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ŠUMARSKI LIST 3-4/2021 str. 66     <-- 66 -->        PDF

(black and brown) tedders traps were more effective for Hylobius pales (Herbst) and Pachylobius picivorus (Germar) insects than yellow-colored and white-colored traps. Mizell III and Tedders (1999) stated that due to the dark color of coniferous trees’ stem, the insects damaging these trees may tend to dark traps.
Yellow colored sticky traps resembling the color of flowers are used in order to catch insect species of agricultural pests. On the other hand, light colors (white or yellow) probably resemble the color of non-host angiosperm tree trunks, which is a strong visual barrier for conifer bark beetles (Strom et al. 1999, Strom and Goyer 2001, Campbell and Borden 2009).
In this study, although there was no significant difference, dark-color traps (black, green, red) attracted more Thanasimus formicarius than light ones (yellow and white). Since black color traps are widely used today for monitoring and mass trapping of bark beetles, this result creates an undesirable situation in terms of biological control of bark beetles.
Trap installation height – Visina postavljanja klopke
Pheromone traps set at a height of 2 m had the highest mean attractiveness for Ips sexdentatus, followed by 1.5 m, 2.5 m, and 1 m. On the other hand, the number of trapped Thanasimus formicarius at 2.5 m-trap height was the highest, followed by 2 m, 1.5 m, and 1 m (Fig. 2). The results howewer showed that trap height on Ips sexdentatus (p<0.534) and Thanasimus formicarius (p<0.416) attraction was not significant (Table 5).
Chen et al. (2009) partially supports our findings in their study on I. duplicatus. Chen et al. (2009) reported that the trap height at 1.5-2 m captured more insects then the trap height at ground level or 3.5-4 m. According to Göktürk et al. (2010), the most effective trap height for I. typographus was 2m, followed by a height of 5, 3, 4, and as in our findings the least effective was 1 m-height traps. Göktürk et al. (2010) evaluated that shrub and herbaceous cover or forest floor may interrup the functioning of 1 m height-pheromone traps, and since the flying height of I. typographus is about 2 m, most of the pest may be captured by the traps hung at height of 1 m.
Pearson correlation analysis was performed to determine the relationship between the number of Ips sexdentatus and Thanasimus formicarius captured by pheromone traps depending on trap heights from the ground (Table 4.10). The test indicated that a significant and positive relationship existed between the pest and the predator (p <0.01) (Table 6).
Thanasimus formicarius is attracted to bark beetle pheromones and host plant volatile compounds that bark beetles use for locating host trees and their mates (Bakke and Kvamme 1981, Kohnle and Vite 1984, Tommeras 1988, Seybold et al. 2006). Indeed, Lopez and Goldarazena (2012) reported that the most common predator in the traps was Thanasimus formicarius in their study. This proves that Thanasimus formicarius has a strong orientation towards Ips sexdentatus pheromone.
Acknowledgement
Zahvala
This paper is produced from the master thesis of Mustafa ªahin titled “Effect of Type, Color and Hanging Height of Ips sexdentatus Pheromone Traps on Capture Rates” at Kastamonu University, Institute of Science and Technology.