The species Petrobia (Tetranychina) harti (Ewing, 1909) is reported for the first time in Serbia, also representing the first record of the tribe Petrobiini Reck, 1952 in the country. Including this finding, the number of spider mite species recorded in Serbia now totals 45. This spider mite species was found exclusively on wood-sorrel plants, Oxalis corniculata L. and O. articulata Savigny., at several localities in the cities of Belgrade and Zrenjanin. The samples were collected during the growing season of 2018 and 2023. Identification of the oxalis mite was based on morphological characteristics. To date, the occurrence of P. (T.) harti on other host plants has not been confirmed anywhere in Serbia. On the observed wood-sorrel plants, P. (T.) harti was recorded in cohabitation only with Tetranychus urticae Koch, 1836.

Fungus Fistulina hepatica represents one of the especially important fungi in forestry. Due to better knowledge of Fistulina hepatica bioecology as well as the possibility of usage, effect of temperature and nutrient media on pure cultures was investigated. Temperature of 25 °C was optimal for mycelium growth, while the biggest growth of cultures was recorded on MEA nutrient medium. Somewhat slower growth was recorded on SMA and PDA nutrient medium while the slowest growth was on CMA nutrient medium. On all nutrient media mycelium was white, while there were differences in shape of cultures. Obtained results indicate better possibility of stimulating and growing certain strains of Fistulina hepatica. Medicinal properties and usage of obtained results were discussed.

Fungus Epicoccum nigrum is one of the most important potential biocontrol agents of plant pathogens. To optimise the application methods, the study investigated the influence of temperature and nutrient media on Epicoccum nigrum mycelium growth. The optimal temperature for Epicoccum nigrum growth ranged from 17 to 25⁰C. At 9 ⁰C, Epicoccum nigrum showed a delayed beginning of the growth compared to the other temperatures. The lowest mycelial growth was recorded on Sabouraud maltose agar (SMA), while cultures on malt extract agar (MEA), cornmeal agar (CMA) and potato dextrose agar (PDA) showed the same growth. The colour of cultures varied depending on temperature and nutrient media. The application of Epicoccum nigrum in biotechnical purposes was discussed.

This paper analyzes structural characteristics of mixed stands of beech in the territory of Eastern Serbia. The research was carried out on three experimental fields by applying classic stand inventory parameters and structural indices (Gini coefficient, Stand Density Index, Hart-Becking Index), with additional analysis of spatial structure of trees. A special contribution of the paper is the application of an innovative approach in the analysis of the spatial distribution of trees. Due to limited applicability of Hart-Becking Index in heterogeneous stands, Delaunay triangulation, which enables defining real neighboring trees was applied in the paper and thereby the stated limitation was overcome. The established differences in structural characteristics between the researched stands can be related to combined effect of habitat conditions and silvicultural treatments carried out in the past. Also, the obtained results indicate the importance of application of comprehensive and combined approach in defining the structural build of the stand, which can serve as a reliable tool in the process of defining silvicultural measures aimed at achieving the target stand structure.

Various symptoms of diseases, including primarily rotting and dieback of branches were recorded on individual trees of boxelder maple (Acer negundo), honey locust (Gleditsia triacanthos), and green ash (Fraxinus pennsylvanica) during the urban forest health monitoring in the territory of Serbia. This paper presents the most frequent parasitic and saprophytic fungi related to the decline of these tree species. 14 species in total of lignicolous fungi and 1 species that causes necroses and die-back of trees were recorded. The greatest damages were recorded on boxelder maple (Acer negundo) and green ash (Fraxinus pennsylvanica) and the smallest on honey locust (Gleditsia triacanthos). The application of protection strategies should be aimed at reducing the source of inoculum for healthy trees. This can be achieved using various forestry measures, which primarily should be aimed at better phytosanitary treatments of parks and park forests of Serbia, as well as the papers aimed at production of phenotypically adequate trees.