Tag: invasive species

How to get people interested in invasive species?

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 the University of Primorska, Slovenia, and Sandro Bertolino from the University 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 the coypu – 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

Unwelcome guests: International tourism and travel can be a pathway for introducing invasive species

International tourism can facilitate the dispersal of exotic species. A new analysis of data from tourism accommodations and exotic organism detections in New Zealand, published in NeoBiota, shows that levels of detection significantly correlated to international and domestic tourist movement, even with population levels taken into account. There was no detectable difference between the risk from international and domestic tourists, indicating that tourism as an activity correlates with the introduction and spread of exotic species.

Tourists, albeit unwittingly, may help such unwanted organisms spread further and conquer new lands – they can carry them over in their luggage or on their clothes and shoes. In 2011, a study from New Zealand found that, for every gram of soil on the footwear of aircraft passengers arriving from abroad, there were 2.5 plant seeds, 41 roundworms, 0.004 insects and mites, and many microorganisms, such as fungi that could cause plant diseases. Moreover, these organisms were alive, and some of them were known to be biosecurity threats. Importantly, tourism can introduce risk in two directions, namely from the arrival of international travellers and also the return of residents from international travel.

An important question, then, is to what degree they play a role in the spread of exotic organisms. A study, carried out by Dr Andrew Robinson of the Centre of Excellence for Biosecurity Risk Analysis at the University of Melbourne and Mark McNeill of AgResearch New Zealand, looks to answer that question.

To do so, the researchers compared data on the interceptions of exotic organisms in New Zealand against accommodation data for international and domestic tourists, factoring for the country’s population distribution. The study, recently published in the open-access journal NeoBiota, covered the period between 2011 and 2017, and the exotic organisms that were detected included insects, spiders, mites, snails, plants, and roundworms. 

Robinson and McNeill found a significant relationship between levels of incursion detection and tourism accommodation records: the number of nights spent in hotels significantly correlated to the detection of exotic pests for that period. Importantly, the study found no significant difference between the effect of international and domestic tourism, proving that even travel within the country can facilitate the spread of exotic species. A significant positive correlation was also found between the detection of exotic organisms and population numbers across different regions. 

“The core take-home message is that within-country tourism movements are significantly correlated to the detection of exotic pests,” the researchers explained. That is, tourists and returning residents bring bugs in, and both are implicated at spreading them once they are in the country. They suggest that biosecurity authorities should continue allocating resources to the management of invasive species and pests that get carried around by tourists and their activities. 

However, they also point to the biosecurity risk posed by other possible pathways for of exotic organisms, such as sea freight. A comparison between the different ways of introduction and dispersal would provide a better understanding of relative risk, they conclude.

Research article:

Robinson AP, McNeill MR (2022) Biosecurity and post-arrival pathways in New Zealand: relating alien organism detections to tourism indicators. NeoBiota 71: 51-69. https://doi.org/10.3897/neobiota.71.64618

An invasive plant may cost a Caribbean island 576,704 dollars per year

Guest blog post by Wendy Jesse

Coralita overgrowing vegetation. Photo from https://www.wur.nl/en/show/invasive-plants-in-caribbean-netherlands.htm

A recent study in One Ecosystem has estimated the severe loss of ecosystem service value as a result of the widespread invasion by the plant species Coralita (Antigonon leptopus) on the Caribbean island of St. Eustatius. The results illustrate the drastic impact that a single invader can have on the economy of a small island and inform policy makers about priority areas for invasive species management.

See for full article: Huisman, S., Jesse, W., Ellers, J., & van Beukering, P. (2021). Mapping the economic loss of ecosystem services caused by the invasive plant species Antigonon leptopus on the Dutch Caribbean Island of St. Eustatius. One Ecosystem, 6, e72881. https://doi.org/10.3897/oneeco.6.e72881

The invader: Coralita

  • Flowering coralita, creeping vertically over fences and horizontally across the ground.
  • Coralita intertwined with electricity box and cables. Photo by Adam Mitchell

Coralita is a fast-growing, climbing vine with beautiful pink or white flowers. Originally from Mexico, it was introduced as a popular garden plant to many Caribbean islands and around the world. Its fast-growing nature means that it can outcompete most native species for terrain, quickly becoming the dominant species and reducing overall diversity (Jesse et al. 2020, Nature Today 2020, Eppinga et al. 2021a). This is especially the case on St. Eustatius, where published ground surveys indicate that the plant already appears on 33 percent of the island.

Losses of ecosystem services

Coralita overgrowing cars. Photo by Rotem Zilber

We estimated the total terrestrial ecosystem service (ES) value on St. Eustatius to be $2.7 million per year by mapping five important terrestrial ecosystem services: Tourism, Carbon sequestration, Non-use (i.e., intrinsic biodiversity) value, Local recreational value, and Archeological value. Subsequently, we calculated Coralita-induced loss of ecosystem services under two realistic distributional scenarios of Coralita cover on the island: 3% of island dominantly covered (based on Haber et al. 2021, Nature Today 2021) and 36% dominant cover (if entire range would reach dominant coverage), causing an annual ES value loss of $39,804 and $576,704 respectively. The highest ES value (17,584 $/ha/year) as well as the most severe losses (3% scenario: 184 $/ha/year; 36% scenario: 1,257 $/ha/year) were located on the dormant Quill volcano; a highly biodiverse location with popular hiking trails for locals and tourists alike.

Consequences for policy makers and practitioners

Coralita blocking water a drainage channel. Photo by Wendy Jesse.

There is an urgent need for studies such as this one that help to bridge the gap between academia and policy planning, as these translate abstract numbers into intuitive information. Instead of invasive species being just a biological term, direct impacts on people’s value systems and sources of income immediately strike a chord. I experience this on a daily basis, because in addition to being a coauthor on this paper, I currently work as a policy employee in nature protection and management.

Coralita overgrowing archeological heritage on St. Eustatius. Photo from St. Eustatius Center for Archeological Research (SECAR)

This study helps to prioritize locations for invasive species prevention, management, eradication, and restoration. It is imperative that invasive species do not reach locations of high ecosystem service value. Management of isolated satellite patches of Coralita close to locations of high ES value will likely be most effective in halting the plant’s invasive spread (Eppinga et al. 2021b). Setting up a targeted monitoring and rapid response strategy, as well as legislation for biosecurity measures to prevent other invasive species from entering the island, would likely help to reduce impacts on the important ecosystem services on St. Eustatius.

References

Academic literature:

Eppinga, M. B., Haber, E. A., Sweeney, L., Santos, M. J., Rietkerk, M., & Wassen, M. J. (2021a). Antigonon leptopus invasion is associated with plant community disassembly in a Caribbean island ecosystem. Biological Invasions, 1-19.

Eppinga M, Baudena M, Haber E, Rietkerk M, Wassen M, Santos M (2021b) Spatially explicit removal strategies increase the efficiency of invasive plant species control.

Ecological Applications 31 (3): 1‑13. https://doi.org/10.1002/eap.2257Haber E, Santos M, Leitão P, Schwieder M, Ketner P, Ernst J, Rietkerk M, Wassen M, Eppinga M (2021) High spatial resolution mapping identifies habitat characteristics of the invasive vine Antigonon leptopuson St. Eustatius (Lesser Antilles). Biotropica 53 (3): 941‑953. https://doi.org/10.1111/btp.12939

Jesse, W. A., Molleman, J., Franken, O., Lammers, M., Berg, M. P., Behm, J. E., … & Ellers, J. (2020). Disentangling the effects of plant species invasion and urban development on arthropod community composition. Global change biology, 26(6), 3294-3306.

Blog posts on Nature Today website:

van Maanen, G. Molleman, J., Jesse, W.A.M. (2020) Drastic effects of coralita on the biodiversity of insects and spiders. Nature Today. naturetoday.com/intl/en/nature-reports/message/?msg=26339

Dutch Caribbean Nature Alliance (2021) Using satellite imagery to map St. Eustatius’ coralita invasion. Nature Today. naturetoday.com/intl/en/nature-reports/message/?msg=28317

NeoBiota invites risk analysis studies in a new Special Issue on advancements in the screening of freshwater and terrestrial non-native species

The “Recent advancements in the risk screening of freshwater and terrestrial non-native species” Special Issue in the open-access, peer-reviewed scholarly journal NeoBiota is now open for submissions. The deadline for submission is 30 April 2022, with the issue scheduled for publication in August 2022.

The “Recent advancements in the risk screening of freshwater and terrestrial non-native species” Special Issue in the open-access, peer-reviewed scholarly journal NeoBiota is now open for submissions.

The issue is managed by the international team of guest editors of Dr Daniela Giannetto (Mugla Sitki Kocman University, Turkey), Prof. Marina Piria (University of Zagreb, Croatia), Prof. Ali Serhan Tarkan (Mugla Sitki Kocman University, Turkey) and Dr Grzegorz Zięba (University of Lodz, Poland).

Update: The deadline for submission has been extended to 30 April 2022, with the issue expected to be published in August 2022. 

The new special issue is expected to collate prominent contributors from the field of invasive ecology, thereby addressing existing gaps in the knowledge about both freshwater and terrestrial non-native species and their management.

The editors note that despite the current efforts and measures to monitor and tackle the spread of non-native species, and especially those posing imminent threat to local biodiversity and ecosystems, further expansion of such populations has increasingly been recorded in recent years. Of special concern are developing countries, where legislation for controlling non-native species is still lacking.

A major problem is that – as of today – we are still missing on risk screening studies needed to provide evidence for the invasiveness potential of many non-native species across several taxonomic groups, which would then be used to support specific conservation efforts. Unfortunately, this is particularly true for species inhabiting the world’s biodiversity hotspots, point out the editors.

Risk-based identification of non-native species is an essential process to inform policy and actions for conservation and management of biodiversity. Previously published papers on risk screening of aquatic non-native species, and especially those using the most widely-employed ‘-ISK’ decision-support toolkits, have attracted mounting interest from the wider scientific community.

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Roadside invader: the higher the traffic, the easier the invasive common ragweed disperses

Common ragweed is an annual plant native to parts of the United States and southern Canada. It’s an invasive species that has spread to Europe. An important agricultural weed, this plant is particularly well-adapted to living at roadsides, and there are several theories why.

Its rapid expansion in Europe can’t be explained by its natural dispersal rate, which is limited to distances of around 1 meter. Rather, there are other factors in play, human-mediated, that support its invasion success – along roads, for example, it spreads mainly thanks to agricultural machineries, soil movements, roadside maintenance and road traffic.

Common ragweed. Photo: Uwe Starfinger

Studying common ragweed’s distribution patterns is important, because its allergenic pollen affects human health, mainly in southeast Central Europe, Italy and France. Finding out where it thrives, and why, can help with the management and control of its populations.

This is why scientists Andreas Lemke, Sascha Buchholz, Ingo Kowarik and Moritz von der Lippe of the Technical University of Berlin and Uwe Starfinger of the Julius Kühn Institute set out to explore the drivers of roadside invasions by common ragweed. Mapping 300 km of roadsides in a known ragweed hotspot in Germany’s state of Brandenburg, they recorded plant densities at roadsides along different types of road corridors and subject to different intensities of traffic over a period of five years. They then explored the effect of traffic density and habitat type, and their interactions, on the dynamics of these populations. Their research is published in the open-access, peer-reviewed journal NeoBiota.

Surprisingly, high-traffic road cells displayed a consistently high population growth rate even in shaded and less disturbed road sections – meaning that shading alone would not be enough to control ragweed invasions in these sections.  Population growth proceeded even on roadsides with less suitable habitat conditions – but only along high-traffic roads, and declined with reduced traffic intensity. This indicates that seed dispersal by vehicles and by road maintenance can compensate, at least partly, for less favorable habitat conditions. Disturbed low-traffic road cells showed constantly high population growth, highlighting the importance of disturbance events in road corridors as a driver for common ragweed invasions.

These findings have practical implications for habitat and population management of ragweed invasions along road networks. Reducing the established roadside populations and their seed bank in critical parts of the road network, introducing an adjusted mowing regime and establishing a dense vegetation layer can locally weaken, suppress or eradicate roadside ragweed populations.

Original source:Lemke A, Buchholz S, Kowarik I, Starfinger U, von der Lippe M (2021) Interaction of traffic intensity and habitat features shape invasion dynamics of an invasive alien species (Ambrosia artemisiifolia) in a regional road network. NeoBiota 64: 55-175. https://doi.org/10.3897/neobiota.64.58775

Citizen scientists help expose presence of invasive Asian bamboo longhorn beetle in Europe

A worryingly high number of Asian bamboo longhorn beetles turn out to have been emerging across Europe for about a century already, finds an international research team. Curiously, the records of the invasive, non-native to the Old Continent species are mostly sourced from citizen scientists and online platforms, which proves the power of involving the public in species monitoring. The study is published in the open-access, peer-reviewed scientific journal BioRisk.

A worryingly high number of Asian bamboo longhorn beetles (Chlorophorus annularis) turn out to have been emerging across Europe for about a century already, finds an international research team, headed by researchers from the Center of Natural History, University of Hamburg, Germany. Curiously, the recent records of the invasive, non-native to the Old Continent species are mostly sourced from citizen scientists and online platforms, which proves the power of involving the public in species monitoring. The study is published in the open-access, peer-reviewed scientific journal BioRisk.

In our globalised world, which has already become victim to climate change and biodiversity loss, non-native species present a further threat to our ecosystems. Thus, the rising accounts of newly recorded alien species are of serious concern to both scientists and (inter)national institutions. However, surveying non-native species remains limited to a small fraction of species: those known to be particularly invasive and harmful.

One of the multitude of non-native species that are currently lacking efficient and coordinated surveying efforts is the Asian bamboo longhorn beetle (Chlorophorus annularis). Naturally occurring in temperate and tropical Southeast Asia, the insect feeds on a variety of plants, but prefers bamboo. Thus, due to the international trade of bamboo and the insects ‘travelling’ with the wood, the species has continuously been expanding its distribution around the world. Its first appearance in Europe was recorded back in 1924, when it was identified in England.

Bamboo longhorn beetle captured in Braintree, United Kingdom
Photo by Stephen Rolls

Back to our days, during a fieldwork practice for students at the University of Hamburg, held within the city because of the COVID-19 travelling restrictions, the team stumbled across a longhorn beetle, later identified by scientists as the Asian bamboo borer. Furthermore, it became clear that there were even more recent records published across different citizen science platforms, such as iNaturalist, iRecord and Waarneming.nl. Having taken the contacts of the citizen scientists from there, the researchers approached them to ask for additional collection details and images, which were readily provided. As a result, the researchers formally confirmed the presence of the Asian bamboo borer in Belgium and the Netherlands. In total, they reported thirteen new introductions of the species in Europe, which translates to a 42% increase of the records of the species for the continent.

“In light of the warming climate and a growing abundance of ornamental bamboo plants in Europe, the beetle might get permanently established. Not only could it become a garden pest, but it could also incur significant costs to the bamboo-processing industry,”

comments Dr Matthias Seidel, lead author of the study.

Having realised the potential of citizen science for bridging the gaps in invasive species monitoring, the researchers now propose for specialised platforms to be established with the aim to familiarise non-professional scientists with non-native species of interest and provide them with more sophisticated reporting tools. The aim is to speed up the identification of important alien species by collating records of specific species of interest, which are flagged and regularly exported from other citizen science databases and platforms. 

Bamboo longhorn beetle captured in Lincoln, United Kingdom
Photo by Sheena Cotter

Original source: 

Seidel M, Lüttke M, Cocquempot C, Potts K, Heeney WJ, Husemann M (2021) Citizen scientists significantly improve our knowledge on the non-native longhorn beetle Chlorophorus annularis (Fabricius, 1787) (Coleoptera, Cerambycidae) in Europe. BioRisk 16: 1–13. https://doi.org/10.3897/biorisk.16.61099

Australia’s wish list of exotic pets

In a new study, published in the peer-reviewed open-access scholarly journal Neobiota, scientists estimated the desire of Australians to own non-native and/or illegal alien pets and the major trends in this practice. In addition, the team suggests ways to improve biosecurity awareness in the country.

Juvenile green iguanas for sale at Repticon Trading Convention 2018 in Palm Springs, Florida
Photo by Adam Toomes

Unsustainable trade of species is a major pathway for the introduction of invasive alien species at distant localities and at higher frequencies. It is also a major driver of over-exploitation of wild native populations. In a new study, published in the peer-reviewed open-access scholarly journal Neobiota, scientists estimated the desire of Australians to own non-native and/or illegal alien pets and the major trends in this practice. In addition, the team suggests ways to improve biosecurity awareness in the country.

Over the last two decades, Australia has been experiencing an increased amount of non-native incursions from species prominent in the international pet trade, such as rose-ringed parakeets, corn snakes and red-eared sliders. On many occasions, these animals are smuggled into the country only to escape or be released in the wild.

In general, the Australian regulations on international pet trade are highly stringent, in order to minimise biosecurity and conservation risks. Some highly-desirable species represent an ongoing conservation threat and biosecurity risk via the pet-release invasion pathway. However, lack of consistent surveillance of alien pets held, legally or otherwise, in Australia remains the main challenge. While there are species which are not allowed to be imported, they are legal for domestic trade within the country. Pet keepers have the capacity to legally or illegally acquire desired pets if they are not accessible through importation, and the number of such traders is unquantified.

Since keeping most of the alien pets in Australia is either illegal or not properly regulated, it is really difficult to quantify and assess the public demand for alien wildlife.

A juvenile ball python for sale at Repticon Trading Convention 2018 in Palm Springs, Florida
Photo by Adam Toomes

“We obtained records of anonymous public enquiries to the Australian Commonwealth Department of Agriculture, Water and the Environment relating to the legality of importation of various alien taxa. We aimed to investigate whether species desired in Australia were biased towards being threatened by extinction, as indicated by broader research on pet demand or towards being invasive species elsewhere, which would indicate trade-related biosecurity risks”,

shares the lead author Mr. Adam Toomes from the University of Adelaide.

According to the research team’s analysis, pets desired by Australians are significantly biased towards threatened species, invasive species and species prominent in the U.S. pet trade.

“This novel finding is of great concern for biosecurity agencies because it suggests that a filtering process is occurring where illegally smuggled animals may already be “pre-selected” to have the characteristics that are correlated with invasive species,”

warns Mr. Adam Toomes.

However, the bias towards species already traded within the U.S. suggests that there is potential to use this as a means of predicting future Australian desire, as well as the acquisition of pets driven by desire. Future research from the Invasion Science & Wildlife Ecology Group at The University of Adelaide will investigate whether Australian seizures of illegal pets can be predicted using U.S. trade data.

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Original source:

Toomes A, Stringham OC, Mitchell L, Ross JV, Cassey P (2020) Australia’s wish list of exotic pets: biosecurity and conservation implications of desired alien and illegal pet species. NeoBiota 60: 43-59. https://doi.org/10.3897/neobiota.60.51431

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A new species of black endemic iguanas in Caribbeans is proposed for urgent conservation

A newly discovered endemic species of melanistic black iguana (Iguana melanoderma), discovered in Saba and Montserrat islands, the Lesser Antilles (Eastern Caribbean) appears to be threatened by unsustainable harvesting (including pet trade) and both competition and hybridization from escaped or released invasive alien iguanas from South and Central America. Scientists call for urgent conservation measures in the article, recently published in the open-access journal Zookeys.

A newly discovered endemic species of melanistic black iguana (Iguana melanoderma), discovered in Saba and Montserrat islands, the Lesser Antilles (Eastern Caribbean), appears to be threatened by unsustainable harvesting (including pet trade) and both competition and hybridization from escaped or released invasive alien iguanas from South and Central America. International research group calls for urgent conservation measures in the article, recently published in the open-access journal Zookeys.

So far, there have been three species of iguana known from The Lesser Antilles: the Lesser Antillean iguana (Iguana delicatissima), a species endemic to the northernmost islands of the Lesser Antilles; and two introduced ones: the common iguana (Iguana iguana iguana) from South America and the green iguana (Iguana rhinolopha) from Central America.

The newly described species is characterised with private microsatellite alleles, unique mitochondrial ND4 haplotypes and a distinctive black spot between the eye and the ear cavity (tympanum). Juveniles and young adults have a dorsal carpet pattern, the colouration is darkening with aging (except for the anterior part of the snout). 

A basking iguana optimizing after different trials its warming by a curved position when the sun is low on the horizon on the Windward coast of Saba.
Сredit: M. Breuil
License: CC-BY 4.0

It has already occurred before in Guadeloupe that Common Green Iguana displaced the Lesser Antilles iguanas through competition and hybridization which is on the way also in the Lesser Antilles. Potentially invasive common iguanas from the Central and South American lineages are likely to invade other islands and need to be differentiated from the endemic melanistic iguanas of the area.

The IUCN Red List lists the green iguana to be of “Least Concern”, but failed to differentiate between populations, some of which are threatened by extinction. With the new taxonomic proposal, these endemic insular populations can be considered as a conservation unit with their own assessments.

“With the increase in trade and shipping in the Caribbean region and post-hurricane restoration activities, it is very likely that there will be new opportunities for invasive iguanas to colonize new islands inhabited by endemic lineages”,

shares the lead researcher prof. Frédéric Grandjean from the University of Poitiers (France).
Iguana melanoderma sunbathing at dawn on the Windward coast of Saba.
Сredit: M. Breuil
License: CC-BY 4.0

Scientists describe the common melanistic iguanas from the islands of Saba and Montserrat as a new taxon and aim to establish its relationships with other green iguanas. That can help conservationists to accurately differentiate this endemic lineage from invasive iguanas and investigate its ecology and biology population on these two very small islands that are subject to a range of environmental disturbances including hurricanes, earthquakes and volcanic eruptions.

“Priority actions for the conservation of the species Iguana melanoderma are biosecurity, minimization of hunting, and habitat conservation. The maritime and airport authorities of both islands must be vigilant about the movements of iguanas, or their sub-products, in either direction, even if the animals remain within the same nation’s territory. Capacity-building and awareness-raising should strengthen the islands’ biosecurity system and could enhance pride in this flagship species”,

concludes Prof. Grandjean.

The key stakeholders in conservation efforts for the area are the Dutch Caribbean Nature Alliance (DCNA), the Saba Conservation Foundation (SCF), the Montserrat National Trust (MNT) and the UK Overseas Territories Conservation Forum (UKOTCF), which, the research team hope, could take measures in order to protect the flagship insular iguana species, mainly against alien iguanas.

Geographical distribution of the three iguana groups identified by Lazell (1973) in the 1960s and new taxonomic proposition.
Credit: Breuil et al. (2020)
License: CC-BY 4.0

***

Original source:

Breuil M, Schikorski D, Vuillaume B, Krauss U, Morton MN, Corry E, Bech N, Jelić M, Grandjean F (2020) Painted black: Iguana melanoderma (Reptilia, Squamata, Iguanidae) a new melanistic endemic species from Saba and Montserrat islands (Lesser Antilles). ZooKeys 926: 95-131. https://doi.org/10.3897/zookeys.926.48679

Contact:

Frédéric Grandjean 
Email: frederic.grandjean@univ-poitiers.fr

What is the Asian hornet invasion going to cost Europe?

Since its accidental introduction in 2003 in France, the yellow-legged Asian hornet Vespa velutina nigrithorax is rapidly spreading through Europe. In a new paper, published in the open-access journal Neobiota, French scientists try to estimate the costs of the invasion regarding the potential damage to apiculture and pollination services.

Since its accidental introduction in 2003 in France, the yellow-legged Asian hornet (Vespa velutina nigrithorax) is rapidly spreading through Europe. Both experts and citizen scientists keep on identifying the new invader spreading all over the Old Continent in the last decades. 

In a recent study, French scientists led by Prof. Franck Courchamp at the Université Paris-Saclay and the CNRS, tried to evaluate the first estimated control costs for this invasion. Supported by the INVACOST project, their findings are published in the open-access journal Neobiota.

Since its invasion to France in 2004 when it was accidentally introduced from China, the Asian hornet has been spreading rapidly, colonising most of France at an approximate rate of 60-80 km per year, and also invading other European countries: Spain in 2010, Portugal and Belgium in 2011, Italy in 2012, Germany in 2014 and the UK in 2016. In the recent paper, published in the open-access journal Evolutionary Systematics, Dr. Martin Hussemann from CeNaK, University of Hamburg has recorded the northernmost capture of the Asian hornet in Hamburg in September 2019.

These data show that the Asian hornet is spreading all around Europe faster and faster with every year, even in climatically less favourable regions. The rapid invasion of the species is not necessarily caused by human-mediated dispersal, the species can rapidly spread on its own, but nevertheless, it is not uncommon.

Within its native and invasive range, V. velutina nigrithorax actively preys on honeybees, thus, causing harm to apiculture. Due to its active praying on wild insects, the Asian hornet also has a negative impact on ecosystems in general and contributes to the global decline of pollination services and honey production. Furthermore, by nesting in urban areas, the Asian hornet, which is well known for its aggressive behaviour, is a potential threat to human activities.

Currently, the control of the invasion is mainly undertaken by nest destruction and bait trapping, but none of these methods is sufficient enough to achieve complete eradication.

To proceed with the further control of the invasion, there is the need to evaluate economic costs. Those costs are divided into 3 main categories: (1) prevention of the invasion, (2) fighting the invasion and (3) damage caused by the invasion.

The cost of fighting the invasion of the Asian hornet is the cost of nest destruction. To identify those costs, the research team has studied information about the companies providing the services in the nest destruction, extrapolated the cost of nest destruction spatially and modelled the potential distribution of the invasive.


Estimated yearly cost of nest destruction if climatically suitable areas are fully invaded. Grey bars represent countries invasion hasn’t reached yet.
Credit: Prof. Franck Courchamp
License: CC-BY 4.0

As the calculations show, at the moment, the estimated yearly costs for eradication would be €11.9M for France, €9.0M for Italy and €8.6M for the United Kingdom.

“In 2006, only two years after the hornet was first observed in France, three departments were already invaded and the cost of nest destruction was estimated at €408k. Since then, the estimated yearly costs have been increasing by ~€450k each year, as the hornet keeps spreading and invades new departments. Overall, we estimated €23M as the cost of nest destruction between 2006 and 2015. If this temporal trend can be extrapolated for the next few years (i.e. if the hornet keeps spreading at a similar rate), we expect the yearly cost of nest destruction to reach an estimated value of €11.9M (given all suitable areas are invaded) in just 12 years,”

shares Prof. Franck Courchamp.

In Japan and South Korea, where the species has already been observed, the total yearly cost of nest destruction is estimated at €19.5M and €11.9M respectively.

So far, nests eradication is the most effective way to fight the invasion, though, it is not sufficient enough. As a result, so far, only 30-40% of the detected nests are destroyed each year in France. Moreover, rather than the result of a controlled strategy, those destroyed nests are only the ones that have been determined of particular potential harm to human or beekeeping activities. The researchers point out that this is not enough.


Estimated yearly cost of nest destruction in France since the start of the invasion given the yearly invasive range.
Credit: Prof. Franck Courchamp
License: CC-BY 4.0

In conclusion, the scientists call for more active measures and research, related to the invasion of V. velutina nigrithorax. Provided that other countries, including the USA, Australia, Turkey and Argentina appear to be climatically suitable for the species, they are also in danger (e.g., €26.9M for the USA).

The current study presents only the first estimates of the economic costs resulting from the Asian hornet, but definitely more actions need to be taken in order to handle harmful invasive species – one of the greatest threats to biodiversity and ecosystem functioning.

Consensus climate suitability of the yellow-legged hornet predicted from species distribution modelling.
Credit: Prof. Franck Courchamp
License: CC-BY 4.0

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Original source:

Barbet-Massin M, Salles J-M, Courchamp F (2020) The economic cost of control of the invasive yellow-legged Asian hornet. NeoBiota 55: 11-25. https://doi.org/10.3897/neobiota.55.38550

Faster than a speeding bullet: Asian hornet invasion spreads to Northern Germany

Known to prey on many insects, including honey bees and other beneficiary species, the Asian hornet, which had recently invaded parts of Europe, presents a serious threat to apiculture and even to ecosystems. In their paper, published in the open-access journal Evolutionary Systematics, German scientists share concerns about this fast invader spreading to the north. In early September 2019, a single specimen was collected alive in Hamburg (Germany), representing the northernmost find of the species so far.

In early September 2019, an Asian hornet (Vespa velutina nigrithorax) was collected alive in Hamburg, Germany, representing the northernmost find of the species so far in Europe and indicating its further spread to the north. The paper by the research group from Hamburg, which also serves to update the occurrence of the dangerous invader, was published in the open-access journal Evolutionary Systematics. 

Known to prey on many insects, including honey bees and other beneficiary species, the Asian hornet, which had already invaded parts of Southern and Central Europe, is a potential threat to apiculture and even to ecosystems. 

The first specimen was captured in south-western France in 2005 and started to spread quickly. Over the next years, it invaded large parts of France and regions of Spain, Portugal, Belgium, Italy, the Netherlands, Great Britain and south-western parts of Germany. The estimated invasion speed for France has been estimated at around 78 km/year, but in reality, the species spread might be occurring much faster due to anthropogenic factors.

It’s not yet clear if the collected Asian hornet belonged to an already settled population or it’s rather the first record of a new invasion. Nevertheless, considering the fast invasion speed of the species and its relatively high climatic tolerance, it’s quite possible that it had reached Hamburg on natural routes and now reproduces there.

Even though other models suggest that the Hamburg area is not suitable for the species today, the new find might be a sign that the Asian hornet has begun spreading at a speed above that previously known and even in climatically less favourable regions.

“Therefore, the current find needs to be taken seriously, no matter if it is only a single specimen or a member of an established population”, shares the lead researcher Martin Husemann from Centrum für Naturkunde, University of Hamburg.

Invasive species are one of the great challenges in the modern world. Their occurrence can be considered as one of the key important ecological and evolutionary drivers.

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Original source:
Husemann M, Sterr A, Maack S, Abraham R (2020) The northernmost record of the Asian hornet Vespa velutina nigrithorax (Hymenoptera, Vespidae). Evolutionary Systematics 4(1): 1-4.
https://doi.org/10.3897/evolsyst.4.47358