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Pathogenic fungi can survive and develop in living plants, often causing diseases in the host. Some theories speculate that pathogenic ophiostomatoid fungi provide benefits to its vectorsbark beetlesby overcoming the tree's defence mechanisms. This study reports the results of an experiment in south-eastern Europe in which mature and seedling Norway spruce trees were artificially inoculated with various ophiostomatoid fungi. The aim of the experiment was to determine the relative virulence of ophiostomatoid fungi by assessing the ability of the fungi to stimulate host tree defence mechanisms through inoculation experiments. Experiments were performed by inoculation of Picea abies in seedling and mature trees. The following fungi were used in low-density and seedling inoculations: Ophiostoma ainoae, O. brunneo-ciliatum, Grosmannia cucullata and an unidentified Leptographium sp., O. bicolor, O. fuscum, O. piceae, G. penicillata and G. piceiperda. Endoconidiophora polonica was used in mass and seedling inoculations. Various characteristics such as host vitality, blue stain, lesion and resin outflow were measured before and after the trees were felled. E. polonica caused blue stain, induced large lesions and killed some of the mature trees and seedlings, confirming earlier reports that it is a strong wound pathogen. Only E. polonica, Leptographium sp. and O. ainoae caused blue stains in the sapwood of inoculated seedlings. In low-density inoculations, G. piceiperda induced intense necrosis and had higher values for all the characteristics monitored. Some of the other ophiostomatoid fungi showed a moderate level of pathogenicity. Fungi with the capacity to stimulate a host defence mechanism could play a role in the establishment of bark beetle populations.

Discovery and development of new antibiotics is still very important because of the constant appearance of drug-resistant pathogenic bacteria. The broth microdilution test was applied for screening of antibacterial activity in extracts of higher and endophytic fungi. Among tested extracts, three possessed significant antibacterial activity: extracts of mushrooms Amanita virosa (Fr.) Bertill. (Amanitaceae) and Cortinarius praestans Cordier (Cortinariaceae) against Pseudomonas aeruginosa and Staphylococcus aureus, respectively, and extract of endophytic fungus Trucatella hartigii (Tubeuf) Steyaert (Amphisphaeriaceae) against Enterococcus faecalis and S. aureus. The extract of Truncatella hartigii was further analyzed by one-and two-dimensional thin-layer chromatography, and the position of the active compound was determined on the chromatogram.

O nalazu hrastove mrežaste stjenice (Corythucha arcuata) u parku dvorca Lužnica kod Zaprešića, Hrvatska, 6 km od slovenske granice, obavijestio nas je prof. Boris Hrašovec sa Šumarskog fakulteta Sveučilišta u Zagrebu u jesen 2016. godine. 17. 11. 2016 obavili smo potragu za štetnikom na sedam lokacijama u jugoistočnoj Slove­niji (Mokrice, Obrežje, Rigonce, Dobova, Mostec, Zakot i Bukošek). Pričvršćeno i djelomično zeleno lišće, kao i otpalo lišće Quercus robur je bilo na terenu pomno pregledano i sumnjivi uzorci su stavljeni u plastične vrećice i donijeti u laboratorij za daljnju analizu. Morfološka identifikacija je provedena na uzorku jajnih grupa na do­njoj strani lišća i svlakova ličinki (exuviae) koje su bile prisutni na otpalom lišću Q. robur. Izvršeno je mjerenje broja jaja u 9 jajnih grupa i dužina i širina 30 jajnih čahura. Jajne ljuske (čahure) i svlakovi ličinaka na otpalom lišću Quercus robur bile su na pretraženom području nađene samo u hrastovoj šumi kod sela Zakot u blizini Brežica (E, 45°54’48“ N), koji je 14 km od najbližjeg nalaza u Hrvatskoj kod dvorca Lužnica. Jajne grupe sadržale su od 12 do 61 jajnih čahura. Jajne čahure su bile vretenastog oblika i crna s apikalnim otvorom i rubnim zadebeljenjem, duge 560 μm (475-596 μm) i široke 196 μm (183-196 μm). Ličinke su bile uglavnom tamne sa prozirnim žućkastim dijelovima na obje strane tijela. Imale su brojne bodlje. Brojne katranasto crne mrlje izmeta (faeces) hrastove mrežaste stjenice nalazile su se ravnomjerno na donjoj površini hrastovog lišća na kojem su bile prisutne jajne čahure i svlakovi ličinki. C. arcuata najvjerovatnije se proširila u Sloveniju iz Hrvatske, gdje je bila opažena kod dvorca Lužnica, ili kao autostoper sa željezničkom transportom, jer sjevernu granicu šume kod sela Zakot predstavlja željeznička pruga koja vodi od balkanske regije prema srednjoj Europi. U početku srpnja 2017. ustanovili smo namnoženje C. arcuata na lokaciji prvog nalaza i širjenje vrste na područje Krakovske hrastove šume, udaljeno 17 km zračne linije od sela Zakot.