Category Archives: News

The large-scale and continuous introduction of non-native species poses unprecedented challenges to ecosystems, agriculture, livestock production, and human health.

In response to these challenges, the HUN-REN Centre for Ecological Research has published a 60-page science-based booklet entitled Új fajok, új kihívások – Az inváziós fajok terjedése és kezelési lehetőségei Magyarországon (New Species, New Challenges – The Spread and Management of Invasive Non-Native Species in Hungary). The publication was prepared within the framework of the Invasion Biology Division of the National Laboratory for Health Security.

The booklet aims to provide accessible yet scientifically sound guidance on invasion biology, while also offering practical advice on mitigating the impacts of invasive species.

In a globalised world shaped by international trade and intensive human mobility, completely preventing the arrival of non-native species is unrealistic. However, biological invasions are not beyond control: the spread of species can be slowed, and their impacts reduced. Gaining time in this way is crucial, as it enables both ecosystems and human systems to develop effective responses.

The publication presents the stages of the invasion process in detail, from initial introduction through establishment and spread to large-scale expansion. It emphasises that biological invasion is not a single event but a sequence of interconnected stages — which makes early detection and rapid intervention particularly important.

The impacts of invasive species extend far beyond traditional nature conservation concerns. Some species cause significant crop losses; others threaten livestock or facilitate the spread of pathogens and diseases. Managing invasions is therefore a complex societal challenge, requiring cooperation among natural and social scientists, decision-makers, landowners, practitioners, and the wider public. Effective action depends on cross-sectoral collaboration.

The booklet presents non-native and invasive species already present in Hungary, illustrating risks and management options through concrete case studies.

Its conceptual framework is rooted in the concept of One Biosecurity, recognising that invasive species may simultaneously pose ecological, economic, and public health risks. This interdisciplinary perspective integrates human, animal, plant, and environmental health in addressing biological invasions.

Új fajok, új kihívások (New Species, New Challenges) seeks to raise awareness, foster dialogue, and support long-term, coordinated action against invasive species.

The publication is available online via the website of the HUN-REN Centre for Ecological Research. Additional resources can be found on the Virtual Bookshelf of the Invasion Biology Division.

Heartworm disease, caused by a filarial nematode (Dirofilaria immitis) is an increasingly serious animal health problem for dogs in Hungary. This mosquito-borne disease can cause serious conditions if left untreated, and its incidence has clearly increased in recent years.

The summer period – especially during dog walks and hikes – carries an increased risk, as mosquitoes are most active at this time of the year. That is why it is important for owners to keep their dogs on preventive medication, which significantly reduces the chance of developing the infection. Early signs of heartworm disease may include fatigue, coughing or general weakness – it is recommended to consult a veterinarian as soon as possible if these are noticed.

The aim of our research was to better understand where and how frequent heartworm disease occurs, and what factors may increase the risk of infection. We used two approaches to do this: first, we molecularly examined mosquito specimens, and second, we built on the dog owners’ own experiences using an online questionnaire.

The latter provided particularly valuable information: we received data on approximately1600 dogs from all parts of the country. Based on the responses, the infection rate is highest in the southeastern (47.8%) and eastern (43.4%) regions. In the case of older dogs and dogs kept mainly outdoors the infection is much more common, presumably due to longer and more frequent exposure to mosquitoes. In the mosquito samples, the parasite was also found in invasive species, such as the Asian tiger mosquito (Aedes albopictus) and the Korean mosquito (Aedes koreicus), but the native and common inland floodwater mosquito (Aedes vexans) was also often infected. The spread of invasive mosquito species can be tracked on our Mosquito Monitor website.

Our results clearly demonstrate the key role that dog owners play in gaining a more accurate picture of the spread of heartworm disease in Hungary. Through such citizen science-based questionnaire surveys, we can also collect data from areas, where collecting and examining mosquitoes is not available or is time- and cost-consuming – so the feedback from owners is an irreplaceable tool for prevention and control. Our colleagues have also issued a more detailed scientific paper examining such benefits of community science.

We would like to express our gratitude to all dog owners who filled out the questionnaire, as well as to the Bogáncs Pet Shelter in Esztergom, the Rex Kutyaotthon Foundation in Budapest and Net Vet Kft. in Debrecen, who supported our work with additional data and valuable advice during the survey. Special thanks to András Tóth and the Qubit editorial team for reporting on our preliminary results and encouraging readers to participate in the research.

European freshwater ecosystems face a wide range of threats, and the introductions of non-native species are major drivers of biodiversity loss. Amphipod crustaceans (from the Gammaroidea family), are a particularly damaging group and have been highly successful at establishing, spreading and exerting major impacts in novel habitats.

One recent study led by James Dickey, a researcher from the Invasion Biology Division of the National Laboratory of Health Security of Hungary, James Dickey focused on Gammarus tigrinus, a species native to the brackish tidal estuaries along North America’s Atlantic coast, which has established in freshwater systems across Europe. As well as exerting negative impacts on native biodiversity, it has led to socio-economic costs to fishermen through damaged fishing gear and injured catches. Interference competition with native species – where individuals interact, often aggressively, to prevent access to a resource – is just one of many impacts the species exerts, but this has received limited study to date. In this study the authors staged dyadic contests, pitting the North American amphipod against the native European Gammarus duebeni in a battle over an insect larva as a single food resource. The invasive gammerid was found to secure the prey faster and defend it more strongly than the native. Further, they exhibited more aggressive interactions and activity levels with increasing size and mass, whereas larger G. duebeni were shown to be less aggressive and less active. The non-native was also less thigmotactic, or “bolder”, being more explorative and spending a smaller proportion of time in the outer zone of the arena.

James Dickey hopes to develop this method further, applying it to a number of non-native ampipods from the Ponto-Caspian region. This is a notorious donor hotspot for invasive species, many of which have established in the Danube. “The Danube is a dream study system for an invasion ecologist, acting as a conveyor belt for non-native species across Europe. Learning more about the impacts posed by species that have established here in Hungary can help inform prevention and management elsewhere in Europe.” Currently setting up a lab and collaborating closely with András Abonyi and Péter Borza of the Lendület Fluvial Ecology Research Group at HUN-REN CER, Dickey will focus on Dikerogammarus bispinosus (pictured) and the notorious “killer shrimp”, D. villosus, determining how their behaviours drive impacts and how these might change in the future under climate change and other anthropogenic stressors.

We are pleased to announce that our researchers participated in the 22nd National Conference of the Association of Hungarian Pest Control Operators, which was held in Tapolca, Hungary this year. The event provided us with a great opportunity to present the results of the Mosquito Monitor project so far and to establish valuable professional relationships with companies and organisations responsible for mosquito control in Hungary.

During the conference, we also attended several exciting and informative presentations that provided inspiration for our future work. By exchanging experiences and building relations, we can contribute to the planning and implementation of a more effective and more eco-conscious mosquito control strategy.

In addition to its many direct negative effects, fragmentation of natural habitats can also facilitate the establishment and spread of invasive plants, which can further damage native wildlife. However, the exact nature of these effects may vary depending on the habitats affected and the group of organisms being studied. Most of the information we have are limited to native plants, yet the changes caused in arthropod communities are poorly understood. Therefore, we investigated the impacts of fragmentation and the presence of milkweed, which is a major conservation problem in the Great Hungarian Plain, on invertebrate communities in sandy grasslands of forest-steppe habitats.

In total, we surveyed pollinators (wild bees) and collected ground-dwelling arthropods, mainly herbivores (true bugs) and predators (spiders), and examined their characteristics in 60 habitat patches. We demonstrated the interaction between the effects of fragmentation and invasion, which usually modify and can strengthen each other’s effects. Milkweed has a stronger direct impact on herbivorous bugs and pollinators, while it affects ground-dwelling spiders only indirectly. The interaction between fragmentation, invasion and the conservation of biodiversity is very complex, and continuous monitoring and the use of adaptive management techniques are essential for its effective management.

Climate change and biological invasions are two of the most significant challenges facing ecological restoration efforts today. In the sand grasslands of Hungary, these pressures interact in complex ways, affecting how restored ecosystems develop over time. Researchers from the HUN-REN Centre for Ecological Research, Invasion Biology Division of the National Laboratory of Health Security, conducted a long-term study to understand how drought severity and restorative mowing influence the recovery and vulnerability of sand grassland ecosystems.

The research focused on three locations within the Kiskunság region, where invasive black locust stands (Robinia pseudoacacia) were removed between 1994 and 1995, and regular mowing was applied until 2001 to prevent regrowth. Using comprehensive vegetation data collected from 1995 to 2019, alongside long-term weather data, the team analysed the dynamics of native target species, invasive species, and drought-tolerant C4 plants under changing drought conditions.

The findings reveal that native sand grassland species demonstrated notable resistance to drought, maintaining stable populations even as summer droughts became more frequent and severe. In contrast, invasive species tended to decline during severe droughts, while C4 species, which are more tolerant of heat and dryness, became more dominant. Although mowing — commonly used to aid grassland restoration — effectively prevented the reinvasion of the targeted black locust, it did not enhance the recovery of native sand grassland species. Instead, it facilitated the spread of invasive herbaceous species, particularly under drought conditions. This unintended consequence highlights the complexity of restoration practices: interventions that control one problem may inadvertently create new vulnerabilities. In fragmented landscapes, where nearby habitats serve as reservoirs for invasive species, this risk is even greater.

The study emphasises that sand grasslands are naturally resilient to many disturbances, but their long-term stability depends on considering multiple ecological factors. Restoration strategies must go beyond local-level interventions and should consider landscape-scale dynamics and climatic impacts. The research underscores the need for adaptive, flexible restoration practices that anticipate future climatic stresses and invasion risks. It also highlights the importance of frequent, long-term monitoring to capture the delayed and sometimes subtle responses of ecosystems to environmental change.

The raccoon is one of the most widespread invasive mammal species in Europe. Its expansion on the continent dates back to 1934, when the first few individuals were released in Germany. Since then, their numbers have grown to several hundred thousand, and they are becoming increasingly common in many other European countries, including Hungary.

The 3^rd EURORACCOON Meeting was recently held, where raccoon researchers presented their latest work and discussed the management of the species. Three of us from the Hungarian University of Agriculture and Life Sciences participated in the event and gave presentations about our work in the Invasion Biology Division of the National Laboratory for Health Security, Hungary. We presented the raccoon wildlife camera trap studies, which confirmed the nest predation effect of the species, and described the annual occurrence of raccoons in their most important habitat in Hungary; our results on the condition and reproductive biology of raccoons in Hungary; and the experiences of the first local eradication program of the country, implemented for the species.

The conference took place at the Seminarzentrum Edersee event venue in the Kellerwald-Edersee National Park, Germany – at the historic site where the raccoon’s European conquest began.

During the three-day event, in addition to the professional activities, the researchers visited natural habitats, including a primeval beech forest, where raccoons are becoming an increasingly significant part of the ecological community, and also took an evening raccoon-watching tour in the nearby “raccoon capital” of Kassel, where they witnessed the species in large numbers and discussed their management in the city. For those who were up to some culinary adventures, the program was also enriched with a “raccoon barbecue”.

One of the important findings of the meeting was that although the raccoon is an extremely successful predator with a diverse diet and can also spread infections, there is hardly any research that would prove its actual significant impact. Therefore, there is a great need for such targeted research. In some places, the complete eradication of the species seems hopeless, but its spread to areas not yet occupied can be prevented. In Hungary, its population could still be kept under control with well-organized interventions.

Participants of the event would like to see next year’s conference on the Gödöllő Campus of the Hungarian University of Agriculture and Life Sciences, in Hungary.

Participants from the Division of Invasion Biology of NLHS: Dr. Krisztián Katona, Dr. Zsolt Biró, Balázs Bócsi

The “first of its kind” conference in Hungary enabled nationwide and international discussion on invasive alien species – a cohesive action plan is finally on the horizon

The conference took place in Sarlóspuszta, Hungary between 26 and 28 February 2025, organised by the HUN-REN Centre for Ecological Research and the Invasion Biology Division of NLHS. It was aimed to foster knowledge exchange and proactivity among researchers, practitioners, and policymakers on managing invasive species through the interdisciplinary “One Biosecurity” framework. This approach integrates plant, animal, human, and environmental health to mitigate the impacts of biological invasions.

On the first day, the “One Biosecurity” concept was introduced by the day’s plenary speaker, Dr. Philip Hulme, a distinguished professor of plant biosecurity at Lincoln University, New Zealand. He highlighted its potential to unify decision-making across sectors for better biosecurity outcomes while emphasizing its holistic approach to biosecurity threats. Speakers of the day presented their studies on such threats imposed by human, animal and plant parasites and their vectors, such as alien mosquito species and their spread diseases or fungal diseases of plants, as well as invasive species with a high risk to native animals and environmental health, i.e., the raccoon and the raccoon dog, or released exotic pet fish and reptile species.

The second day featured scientific presentations on invasion biology topics such as spread mechanisms, monitoring and control, ecological roles, and socio-economic impacts. Dr. Petr Pyšek, a senior research scientist at the Czech Academy of Sciences, and Dr. Piero Genovesi, chair at the IUCN SSC Invasive Species Specialist Group, delivered plenary talks on cutting-edge research and control methods. Dr. Petr Pyšek’s presentation focused on mechanisms of species invasiveness and global biogeography of alien floras. Whereas Dr. Piero Genovesi discussed strategies for controlling invasive species and related policymaking. Some of the highlights from other speakers were mapping the spread of invasive plant species and using AI technology for maximising efficiency; unintentional dispersal of plant seeds; targeted control of invasive trees; biological control of insect pests; the control issues with the coypu and alien aquatic macrofauna, the damage they cause, and the potential to reduce the impact of invasive fish with the reintroduction of beavers.

Finally, the third day was comprised of a day-long workshop that facilitated collaboration between researchers and practitioners from various fields, focusing on co-producing actionable knowledge for managing invasive species effectively. One of their conclusions was that involving and helping the lay public in reporting and managing invasions is as important as cooperating with farmers, foresters, gardeners, and other related professionals. Understanding and mitigating the spread of alien species requires a combined effort from all layers of society, and finding the appropriate channels of communication to each layer is a key factor in doing so.

In summary, the conference emphasized the importance of prioritising invasive species management efforts on high-risk, early-stage invasions. Geographic context was highlighted as crucial, with island nations better focusing on border controls and mainland countries with open borders, like Hungary, are advised to prioritise nationwide monitoring focusing on high-risk hubs of travel and trade. Key recommendations included legislative improvements, increased government support and investment, multi-stakeholder and sectorial collaboration, education on biosecurity in schools, and the use of clear terminology in media.

A key conference goal was translating the One Biosecurity concept into Hungarian to ensure effective communication through media channels. The result is “ökobiztonság” which translates to “Eco-Security” in English – a much more widely understood term in Hungarian that, with the right contextualisation, can also cover the unified concept of the protection of plant, animal, human, and environmental health.

Book of Abstracts »
One Biosecurity workshop, Mentimeter results »

The loss of biodiversity on our planet is partly due to the presence and spread of alien invasive species. Once an invasive species has established in a new habitat, it can alter the structure and function of the ecosystem to such an extent that it has an impact even after removal, making it very difficult to control and eradicate. Ecological restoration, when carried out in an effective and sustainable way, contributes to biodiversity conservation and climate change mitigation, resilience and adaptation, and has proven to be an effective method of controlling invasive species. At the same time, the presence of invasive species in the landscape can compromise restoration objectives. The aim of this study is to assess how the abundance of annual and perennial invasive species varies with location, direction and distance around the restoration site, and which factors should be considered when planning restoration interventions.

Seeds of plant species are often dispersed unintentionally on our clothes, which thanks to the increasing mobility of people, can be important events in the process of biological invasions. Researchers from the HUN-REN Centre for Ecological Research, ‘Lendület’ Seed Ecology Research Group, investigated this topic, and published their results in the D1-ranked scientific journal Journal of Environmental Management. This study provides critical insights into the unintentional spread of plant species through human-vectored dispersal via clothing, a pathway that has received limited attention so far. Their findings show that most seeds remain viable after typical household washing, even at common temperatures and a wide range of detergent types, highlighting a largely overlooked vector of plant dispersal. Since most of the plants that are capable of cloth-dispersal are weeds and invasive species, the results have important implications for invasion control. They emphasize the need for targeted biosecurity measures, especially among those working outdoors, to mitigate the spread of invasive species. The results also offer actionable strategies for environmental management by integrating behavioural changes and public awareness to reduce the environmental impact of human-vectored dispersal. According to their questionnaire survey, raising awareness is especially important for nature conservation professionals who are among the most important potential vectors.

Citation of the paper:

Lukács, K., Kiss, R., Tóth, Á., Godó, L., Deák, B., Valkó, O. (2025): Effects of laundry washing on germination of cloth-dispersed seeds depends on washing intensity not on detergent type. Journal of Environmental Management 375: 124345.