Occurrence of invasive insects on woody plants in the main green areas from Bucharest city

In the current context of globalization, biological invasion of alien species has an important impact on environment, economics or human health. Particularly, the spread of these species in urban green areas, is problematic due to several reasons. The aim of this research was to report the presence of invasive insects on woody plants in the main parks across Bucharest (namely Alexandru Ioan Cuza Park, Bucharest Botanical Garden, Cișmigiu Gardens, King Michael I Park, USAMV Campus, Youth Park). Field observations were done during the summer of 2019 (July) and the protocols recently developed by the experts from “Marin Drăcea” National Institute for Research and Development in Forestry were used. It was identified twelve invasive insects species: Aproceros leucopoda (Hymenoptera: Argidae), Cameraria ohridella (Lepidoptera: Gracillariidae), Corythucha arcuata (Hemiptera: Tingidae), Corythucha ciliata (Hemiptera: Tingidae), Cydalima perspectalis (Lepidoptera: Crambidae), Dasineura gledithchiae (Diptera: Cecidomyiidae), Eopineus strobus (Hemiptera: Adelgidae), Macrosaccus robiniella (Lepidoptera: Gracillariidae), Nematus tibialis (Hymenoptera: Tenthredinidae),  Obolodiplosis robiniae (Diptera: Cecidomyiidae), Parectopa robiniella (Lepidoptera: Gracillariidae),  Prociphilus fraxinifoli (Hemiptera: Aphididae)

Invasive alien forest insect species in south-eastern Romania

Biological invasions in forest ecosystems are recognised as a global scale challenge. However, our current knowledge of invasive alien forest insect species (IAFIS) in Romania is still lacking and rather insufficient to support clear policies. The aim of this study is to contribute to a better understanding of the distribution of IAFIS in the Muntenia and Dobrogea provinces of Romania. For this purpose, direct observations and insect collections were made two consecutive years, in 76 locations. Of these, 67 sampling locations forming a long field observation route were visited only once, and nine sampling locations were fixed monitoring points with primed traps used in first year for regular collection of insects at 1-2-week intervals. Seventeen non-native forest insect species from five orders and 11 families were detected: Aproceros leucopoda, Cameraria ohridella, Corythucha arcuata, Cydalima perspectalis, Dasineura gleditchiae, Eopineus strobus, Euura tibialis, Gilletteella cooleyi, Hyphantria cunea, Ips duplicatus, Macrosaccus robiniella, Neoclytus acuminatus, Obolodiplosis robiniae, Parectopa robiniella, Phyllonorycter issikii, Prociphilus fraxinifolii and Xylosandrus germanus.  Eleven IAFIS species originate from North America, four from Asia and two from Europe. All detected species were previously reported from Romania, but eight species had not been recorded in these two provinces. Seven species live on native tree species, while 10 thrive on exotic trees or shrubs. The highest number of IAFIS was recorded in urban areas. Except for E. tibialis, all found IAFIS have a significant ecological or economic impact across invaded habitats. The risks posed by biological invasions need more thorough consideration that deserves greater attention and scientific support

Black locust stand structure on the sterile dump in the middle basin of Jiu River (Romania)

Introduced in 1750 as an ornamental tree and then in 1852 as a forest tree species, black locust occupied nowadays 250,000 ha in Romania. The tree species is important for its wood (lumber, poles, firewood, etc.), its honey-related production as well as its environmental role (afforestation of sand dunes and sterile dumps). One of the most important activities in the middle basin of Jiu River is coal mining. After 1956 this activity has developed very quickly and two power plants were built in Rovinari and Turceni. As a result, sterile dumps and coal ash dumps have established so it was necessary to restore the area by afforestation. This activity started with the sterile dump Viaduct Rovinari, using Austrian pine and black locust, and continued with others such as Cocoreni and Moi. The most used tree species for ecological restoration was black locust. In order to express the stand structure, diameter at breast height (DBH), total height (H) and crown diameter were measured. The soil analysis were performed and showed differences in the content of heavy metals and radionuclides for both location. The study revealed positive correlations between DBH and H, a stronger one for Moi plantation. Our research highlights the capacity of black locust to establish and grow under very difficult site conditions

The Database of European Forest Insect and Disease Disturbances: DEFID2

[EN] Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of bio-diversity, could be increasingly compromised. Despite the relevance of these detri-mental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including se-verity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite- based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and dam-age metrics derived from them using the LandTrendr spectral–temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and pos-sible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is en-couraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc- opend ata/FOREST/DISTURBANCES/DEFID2/SIEC Joint Research Centre; European Commission, Grant/Award Number: 101059498; European Research Council, Grant/Award Number: 101039567; Ministry of Research, Innovation and Digitalization of Romania; LifeWatch— POC project, Grant/Award Number: 327/390003/06-11-202

From Field Data to Practical Knowledge: Investigating the Bioecology of the Oak Lace Bug—An Invasive Insect Species in Europe

Corythucha arcuata, commonly known as the oak lace bug (OLB), is an insect species originally native to North America that has become an invasive species of significant concern in Europe. This invasive pest has been observed in various European countries, raising concerns about its impact on forest ecosystems. In 2015, it was first documented in Romania, further highlighting the need for research on its bioecology and life cycle. This study investigated the bioecology of the OLB in the southern region of Romania, focusing on its life cycle, development, and population dynamics. The results indicated that the OLB has three generations per year and overwinters in the adult stage in sheltered locations. Temperature significantly influenced the timing of egg hatching, nymph appearance, and adult development, with variation observed between generations. Additionally, a life table analysis provided insights into the population dynamics of the OLB in its natural environment, revealing variation in egg laying trends across generations. This research contributes to a better understanding of the OLB’s bioecology and provides essential data for forest managers developing science-based management strategies to mitigate its impact. By elucidating the life cycle and development patterns of the OLB in southern Romania, this study aids in the development of predictive models and life tables tailored to the region. These findings empower forest managers with the knowledge needed to make informed decisions for effective OLB management, ultimately preserving the health of forest ecosystems

The Seasonal Population Dynamics of Corythucha arcuata (Say, 1832) (Hemiptera: Tingidae) and the Relationship between Meteorological Factors and the Diurnal Flight Intensity of the Adults in Romanian Oak Forests

To control a forest pest, it is necessary to understand the biotic and/or abiotic factors that can lead to population regulation. Such knowledge is even more critical if the pest is an invasive alien species. This is the case for Corythucha arcuata (Say, 1832), commonly known as the oak lace bug (OLB), an alien insect species that has invaded oak forests on a large scale, both in Romania and other European countries. In this study, we set out to examine the relationship between adults of this species and meteorological factors, such as air temperature and humidity. The study lasted for two years (2019–2020) and was performed on three plots in Romania, in Ilfov, Giurgiu, and Călărași counties. In the first year, the seasonal dynamics of the OLB populations and the meteorological factors potentially influencing those were studied, whilst in the second year, the dynamics of the diurnal activity of the insect population were examined. We found that Corythucha arcuata experienced two population peaks—in July and August—and a diurnal population dynamic that reached a maximum at midday. Data analysis indicated that, for most of the time, the adult activity was influenced by both temperature and humidity. In addition, the population dynamics were not constant over the course of the day, preferring relatively high temperatures and low humidity but not exceeding certain thresholds of thermal discomfort

The Seasonal Population Dynamics of <i>Corythucha arcuata</i> (Say, 1832) (Hemiptera: Tingidae) and the Relationship between Meteorological Factors and the Diurnal Flight Intensity of the Adults in Romanian Oak Forests

To control a forest pest, it is necessary to understand the biotic and/or abiotic factors that can lead to population regulation. Such knowledge is even more critical if the pest is an invasive alien species. This is the case for Corythucha arcuata (Say, 1832), commonly known as the oak lace bug (OLB), an alien insect species that has invaded oak forests on a large scale, both in Romania and other European countries. In this study, we set out to examine the relationship between adults of this species and meteorological factors, such as air temperature and humidity. The study lasted for two years (2019–2020) and was performed on three plots in Romania, in Ilfov, Giurgiu, and Călărași counties. In the first year, the seasonal dynamics of the OLB populations and the meteorological factors potentially influencing those were studied, whilst in the second year, the dynamics of the diurnal activity of the insect population were examined. We found that Corythucha arcuata experienced two population peaks—in July and August—and a diurnal population dynamic that reached a maximum at midday. Data analysis indicated that, for most of the time, the adult activity was influenced by both temperature and humidity. In addition, the population dynamics were not constant over the course of the day, preferring relatively high temperatures and low humidity but not exceeding certain thresholds of thermal discomfort

The Database of European Forest Insect and Disease Disturbances: DEFID2

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity, could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral–temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/