magistrsko delo
Nastja Mencinger (Author), Dušan Devetak (Mentor), Jan Podlesnik (Co-mentor)

Abstract

Velikost populacije osmerozobega smrekovega lubadarja (I. typographus) (Coleoptera: Scolytinae) lahko ocenjujemo po različnih metodah. Ena od teh je uporaba feromonskih pasti. Z njihovo pomočjo lahko iz gozda odstranimo veliko število ciljnih osebkov (I. typographus). V pasti pa se ujamejo tudi neciljne žuželke - gre namreč za prestrezne pasti, v katere se po naključju zaletijo predvsem tiste žuželke, ki jih privlači vonj feromonov I. typographus in vonj po razkroju živali. Med njih spadajo plenilci in parazitoidi smrekovega lubadarja in drugi saproksilni hrošči, ki predstavljajo pomemben element gozdnih ekosistemov in vplivajo na dinamiko populacij podlubnika. Z masovnim lovom lubadarjev iz ekosistema odstranimo tudi njihove plenilce in parazitoide, kar lahko celo podaljša izbruh lubadarjev. V magistrskem delu nas je zanimala številčnost stranskega ulova v različnih tipih feromonskih pasti. Raziskava je potekala leta 2016 na Hrvaškem, na območju Žitnik (občina Gospič). Uporabili smo tri tipe pasti - Theysohnova past, Lindgrenova večlijakasta past s 6 posodami in Lindgrenova več lijakasta past z 12 posodami, ki so bile opremljene s feromonom za vrsto I. typographus (Pheroprax). Z vstavljanjem mrežic, z velikostjo odprtine 5 mm, nad zbirne posode v polovico feromonskih pasti smo skušali ugotoviti, ali takšna modifikacija pasti vpliva na zmanjšanje stranskega ulova. Za testiranje vpliva pasti in prisotnosti mreže nad zbirno posodo smo uporabili posplošen linearni mešan model (angl. Generalized linear mixed model - GLMM) na osnovi negativne binomske porazdelitve in izračunali indeks specifičnosti pasti (Specificity index). Ugotovili smo, da pasti, ki so modificirane z mrežo, ulovijo manjše število I. typographus, razen v primeru Theysohnove pasti, ki je ulovila enako število ciljnih osebkov. Pasti z mrežo ulovijo statistično značilno manj neciljnih osebkov velikosti nad 6 mm. Pri kategorijah velikosti pod 4 mm in med 4 in 6 mm je viden vpliv tipa pasti, medtem ko mreža ni imela vpliva na količino ulova.

Keywords

magistrska dela;podlubniki;Ips typographus;kairomoni;feromonske pasti;Theysohnova past;Lindgrenova večlijakasta past;plenilci;parazitoidi;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FNM - Faculty of Natural Sciences and Mathematics
Publisher: [N. Mencinger]
UDC: 595.768.2(043.2)
COBISS: 24217864 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Bycatch abundance in different types of pheromone traps for the European spruce bark beetle (Ips typographus)
Secondary abstract: Pheromone traps are an important method for estimating the population density of Ips typographus (Coleoptera: Scolytinae). Catching the European spruce bark beetle by using pheromone traps can remove a large number of target individuals from the forest. These interception traps accidentally catch also non-target insects particularly those insects that are attracted by the smell of pheromones of I. typographus and the smell of animal decay. Among them are predators and parasitoids of spruce bark beetles and other saproxylic beetles, which represent an important element of forest ecosystems and influence the population dynamics of the European spruce bark beetle. Removing predators and parasitoids during the mass catches with pheromone traps can even prolong the outbreak of I. typographus. In the master's thesis we were interested in the abundance of bycatch in various types of pheromone traps. The study was conducted in Croatia in year 2016 in the area of Žitnik (Municipality of Gospič). We used three types of traps - Theysohn's trap, Multi-funnel trap with 6 funnels and Multi-funnel trap with 12 funnels equipped with pheromone for I. typographus (Pheroprax). By inserting 5-mm mesh screen on top of the collection container in the half of the pheromone traps, we tried to determine whether such a modification of the trap has an effect on the reduction of bycatch. To test the impact of the traps and presence of net over the collection containers, we used a generalised linear mixed model (GLMM) based on the negative binomial distribution and calculated the Specificity index for traps. We found out that traps modified with the net caught a smaller number of I. typographus, except in the case of the Theysohn's trap that caught the same number. Non-target animals were divided in three size classes. Traps with the net are catching statistically less specimens of bycatch organisms that are larger than 6 mm. For size class below 4 mm and size class between 4 and 6 mm, the effect of the type of the trap can be seen, while the net has no effect on the amount of catch.
Secondary keywords: master theses;bark beetles;Ips typographus;kairomones;pheromone traps;Theysohn slot trap;Lindgren Multi-funnel trap;predators;parasitoids;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za biologijo
Pages: VIII, 32 str.
ID: 10982051