Every year, new alien species of insects and fungi invade European forests. Some of them are exotic pests and diseases that can affect the survival and growth of trees.
To help develop strategies for monitoring and managing these non-native forest pests, a consortium of over 50 scientists representing 23 research institutions and 15 countries from across the globe joined their skills in the Horizon 2020 project HOMED “Holistic management of emerging forest pests and diseases.”
Alex Stemmelen during his presentation at the XXVI ICE Congress 2022. He is the first author of a paper on the pests of Douglas fir in NeoBiota‘s special issue.
Between 2018 and 2022, the HOMED consortium developed a full panel of scientific knowledge and practical solutions to better deal with emerging native and alien invasive pests and diseases.
Fruiting bodies of Austropuccinia psidii on Myrtus communis (symptoms of myrtle rust). Photo by Alberto Santini
This includes targeting the successive phases of invasion, and developing innovative methods for each phase: risk analysis, prevention/detection, surveillance, eradication/containment, and control.
To share the results of this cooperation and help researchers further improve the management of emerging forest pests and pathogens, HOMED has made the main outcomes of its research publically available.
They are now published in a special issue in the open-access journal NeoBiota, called “Conceptual and technical innovations to better manage invasions of alien pests and pathogens in forests”. The issue comprises 16 articles on various aspects of the ecology and management of invasive alien insects and fungal pathogens in Europe’s forests.
“Because forests provide irreplaceable goods and materials for people and the European economy, because maintaining healthy forests is essential for their contribution to climate change mitigation through sequestration and storage of atmospheric carbon, it is urgent to develop more effective protective measures against the ever-increasing threat of invasive forest pests,” the editors of the special issue write in an editorial.
More tools are needed that can help identify, prevent and monitor invasive alien species and improve early warning methods, which makes the research in this issue so crucial and timely.
The European project Homed, leaded by Hervé Jactel, gave the opportunity to produce a lot of important scientific results, these are just a part! Incredibly happy and proud!https://t.co/VeIK5zvC7I
“The role of researchers is to develop, test and promote the most relevant methods and tools at each stage of the invasion framework, i.e., for the early detection of these invasive alien organisms, for the identification of the species and for the monitoring of their damage and spread, but also for new eradication and control solutions,” the editors continue.
Hervé Jactel, Lukas Seehausen and Martin Gossner at HOMED’s and Pensoft’s stand during the XXVI ICE Congress 2022.
One highlight in the published research is a study exploring how using the methods of citizen science at schools can increase invasive species awareness. Another explores the efficiency of artificial intelligence in pest detection.
“The publications collected in this special issue demonstrate that current conceptual, methodological, and technological advances allow a great progress in the anticipation, monitoring and management of invasive pest species in forests,” the editors conclude.
Follow HOMED on Twitter. Follow NeoBiota on Twitter and Facebook.See the latest tweets on the special issue using the hashtag #HOMED_SI.
Invasive land snail species can displace native species and harm human health. A recent study by the Leibniz Institute for Biodiversity Change Analysis (LIB) compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean from other continents.
To date, there is a lack of information for the spread of alien species, especially invertebrates such as snails. “Despite efforts to compile lists of alien species, there is not even a well-documented inventory of alien invertebrate species for Europe,” emphasizes Prof. Dr. Bernhard Hausdorf, section leader Mollusca at LIB. His study, just published in the journal NeoBiota, provides a basis for decisions on further measures to control or eradicate introduced populations.
Alien land snail species in the Western Palaearctic Region: Zonitoides arboreus, Hawaiia minuscula, Guppya gundlachii, Polygyra cereolus
Land snails play a supporting role in ecosystems. They decompose decaying plants and thus play an important role in nutrient cycling and soil formation. However, more and more species are being spread beyond their native range, usually by humans, sometimes intentionally, but often unintentionally by goods or travellers.
The study examines 22 land snail species introduced to Europe and the Mediterranean from other continents. Most of them are small, live on decaying plant parts and apparently cause few problems. In contrast, carnivorous species can threaten native species; and species that feed on living plants can cause damage to agriculture. Some even serve as hosts and vectors of parasites that can cause brain encephalitis, for example, and thus can indirectly harm human health.
Alien land snail species in the Western Palaearctic Region: Paralaoma servilis and Helicodiscus parallelus.
Harmful species include the Laevicaulis species recently introduced to the Mediterranean from tropical Africa and the African giant snail Lissachatina fulica. They can cause economic damage on irrigated farmland or in greenhouses by destroying or contaminating crops, making them unsaleable.
Hausdorf’s study compiles records of land snail species introduced to the Western Palearctic region, Europe and the Mediterranean, from other regions after 1492 and established in the wild. In doing so, he observes that the number of alien species has increased steadily since the 19th century, even exponentially from the 1970s onward, and that the introduced species have become more widespread.
Within Europe, alien species generally spread from south to north and from west to east. Thirteen of the 22 species studied were from North America, three from sub-Saharan Africa, two from the Australian region, three probably from the Oriental region, and one from South America.
Alien land snail species in the Western Palaearctic Region: llopeas clavulinum, Allopeas gracile, Lissachatina fulica, Paropeas achatinaceum, and Discocharopa aperta.
Even if trade relations and the spread of species can be correlated, Hausdorf believes that the prevailing climate is primarily decisive: “The spread of many of the introduced species, especially the tropical species dispersing in Mediterranean, is probably favored by climate change.”
Bernhard Hausdorf, “Distribution patterns of established alien land snail species in the Western Palaearctic Region”, NeoBiota, Pensoft https://doi.org/10.3897/neobiota.81.96360
👏Congrats to Giovanni Vimercati (Postdoc, @unifr) who received the Best Talk Award at #NeoBiota2022 for his presentation: "Assessing positive #socioeconomic impacts of alien #taxa within a unified framework"!🎉 Will be looking forward to your complimentary submission!😊 https://t.co/sDsgd747du
Giovanni Vimercati is a postdoctoral researcher at the University of Fribourg, Switzerland, and most recently recipient of the Best Talk award (Early Career Researcher) at the 2022 NEOBIOTA conference held in mid-September in Tartu, Estonia.
As a sponsor of the event and publisher of the NeoBiota journal, Pensoft granted a complimentary publication in it to the awardee.
NeoBiota readers might already be familiar with Vimercati, whose name first appeared on its pages in a 2017 paper that used alien amphibians as a case study to identify the differences and potential difficulties with two impact assessment scoring tools: the Environmental Impact Classification of Alien Taxa (EICAT) and the Generic Impact Scoring System (GISS).
Then, in 2020 and 2021, the researcher had two research articles published in NeoBiota as lead author. The 2020 paper provided a summary of the frameworks assessing beneficial impacts of alien species, while in the 2021 study his team used a spatially-explicit stage-structured model to assess efficacy of past, present and alternative control strategies for invasive guttural toads (Sclerophrys gutturalis) in Cape Town.
Giovanni Vimercati being awarded at NEOBIOTA 2022. Photo by Ana Novoa.
In anticipation of Vimercati claiming the Best Talk award with a forthcoming submission to the journal, we asked him to join us for an interview and share his thoughts on his research.
Going back to the beginning, what sparked your interest in the study of invasive species in particular? What are the unique aspects of your research?
Like the episodic nature of many biological invasions, my first contact with the study of alien species was quite “unexpected”. Having a strong interest in herpetology, I had the luck to pursue my doctoral research at the Center of Excellence for Invasion Biology (CIB) in Stellenbosch, South Africa, where I studied the invasion of an alien amphibian species. My PhD study, and the highly stimulating community of researchers that characterized the CIB, made me realize not only that invasive species provide an invaluable opportunity to address ecological and evolutionary questions, but also how important it is to study their impact on biodiversity and human communities.
One unique aspect of my research since then has been its multidisciplinary character, as I have studied biological invasions from multiple angles simultaneously, by using mathematical models, physiological experiments, field surveys, remote sensing, literature reviews, meta analysis, and questionnaires. It seems a paradox, but the uniqueness of my research on biological invasions is that it has never really been unique!
Are there recent developments in the field that you find particularly interesting to explore?
As many other scientific disciplines, the field of invasion science is highly dynamic, and novel developments emerge every year. However, I find of particular interest the development of new approaches and tools to explore the links between biological invasions and the various socio-economic contexts. The use of online structured and semi-structured interviews, or the development of standardized socio-economic indicators are, for example, particularly promising for future studies.
In addition, the emergence of novel technological tools, for instance, linked to remote sensing, eDNA, stable isotopes and camera trapping, or the rapid increase in the computational power of modern CPUs, are allowing invasion scientists to collect and analyze data that used to be unaffordable, or simply unavailable. It is certainly an exciting moment to be an invasion scientist.
What do you find to be the biggest challenges as a researcher in your field?
I find that the proliferation of hypotheses and frameworks that characterize the field of invasion biology are particularly intriguing and challenging. Many of them work extremely well in certain conditions or across specific taxonomic groups, but they often lack generality or are marred by context dependence, which may limit their predictive power.
Addressing such a context dependence and finding ways to integrate various hypotheses and frameworks in invasion biology will be highly beneficial for understanding and forecasting biological invasions in the next decades.
Another challenge is to communicate the implications of our research to non-experts. I often wonder how stakeholders and policymakers from different cultural backgrounds or geographic regions perceive alien species and their impacts.
The theme of this year’s NEOBIOTA conference was “Biological Invasions in a Changing World”. To what extent can changes be anticipated and forecasted in order to make the work of assessing their impacts and mitigating damage easier?
I think that a key point would be to focus on specific indicators or proxies to measure these changes, so that different impacts and species can be quantified, both transparently and consistently.
In recent years, the field has produced a huge body of literature regarding impacts caused by alien species, but the results of these studies have not always been comparable. I feel that the development of the EICAT framework and its recent adoption by the IUCN as a global standard for measuring the magnitude of environmental impacts of alien species were two very important steps in this direction.
Your talk at the NEOBIOTA conference focused on the positive socio-economic impacts of invasive species. Why is this important for different stakeholders, including policy makers, but also local communities and individuals?
In my opinion, invasive species, and more generally alien species, can have various positive socio-economic impacts that should be identified and assessed rigorously. These impacts are often anecdotally reported or vaguely stated in the literature, a tendency that hampers our capacity to identify (and forecast) conflicts of interest among different stakeholders or understand their perceptions toward alien species.
In my talk, I presented the preliminary version of a framework that assesses positive socio-economic impacts. The framework is based on the capability approach, and aims to quantify the degree to which the well-being of certain human communities increases after the introduction of alien species. Of course, the scheme won’t be used in isolation, but rather in combination with other frameworks that assess the negative socio-economic and environmental impacts of alien species, so that their effects can be understood in their full complexity.
An international collaboration led by the Doñana Biological Station (EBD-CSIC) has shown that experts are consistent when assessing the economic, health and ecological impacts of alien species. These assessments are therefore reliable to guide the prioritization of resources invested against biological invasions.
These results have a great impact on the management by national and international institutions, which have limited resources to fight against the growing and worrying increase of alien species invasions and the damage they caused to society and environment.
Biological invasions annually cause huge food losses, disease transmissions, species extinctions and ecosystem perturbations. For these reasons, it is one of the biggest problems that humankind currently faces, and its relevance will alarmingly increase due to the extreme situations that climate change will expose society to.
The seriousness of this problem lies in the limited human resources available to fight against it, that force to prioritize its management. Here is where tools such as impact assessments play a key role. Assessments report the impact of invasive species in different areas, including economy, health and environment, and allow us to rank the most harmful species.
For instance, in aquatic ecosystems like the Ebro Delta in Spain, there are dozens of invasive alien co-occurring species that cause millions of economic losses and irreparable ecological damage.
Such is the case of the Zebra mussel, which affects irrigation; the apple snail that devours rice fields; and the blue crab causing the local extinction and declines of many native species.
“That’s why it is crucial to ensure that the results are not dependent on the assessors and to understand what factors affect discrepancies among experts,”
explains Rubén Bernardo-Madrid, lead author and researcher at Doñana Biological Station – CSIC.
One of the relevant aspects of this study is the quantification of the consistency of responses across assessors for a large number of invasive species of vertebrates, invertebrates and plants. In addition, the researchers have studied multiple protocols focused on different aspects, providing a global view of this problem.
“The study has shown that the great majority of assessments are consistent and therefore valid to aid in decision-making. These results are encouraging as they suggest that these protocols may be useful when facing the worrying forecasts of increasing biological invasions and their damages,”
explains Rubén.
On the other hand, the researchers have observed that discrepancies across assessments might be due to multiple factors, such as the type of impact asked or the linguistic formulation used in the protocols.
The results suggest that there is room for improvement in assessments, but it will require more funding for research, and more multidisciplinary collaborations between ecologists and linguists to develop less ambiguous protocols.
As always, the most effective measure against biological invasions turns out to be prevention.
However, given the incapacity to control every voluntary and involuntary introduction, other tools such as impact assessments are essential to reduce as far as possible the damage caused by these species on human welfare and environment. Its continuous improvement and evaluation, such as the one made in this study, are decisive.
***
Research article:
Bernardo-Madrid R, González-Moreno P, Gallardo B, Bacher S, Vilà M (2022) Consistency in impact assessments of invasive species is generally high and depends on protocols and impact types. In: Giannetto D, Piria M, Tarkan AS, Zięba G (Eds) Recent advancements in the risk screening of freshwater and terrestrial non-native species. NeoBiota 76: 163-190. https://doi.org/10.3897/neobiota.76.83028
But gene drives are not a one-size-fits-all solution
Invasive alien mammals can have catastrophic impacts on native flora and fauna, causing species extinctions and driving profound environmental change. Classical control methods such as poison baiting, trapping, or hunting are currently not feasible on a large scale, which is why researchers are looking for alternatives.
CRISPR-based genome engineering is often seen as a “silver bullet” for pest control. Despite the increasing interest in the development of this technology for invasive mammals like mice, rats, rabbits, feral cats, and foxes, studies have so far only focused on mice.
Scientists have been pondering whether genome editing technologies could help eradicate larger mammals, and if so, how long it would take.
In order to address these questions, a team of researchers from the University of Adelaide developed a mathematical model able to simulate the impact of gene drives on mammal populations at a landscape scale. Published in the open-access NeoBiotajournal, their study is the first to estimate the time it would take to eradicate long-lived alien mammals.
Using CRISPR-Cas9 technology, the simulated gene drive relies on “molecular scissors” inserted into the Y-chromosome that target and slice up the X-chromosome at the right time during meiosis, so that only Y-chromosome carrying sperms are functional and can successfully fertilize the egg. In this way, the drive carrying males should only produce sons that also carry the molecular scissors on their Y-chromosome. Over multiple generations, females will become rarer and produce fewer offspring; as a result, the population size will fall.
This “X-shredder” drive has been successfully developed and demonstrated to suppress cage populations of malaria-carrying mosquitos, but has not yet been developed in mammals. The model shows that the X-shredder drive could potentially achieve landscape-scale eradication of mice, rats, rabbits, feral cats, and red foxes, but the probability of success and the time it would take to eradicate them vary greatly.
The researchers investigated the ability of the X-shredder drive to eradicate a population of 200,000 individuals of each species. “CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales,” they concluded.
The method could be effective in small-sized pests, such as rodents and rabbits. The expected time to eradication is 18 years for mice, 19 years for rats, and 48 years for rabbits, with 90% population suppression achieved in around half those times.
However, the results suggest that gene drives are not a one-size-fits-all solution: they might not be so useful in larger species like cats and foxes.
“The probability of eradicating feral cats with gene drives is identical to flipping a coin, 50/50; and provided that the coin lands on the right side, it would take about 140 years to get rid of them,” says Dr. Aysegul Birand, part of the research team. “The probability of eradication is higher for foxes, but the wait is even longer.”
Original source:
Birand A, Cassey P, Ross JV, Thomas PQ, Prowse TAA (2022) Scalability of genetic biocontrols for eradicating invasive alien mammals. NeoBiota 74: 93-103. https://doi.org/10.3897/neobiota.74.82394
From the infamous cane toad to the notorious spotted lanternfly, we all know the drastic effects that introduced species can have on both ecosystems and agriculture.
In today’s interconnected world, these alien species are being moved around the globe more frequently than ever before. Hitchhikers and stowaways on ships, planes, and other vehicles can cause irreversible and catastrophic damage to fragile native ecosystems and to us humans, and tens of billions of dollars are spent every year trying to control these invaders.
But one of the greatest problems for researchers and government bodies trying to combat these threats is that it can be incredibly difficult to monitor the invaders even when we know they’re here.
So how on earth is anyone supposed to detect when a new species has invaded?Many of these organisms are small, inconspicuous, and difficult to identify, and by the time they’ve been spotted it’s often already too late to act.
What if there was a way to quickly and easily find invasive organisms all over the world? Enter the world of Citizen Science, where anybody and everybody can produce important scientific data without even leaving their backyard. Just by taking a photograph of an organism and uploading it to a citizen science platform like iNaturalist or QuestaGame, amateurs and enthusiasts can provide scientists with invaluable records from across the globe.
A screenshot from the iNaturalist homepage, captured on July 7, 2022.
Back in 2015, when amateur naturalist Adam Edmonds spotted an unusual praying mantis in his garden, he took a photo and posted it to the Australian citizen science platform BowerBird. When even the local experts didn’t recognise it, a specimen was sent off to mantis specialist Graham Milledge. He confirmed that it was a newly introduced species – the South African Mantis (Miomantis caffra).
Miomantis caffra, an adult female from Victoria, Australia. Photo by Adam Edmonds
Since then, this alien mantis has spread across Australia from Sydney to Perth. And every step of the way, citizen scientists have been there to document its spread.
Last month, all of these citizen science records were compiled by entomologist Matthew Connors of James Cook University (Queensland, Australia) into the first comprehensive report of the mantis’s presence in Australia. Understanding where the species has spread and what impacts it has had on native species is crucial to managing and controlling it.
The introduced South African Mantis (Miomantis caffra) preys on a native Harlequin Bug (Dindymus versicolor) in Geelong, Australia. Photo by Kelly Clitheroe
The research found that the South African Mantis has spread through suburban habitats in three Australian states (Victoria, New South Wales, and Western Australia) and one offshore territory (Norfolk Island). It probably arrived in these regions as egg cases attached to plants and equipment, and it can now be found in high numbers, especially during late summer and early autumn. Despite this, it appears to be highly localised and has only been recorded in suburbia, and furthermore there has not been any noticeable impact on native species.
Miomantis caffra, egg case (ootheca) from Victoria, Australia. Photo by Ken Walker
None of this research would have been possible without citizen scientists – the dedicated community of enthusiasts and amateurs who share their finds with researchers online. Photographs from citizen science platforms and social media sites have been instrumental in showing just how far the South African Mantis has spread. In fact, more than 90% of the records of the species come from citizen scientists, and without them we would barely know anything.
These days, more and more researchers are realising just how useful citizen science can be. As well as tracking introduced species, citizen scientists have rediscovered rare creatures, documented never-before-seen behaviours, and even discovered completely new species.
Miomantis caffra, an adult female from Victoria, Australia. Photo by Matthew Connors
This latest research, published in the Journal of Orthoptera Research, is among a handful of recent studies that have gone a step further though – instead of just being a source of data, the citizen scientists were invited to take part in the entire research process, from data collection all the way through to publishing. After all, they did all of the fieldwork!
Research like this is proof that anyone can be a citizen scientist in today’s day and age – so what are you waiting for?
Research article: Connors MG, Chen H, Li H, Edmonds A, Smith KA, Gell C, Clitheroe K, Miller IM, Walker KL, Nunn JS, Nguyen L, Quinane LN, Andreoli CM, Galea JA, Quan B, Sandiford K, Wallis B, Anderson ML, Canziani EV, Craven J, Hakim RRC, Lowther R, Maneylaws C, Menz BA, Newman J, Perkins HD, Smith AR, Webber VH, Wishart D (2022) Citizen scientists track a charismatic carnivore: Mapping the spread and impact of the South African Mantis (Miomantidae, Miomantis caffra) in Australia. Journal of Orthoptera Research 31(1): 69-82. https://doi.org/10.3897/jor.31.79332
Invasive insects can be vectors of diseases, cause damage to agriculture and forestry, and threaten native biodiversity. Recognising this dramatic impact, the open-access journal Alpine Entomology, published by Pensoft on behalf of the Swiss Entomological Society, opened a dedicated topical collection that is already accepting submissions.
Impacts of alien insects in the Alpine ecosysteminvites scientists working on invasive species and plant-insect interactions in Alpine regions to openly publish their research articles, review articles, and short communications on, among others, trends or changes in biogeography of emblematic species, shifts in current distributions, or niche replacement.
The new article collection will be edited by Oliver Martin of ETH Zürich, subject editor and editorial board member at Alpine Entomology, Stève Breitenmoser, and Dominique Mazzi.
“Recent years have seen a worldwide increase in invasions by alien species, especially plants and insects, mostly due to trade and climate change,” they explain, noting that although numerous studies exist on the topic, few of them focus on the Alpine areas.
“With this collection we hope to generate exciting discussions and exchange within the scientific community interested in this very particular and sensitive ecosystem,” the editors say, inviting authors to submit their manuscripts assessing the possible impacts of invasive insects on mountain areas.
The collection will remain open for submissions for the next two years. In the meantime, the accepted manuscripts will be published on a rolling basis, as soon as they are ready for publication.
Invasive alien species (IAS) are a leading contributor to biodiversity loss, and they cause annual economic damage in the order of hundreds of billions of US dollars in each of many countries around the world. Smartphone apps are one relatively new tool that could help monitor, predict, and ideally prevent their spread. But are they living up to their full potential?
A team of researchers from the University of Montana, the Flathead Lake Biological Station and the University of Georgia River Basin Center tried to answer that in a recent research paper in the open access, peer-reviewed journal NeoBiota. Going through nearly 500 peer-reviewed articles, they identified the key features of the perfect IAS reporting app and then rated all known English-language IAS reporting apps available to North America users against this ideal.
Smartphone apps have the potential to be powerful reporting tools. Citizen scientists the world around have made major contributions to the reporting of biodiversity using apps like iNaturalist and eBird. But apps for reporting invasive species never reached that level of popularity; Howard and his team investigated why.
Smartphone apps like the soon-to-be-released new EDDmapS platform are promising tools for monitoring, predicting, and reducing the spread of invasive species. However, the same explosion of reports has not been realized as that which has been experienced by biodiversity-wide platforms. Howard et al. investigate why there has not been the same boom in use observed for these invasive species-specific apps. Image by Leif Howard and Charles van Rees
User uptake and retention are just as important as collecting data. Howard and colleagues found that apps tend to do a good job with one of these, and rarely with both. In their paper, they emphasize that making apps user-friendly and fun to use, involving games and useful functions like species identification and social media plug-ins is a major missing piece among current apps.
“The greatest advancement in IAS early detection would likely result from app gamification,” they write.
Another feature they would like to see more of is artificial intelligence or machine learning for photo identification, which they believe would greatly enhance species identification and might increase public participation.
The authors also make suggestions for future innovations that could make IAS reporting apps even more effective. Their biggest suggestion is coordination.
“Currently, most invasive species apps are developed by many separate organizations, leading to duplicated effort and inconsistent implementation”, they say. “The valuable data collected by these apps is also sent to different databases, making it harder for scientists to combine them for useful research.”
A more efficient way to implement these technologies might be providing open-source code and app templates, with which local organizations can make regional apps that contribute data to centralized databases.
Overall, this research shows how with broader participation, more complete and informative reporting forms, and more consistent and structured data management, IAS reporting apps could make much larger contributions to invasive species management worldwide. This, in turn, could save local, regional, and national economies hundreds of millions or billions of dollars annually, while protecting valuable ecological and agricultural systems for future generations.
Research article:
Howard L, van Rees C, Dahquist Z, Luikart G, Hand B (2022) A review of invasive species reporting apps for citizen science and opportunities for innovation. NeoBiota 71: 165-188. https://doi.org/10.3897/neobiota.71.79597
A CABI-led study has conducted a comprehensive survey of nearly 200 potentially harmful alien plant species that could have a detrimental impact upon agriculture, forestry and biodiversity in Ghana once they enter the country.
Invasive Alien Species (IAS) continue to shape the global landscape through their effects on biological diversity and agricultural productivity. The effects are particularly pronounced in Sub-Saharan Africa, which has seen the arrival of many IAS in recent years. This has been attributed to porous borders, weak cross border biosecurity, and inadequate capacity to limit or stop invasions.
A farmer shows cassava root affected by cassava brown streak virus alongside a healthy root in a country where the disease is present – one of the 64 pathogens assessed by the scientists. Credit: CABI
The research, the findings of which are published in the journal NeoBiota, ranks 110 arthropod and 64 pathogenic species that pose the greatest threat but are not yet officially present in the country. However, they could arrive as ‘stowaways’ in cargo from other countries around the world, the scientists believe.
Dr Marc Kenis, Head Risk Analysis and Invasion Ecology at CABI, led on the horizon scanning exercise supported by colleagues from a range of institutions including Ghana’s Plant Protection and Regulatory Services Directorate (PPRSD).
Among the top arthropods prioritised by Dr Kenis and his team were the pink hibiscus mealybug (Maconellicoccus hirsutus Green) and melon thrips (Thrips palmi Karny) while the top pathogens highlighted include cassava brown streak virus and Maize lethal necrosis disease.
Cassava in Ghana, for example, is a main staple crop and contributes about 22% and 30% to the Agricultural Gross Domestic Product (AGDP) and daily calories intake respectively. The crop, however, can be at risk from cassava brown streak virus which can reduce yields by up to 70%.
Maize lethal necrosis disease, on the other hand for instance, can be a major disruptor of maize crops in Ghana where maize accounts for more than 50% of the country’s total cereal production. The disease can cause losses of between 50-90% depending on the variety of maize and the growing conditions of the year.
The scientists also found other species recorded in Africa that included 19 arthropod and 46 pathogenic species which were already recorded in the neighbouring countries of Burkina Faso, Côte d’Ivoire, and Togo.
Dr Kenis, who is based at CABI’s centre in Switzerland, said, “The ultimate objective of this research was to enable prioritization of actions including pest risk analysis, prevention, surveillance and contingency plans. Prioritisation was carried out using an adapted version of horizon scanning and consensus methods developed for ranking IAS worldwide.
“We have demonstrated that through horizon scanning, a country can identify potential invasive plant pests, both invertebrates and pathogens, and use the information to determine the risk associated with each.
“This will enable the country to invest the limited resources in priority actions such as preventing arrival and establishment of IAS, Pest Risk Analysis (PRA), surveillance and developing contingency plans.
“This study can serve as a model for future projects on plant pests’ prioritisation in Africa and elsewhere. It would be applicable for assessing the risk of invasive plant pests in any country or region, e.g. trade blocks, with minor modifications of the method, particularly in the mini-PRA protocol used to score species.”
The full lists of arthropod and pathogenic species surveyed can be found within the full paper which can be read online.
Mr Prudence Attipoe, Deputy Director Head Plant Quarantine Division, PPRSD, said, “The horizon scanning exercise for Ghana would give the PPRSD an insight into invasive pests which could possibly enter the Nation. The tool is timely and appropriate for conducting PRA for planning, training and future preparedness. The success of this exercise would pre-empt the introduction of these invasive pests into the country in order to protect Ghana’s agriculture, forestry and also cause staff of PPRSD to be more vigilant at the borders for these pests.”
Research paper:
Kenis M, Agboyi LK, Adu-Acheampong R, Ansong M, Arthur S, Attipoe PT, Baba A-SM, Beseh P, Clottey VA, Combey R, Dzomeku I, Eddy-Doh MA, Fening KO, Frimpong-Anin K, Hevi W, Lekete-Lawson E, Nboyine JA, Ohene-Mensah G, Oppong-Mensah B, Nuamah HSA, van der Puije G, Mulema J (2022) Horizon scanning for prioritising invasive alien species with potential to threaten agriculture and biodiversity in Ghana. NeoBiota 71: 129 148. https://doi.org/10.3897/neobiota.71.72577
While blacklists are an effective tool for preventing and managing new biological invasions, they don’t always raise public awareness of invasive alien species, a new study published in the open-access journal NeoBiota found. Important policy-making initiatives do not necessarily raise public awareness about biological invasions, and efforts should be more focused on supporting policy-making with well-planned communication campaigns, the research concludes.
Catchy news and viral videos work best to attract public attention to invasive alien species
Blacklists are one of the most common policy measures to limit biological invasions. They identify small groups of highly impactful invasive alien species: species introduced outside their native range that threaten biodiversity. By doing so, they inform key decision-makers, who then impose limitations or bans on their trade and introduction, or set requirements about specific actions to manage already established populations.
While they have been found to be effective at preventing and managing new biological invasions, we don’t know if blacklists actually raise public awareness of invasive alien species. In principle, they could do so, as they might attain a certain echo in the media and provide the general public with notorious examples of invasive alien species.
Coypu. Photo by Aurelio Perrone
In 2016, the European Union published the List of Invasive Alien Species of Union concern, which contains species that are banned from import, trade, and release in Europe. It had a certain echo in the media, and having come at a time where Internet searches are so pervasive that they can be used to measure public attention, the Union List made a good case study for exploring blacklist impact on public awareness.
Grey squirrels. Photos by Sandro Bertolino
A research study, coordinated by Jacopo Cerri from theUniversity of Primorska, Slovenia, and Sandro Bertolino from theUniversity of Turin, Italy, explored if the publication of the Union List increased visits of the Italian Wikipedia pages about invasive alien mammals, many of which were included in the list. Wikipedia is the largest online encyclopedia and a major source of information for motivated Internet users who go beyond search engines such as Google. As a comparison, the researchers used visits to Wikipedia pages about native mammals in Italy, and adopted a causal impact analysis to quantify differences.
The study found no effect of the publication of the Union lists over visits to Italian Wikipedia pages of invasive alien mammals, compared to pages about native mammals. After 2016, there were single peaks of visits to pages of some of the species, probably caused by viral videos and news about large-scale control initiatives or mass escapes from captivity. In one instance, peaks in visits aligned with news about thecoypu – at the time, several national media outlets ran stories addressing the concerns of public administrations regarding the rodent’s impact on the stability of river banks. Similarly, a peak observed between late 2018 and February 2019 was likely caused by news about the release of 4,000 minks from a fur factory in Northern Italy, which attracted considerable attention in the national and regional media.
These attention peaks, however, did not last in time and don’t reflect a systematic change in public awareness about invasive alien species.
“Overall, our findings indicate that blacklists, despite having the potential to raise public awareness towards biological invasions, might fail to do so in practice,” the researchers conclude.
“Agencies who want to achieve this goal should rather develop tailored communication campaigns, or leverage on sensational news published in the media.”
Research article:
Cerri J, Carnevali L, Monaco A, Genovesi P, Bertolino S (2022) Blacklists do not necessarily make people curious about invasive alien species. A case study with Bayesian structural time series and Wikipedia searches about invasive mammals in Italy. NeoBiota 71: 113-128. https://doi.org/10.3897/neobiota.71.69422
