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ŠUMARSKI LIST 3-4/2021 str. 64     <-- 64 -->        PDF

Among them, commercially produced pheromone traps against bark beetles and wood-boring insects have been used in forestry practice for more than 40 years (Galko et al. 2016).
The eyes of scolytids have about 100-240 ommatidia, relatively less than many insects (Chapman 1972, Byers et al. 1989). Although scolytids have low visual acuity (Byers et al. 1989, Byers 1995), many factors such as trap design and shape may influence the number of pests captured (McLean and Borden 1979, Lindgren et al. 1983, Borden et al. 1986).
Thanasimus formicarius (Linnaeus, 1758) (Col. Cleridae), one of the main predators of Ips sexdentatus (Martin et al. 2013), are saproxylic predators of Scolytinae (bark beetles), both as adults and as larvae (Thomaes et al. 2017). Although pheromone traps are used for monitoring and mass trapping of bark beetles, there are some negative effects on natural enemies. Many insect predators are attracted to pheromone traps and thus are removed along with target beetles (Stephen and Dahlsten 1976, Gregoire et al. 1992, Seybold 1993, Ross and Daterman 1995, Valkama et al. 1997, Dahlsten et al. 2003).
Trap efficacy of pheromone baited traps for bark beetles is affected by many factors: trap color (Paraschiv et al. 2012), trap types (Galko et al. 2016), pheromone dispensers (Zahradníková and Zahradník 2017), and trap placement (Brar et al. 2012, Dodds 2014).
The aim of this study was to compare the positive effects of trap colors and trap heights on the capture of Ips sexdentatus and their negative effects on Thanasimus formicarius.
MATERIAL AND METHODS
Materijali i Metode
Study area – Područje istraživanja
The study area Forest Enterprise Chief of Kastamonu-Yayla (41°24’52’’N−41°31’42’’E) is situated in Western Blacksea region of Turkey. The total area of the study area is 9259.3 ha out of which 6693.9 ha covered with forests. Sites are located on the southern inclination and at altitudes ranging from 1200-1270 m asl.
The main tree species of the study area is Scoth pine (Pinus sylvestris), covering about 90% of the stem basal area mixed with Pedunculate oak (Quercus robur) and Uludağ fir (Abies bornmülleriana).
Experimental Design and Procedure – Eksperimentalni dizajn i postupak
The study was conducted from June 9 to August 18, 2017 in Scoth pine dominated stands mixed with pedunculate oak and Uludag fir. SMC IPSEK® lures targeted for Ips sexdentatus were used in this sdudy. The active ingredient in the lures was 100 mg Ipsdienol/Dispenser. The lure was replaced every 4 weeks on each pheromone trap. The pheromone traps were checked at 7-10 day intervals from June to August 2017. The captured insects were collected in the field and brought into the Entomology Laboratory of Kastamonu University Faculty of Forestry for identification, counting, and photographing.
For the firsth experiment, five different color of traps (black, white, yellow, red and green) were compared to determine the effect of color on the capture of Ips sexdentatus and Thanasimus formicarius. Scandinavian type three funnel traps were used for the experiment and were hung at a height of 1.5 m above the ground. The distance between traps was about 30 m, and each trap was about 5 m away from the nearest tree. A total of 25 traps were installed and each trap color was represented by five traps (replications) per location.
For the second experiment, four black colour Scandinavian type three funnel traps were hung at heights of 1.0, 1.5, 2.0, and 2.5 m as one set to compare the effect of trap height on capturing the pest Ips sexdentatus and the predator Thanasimus formicarius. Five sets of traps (total of 20 traps) were placed along a line in west-easth direction in the field. The distance between traps was about 50 m.
Statistical Analysis – Statistička analiza
All statistical analyses were performed using SPSS® 22 software. The normality of the distributions was tested using a Kolmogorov–Smirnov and Shapiro-Wilk tests. Trap catch data were subjected to Kruskal-Wallis test at a significance limit of p<0.05 followed by multiple comparison test (Post hoc Dunn’s test). Pearson’s correlation analysis was also used to investigate the corelations between the pest Ips sexdentatus and associated predator Thanasimus formicarius.
RESULTS and DISCUSSION
Rezultati i rasprava
Trap color – Boja klopki
In the color-response experiment the highest number of Ips sexdentatus was captured by black color traps followed by red, green, yellow and the lowest was white color trap.