I report here the first six casual records of the Chinese windmill palm Trachycarpus fortunei (Arecaceae, Magnoliopsida) in Austria (and eastern Central Europe). All records are located in cities and villages in the eastern warm lowlands, and in most cases, the escaped self-sown young specimens survived at least one winter. However, as all sites are located on horticulturally used public and private spaces, long-term survival was impossible. Given that the pronounced climate warming-trend of the last two decades in Central Europe will most likely continue, it is probable that Trachycarpus fortunei will become more frequent in Austria (and beyond), populations will become more long-lived, and natural habitats will likely be colonized.

Chilean needle grass, Nassella neesiana belonging to the tribe Stipeae (Poaceae), native to South America was recorded for the first time in Croatia. It was found in ruderal vegetation on the island of Veli Brijun in the Brijuni National Park (Istria, NW Croatia). This species can cause negative impacts to native grasslands, outcompeting native grasses or can increase fire hazards in peri-urban areas. Considering the species has already naturalized in a number of European countries, and the fact that the territory of Northern Croatia has been evaluated as suitable for its eastward expansion, it is of great importance to monitor and control the spread of the species in the Adriatic and possibly promote an early eradication. Notes on the environment in which it was found and its invasive status in Croatia are discussed.

Mature subtropical forests can resist the invasion of Mikania micrantha, a notorious exotic invasive plant, but the underlying mechanism for this resistance is still debated. In this study, we explored whether allelochemicals produced by the dominant species in a subtropical forest were sufficient to inhibit the invasion of M. micrantha. Allelopathic effects of three tree species (Syzygium rehderianum, Cryptocarya concinna and C. chinensis) on the germination and vegetative growth of M. micrantha were investigated. The results showed that aqueous extracts from the leaves of all tree species had allelopathic inhibitory effects on M. micrantha seed germination at a concentration of 5% aqueous extract. Variations were observed in the allelopathic effects of the tree species on germination rate (GR), germination energy (GE) and radicle length (RL), but all the tree species had the same synthetic allelopathic effect (SE). Reduced height, biomass, Chlorophyll (Chl a/b), Carotenoid/Chlorophyll (Car/Chl), antioxidant capacity, nonphotochemical quenching coefficient (NPQ) and increased specific leaf area (SLA) were observed in M. micrantha planted with the tree species. The allelopathic potential of the tree species on M. micrantha in a vegetative growth stage was weak. Our results indicated allelopathy alone was not sufficient to inhibit the invasion of exotic plants in subtropical forests, but the combination of allelopathy and shading may be sufficient.

New alien species are added every year to the European fauna. Although there are a few indigenous terrestrial flatworms in Europe, only one species has been recorded so far in Greece. For the first time, an alien flatworm species, Caenoplana bicolor, is recorded on the island of Crete. This finding suggests the need for control measures to prevent impacts from this bioinvasion.

We report the first observation of the invasive longhorn crazy ant (Paratrechina longicornis) in the Mount Elgon region of eastern Uganda. About 43 000 ants were sampled in 256 locations throughout the Ugandan foot slopes of Mt. Elgon in the years 2014, 2015 and 2016. We found P. longicornis in five locations in and around the town of Budadiri, Sironko district. The visual species identification was confirmed by COI gene-based DNA barcoding. That this species was found in only a small area suggests that it has only been recently introduced. The impact that P. longicornis will have on the local agricultural system or the biodiversity within the Mount Elgon National Park remains unclear. The Mt. Elgon region is a unique key biodiversity area where baseline data can be collected now to quantify the effects of P. longicornis as it increases its distribution within the region.

This contribution serves to formally report the first record of the non-native Asian seed beetle Megabruchidius dorsalis in Slovenia, found in 2017 and 2018 in Maribor. Within the range known at present in Europe this species has found a new food source – the seeds of the ornamental North American tree species Gleditsia triacanthos. From seeds collected in autumn of 2017 adult beetles emerged in the spring of 2018. Later in 2018, seeds in pods, which overwintered and were kept outdoors in summer, were collected in the beginning of autumn. Fully developed beetles were found and the inspection of 500 seeds showed heavy infestation from various life-stages, sometimes co-occurring, indicating that the multivoltine life cycle has been retained in the new range. Additionally, in two of seven locations both live and dead Hymenoptera parasitoids inside the pods with damaged seeds and beetle remains were observed.

Ophraella communa was found for the first time in Croatia. After the accidental discovery, further work was done to ascertain its extent of occurrence, density of adults and severity of host plant attack. Additional data pertaining to its current status in Croatia were also gathered. It was found on ten locations, with the highest recorded density in the SE part of Lonjsko Polje Nature Park. The damage levels of attack were never as high as in Italy or Switzerland. It is unknown whether this species was introduced intentionally or accidentally. Future work should focus on monitoring the spread and influence of this alien species in Croatia.

Bactrocera correcta (Bezzi, 1916), commonly known as the guava fruit fly, is of concern as an invasive pest in tropical and subtropical countries. It was first recorded in China in 1982 in Yuanjiang, in southern Yunnan Province. We monitored the spread of B. correcta in the field during 2017 and 2018, and found that it had moved about 300 kilometers eastward from its known range in 2011 in Yunnan and has now entered the neighboring Guangxi Province. A species distribution model used to predict the potential distribution of B. correcta in China revealed that southern China provides the most suitable habitat for B. correcta, and that further eastward expansion threatens large areas of southeastern China. Results from this study suggest that the rapid eastward migration of B. correcta is related to improved highway and high-speed railway systems in China that transport fruits and vegetables to eastern markets. This paper also discusses methods to slow the expansion of B. correcta in China.

We hereby report the finding of Ctenolepisma longicaudata (Escherich, 1905) in the Faroe Islands (62°N; 7°W), an isolated group of islands in the Northern Atlantic, approximately midway between Scotland and Iceland and > 300 km from the nearest land mass (Shetland). C. longicaudata is a wingless insect belonging to the order Zygentoma. Other insects in this group include the common silverfish, Lepisma saccharina, which has previously been reported in the Faroe Islands, but it seems less common than C. longicaudata. C. longicaudata and L. saccharina are superficially similar, but there are several features that distinguish the two species, such as the much longer tail filaments in the former. Although previously unregistered in the Faroes, a citizen-science approach using social media showed that C. longicaudata is widespread and common. Both insects often live in households. Although generally harmless, they may cause damage on paper, tapestries, etc. While L. saccharina needs warm and humid conditions, C. longicaudata can stand drier conditions, and thus can be more of a problem in archives, museums and alike.

Aedes aegypti is an important vector mosquito for arboviruses globally. It is believed to originate from North Africa and was introduced to other parts of the world through trade systems and transportation. Despite its now widespread distribution, there are still many regions in which the species is likely to occur, but is yet to be reported, hindering our understanding of invasion debt dynamics. Here, we record Ae. aegypti, a semi-aquatic invasive species, for the first time in Botswana. The species was sampled from an urban location in Palapye, a village in the arid central district of the country. The larvae were collected from plastic containers with rain water, reared to adults and subsequently identified using morphological and molecular techniques.

Two species of social wasps have established in the Faroe Islands in 1999 – common wasp Vespula vulgaris and German wasp Vespula germanica. The population growth, and dispersal in the Faroes has been followed in detail through correspondence and contact with local residents and authorities throughout the Faroes. Collected wasps have been identified, and nest eradication data from the local municipalities is also presented. In total there have been 1.222 nests located and destroyed, mostly in Tórshavn, where they were first introduced, but nests have also been found on neighbouring islands. Both the introduction and the spread within the Faroes suggest a strong relationship with human settlements and travel. Social wasps have established on four out of 18 islands – all of which are connected by land, suggesting that their spread within the islands is also human aided. With no active biosecurity measures to prevent the introduction of invasive alien species to the Faroes, we predict that the introduction of more species of social wasps to be very likely, and wasps already present will likely invade new islands. Although social wasps represent a public nuisance in the Faroes, the potential ecosystem impacts are grossly underappreciated and understudied.

The occurrence of the invasive Brown anole, Anolis sagrei from the Pacific coast of Mexico is confirmed based on squamation and the use of morphological characters. A PCA was performed to explore the morphological differences between the invasive anole and the native Clouded anole Anolis nebulosus. Some of the potential implications for dry tropical ecosystems and native anoles are discussed.

The Japanese seaweed Sargassum muticum (Yendo) Fensholt is reported for the first time from the Algerian coasts in Cherchell and Sidi Fredj, which are approximately 80 and 30 km, respectively, west of Algiers. Observations of drifting specimens, collected in March 2015 and March and April 2017, suggest that this non-indigenous species has reached Algerian waters. However, S. muticum cannot yet be considered established since the collected seaweeds were not fixed to substrata, were not fertile, and there was no evidence of colonization. Potential vectors of spread for S. muticum into the area include shipping, oyster farming and ocean circulation. In the future, intensive survey and monitoring actions are needed to detect any fertile or attached fronds.

Non-native ascidians are becoming a global problem and several species have recently been used as models for studying invasion success in the marine realm. Despite a limited dispersal due to their short-lived larvae, they are often found in coastal habitats as a result of human activities. As one of the warmest waterways in the world characterized by heavy marine traffic, the Persian Gulf is particularly prone to invasive ascidians. This study is the first to have documented the occurrence of the colonial ascidian Didemnum psammatodes in natural and man-made substrates in intertidal zones at 15 study sites in Qeshm and Hengam Islands in the Eastern Persian Gulf. High densities of D. psammatodes were observed at several study sites located far from major ports, but close to human residences, which may be explained by the prevalence of hard-surface man-made substrates.

New records of alien and cryptogenic invertebrate marine species in Libya are reported here based on field surveys conducted from June to November 2018, in a shallow bay next to the city of Tripoli. Those identified here include the cerithiid gastropod Cerithium scabridum Philippi, 1848, the goniodoridid sea slug Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli and Crocetta, 2019, the “spaghetti bryozoan” Amathia verticillata (delle Chiaje, 1822), and the ascidian Symplegma brakenhielmi (Michaelsen, 1904).

The cribrimorph bryozoan Cribrilina (Juxtacribrilina) mutabilis (Ito, Onishi and Dick, 2015), originally described from Hokkaido, Japan, is reported for the first time in the Gulf of Maine and the whole of the Northwest Atlantic coast. In September 2018, numerous colonies of C. mutabilis were collected from eelgrass (Zostera marina Linnaeus, 1753) beds near Clapboard and Mackworth Islands, and Hog Island Ledge, all located within inner Casco Bay, Maine. Bryozoan colonies encrusted eelgrass, rockweed (Ascophyllum nodosum (Linnaeus) LeJolis, 1863), and laminarian drift algae. Situated near the discovery location, the city of Portland (Maine, USA) is an active seaport, suggesting introduction through shipping as a likely introduction mechanism. The North Sea is hypothesized to be the most probable area for the source population. Since C. mutabilis appears to have high potential for introduction, it likely occurs on other parts of the Northwest Atlantic coast where it has yet to be identified and recorded.

A single specimen of a Pelagiidae jellyfish (Scyphozoa) referable to the genus Chrysaora Péron and Lesueur, 1810 is reported from the port of Elefsina (Saronikos Gulf, Greece) on the basis of photographic evidence. Despite the absence of a voucher and the impossibility to check fine morphological features of diagnostic value, its recognizable features (coloration, umbrellar and oral arms morphology, number of tentacles, and squared shape of marginal lappets) are consistent with the group of the “Pacific” Chrysaora, and in particular with Chrysaora achlyos Martin, Gershwin, Burnett, Cargo and Bloom, 1997. The specimen is therefore identified here as Chrysaora cf. achlyos, a candidate as a new non-indigenous species in the Mediterranean Sea. Although this rare species has been often observed as single specimens even in its native range (northeastern Pacific Ocean), the occurrence of additional individuals cannot be excluded due to possible misidentifications with the native Chrysaora hysoscella (Linnaeus, 1767). Citizen science proved again to be a useful tool for NIS detection and monitoring, which overall calls for the necessity of focused and joint programmes along the whole Mediterranean coastline.

The ctenopod Diaphanosoma fluviatile has been reported primarily from the Neotropical region and occasionally from the southern United States. D. fluviatile was collected in the Great Lakes basin (the Maumee River, Western Lake Erie, and Lake Michigan) in 2015 and 2018, far north from its previously known distribution. The occurrence of this southern species in the Maumee River and Great Lakes may be the result of an anthropogenic introduction, although a natural range expansion cannot be excluded. This report documents the northernmost record of D. fluviatile in the Nearctic region, extending the known distribution of the species to 42°N, which is a notable increase of 11 degrees latitude. Our detection of D. fluviatile is the first record of this southern species from the Laurentian Great Lakes drainage.

The parasitic copepod Mytilicola orientalis infesting mussels and oysters was so far only described in saline waters – such as the North Sea. In April 2018, it was recorded for the first time at a low salinity location in the Kiel Bight, Baltic Sea. Two mature females of M. orientalis were found in two separate individuals of Baltic blue mussels (Mytilus spp.). Prevalence of parasites in the whole sample was low (3.6%), and no males or eggs were detected. In a second sample from October 2018, another adult female was found indicating spread over larger areas and longer time periods. The findings of this study further indicated that larvae from introduced M. orientalis adults can hatch under low saline conditions of Kiel Fjord and are able to infest and to develop within tissues of Baltic blue mussels. It therefore may just be a matter of time before the establishment of the full life cycle of M. orientalis in the Baltic Sea.

The Barbronia weberi (Blanchard, 1897) appeared as a new species in the Hungarian aquatic macroinvertebrate fauna. In 2018, the B. weberi was found on two sampling sites in the River Danube and the stream called Perint. The occurrence location in the Danube is at Paks, while the location in the Perint is near the wastewater treatment plant of Szombathely. To collect the animals we used „kick and sweep” with a standard pond net. According to the results obtained B. weberi has self-sustaining populations in the warmer section of the Danube, which is affected by the cooling water of the power plant. Both direct and indirect vectors form the distribution pattern of the species. On the one hand the Danube is one of the major spreading routes of non-native species in Europe. So B. weberi can spread directly; on the other hand, the sampling points of the Danube and the Perint are almost 200 km away from each other, which suggests the possibility of indirect spreading; i.e. through waterfowls or aquarium trade.

The Vicente Guerrero reservoir is the sixth largest water reservoir in Mexico. This is a primary water source for the northeast region as well as a frequently holiday touristic site. In this paper we report aquatic specimens of the bivalve Corbicula fluminea, along with the gastropods Melanoides tuberculata and Tarebia granifera for the first time in the reservoir. This is also the first report of M. tuberculata and T. granifera for the Soto la Marina basin, and the first record of T. granifera for Northeast Mexico. The establishment of these species in the water body represents a potential threat to the native species and human health, since they are intermediate hosts in the life cycle of some parasites, such as Centrocestus formosanus trematode. Their arrival may be due to aerial, aquatic or commercial dispersion, since they can become adhered to, and hidden easily on birds, boats or aquarium ornamental plants, respectively. The introduction of these species may also cause potential economic losses for the agricultural, aquaculture and fishing activities in the local area. Due to high potential of dispersion, displacement of native species and pathogen transmission, the establishment of preventive actions is recommended to avoid their potential expansion in other aquatic bodies of the Soto la Marina basin.

The invasive Asian green mussel Perna viridis is native to the Indo-Pacific Ocean but introduction events of this species have been reported from other locations in the Pacific basin (Japan); the Caribbean (Trinidad and northeastern Venezuela) as well as North Atlantic (Florida). In this communication, we report the first record of the bivalve Perna viridis in the South Atlantic. Two specimens were found on experimental plates installed at Guanabara Bay (23°S and 43°W) Rio de Janeiro, Brazil in May 2018. Thereafter, a survey was carried out in the surroundings and five others individuals were found. The mussels had on average a length of 48.5 mm ± 29.7; width of 25.1 mm ± 12.2 and height of 16.1 mm ± 9.9. Guanabara Bay is a heavily urbanized and polluted estuary, which houses a large port area with high maritime traffic. Fouling on vessels may be the most likely vector of introduction of P. viridis. The occurrence of this species in the Guanabara Bay port area represents a risk to other areas of the Brazilian coast and neighboring countries, connected by maritime trade and recreational vessels. Our findings emphasize the need to implement a monitoring programme for P. viridis presence and potential spread in Guanabara Bay and to surroundings areas.

A decade long monitoring programme has revealed a flourishing population of the non-indigenous skeleton shrimp Paracaprella pusilla in the vicinity of outfalls of desalination plants off the Mediterranean coast of Israel. The first specimens were collected in 2010, thus predating all previously published records of this species in the Mediterranean Sea. A decade-long disturbance regime related to the construction and operation of the plants may have had a critical role in driving the population growth.

This is the first report of Charybdis (Charybdis) hellerii (A. Milne-Edwards, 1867) on the Mexican coast of the Gulf of Mexico. Six specimens were collected with crab traps in Sisal, Yucatan, and one in Bahamita on the marine coast of the Laguna de Términos in Campeche, Mexico, with a seabob trawl net. Further sampling and monitoring are required to find conclusive evidence that the species is established in this area. The appearance of this species is a concern due to the potential impact it could have on the populations of other native species of crabs of economic importance.

Invasive marbled crayfish Procambarus virginalis (Lyko, 2017) is spreading alarmingly fast across European countries and beyond. Early maturation, parthenogenetic reproduction mode and high growth rate contribute to a high potential invasiveness. Marbled crayfish can pose severe effects on native communities impacting the native crayfish populations being carrier of the crayfish plague disease caused by Aphanomyces astaci. Here we report the first record of marbled crayfish in Estonia. In total, 104 individuals were found in the artificially warm outflow channel of the cooling system of Balti Power Plant, entering to the water reservoir of the River Narva. Molecular analyses confirmed the morphological identification of captured specimens as a marbled crayfish. Four out of six marbled crayfish individuals exhibited the presence of crayfish plague agent, though at very low level. This suggests that marbled crayfish can potentially be a new vector of crayfish plague in Estonian freshwater ecosystems containing native noble crayfish Astacus astacus populations. Monitoring and eradication actions are urgently needed not only in the outflow channel where the species was found but in the whole water reservoir and River Narva itself.

The western tubenose goby (Proterorhinus semilunaris) has been documented in the Great Lakes basin since the 1990s, when it was introduced to the system via the discharge of ballast water originating in the Ponto-Caspian region of eastern Europe. The first report of this species in the eastern Lake Ontario-St. Lawrence River Basin occurred in 2011, outside of Kingston, Ontario, but beginning in 2016 it has consistently appeared in annual ichthyological surveys in the Thousand Islands region of the upper St. Lawrence River. While these fish have not been detected in great numbers, their presence marks an expanding eastern invasion front into the St. Lawrence River, which could have ecological implications systemwide. Both active adult movement and passive downstream drift of larval tubenose goby coupled with introduction of this species via domestic ballast water discharge within the Great Lakes could be providing a secondary invasion route along the St. Lawrence Seaway.

The sohal surgeonfish Acanthurus sohal and the reef stonefish Synanceia verrucosa are marine fishes native to the Indo-Pacific realm. A single individual of each of the two species was captured from the coastal waters of the city of Gaza and their pictures were shared on social media. This constitutes the second record of the surgeonfish and the fourth record of the stonefish in the Mediterranean Sea. The proximity to the Suez Canal suggests Lessepsian migration as a likely mode of entry to the Mediterranean Sea for A. sohal and adds another record of S. verrucosa in the basin.

A specimen of Cichla kelberi Kullander and Ferreira, 2006 was captured for the first time from Lake Kinneret (Sea of Galilee or Lake Tiberias), Israel. Its identification was made by morphological and molecular means. Although importation of this species to Israel is prohibited, commercial importers have smuggled juveniles as aquarium fish. The introduction vector of the specimen in Lake Kinneret is probably due to release or escape from the aquariums of hobbyists.

The invasive alien species (IAS) and adult trematode parasite of reptiles, birds and mammals (including humans), Haplorchis pumilio (Looss, 1896), is recorded for the first time from Yucatán state in Mexico. The ornamental freshwater fish species, Carassius auratus (“goldfish”) from pet shops from Mérida City, were necropsied to search for parasites. The trematode was identified based on molecular and morphological data of metacercariae collected from seven out of ten pet shops sampled. Partial sequences of the 28S ribosomal and COI mitochondrial genes corroborate the identifications based on morphological characters. DNA sequences from GenBank showed low genetic divergence in both genes from H. pumilio associated with three different host groups during larval and adult stages around the world, e.g., cercariae from Melanoides tuberculata (“red-rimmed melania”), from Trichogaster trichopterus (“three spot gourami”) and trematode adults from Homo sapiens. We infer that this trematode was likely introduced by accident through pet shop commerce together with the complex of the IASs, M. tuberculata and C. auratus. As Yucatán is the second major ornamental fish producing state in Mexico, accidental release of these IASs into the aquatic environment could result in the introduction of H. pumilio into regional freshwater bodies. The introduction of H. pumilio in Yucatán is probably relatively recent and due to the paucity of studies directed at this parasite, its distribution is not well known, but since its potential pathogenicity can cause an emergence of diseases, not only in wildlife, but also in local human populations, particular attention should be given to the findings of this study.

The trematode parasite Transversotrema patialense (Soparkar, 1924) (Digenea: Transversotrematidae) is reported from New Zealand for the first time. The parasite was first observed serendipitously within water surrounding the non-indigenous thiarid snail Melanoides tuberculata, a known intermediate host, bought from an online Auckland aquarium trade supplier in April 2016. In 2019, we systematically surveyed M. tuberculata from three online suppliers, a home and university laboratory aquaria, and from the only known New Zealand “wild” population, to determine its prevalence. The parasite was found to be present only from snails bought from a single Christchurch supplier. The establishment of T. patialense in New Zealand’s natural waters will be dependent on the presence of M. tuberculata, and appropriate fish hosts, and will therefore likely be limited to geothermally warmed waters. Release of infected snails from aquaria would be required for the establishment of the parasite in the “wild” population, and in other suitable habitats. Further research is necessary to quantify the threat that T. patialense poses to native fish in New Zealand, though these are not typically found in geothermally heated waters. The greatest risk of the parasite currently is to the health of captive tropical aquarium fish.