburg, 1837) representing 49.28% (12,174 specimens) of the total. Other dominant species captured in the traps were Anisandrus dispar (F., 1792) (27.84%), Xyleborus monographus (F., 1792) (9.72%) and Trypodendron signatum (F., 1792) (6.04%). During this experiment, Xylosandrus germanus (Blandford, 1894) was detected for the first time in Slovakia with an increase in capture each year (19, 40 and 77 specimens, respectively). Flight period for ambrosia beetles in Slovakia occurs from the beginning of April through the end of September. This is the first time that ethanol baited traps were deployed in Slovakian oak forests and the lures were an effective tool for monitoring native and non-native ambrosia beetles.

Salvage felling in the Slovak forests in the period 2004–2013

Abstract Salvage felling is one of the indicators of the forest health quality and stability. Most of the European Union countries monitor forest harmful agents, which account for salvage felling, in order to see trends or functionality between factors and to be able to predict their development. The systematic evidence of forest harmful agents and volume of salvage felling in Slovakia started at the Forest Research Institute in Zvolen in 1960. The paper focuses on the occurrence of the most relevant harmful agents and volume of salvage felling in the Slovak forests over the last decade. Within the 10 years period (2004–2013) salvage felling in Slovakia reached 42.31 mil. m3 of wood, which was 53.2% of the total felling. Wind and European spruce bark beetle Ips typographus damaged 78.4% of salvage wood, i.e. they were the most important pest agents. Norway spruce (Picea abies) was the most frequently damaged tree species that represented the amount of 35.6 mil. m3 of wood (81.2% of total volume of salvage felling). As Norway spruce grows mostly in mountains, these regions of Central and Northern Slovakia were most affected. At the damaged localities new forests were prevailingly established with regard to suitable ecological conditions for trees, climate change scenarios and if possible, natural regeneration has been preferred. These approaches in forest stand regeneration together with silvicultural and control measures are assumed to gradually decrease the amount of salvage felling over long term perspective.

Influence of selected factors on bark beetle outbreak dynamics in the Western Carpathians

Abstract In the period from 1992 to 2013, more than 3.8 million m3 of spruce wood from an area of 55 thousand ha of forests in the Kysuce region (Western Carpathians) was affected by bark beetles. This region has had the highest volume of salvage fellings in Slovakia. While before 1991, bark-beetle outbreak usually occurred after snow and wind disturbances, since 1992 they have occurred in the years with extremely warm and dry growing seasons and the years following them. These years were also characterised by high volumes of wood affected by honey fungus (Armillaria spp.), which only rarely took part in the calamities before 1992. Extreme deterioration of the situation occurred after 2003. In fragmented and sparse stands, the volume of wood damaged by wind increased. Artificial origin of spruce stands, their high occurrence, high age and even-agedness are likely pre-disposing factors of spruce forest decline. Bark beetles have become the most important factor of spruce decline. The most important factors driving the bark beetle attack on forest stands in the period 1973–2013 were the amount of unprocessed wood in the previous year; the amount of wood affected by honey fungus, precipitation total, and average temperature in the current growing season. Another important factor that complicated the situation was also the inferior quality of forest management.

Impact of irrigation on the gallery parameters of spruce bark beetle (Ips typographus L., Coleoptera: Curculionidae, Scolytinae)

Abstract In the spruce stand situated in Central Slovakia, a manipulation experiment was performed aimed at attracting spruce bark beetle (Ips typographus) to living and healthy spruce trees using pheromone dispensers. The goal of the experiment was to show that the galleries of the Ips typographus in the irrigated spruce trees differed in the parameters from the galleries in drought-stressed trees. Significant differences were revealed mainly in those gallery parameters that occur after the excavation of a nuptial chamber, or after the mating of parental beetles. The revealed differences prove that drought in combination with extreme temperatures significantly reduces defence reactions of spruce against the attack of Ips typographus. Water deficit together with high temperatures significantly postpone and retard the activation of defence reactions of spruce on one side, and accelerates the regeneration and the development of Ips typographus on the other side. Abstrakt V smrekovom poraste stredného Slovenska bol realizovaný manipulovaný experiment s lákaním lykožrúta smrekového (Ips typographus) pomocou feromónových odparníkov na živé a zdravé smreky. Cieľom experimentu bolo preukázať, že zavlažované smreky budú vykazovať odlišné hodnoty parametrov požerkov lykožrúta smrekového v porovnaní so suchom stresovanými smrekmi. Štatisticky významné rozdiely boli zistené predovšetkým v parametroch požerkov, ktoré vznikajú po vytvorení snubnej komôrky, resp. po párení rodičovských chrobákov. Preukázané rozdiely dokazujú, že sucho v kombinácii s extrémnymi teplotami významne oslabuje obranné reakcie smreka voči ataku lykožrúta smrekového. Vodný deficit v spojitosti s vysokými teplotami na jednej strane významne oneskoruje a spomaľuje aktivizáciu obranných reakcii smreka a na strane druhej urýchľuje rozmnožovanie a vývoj lykožrúta smrekového.

Effectiveness of pheromone traps for the European spruce bark beetle: a comparative study of four commercial products and two new models

Abstract Six types of pheromone traps were tested between 2012 and 2014 in the High Tatra Mountains, northern Slovakia. Traps were baited with lures for attracting the European spruce bark beetle (Ips typographus L.) (Coleoptera: Curculionidae, Scolytinae). Among the tested traps, four types are commercial products; Theysohn (T-trap), Ecotrap (E-trap), Lindgren funnel trap (L-trap), BEKA trap (B-trap) and two are our newly developed models; Funnel trap (P-trap) and Cross trap (K-trap). The traps were set up on ten selected sites and tested during three growing seasons (2012, 2013 and 2014). The newly developed models were compared to the commercially available models for trapping efficiency of target pest, easy to use and impact on non-target insect species. We found that the best commercially available model is the L-trap, however the bottom of L-trap is considered too shallow resulting in an accumulation of rainwater that increases the traps attractiveness for Silphids. In our experiment, the newly developed models; P-trap and K-trap performed better compared to commercially used models. P-trap caught 28% more I. typographus and K-trap caught 57% more beetles compared to T-trap in 2014. There are additional advantages of the newly developed traps such as easy handling, good rainwater drainage, higher collection container volume, and scale marking within the collection container. The results of this study have encouraged us to patent P-trap and K-trap as utility models.

POROVNANIE ODCHYTOV LYKOŽRÚTA SMREKOVÉHO (IPS TYPOGRAPHUS L.) (COLEOPTERA: SCOLYTIDAE) DO FEROMÓNOVÝCH LAPAČOV KANADSKEJ A EURÓPSKEJ PRODUKCIE

Porovnanie odchytov lykožrúta smrekového (Ips typographus L.) (Coleoptera: Scolytidae) do feromónových lapačov kanadskej a európskej produkcie Research was carried out in High Tatra and Low Tatra Mountains in 2009. It was aimed to compare the efficiency of two types of pheromone traps (Lindgren funnel trap and Theysohn trap), two types of lures (Ipslure and Pheroprax A) to control the spruce bark beetle (Ips typographus), characterize flight activity pattern of I. typographus and identify bark beetle species caught in traps. Altogether 40 traps were set up for bark beetles (16 traps in Low Tatra Mountains and 24 traps in High Tatra Mountains). Lindgren funnel traps yielded higher catches of I. typographus (by 18.2% on average) than Theysohn traps, although this was not statistically significant (p > 0.05). The traps baited with Pheroprax A caught a total of 3,833 individuals of I. typographus per trap, those baited with Ipslure 1,587 individuals per trap. In this particular case, the difference in the bark beetle catches between the two lures was statistically significant (p < 0.05). The flight pattern of I. typographus in both mountain areas was similar. It showed great decrease in abundance of flying individuals of I. typographus as a result of low temperatures in the middle of June. Flight patterns of the bark beetle in the two mountain areas were similar to those documented from other sites monitored in Slovakia over the growing season 2009. Altogether 25 bark beetle species (22 species in High Tatra Mts., 18 species in Low Tatra Mts.) and 1,066,494 individuals were caught. I. typographus was the dominant scolytid species in traps (over one million adults caught). Other important (abundant) bark beetles included Pityogenes chalcographus (15,914 adults), Xyloterus lineatus (2,008 adults), Dryocoetes autographus (308 adults), Hylastes cunicularius (421 adults), Hylurgops palliatus (227 adults), Orthotomicus laricis (77 adults), Crypturgus cinereus (76 adults), Polygraphus poligraphus (45 adults), followed by other less abundant and less important bark beetle species. Comparison of catches of the spruce bark beetle (Ips typographus L.) (Coleoptera: Scolytidae) in pheromone traps of Canadian and European production Výskum prebiehal vo Vysokých a Nízkych Tatrách v roku 2009. Jeho cieľom bolo porovnať účinnosť dvoch typov feromónových lapačov (Lindgren funnel trap a Theysohn), dvoch typov odparníkov na lákanie lykožrúta smrekového (Ips typographus) (Ipslure a Pheroprax A), zistiť priebeh rojenia I. typographus a zistiť druhové spektrum podkôrneho hmyzu v lapačoch. Celkovo bolo inštalovaných 40 lapačov (16 v Nízkych Tatrách, 24 vo Vysokých Tatrách). Lapač typu Lindgren chytil priemerne o 18,2% viac jedincov I. typographus ako lapač typu Theysohn, tento rozdiel však nebol štatisticky významný (p > 0,05). Štatisticky významný rozdiel (p < 0,05) sme zistili pri porovnaní odparníkov, keď Pheroprax A dosiahol priemerné odchyty 3,833 imág na lapač a Ipslure len 1,587 imág na lapač. Rojenie prebiehalo v oboch pohoriach podobne s výrazným poklesom v prvej polovici júna, kedy prišlo výrazné ochladenie. Priebeh rojenia sa približne zhodoval s údajmi monitoringu rojenia tohto škodcu na Slovensku. Celkom sa odchytilo a determinovalo 25 druhov podkôrneho hmyzu v celkovej početnosti 1 066 494 imág (22 druhov vo Vysokých Tatrách, 18 druhov v Nízkych Tatrách). Dominantné zastúpenie mal I. typographus (viac ako milión jedincov). Z významnejších druhov podkôrnikovitých sme determinovali Pityogenes chalcographus (15,914 jedincov), Xyloterus lineatus (2,008 jedincov), Dryocoetes autographus (308 jedincov), Hylastes cunicularius (421 jedincov), Hylurgops palliatus (227 jedincov), Orthotomicus laricis (77 jedincov), Crypturgus cinereus (76 druhov), Polygraphus poligraphus (45 jedincov). V odchytoch boli zastúpené aj ďalšie menej významné druhy.