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.
In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended ...its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe.
We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021–2040, 2061–2080, and 2081–2100) to project and evaluate the species' potential distribution in the future.
Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape.
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•Oak lace bug occurrence data compiled from 21 countries.•Realized niche and potential distribution was projected using an SDM ensemble model.•The invasive species has not yet colonized all suitable areas.•By 2100, >80 % of oak species distributions could be colonized.
In addition to the classic biotic and abiotic factors that have disrupted the health of forests throughout history, lately, the balance of forest ecosystems has been disturbed by different phenomena ...such as climate change, pollution, and, especially, biological invasions of invasive alien species. One of the alien species that has invaded Europe relatively quickly is an insect species of North American origin, the oak lace bug (Corythucha arcuata Say, 1832 Heteroptera: Tingidae). In the context of the rapid spread of infestations and the severity of attacks on oak trees in infested forests, this paper aims to assess measures to manage this species in the future. Namely, the effect of aerial chemical treatments on oak lace bug has been investigated with two influencing factors: the mode of insecticide action (contact and systemic) and the treatment volume (low volume and ultra-low volume). The experiment was conducted in two forests over a total area of 350 hectares. The results show that the reduction of the nymph population varied from 91% to 96%. However, the residual population was sufficient to allow differentiated re-infestations over time, more quickly after contact insecticide sprays (22 days after treatment) and slowly after systemic insecticide sprays (more than a month after treatment). This re-infestation time difference had implications on attack intensity as well, with stronger leaf discoloration observed in areas treated with a contact insecticide compared with those treated with a systemic insecticide.
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.
The oak lace bug (OLB)
Corythucha arcuata
(Say, 1832) is an invasive alien species (IAS) that potentially could have many negative impacts on European oak health. Certain measures can be applied to ...counteract these effects. However, these measures may not be acceptable for forest managers or other stakeholder groups, such as private forest owners, environmental NGOs or the general public. Thereby, we set out to study the perception and knowledge of foresters and other stakeholders on the health status of European oak forests affected by oak lace bug and to investigate what forest health management measures would be acceptable to these target groups. An online survey questionnaire was designed and distributed via social networks, as well as professional networks via e-mails. The survey questionnaire was completed by 2084 respondents from nine European countries: Austria, Croatia, Belgium, France, Hungary, Italy, Romania, Serbia and Slovenia. Even though only a little over 60% of respondents reported they had noticed the discolouration of oak leaves caused by OLB, almost all (93%) considered it to be a problem. As respondents come from a country where
C. arcuata
is widespread and established, people’s general knowledge and awareness of OLB began to increase. The survey revealed that foresters thought that the insect affected photosynthesis, acorn crop and the aesthetics of the trees, but cannot cause death of trees. However, they assume that the value of the wood would decrease (this fact is also supported by the respondents who are connected to an environmental NGO), but that OLB does not affect property value. However, forest owners claim that the value of the property can be affected and that people would avoid entering the forest. In terms of potential control methods, respondents preferred biological or mechanical measures over chemical ones. We consider this study to be a good basis for further research on the topic of perception, knowledge and attitudes related to OLB since we can expect that the IAS, such as OLB, will certainly spread to European countries that were not included in this survey.
Against the background of the phenomenon of globalisation, which has increasingly intensified in recent decades, invasive alien species (IAS) have led to biological invasions that have resulted in ...multiple negative effects on economies, human health, and especially on the environment. In order to control invasive alien species, preventive actions are considered the most effective methods. In this context, society can actively participate in the process of early detection and preventing the spread of these organisms, but there is a need to raise public awareness. In order for this process to take place in the most efficient way, it is necessary to initially evaluate the knowledge of the general public to IAS. Through a questionnaire that was circulated in ten European countries and had over two thousand respondents, this study aimed to investigate the level of knowledge of some stakeholders in the forestry sector regarding IAS. The results showed that a vast majority of respondents who participated in the study had heard about IAS and provided a correct definition of these organisms. Most of the respondents in this study heard for the first time about IAS from school, the Internet, or journal articles. Data analysis also showed that stakeholders in the forestry sector (foresters, forest owners, and members of environmental NGOs) were more likely than the other respondents to be aware of the impact of IAS. The results of this study offer an insight to researchers and decision makers assessing the differences of opinion regarding invasive alien species, and the necessary steps that could be adopted in the process of raising awareness in society.
The North American oak lace bug feeds on leaves of ‘white oaks” in its native range. In Europe, it was first discovered in northern Italy in 2000. In recent years, it has subsequently spread rapidly ...and population outbreaks have been observed in several European countries. In the present study, we summarize the steps of its expansion.
To predict its potential host range, we checked 48 oak species in 20 sentinel gardens in seven countries between 2013 and 2018.
In total, 27 oak species were recorded as suitable hosts; 13 of them are globally new ones, 23 out of the 29 in section Quercus (∼ white oaks, an intrageneric taxonomic unit within genus Quercus), including Asian oaks, native to Japan, Korea and China, and four out of five in section Cerris (another intrageneric unit of the same genus), were accepted as hosts. None of the species in section Lobatae (red oaks) or in the Ilex group was accepted.
Host records were also collected in forest stands of 10 countries. We found 11 oak species that were infested. Outbreak populations were most commonly found on Quercus robur, Quercus frainetto, Quercus petraea and Quercus cerris, comprising widespread and outstandingly important oaks species in Europe.
Based on our findings, we conclude that suitable hosts for oak lace bug are present in most of Europe and Asia. This means that a lack of hosts will likely not restrict further range expansion.
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.
This paper investigates the biodiversity of adult arthropods in two grapevine plantations influenced by two adjacent groves over a three-year period (2020–2022) in the viticultural center of ...Stefănești Argeș, located in southern Romania. The study holds significant implications for introducing parasitoid/predatory insect species into vineyards to control grapevine pests. A total of 164 arthropod species were identified, including 27 beneficial species. Additionally, two moth species, Lobesia botrana and Sparganothis pilleriana, were identified. L. botrana was consistently observed throughout the study, while S. pilleriana was only observed in 2022. The research reveals that the location with the highest number of identified species was in a grove near a black field, with 103 species. Other areas with notable species diversity included a vineyard maintained as a black field (89 species), a grove near permanent natural grassland (88 species), and a vineyard with intervals between rows of grapevines maintained as natural permanent grassland (81 species). Introducing beneficial organisms, such as the predator Crysoperla carnea, is recommended to control grapevine moths in this ecosystem.
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).
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