The future of invasion biology, like any other science, is dependent on its ability to successfully recruit and train the next generation of scientists. A major obstacle in accomplishing this goal is the lack of inclusivity in the field, which has historically maintained a monolithic and relatively homogenous workforce. Here, I provide three action-items, which can be deployed to help diversify the field of invasion biology: (i) diversify the gatekeepers, (ii) secure representation and (iii) contextualize and reframe terminology. The problem of invasive species has an extensive global reach and therefore it is only logical that the demographics of the invasion biology community should reflect this.

Sisyrinchium montanum is a perennial herb native to North America, introduced in Europe and considered weedy in many countries here. In Central Europe, it grows predominantly in the Eastern Carpathians in road verges, wet meadows and fens. The paper summarizes the occurrence in Slovakia within the whole of the Carpathians. The first report in Slovakia was dated back to 1931. In the western part of the country the species can be considered only a casual and a short-term one. In the eastern part, the Bukovské vrchy Mts and the eastern part of the Vihorlat Mts seem to be the centre of its naturalisation with clearly spreading along the forest roads. In the territory of Slovakia the species prefers sunny and open places, mostly the wet ones and it colonizes abandoned forest wood warehouses, forest clearings and wet meadows and fens.

New occurrences in Lithuania of Heracleum mantegazzianum Sommier & Levier, a species on the list of invasive alien species of European Union concern, are reported for the first time. Heracleum mantegazzianum was intentionally introduced in the 1990s and grown in a garden as an ornamental plant. After the abandonment of the homestead in ca. 1998, this plant gradually occupied open spaces and formed a dense stand around the place of cultivation and by mid-2000 it had begun to spread into the surrounding areas. The species was found at three sites in the vicinity of Bertaučiai village (Joniškis district, North Lithuania) in 2020. In 2020, the species occupied a total area of 0.35 ha, with different densities within the three sites. Considering the recent records of H. mantegazzianum in the vicinity of Bertaučiai village and the newly invaded areas, this species should be treated as already naturalized in Lithuania with a high potential for further spread and invasion into new areas. Therefore, immediate control and eradication measures should be implemented.

Centaurea macrocephala Muss. Puschk. ex Willd. (Asteraceae) is a perennial herb native to the Caucasus, Iran and Turkey. It has been introduced as an ornamental plant to Northern, Western and Central Europe, North America and New Zealand. In its primary range, the species occurs in glades of the upper montane zone, tall-herb vegetation and subalpine meadows. On secondary habitats, it occurs mainly in abandoned gardens, ruderal habitat, meadows and grassy clearings. In Poland, C. macrocephala is treated as a cultivated species and its naturalisation has not been confirmed so far. In this paper, we report a first spontaneous occurrence of the species in Poland. It was found in July 2018 in south Poland (Korzecko near Chęciny), growing on the secondary grassland near the bottom of an abandoned dolomite quarry. Most likely, the diaspores of C. macrocephala were introduced to the quarry with garden waste. The locality is mapped using the ATPOL cartogram method, photographic documentation of the species and phytosociological relevé documenting the floristic composition and plant cover of its habitat are provided. The species seems to be in an early stage of naturalisation; however, based on our own field observations we suggest that it should currently be classified as a casual alien species in Poland.

Sphaeralcea bonariensis (Cav.) Griseb. is here reported for the first time as alien species in Italy and in the Mediterranean area. It is a perennial shrub native to Southern America, where it is often considered a ruderal species frequent in cultivated areas. It was found in a population of a few individuals within Opuntia ficus-indica groves of Rocca Palumba territory (Western Sicily). Actually, due to short-term observational period and the low number of plants, Sphaeralcea bonariensis should be considered as a casual species in Italy. The ecological characteristics of the growing stand and the consistency of the population, as well as the possible causes of its introduction, are briefly discussed.

Opuntia macrorhiza (Cactaceae) was first found in Turkey in 2020 during floristic surveys in the Boyabat district of the Sinop province and in the Cide district of the Kastamonu province. We provide an identification key to distinguish it from Opuntia ficus-indica, a morphological description, as well as some basic information on invaded habitat and potential threats. Considering the traits of this new alien plant, allowing for rapid reproduction, and spread, it is expected it might invade further land without adequate interventions.

During field work carried out in northeastern Algeria between 2016 and 2021, a population of Austrocylindropuntia cylindrica (Lam.) Backeb. was discovered, a casual species not reported before from Algeria. We also report, for the first time, further data on the naturalization of Austrocylindropuntia subulata (Muehlenpf.) Backeb. in Algeria, a species already reported by the first author in 2019. We present a map of the current distribution of the two species in Algeria, field photographs, as well as information concerning their habitat and their biological characteristics, in particular their mode of reproduction.

Austrocylindropuntia subulata is an invasive new opuntioid cactus to the flora of Saudi Arabia collected from Al-Sarah highlands (south-western region). This is the second cylindrical cactus from the Cactus family recorded in the Kingdom after the discovery of Cylindropuntia rosea in the same region. It differs from C. rosea by lacking of jointed stem and absence of the spines sheath and having long conspicuous leaves. The plant was not widespread in the region. It is only confined to a limited protected area at an elevation of 1630 – 2160 m above sea level. Taxonomic key, general descriptions, diagnostic features and colored photographs are provided. As A. subulata is one of the restricted invasive plants worldwide, actions must be taken by the government to restrict the spreading risks of this taxon into the environment. No records have found regarding the uses of this species by the native people. Eradication steps should be taken to minimize its further distribution in the productive regions of the Kingdom.

Non-native aquatic plants have caused significant negative ecological and economic impacts in freshwater ecosystems. Waterpoppy (Hydrocleys nymphoides) is a rooted floating-leaf vascular plant native to South America that has been introduced to Europe, Oceania, and Africa through the aquarium trade. Recently, this species was brought to China where it has established widespread feral and naturalized populations in the south, southwest and lower reach of Yangtze River. Information about this species in China is very limited. We provide a preliminary overview of its introduction pathway, current distribution, and the ecological and economic impacts caused by waterpoppy in China.

In recent years, there have been numerous reports of species of both exotic and invasive predatory flatworms (Geoplanidae) across several islands of the Caribbean. During the rainy season from September to November 2020, citizen scientists reported and submitted photographs of sightings of exotic species of flatworms across eight of 14 parishes in Jamaica. This stimulated a collection of 439 samples of land planarians which were photographed and carefully identified using morphologically distinguishing features. The collections included three exotic species not previously reported from any Jamaican ecosystem, namely Bipalium vagum, Dolichoplana striata and Platydemus manokwari. The economic, environmental, or social impacts of these worms in Jamaican ecosystems are unknown as these species, among other planarians, are poorly studied. This paper reports the potential implications of exotic flatworm invasion in Jamaica, with emphasis on P. manokwari which, according to the ISSG Global Invasive Species Database, is among the world’s 100 worst invasive species. P. manokwari is also a known paratenic host species of a zoonotic parasite, Angiostrongylus cantonensis, which is the most common causal agent of eosinophilic meningitis in the world.

The number of alien insect species is increasing worldwide. An update of new records in particular countries is highly needed. Altogether, seven alien Orthoptera species were known until now in Slovakia, four of them already having been established. We present here the first records of the other two alien brachypterous bush-cricket species, Rhacocleis annulata and Yersinella raymondii in Slovakia, found during the Orthoptera survey in Bratislava city. Habitats, phenology, accompanying species in studied sites as well as morphology of adults and eggs are described and discussed. The most important pathway of introduction in both these species seems to be transport of eggs with ornamental plants or soil.

A five-month survey on Eucalyptus spp., one of the most commonly planted trees in Cyprus, was undertaken in Limassol and Akrotiri in urban, rural and protected habitats. Two alien gall-inducing Eucalyptus wasps: Leptocybe invasa Fisher and La Salle, 2004 and Ophelimus maskelli (Ashmead, 1900) (Hymenoptera: Eulophidae) were recorded for the first time from Cyprus. In addition, three new alien parasitoids: Stethynium ophelimi (Huber, 2006) (Hymenoptera: Mymaridae), Closterocerus chamaeleon (Girault, 1922) (Hymenoptera: Eulophidae) and Megastigmus lawsoni Doğanlar and Hassan, 2010 (Hymenoptera: Torymidae), were reared from O. maskelli and L. invasa galls. The distribution, introduction and management actions for Eucalyptus spp. and their alien Chalcidoidea associates are discussed.

Biological invasions are a driving force for biodiversity decline, worldwide. These dynamic systems often include the transference of symbiotic or pathogenic organisms that display their own threat to local fauna. Alternatively, parasites introduced during an invasion can help to control the invasive host population and limit ecological damage. To understand invasion systems that include parasites, it is important to record the presence of invasive parasites as they travel to novel locations. In this study, we screen non-native Dikerogammarus haemobaphes located in Boroughbridge (United Kingdom) for microsporidian parasites, using a PCR diagnostic. We found a prevalence of 9.1% for two microsporidian pathogens: Cucumispora ornata and Dictyocoela berillonum. Genetic data for the two parasites and accompanying haplotype maps are used to determine potential origin and relatedness. Our hapmap for C. ornata indicates two haplotypes of this parasite in the UK, sharing similarities with isolates from Poland and Germany. For D. berillonum, our data concur with recent findings that this parasite does not appear to have high relative genetic variability and shares similarities with isolates across the EU and from multiple hosts. These microsporidian pathogens have a wide host range and pose a risk to surrounding native crustacean fauna. We report the presence of these two parasites in their most northern range and consider their likely origin and connectivity with other isolates across the UK, Europe, and Russia.

Cymbella janischii (A. Schmidt) De Toni 1891, an endemic diatom of the Pacific Northwest, was found in 2006 in Japan, and since then, its distribution has been expanding. Here, we analyzed rbcL, psaB, psbA, 18S rRNA, and 28S rRNA gene sequences (6526 bp in total) of the C. janischii specimens from several locations in Japan and explored their genetic relatedness with C. janischii from its country of origin (the United States) and its closely related species. We showed that all Japanese specimens had the same sequences, regardless of geographical distance, and formed a clade with the US C. janischii. The identities and the pairwise distance between the sequences of the Japanese and the US diatoms were 99.937% and 0.0003, respectively, indicating that these diatoms are extremely similar. These results provide potential genetic evidence of the recent invasion and rapid spread of C. janischii from the US in Japan.

In 2019 the first specimens of the European ascidian Ascidiella aspersa were recorded at two southern California locations in and near Long Beach, the first records for the NE Pacific. Subsequent surveys during 2020-2021 of numerous sites have now recorded this species in nine locations from San Diego to Ventura. The non-indigenous status of Ascidiella aspersa in southern California is now considered Established, with populations reproductive and individuals of all sizes present. An increase in abundance of A. aspersa in southern California with new records in additional sites is predicted, with possible further northward movement.

Galba humilis (Say, 1822) is a freshwater mollusc belonging to the family Lymnaeidae, and it is distributed in North America. The present article documented the first record of this mollusc in Japan, which is outside the indigenous distribution range of the species. The species was identified using molecular phylogenetics. This is the first report of G. humilis introduction in the world, including Japan.

Marisa cornuarietis (Linnaeus, 1758) (giant ramshorn snail) is an aquatic snail of the family Ampullariidae Gray, 1824, which are generally referred to as apple snails. Several ampullariids, including M. cornuarietis, are invasive alien species across several islands of the Caribbean, where they are associated with considerable ecological and economic outcomes. During an aquatic snail assessment survey conducted from May to June 2021, 153 giant ramshorn snails were collected from two ponds and trenches exiting those ponds in the parish of St. Andrew, Jamaica. The specimens were photographed and carefully identified using distinguishing morphological features. Here we confirm the presence of the species in Jamaica and discuss potential environmental, economic, and social implications of this invasive species.

The Chinese mystery snail Cipangopaludina chinensis (Gray, 1834), a species native to Asia, is documented for the first time in Alberta, Canada, in McGregor Lake Reservoir in 2019. Here, we describe the initial finding of C. chinensis in Alberta, Canada, and biological information that may aid management efforts. Collected specimens were confirmed as C. chinensis through DNA barcoding. Analysis of growth rate, fecundity, and infection by digenean trematodes was assessed. It is unknown how C. chinensis arrived in Alberta. However, this species’ ability to withstand environmental stressors, such as desiccation, facilitates overland and long-distance transport via recreationists or deliberate release of C. chinensis into waterbodies. Snails collected from McGregor Lake Reservoir matched with GenBank results for C. chinensis from Korea. Analysis of digenean trematodes revealed that the population in McGregor Lake are not infected, as there were no cercariae present after 24 hours. Growth assessment over a period of 60 weeks revealed that shell length growth quickly outpaces growth in shell width. Upon emergence, C. chinensis are larger than many native snail species. The expansion of C. chinensis into Alberta poses potential negative consequences, such as decreased native snail biomass, increased nitrogen to phosphorus ratios, and additive impacts when paired with other invasive species.

The nudibranch Baeolidia moebii Bergh, 1888 is a sea slug widely distributed in the Indo-Pacific, including the Red Sea, from where it presumably entered the Mediterranean Sea through Lessepsian migration. Although the first record of this species in the invaded area dates back to at least 2007, it is only known so far from the Mediterranean basin based on three scattered records of single individuals, all found in the Levant Sea (Turkey and Cyprus). The present study reports the presence of B. moebii in Kalloni Gulf, a semi-enclosed shallow embayment located in Lesvos Island, a record that widens its known distribution to Greece and the Aegean Sea. Field observations of more than 150 individuals encountered in a single sampling event also allowed observation of intraspecific morphological variation and several specimens laying egg masses, thus first reporting of a spawning aggregation and providing concrete confirmation of its establishment success in the entire basin. Monitoring of such spawning events and aggregations may contribute to a better understanding of the population dynamics of the species. The discontinuous known distribution of B. moebii in the eastern Mediterranean can be attributed to false absence of the species due to its cryptic behaviour, its under-sampled habitat, or to a truly very patchy distribution because of secondary dispersion by currents or vessels, with establishment only in areas of particularly favourable conditions, such as the Kalloni Gulf.

Three specimens of the Northern American bivalve Yoldia limatula (Say, 1831) were retrieved from Le Havre Harbour (The English Channel, Normandy, France) for the first time in 2021. This species was initially recorded from Europe in the Netherlands in 2019, after which specimens were found in Belgium in 2020. This is the first record of this species in Normandy and France now extends the invasive range of the species from the eastern part of the English Channel to the southern part of the North Sea. This species is considered as non-indigenous in Normandy and was most likely introduced via ballast water due to intense marine shipping between North American and European harbours.

The long-wristed hermit crab Pagurus longicarpus is native to the East Coast of North America from the Gulf of Mexico to the Gulf of St. Lawrence. Here we present the first record of this species in the German Wadden Sea. Sixty-one individuals of P. longicarpus were found during a regular beam trawl survey at nine stations in the Meldorf Bight in late August 2020. The identity of the new species was confirmed by DNA barcoding of mitochondrial subunit I of cytochrome c oxydase (COI). The northward spread up to Hallig Hooge was documented in 2021, with a total of 122 P. longicarpus found at 12 stations. Pagurus longicarpus was found in 2.5 m to 18.0 m depth at salinities of 24.89 to 30.43 PSU and temperatures ranging from 16.46 °C to 22.22 °C. We compared these parameters with the environmental conditions in its native range by using data from the Global Biodiversity Information Facility (GBIF) and the GIS database MARSPEC. The results revealed that environmental conditions in the North Frisian Wadden Sea closely fits those in the native range of P. longicarpus. Different size classes and sexes were identified, including ovigerous females, indicating a reproducing population in the North Frisian Wadden Sea. The species was most likely introduced via ballast water transport and seems to be already well established.

The introduction of Australian Cherax quadricarinatus into Malaysia as an aquaculture species has resulted in wild populations in several Malaysian states, and it is now considered an invasive species. The introduction coincidentally co-introduced Diceratocephalid, flatworms that externally inhabit C. quadricarinatus. Thirty-three wild C. quadricarinatus were caught alive in Tasik Ayer Keroh, Melaka; while 32 cultured C. quadricarinatus were bought in Bandar Tenggara, Johor. Two species of ecto-symbiont (Diceratocephala boschmai and Decadidymus sp.) were morphologically identified and genetically 18S rDNA sequenced. Currently, only one 18S rDNA sequence is available for Decadidymus sp. in the GenBank, isolated from redclaw crayfish, C. quadricarinatus in Australia. This D. boschmai 18S rDNA phylogenetic analysis was consistent with the data from previous studies.

Platinum Ogon, an ornamental variant of the common carp Cyprinus carpio, is one of the most expensive and sought-after pet fish. Multiple parasite species from Dactylogyrus and Gyrodactylus were recovered from Platinum Ogon specimens during an ongoing nationwide study of the monogenoidean parasites that infect ornamental fish imported into India. The morphological examination, combined with a DNA-sequencing analysis of the 18S–ITS 1 and 28S rRNA genes, identified Dactylogyrus minutus as one of these parasites, establishing this species’ presence in India for the first time. This finding is significant for two reasons. First, D. minutus has been associated with high death rates in carp fry. Second, Cyprinus carpio, its host, has established itself in Indian riverine waters. The nucleotide sequence of the 28S rRNA gene of D. minutus was phylogenetically compared to that of 19 other Dactylogyrus species from three fish families: Cyprinidae (10 species), Leuciscidae (six species), and Xenocyprididae (three species). The phylogenetic tree analysis revealed the monophyletic lineage of Dactylogyrus species from goldfish and common carp, which is likely due to the genetic relatedness of their hosts.

On 21st May 2021, a single specimen of Hemiramphus far was caught by an angler along the southeastern coast of Sicily (Ionian Sea). This species has only been recorded once before in Italian waters, in 2013 in Lampedusa (Strait of Sicily). The presence of H. far in the Sicilian Ionian Sea, eight years after its first observation in Lampedusa, could indicate the spread of this species in Italian waters. We report the first record of the species in the Italian Ionian Sea and discuss its presence in Italian waters. Furthermore, we offer some considerations on its further expansion and the possibility of using this new resource for human consumption.

The whipfin ponyfish Equulites leuciscus (Günther, 1860) was recorded for the first time in the Mediterranean Sea. The species is widely distributed in the Indo-West Pacific and has been recognized as one of the most widespread species of ponyfishes. E. leuciscus has wide and oval body shape, very elongated second dorsal spine, and yellow dots adjacent to its lateral line. One specimen was caught at a depth of 28 m, on September 2021, in the Gulf of Antalya. The specimen was 101.6 mm in total length (TL). The length of second dorsal spine was 26.8 mm and the body depth (BD) to standard length ratio was 40.6%. The probable reason that E. leuciscus was not identified in the Mediterranean until now is that the species has no economic value and is very similar to Equulites klunzingeri.

The Yucatan molly Poecilia velifera (Regan, 1914) is a popular aquarium fish, endemic to the Yucatan Peninsula, Mexico. It has been introduced to many countries worldwide. In this paper, we report the occurrence of Yucatan molly in the Mediterranean lagoon of Ayn Zayanah (Benghazi, Libya). Eighty-two individuals (22 males and 60 females) were collected in July 2020 during a field survey. All individuals were identified as P. velifera based on morphological characters and molecular analyses, providing the first evidence of a Yucatan molly invasion into the Mediterranean region.

The Chinese sleeper Perccottus glenii (Actinopterygii: Odontobutidae), is an invasive alien species (IAS) of fish that has been included into the European IAS list of Union Concern. The present study aims to describe the current distribution of Chinese sleeper in the Ukrainian Lower Danube drainage. Fish assemblage monitoring took place at 70 localities inside the Budjak historical region in south-western Ukraine over a twenty-year period (2001–2021), with Chinese sleeper occurrence confirmed at 24 localities. Our data not only confirm the spread of invasive Chinese sleeper within the Budjak region, but also outside the Danube basin, including the Sasyk Lagoon (2 ind.) and several overgrown banks along sea foreshore. Considering that Chinese sleeper are presently found in waterbodies intensively used as fisheries, in river forefront marshes and at one site outside the Danube basin, it is highly plausible that further expansion of this fish species will be observed in the near future.

Early detection of the introduction of alien species is essential for effective management and to avoid potential detrimental effects. The ocellated skink, Chalcides ocellatus (Forsskål, 1775), is a known invasive species. In April 2017, an introduced free-ranging population was found for the first time on the Iberian Peninsula, in Serra del Molar (Alicante). In the last two years, new records have appeared in areas distinct from the first locality. To assess the actual extent of this species’ range, we conducted transects on foot in natural areas and held interviews with country house and plant nursery owners in the spring and summer of 2020. None of the transects in the natural areas found any C. ocellatus, but five confirmed and two probable records were obtained during interviews. These new localities were found between 6.3 and 12.5 km away from the initial locality. At the most distant locality, four country houses were surveyed and very high densities of C. ocellatus (25 skinks in a backyard of 0.2 ha) were found. The respondents agreed that the species started to be sighted around 2017 and 2018 and it is becoming more frequent with every passing year. Although we cannot rule out alternative scenarios, our data about the wide extension of the species and the high densities reached suggest a phase of rapid population expansion. According to guidelines of the allochthonous herpetofauna management in Spain, eradication and active management are strongly recommended before detrimental interactions with native wildlife, such as the endangered Bedriaga’s skink C. bedriagai (Boscá, 1880) being detected. However, the fossorial behaviour of C. ocellatus, and it extending to private areas can make any management efforts extremely difficult. Altogether, this case illustrates the key role of regulating the horticultural trade to avoid biological introductions.

As the pet industry continues to grow worldwide, reptile species have become increasingly popular, which has increased the trade of these species. However, as various species are bred, some are discovered in the wild after being lost or abandoned, which can result in ecosystem disturbances. Accordingly, in this study, we report a black-headed python (Aspidites melanocephalus) that was found in the wild for the first time, in the Republic of Korea. At the time of discovery, the deceased python was ascertained to be roadkill, and it appeared to have been killed a few days prior to discovery. The reptile was identified as a black-headed python through its appearance (head color, body stripes, etc.) and DNA analysis. It is suspected that the snake was a lost or abandoned pet. The occurrence of exotic reptiles in the wild may disturb Korean ecosystems. Thus, it is necessary to evaluate the current status of potentially exotic reptiles and improve the management of abandoned animals, especially reptiles.

The coypu is a semiaquatic rodent, native to South America and introduced to many parts of the world, mainly due to fur farming and as zoo animal. Nowadays, it is widely distributed in Europe, forming many invasive populations; thus, the species is listed as being of European Union concern according to the EU invasive alien species regulation. Here, we provide an update on the known status and distribution of the coypu in Austria since Spitzenberger (2001), presenting known occurrence records and additionally hunting bag data from the federal state of Styria. We derived 197 spatially explicit records, ranging from 1930 to 2021 and covering all nine federal states of Austria. Currently, the coypu is established in at least three federal states (Burgenland, Lower Austria, Styria) and probably also in Vorarlberg, with its main distribution in the lowlands of eastern to south-eastern Austria. We show a significant relationship between annual fluctuations in hunting bag data and the preceding winter temperatures suggesting that harsh winters might have a regulatory effect on Austrian coypu populations. Further, we emphasize the importance of monitoring and field surveys, not only for a detailed assessment of its distribution, but also to clarify potential metapopulation dynamics with occurrences in neighbouring countries. This is essential for future management, especially in the light of its declaration as invasive alien species of European Union concern.