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.
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.
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.
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.
“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”,
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.
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
Spiders are one of the most successful groups of ‘invaders’ on the planet. Out of over 47,000 species of spiders known today, there are some that tend to follow humans across the globe and settle in habitats far away from their native homelands. A particularly notorious example is the species Steatoda nobilis, the Noble False Widow spider.
Originating from Madeira (Portugal) and the Canary Islands (Spain), the Noble False Widow has been rapidly spreading around the globe over the last few decades. While the species is already well established in Western Europe and large parts of the Mediterranean area, it has recently spread into California, South America and Central Europe. Meanwhile, its populations in England, where the spider used to be restricted to the very southern parts of the country, are now seen to experience a sudden expansion northwards.
As its name suggests, this is a relatively large species that resembles the well-known Black Widow and can inflict a painful – yet mostly harmless to humans – bite. Naturally, its ‘arrival’ causes widespread concerns and public disruptions. Specifically, the Noble False Widow poses a threat to native faunas, since it can prey on nearly every smaller animal thanks to its potent venom and sturdy webs.
Recently, experts and non-professional citizen scientists joined forces to reconstruct the invasion path of the Noble False Widow in Europe and the Americas, so that they could identify patterns and predict which regions are likely to be the next colonised by the spider.
While it had largely been assumed that the Noble False Widow turned up in Europe along with bananas traded from the Canary Islands, a new look at the data revealed that the spiders have most likely been transported via imports of ornamental plants. Further, rather than the result of climate change, the establishment of the species across new, large territories is rather linked to the fact that these habitats all share similar conditions to the spider’s native localities.
“Similar suitable False Widow habitats occur in quite specific regions all around the globe,” explain the researchers. “Most importantly, South Africa, some areas in southern Australia, and a large part of New Zealand turn out to be highly likely targets for future invasions, unless appropriate import control measures are implemented.”
In conclusion, the authors call for enhanced monitoring of the Noble False Widow as well as its still little known ecological impact on the environment in newly colonised areas. They also urge scientists in the predicted potential invasion target regions to search for specimens, especially in coastal cities.
Bauer T, Feldmeier S, Krehenwinkel H, Wieczorrek C, Reiser N, Breitling R (2019) Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends. NeoBiota 42: 19-43. https://doi.org/10.3897/neobiota.42.31582
Staple and economically important crops throughout the world could be at serious risk if efficient measures are not taken soon
Known to be feeding on many economically important crops cultured across the world, including maize, rice, sugarcane, sorghum, beet, tomato, potato, cotton and pasture grasses, the larvae of the native to the Americas fall armyworm moth seem to have already found a successful survival strategy in a diverse and changing world.
Furthermore, having taken no longer than 2 years to invade and spread throughout most of sub-Saharan Africa, the pest has already demonstrated its huge potential in severely affecting livelihoods around the globe.
The alarming reports started in January 2016 when major outbreaks of fall armyworms were registered in Nigeria and Ghana, preceding signals from Benin, Sao Tomé and Togo shortly after. By September 2017, the pest had already been confirmed in 28 sub-Saharan African countries, with nine states expected to follow suit.
While unaided dispersal of the species in Africa is considered unlikely, it is speculated that the pest had arrived on a passenger flight from America. To back this theory, the researchers point out that the first countries to house the invader are also the major air transportation hubs in Africa and have warm, moist climate similar to those in the pest’s natural habitat.
In the aftermath, recent estimates point to up to 50% maize yield loss in Africa attributed to the fall armyworm. However, scientists believe that the species is far from finished spreading and is highly likely to invade new continents.
To find what makes a region an inviting new habitat for the fall armyworm, hence which countries face the highest threat of future invasions, the researchers looked into both the native and African distributions of the species, and the effects different temperatures and precipitation levels have on it.
Having concluded that the lowest temperatures and the maximum amount of rain play the main role in determining whether the fall armyworm is to establish in a certain region, the scientists concluded that South and Southeast Asia, as well as Australia face the most serious risk, since their climate is very similar to the one preferred by the pest.
However, the authors of the study remind that this forecast shall in no way be taken with a sigh of relief by countries with milder climatic conditions. While the moth needs particular temperature and precipitation amplitudes at its year-round habitat, it could easily travel back and forth up to several hundred kilometres during its seasonal migrations. Therefore, if the fall armyworm establishes in North Africa, it could migrate to Europe during the warmer months, just like it has already been observed to travel from its year-round localities in Argentina, Texas and Florida all the way to Canada’s Québec and Ontario in the north.
The increasing transportation and international trade are also likely to facilitate the further spread of the fall armyworm outside Africa. The scientists conclude that, given the current travel air routes, it is Australia, China, India, Indonesia, Malaysia, Philippines and Thailand which are at high risk of becoming the pest’s new habitat.
Having concluded that there is a considerable potential for near global invasion and seasonal migration of fall armyworm, the scientists call for vigilance from farmers and programme managers alike. They remind that early detection of small larvae is crucial, since it is only at this stage that chemical insecticides would work effectively.
“As fall armyworm has huge potential to affect staple and economic crops globally, we urgently need information on the pest’s potential distribution and environmental limitations,” comment the researchers.
“Management decisions would be improved by further research on fall armyworm’s seasonal migration and population dynamics and the environmental dependency of interactions with other species.”
Early R, González-Moreno P, Murphy ST, Day R (2018) Forecasting the global extent of invasion of the cereal pest Spodoptera frugiperda, the fall armyworm. NeoBiota 40: 25-50. https://doi.org/10.3897/neobiota.40.28165
A preprint of the study was published earlier on bioRxiv.
In 2010, moth collector James Vargo began finding numerous specimens of a hitherto unknown pygmy moth in his light traps on his property in Indiana, USA. When handed to Erik van Nieukerken, researcher at Naturalis Biodiversity Center (Leiden, the Netherlands) and specialist in pygmy moths (family Nepticulidae), the scientist failed to identify it as a previously known species.
Then, Erik found a striking similarity of the DNA barcodes with those of a larva he had recently collected on Siberian elm in Beijing’s botanical garden. At the time, the Chinese specimen could not be identified either.
In October 2015, Daniel Owen Gilrein, entomologist at Cornell Cooperative Extension of Suffolk County (New York, USA), received samples of green caterpillars seen to descend en masse from Siberian elm trees in Sagaponack, New York. He also received leafmines from the same trees.
Once they joined forces, the researchers did not take long to find out that the specimens from James Vargo and the caterpillars from New York belonged to one and the same species. The only thing left was its name.
Following further investigation, the scientists identified the moth as Stigmella multispicata – a pygmy moth described in 2014 from Primorye, Russia, by the Lithuanian specialists Agne Rociene and Jonas Stonis.
“Apparently, this meant that we were dealing with a recent invasion from East Asia into North America,” explains Erik.
Once the researchers had figured out how to identify the leafminer, they were quick to spot its existence in plenty of collections and occurrence reports from websites, such as BugGuide and iNaturalist.
With the help of Charley Eiseman, a naturalist from Massachusetts specializing in North American leafminers, the authors managed to conclude the moth’s existence in ten US states and two Canadian provinces. In most cases, the species was found on or near Siberian elm – another species transferred from Asia to North America.
Their study is published in the open access journal ZooKeys.
Despite the oldest records dating from 2010, it turned out that the species had already been well established at the time. The authors suspect that the spread has been assisted by transport of plants across nurseries.
“Even though Stigmella multispicata does not seem to be a real problem, it would be a good idea to follow its invasion over North America, and to monitor whether the species may also attack native elm species,” the researchers point out.
Interestingly, in addition to the newly identified moth, the Siberian elms in North America have been struggling with another, even more common, invasive leafminer from Asia: the weevil species Orchestes steppensis. The beetle had been previously misnamed as the European elm flea weevil.
van Nieukerken EJ, Gilrein DO, Eiseman CS (2018) Stigmella multispicata Rociene & Stonis, an Asian leafminer on Siberian elm, now widespread in eastern North America (Lepidoptera, Nepticulidae). ZooKeys 784: 95-125. https://doi.org/10.3897/zookeys.784.27296