Various biotic and abiotic factors are the cause of the decline of coniferous forests throughout Europe. Trees weakened by unfavorable weather conditions create an ideal environment for a possible outbreak of bark beetles. The damage caused by bark beetles costs billions of dollars worldwide every year. Extreme climate events are responsible for the enormous forest losses in Tara National Park in the last ten years, leading to a massive bark beetle infestation. The understanding of the diversity and role of mites as biological control agents is still insufficient. In this study, we summarize the current knowledge on the diversity of mites associated with Ips typographus L. in Europe and provide information on the diversity of these mites in Serbia. Paraleius leontonychus, Uroobovella ipidis, Dendrolaelaps quadrisetus, Histiostoma piceae, and Trichouropoda polytricha were detected for the first time in Serbia. Moreover, the occurrence of Paraleius leontonychus represents the southernmost occurrence of this species.

The paper presents the results of a one-year study of population dynamics of bark beetles by the method of bark beetle trapping using pheromone traps with the following pheromone dispensers-aggregation pheromones: IAC Ecolure (for Ips acuminatus and I. sexdentatus), IT Ecolure (for I. typographus) and PC Ecolure (for Pityogenes chalcographus), after the ice storm that hit the region of Eastern Serbia, especially the forest estate Timočke šume Boljevac (State enterprise Srbijašume) in November 2014. The population levels of the monitored bark beetle species in the controlled area in 2015 were generally within the limits of normal conditions.

The application of modern technologies makes it easy to collect, process, present, and apply data for logistics in hard to reach areas. Proper delivery of equipment, personnel, and materials directly affects the quality of work. The need for precise and real information about the condition of the terrain and the conditions of the environment has always existed since this knowledge enables proper planning, forecasting and task performing in the field. Improvement in the digital industry enables fast and easy transfer of unchanged digital data from the field to the information processing centers, which consequently improves decision making and planning processes. New workflows made proper logistics even more important because it increased the precision of field work and better anticipation of previously unforeseen circumstances. Work on hard to reach areas, with large slopes, non-existent and/or non-persistent infrastructure, and different degree of vegetation coverage requires precise planning and organization of works, in order to minimize the number of unforeseen situations and make the most expeditious workflows. This paper presents the practical application of small unmanned aerial systems for collecting a large amount of data in a short time, the processing of the data, and the production of relevant information for decision making. There are two most important aspects of this paper. First one is fast, easy, safe and precise collection of large amounts of data which is an alternative to the traditional methods. The second is computer data processing, which enables a fast and automatic transformation of raw data into relevant information in digital formats that are suitable for further processing and easily accessible to decision makers. This work shows that it is possible to record quickly and in detail a large area, and obtain real, current, accurate and high-fidelity information about each point of terrain, with high precision and reliability

Browntail moth, is a well-known pest of broadleaf forests of Bosnia and Herzegovina. Although it is extremely polyphagous, it prefers to consume the leaves of various species of oaks. Browntail moth occurs periodically in high numbers (outbreak). Entomopathogenic fungus Entomophaga aulicae (Reichardt and Bail) Humber (Zygomycotina: Entomophtorales, Entomophtoraceae) is widespread Holarctic species, with many host insects from order Lepidoptera, where are some of the most economically harmful, outbreaking species of forest defoliators. In sessile oak forests of Eastern Bosnia and Herzegovina, the population density of browntail moth was determined by using route measurement during the growing season in the period 2015-2016. Browntail moth newly litters (40) were collected in four oak stands located in the region of Foča, Višegrad and Rogatica (PE Forests of the Republic of Srpska, Forest Estates Maglić, Panos and Sjemeć). In the litters, there were an average of 3,1 of dead old caterpillars and 4.7 pupae.The evaluation of E. aulicae infections was recorded as positive when hyphal bodies, primary conidia, or resting spores were detected on the surface of cadavers and puparia or in their tissues. The species identification was based on the size, shape and structural characteristics of different life forms of the fungus. By the microscopical studies of the causes of the mortality of the browntail moth larvae and pupae, the presence of hyphal bodies, primary conidia and resting spores of the E. aulicae were confirmed in them. The dimension of the resting spores (n=257) are 32.4 - 48.5 µm, a.v. 44.1 µm, primary conidia (n=54) 26.7-38.6 x 21.0-43.1 µm, a.v. 34.1-29.3 µm. Hyphal bodies were not measured. As entomopathogenic fungus on two development stages of the host, larvae and pupae, presented results indicate that E. aulicae is a promising microbial control agent.

Urban greenery, consisting of tree lines, parks and park forests, plays an important role in improving the aesthetics and general well-being of the urban environment. This study focuses on Stromovka Park in České Budejovice and examines the health status of various tree species. The research spans the period from 2021 to 2022 and uses the route method to monitor the occurrence of biotic pests and pathogens, especially mites and insects. Several economically important organisms were identified in the study, including Aceria fraxiniflora (Felt, 1906), Byctiscus betulae (Linnaeus, 1758), Curculio glandium Marsham, 1802, Eriophyes inangulis Nalepa, 1919, Fomes fomentarius (L.) Fr. 1849, Halyomorpha halys (Stål, 1855), Ips typographus (Linnaeus, 1758), Lymantria dispar (Linnaeus, 1758), Loranthus europaeus Jacq., Oxycarenus lavaterae (Fabricius, 1787), Pemphigus spyrothecae Passerini, 1856, Phyllonorycter issikii (Kumata, 1963), Polygraphus poligraphus (Linnaeus, 1758), Prociphilus fraxini (Fabricius, 1777), Rhytisma acerinum Schwein., (1832), Sacchiphantes viridis (Ratzeburg, 1843) and Tetraneura ulmi (Linnaeus, 1758). While most of these organisms showed normal, natural abundance values, increased values were observed in A. fraxiniflora, E. inangulis and O. lavaterae. The application of holistic plant protection principles, from proper cultivation and species selection to monitoring and control measures, remains crucial for maintaining the vitality and longevity of urban green spaces exposed to various biotic and abiotic stress factors.