Ambrosia beetles (Coleoptera, Curculionidae, Scolytinae and Platypodinae) are classified as secondary pests that introduce associated fungi by tunneling into the wood of host trees. These fungi can be more or less harmful to the trees. Mostly, these fungi cause wood staining, but there are documented cases of significant economic and ecological damage. The main goal of the thesis was to review the literature and scientific research findings regarding associated fungi, to collect and describe different techniques for isolating these fungi into pure cultures, and then to test selected techniques in Laboratory for forest protection at Slovenian forestry institute. The literature review focused on four species of ambrosia beetles, specifically Xyleborinus saxesenii, Xylosandrus crassiusculus, Xylosandrus germanus, and Anisandrus dispar. We found that each species is associated with a specific fungus. Dry-catch traps were set in July 2024, and we captured three different species of ambrosia beetles that are most commonly found in Slovenia: X. saxesenii, X. germanus, and A. dispar. The associated fungi were isolated from the beetles using various methods: by allowing live beetles to walk on a culture medium, from mycangia, from the remaining parts of the beetle, and from a single gallery system of X. germanus on an infested branch of Castanea sativa. The isolated fungi were classified into eight different morphotypes (MT). Based on molecular analyses, we confirmed that Ambrosiella grosmanniae is associated with X. germanus, and Ambrosiella. hartigii with A. dispar. Additionally, a Fusarium species was dominant fungus in the gallery system of X. germanus on C. sativa, and the fungus from the same genus was also most often isolated from X. saxesenii. The main conclusions drawn from the results are that different isolation techniques yield different species of fungi, and that each beetle species is associated with a specific fungal species.
|
