Dušan Jurc

The attraction of cerambycids and other xylophagous beetles, potential vectors of Bursaphelenchus xylophilus, to semio-chemicals in Slovenia

The attractiveness of different semio-chemicals to potential vectors of the phytoparasitic nematode Bursaphelenchus xylophilus was investigated in conifer forests in Slovenia. From 2007 to 2009, the presence of xylophagous beetles in Pinus nigra, P. sylvestris, P. halepensis, Picea abies and Abies alba stands was assessed at eight locations. Insects were collected at 1-month intervals during the growing season using four cross vane traps per location with a collecting container with propylene glycol and attractants (ethanol+α-pinene, Pheroprax® and Gallowit®). The trapped insects represented 24 families of the order Coleoptera, and we identified 94 species. The most numerous group was the weevil subfamily Scolytinae (76.55% of all insects collected), followed by the family Cerambycidae (8.12%), and the weevil subfamily Curculioninae (1.67%). With regard to species number, the most frequent wood-borers were Cerambycidae (24 taxa), Scolytinae (12 species) and Buprestidae (8 species). The most abundant species was Spondylis buprestoides, followed by Arhopalus rusticus, Monochamus galloprovincialis and Arhopalus ferus. At all locations, the largest catch of Cerambycidae occurred in July. The most effective attractant was ethanol+α-pinene, followed by Gallowit®; the least effective attractant was Pheroprax®. Among Monochamus species, M. galloprovincialis represented 17.54%, M. sutor 0.09% and M. sartor 0.04% of the long-horned beetles collected. Monochamus individuals were most numerous in the P. nigra stand and were attracted in the greatest numbers by Gallowit®, followed by ethanol+α-pinene. The cerambycid catch was highly correlated with the catch of non-target bark beetle predators (Cleridae, Staphylinidae, Histeridae, Trogositidae, Nitidulidae, Rhizophagidae) in the traps.

Essential-Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps.

The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra) from the Julian Alps were investigated by GC‐FID and GC/MS analyses. In total, 54 of the 57 detected essential‐oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ‐car‐3‐ene, β‐phellandrene, α‐pinene, β‐myrcene, and β‐pinene and the sesquiterpene β‐caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal‐component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II.

Fungal Wood Decay Processes as a Basis for Bioremediation

By-products of wood degradationand fungal activities have an important function in the formation of organic soilcomponents and can positively influence the natural succession pattern. The term mycoremediation usually refers to the exploitation of a unique fungal capacity to break down various organopollutants or to remove heavy metals from contaminated substrates but was also expanded on application of fungi to revitalise degraded and organically poor areas. Natural microbial and fungal communities found in degraded and/or contaminated soils and woody substrates represent a heterogeneous potential for remediation. But different ecological factors can hinder and prolong the revitalisation processes. The remediation potential of indigenous microflora can be enhanced with the addition of nutrients (biostimulation) or with the addition of living exogenous organisms into the remediated substrate (bioaugmentation). The substrate used for biostimulation or as an organic amendmentcan also carry a variability of organisms that can express bioremediation potential. The structures and organisation of main components of wood cell walls and high carbon to nitrogen ratio promote wood stability and cause resistance to deterioration and degradation. To promote wood degradation and production of soil organic matter, white-rot fungi can be exploited. It is essential to understand basic processes involved in the wood degradation and succession of organisms to get an insight into mycoremediation principles. With this chapter we introduce the basis of wood degradation and emphasise the influence of exogenously added fungi on the development and stability of indigenous microbial communities.