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ŠUMARSKI LIST 3-4/2015 str. 68     <-- 68 -->        PDF

in set-up of a large number of pheromone traps in large clear cuts, but it was not widely used.
An alternative set-up approach, known as a "barrier system” was first tested in the Slovak High Tatra National Park and later in the Czech Republic’s Šumava National Park by Jakuš (1998); Jakuš and Blaženec (2003); Jakuš and Šimko (2000). This system was based on the installation of long lines (occasionally many kilometres) of pheromone traps with shorter distances between them and sometimes superimposed into more lines in relation to the distance from the stand wall.
The aim of our work is to establish if there is a more effective system for the set-up of pheromone traps than the current standard set-up along stand walls, to be measured both by the total number of captured beetles and the time required to install/check the traps and any resulting economic savings.
Materials and methods
Materijali i metode
Study area – Područje istraživanja
The study was carried out in 2009 and 2010 in the Boletice military area of the Arnoštov forest district in the Šumava Mountains, the Czech Republic. According to the Climate Atlas of Czechoslovakia (1958) experimental areas are situated in climatic zones: B – moderately warm. The July average temperature above 15 ° C., the average annual temperature is 5.6 ° C, in the growing season 10.4 ° C. The average annual rainfall 700–800 mm, in the growing season 500 mm. The average length of growing period 100–125 days. Soils oligotrophic to mesotrophic (Cambisol with transitions to Ranker soil type, sometimes with gleying). Sandy with different ratio of skeletal fraction. In the forest stands around clearings spruce representation 85–95%, age 115–135 years, altitude 920–1020 m a. s. l. It is an area with a naturally high occurrence of spruce bark beetles, with the number of beetles having risen even further since hurricane Kyrill in 2007. Trappings increased to hundreds of thousands in this forest district.
Trapping systems – Lovni sustavi feromonskih klopki
Nine “Theysohn” (producer THEYSOHN Kunststoff GmbH, Germany) type pheromone traps with FeSex Typo (2-methyl-3-buten-2-ol 95,5-96,8 %; [S]-cis-verbenol 3,2-4,5 %; ipsdienol 0,3–0,4 %; producer Ubik Karel) pheromone dispensers were used in each research plot. There were 8 research plots within 1 km of each other at a height of 950 m a. s. l. Four different pheromone trap set-up systems were compared, each in 2 repetitions. The first (A1) followed the traditional system according to Czech technical standard ON 48 2711 (Zahradník et al. 1988) with pheromone baited-traps set approximately 15 m from forest edge that were placed approximately 20 m apart. The second system (A2) was comprised of pheromone-baited traps set in the middle of the clear cut area with no separation between them. Each trap was baited (a total of 9 dispensers in 9 traps). The third system (A3) was the same as A2, but the pheromone dispensers were only placed at every second trap starting with the 1st (a total of 5 dispensers in 9 traps). The fourth system (A4) was the same as A2 and A3, but the dispensers were only placed in the middle and 2 outside traps (a total of 3 dispensers in 9 traps). Every system was repeated twice (Figure 1).
The pheromone-baited traps were emptied weekly. Beetles were counted individually when fewer were captured and a graduated measuring-glass was used to calculate the number of higher quantities of beetles, with 1 ml considered to be 35 beetles (Zahradník 2006). Before measuring larger quantities of beetles, contaminations such as other beetle species and organic matter like needle debris were removed.
During all of the tests, insect invasion of forest edge was visually checked and no infestation was found.
Statistical analysis – Statistička analiza
ANOVA tests were conducted using QC.Expert statistical software with location as the first factor and the system of trap set-up as the second factor. A second ANOVA tested the statistical significance of pheromone baited and unbaited traps. All tests were carried out at a 95% confidence level.
The efficacy (%) of a particular trapping system was tested. The traditional system (A1) of trapping I. typographus was chosen as the standard (efficacy 100 %).