ABSTRACT:We present the results of testing 10 pheromone dispensers used to lure the spruce bark beetle -Ips typographus (Linnaeus, 1758). A comparison was made between both their efficacy and also the decrease in their efficacy after application. Dispensers Pheagr IT and IT Ecolure Tubus are effective throughout the whole flight activity of I. typographus; the efficacy of IT Pheagr Extra was partly similar. The others are effective for a declared period of efficacy, with the exception of dispenser Pheroprax A, which initially had a very good level of catches, but soon subsided, and the efficacy did not reach either the time or the efficacy of all the declared shelf-life. Overall, the most effective dispenser was IT Ecolure Mega and dispensers IT Ecolure Tubus and FeSex Typo showed a similar efficacy. Completely unsuitable for the trapping of I. typographus were found to be combined dispensers PCHIT Etokap and PCIT Ecolure.

The incidence of salvage felling is a significant indicator of stands‘ health and stability. Health is mainly indicated by biotic and anthropogenic factors, while abiotic effects are primarily an indicator of a stand’s stability. All these factors influence each other and subsequently they can result in salvage felling. For the Czech Republic, there have been relevant data for the period since 1964. Actually, recent data cover approximately 70% of the Czech Republic´s area in the twenty-year period assessed in this text. During this period, the volume of salvage felling amounted to 89.2 million m3 which represents 28.4% of total felling in this period. The largest share is caused by abiotic effects (18.6%), next by biotic agents (9.6%) and anthropogenic are only responsible for 0.2%. In the last two years, the volume of salvage felling caused by biotic agents was higher than the volume of salvage felling caused by abiotic and anthropogenic agents for the first time. In terms of biotic agents, almost the whole volume is represented by bark beetle wood as a result of spruce stands infestation by the European spruce bark beetle – Ips typographus (L.) and double-spined bark beetle – Ips duplicatus (Sahl.), and to a small extent also by other species of bark beetles on spruce, pine and occasionally other wood tree species. In the last three years, mainly the incidence of the Ips typographus L., has concentrated in North Moravia and Silesia. Currently, it is also spreading in South Moravia and Bohemia and in districts along the state borders with Austria and Germany, with the most serious situation in this region being the one in the Bohemian-Moravian Highlands.

Pityogenes chalcographus (Linnaeus, 1758) is a significant pest of young spruce stands up to the age of about 20 years. Predation can be a significant part of decreasing its population density. The aim of the research was to determine the relationships between captured P. chalcographus and its major predator Nemosoma elongatum (Linnaeus, 1761). The research was conducted in 2006 and 2007 in five areas with the following conditions: two clear-cuts covered with freely distributed brushwood, two clear-cuts which had no brushwood remaining and the last locality was an older (more than two years older) clear-cut with no brushwood. The catches from the pheromone baited traps used to lure P. chalcographus showed a strong positive correlation between P. chalcographus and N. elongatum. Furthermore, comparisons were drawn between the N. elongatum catches from each clear-cut. The differences in the proportions of the predator N. elongatum to the trapped P. chalcographus were identified between the types of clear-cuts with the highest proportion of trapped N. elongatum in the clear-cuts with the brushwood and the lowest proportion in the clear-cuts with the removed brushwood.

Zahradníková M., Zahradník P. (2017): The influence of evaporated pheromone upon the trapping of the spruce bark beetle -Ips typographus (l.) (coleoptera: curculionidae: scolytinae) -short communication. J. for. sci., 63: 149-152. this article examines the relative efficacy of releasing a larger pheromone plume volume and the relative efficacy of the number of pheromone dispensers within baited traps in trapping the spruce bark beetle. Pheromone plume is released from a standard pheromone dispenser, and a higher volume of pheromone was provided by an increased number of pheromone dispensers. A field trial with 30 pheromone baited traps was conducted in 2013 that used three dispenser variants over ten replications. ten traps were baited with one pheromone dispenser, ten with two dispensers and ten with three dispensers. the pheromone dispensers were placed according to ePPo standard PP1/152(4) in a fully randomized design. the highest trapping was achieved by the variant using three pheromone dispensers, and the lowest trapping was achieved by the two pheromone dispenser variant. there was no statistically significant difference between the three variants. the results suggest that the efficacy of pheromone traps cannot be increased solely through an increase in the number of pheromone dispensers.

There are only two known methods for determining the sex of Ips typographus (L.) -dissection that cannot be used with live beetles and by distinguishing between the density of the hairs on the head, a less reliable method that requires experienced personnel. As a result, we have sought to find a more reliable method of sex determination for I. typographus which can be used with live specimens but is still reliable and easy to conduct. The aim of the article is to explore the inner structure in data from measurements of morphological parameters of spruce bark beetles and to find correlations which could be used for sex determination. The number of beetles in our sample was 110, all from the first trapping of one pheromone trap. The statistical methods of principal components analysis (PCA) and cluster analysis (CLU) were used to support any correlation between the sex parameter and other morphological parameters (weight, elytra length, elytra width, pronotum length, pronotum width). As no correlation was found in the case of sex, we can claim that it is not possible to determine sex according to the examined morphological parameters. However, we have found an interesting inner structure in the data and it was confirmed that even weight is slightly correlated with other morphological parameters.