Heracleum mantegazzianum, commonly known as giant hogweed, is a highly invasive plant species in Europe, included in the list of invasive alien species subject to regulation in the European Union. Native to the Caucasus Mountains in Southwest Asia, it has established itself in several temperate regions around the world, raising concerns due to its ecological impacts and risks to human health. In Italy, it was introduced in the late 19th century and has since escaped from cultivation and spread, but it has also disappeared from numerous sites, either because it failed to establish or was successfully managed. Consequently, information on its presence is inconsistent, and a comprehensive overview of its distribution is lacking. This study compiles and updates records from multiple sources—including field surveys, herbarium collections, and literature—to provide an overview of its distribution in the country. The results highlight that, despite recent control measures, H. mantegazzianum remains widespread in northern Italy, particularly across the Alpine region. This makes it a priority for monitoring and management strategies, especially as climate change may facilitate its range expansion to higher elevations, increasing the risk of invasion in mountain ecosystems rich in endemic species, which are both vulnerable and of high conservation value.

Centratherum punctatum Cass, a melittophilous shrub endemic to tropical America and Australia, has spread extensively in warm climate countries and has become an invasive species. This paper presents the first official documentation of this species naturalized outside of cultivation in South Africa. Six populations were recorded along roadsides in two provinces, primarily in Limpopo province and Kwa Zulu Natal. One of these populations was identified by a citizen scientist in South Africa. To prevent the spread of this invasive species, efforts are underway to assess the populations for possible early detection and rapid response programs to eradicate them.

Paspalum guenoarum Arechv, (Poaceae) (Ramirez-grass) is a perennial tussock, leafy grass up to 1.0 m tall, with short basal rhizomes. This species is native in subtropical and grasslands of South America, and it is highly palatable to animals with a good distribution of forage production throughout the year. In this study, we present the first record of P. guenoarum in the Gauteng province of South Africa. This new record increases the number of alien and invasive grasses introduced into South Africa.

The invasion of indigenous environments by alien plant species is a major threat to global biodiversity and ecosystems. Ipomoea quamoclit, is a fast-growing vine native to Mexico and South America that is emerging as a potential terrestrial invader in South Africa. It was first reported in Durban, KwaZulu Natal in 1875. This study explores intensity and level of invasion by I. quamoclit in the Vhembe Biosphere Reserve (VBR). The main objective was to map its current distribution and investigate the effect of temperature on its germination potential. Results revealed that I. quamoclit was present in twelve locations within the VBR, as determined by roadside survey. Additionally, germination experiments demonstrated that temperatures outside of the range of 20–40 °C reduced the germination rate of I. quamoclit, with the highest germination potential occurring at 25 and 30 °C. These results underscore the urgent need for comprehensive risk assessments and continuous monitoring of I. quamoclit’s presence in the VBR.

The Danube is highly susceptible to biological invasions, as water is known to be the main vector for the spread and gateway to new areas of many alien plant species. By reviewing the specialized literature, supplemented by field research, we aimed to update previous knowledge regarding the diversity and distribution of alien plant species along the Lower Danube River in Romania. We identified a total of 240 alien plant species, of which 71 are invasive and nine are species of European Union concern (Ailanthus altissima, Asclepias syriaca, Elodea nuttallii, Humulus scandens, Impatiens glandulifera, Ludwigia peploides, Reynoutria japonica, Reynoutria sachalinensis, Reynoutria × bohemica). The most widespread taxa are Ailanthus altissima, Amaranthus albus, Amaranthus retroflexus, Ambrosia artemisiifolia, Amorpha fruticosa, Datura stramonium, Erigeron annuus, Erigeron canadensis, Juglans regia, Lycium barbarum, Medicago sativa subsp. sativa, Morus alba, Oxalis stricta, Phytolacca americana, Portulaca oleracea, Robinia pseudoacacia, Sorghum halepense, Xanthium orientale and the taxa with the highest abundance are Ailanthus altissima, Ambrosia artemisiifolia, Amorpha fruticosa, Robinia pseudoacacia, Xanthium orientale. We also report five new species for the study area (Delosperma cooperi, Impatiens balfourii, Impatiens parviflora, Opuntia sp., Ambrosia trifida). With these results, we update the previously known situation of the alien plant species inventory along the Romanian sector of the Danube and make a valuable contribution to the knowledge of their current presence and distribution.

In early July 2021, the North American leafminer Aspilanta oinophylla (van Nieukerken & Wagner, 2012) was recorded for the first time in several vineyards in western Slovenia. Between 2022 and 2024, further monitoring confirmed its presence at a total of 22 locations across the Goriška region, the Kras, and the coastal part of the country. The species was first reported in Europe in 2007 in northern Italy, and its occurrence in Slovenia is most likely the result of its gradual expansion from the neighbouring Friuli Venezia Giulia. So far, no significant damage has been observed in Slovenian vineyards. In certain vineyards in Goriška Brda, individual leaves with five to six mines were found; however, such cases were rare and limited to single vines. Overall, the number of leafmines was low, typically one to two per leaf. At the time of the first finding, ten leaves with mines were collected, from which three adult specimens of A. oinophylla were reared in the laboratory. During subsequent surveys, additional leaves were sampled, and more specimens were reared. Photographs of leafmines, larvae, and adults are provided.

Lepisiota frauenfeldi (Mayr, 1855), native to southern Europe, is an invasive alien ant species that has spread globally via international trade. It has been recorded in the Mediterranean region, the Middle East, Africa, the Indo-Malay region, Japan and Australia. Known as the browsing ant, it was first discovered around a warehouse in Gwangyang, Jeollanam-do, South Korea, likely introduced through shipping containers. Morphological and genetic analyses, including DNA sequencing confirmed its identity as L. frauenfeldi. This study represents the first report of this alien ant species in Korea and provides basic data on its morphology, ecology, and genetic characteristics. The ants were likely introduced to the country via shipping containers transiting multiple countries.

The tropical fire ant (Solenopsis geminata), originating from South America, was designated as an ecosystem-disturbing species in 2023 due to its negative impact on ecosystem balance. In 2022, it was first identified near Gamman Port, Busan, South Korea. A single nest was eradicated using both physical and chemical methods, and no additional colonies were detected during post-eradication monitoring following the installation of bait traps. However, given the proximity of the nest site to a major port, the potential for further introductions remains a concern. Continuous monitoring is essential to ensure early detection of this invasive species. The species has been successfully eradicated from the port, highlighting the importance of sustained surveillance and the need for rapid response to prevent potential reintroductions.

Insects play critical roles in ecosystems but can become invasive species due to human activities. This study reports the first record of an invasive insect species, Aclees taiwanensis Kȏno, 1933 (Coleoptera: Curculionidae), in Turkiye. Originally from Taiwan, this species has been recorded in Europe since 1997 and causes damage to fig trees (Ficus spp). It was detected on fig trees (Ficus carica) on the 1st of October, 2024, in Sarıyer-Bahçeköy, Istanbul. Although the exact pathway of its introduction remains unknown, it is suspected to have spread through local nurseries and landscaping activities. Turkiye is the world’s largest fig producer, with a production of 356.000 tons in 2023. Aclees taiwanensis has the potential to spread, particularly in warm and temperate regions where the Mediterranean climate prevails. Due to globalization and climate change, the spread of such invasive insects is increasing. Therefore, monitoring and controlling the spread of A. taiwanensis is of great importance.

Badumna longinqua, the grey house spider (Araneae: Desidae), is native to Australia and widely introduced into numerous other countries. Recently, this spider was newly discovered from several southern marine regions of South Korea, viz, Busan, Geoje, Goheung, Sacheon, Tongyeong, Ulsan, Yeosu, and Jeju Island. This species seems to be successfully established at least in coastal habitats in the collected regions, since numerous individuals and their webs were prevalently found in breakwater railings, garden shrubs, inside and outside buildings, and artificial structures in harbors and urban parks. A brief description and photographs of the species are provided to give basic information for monitoring its further spread in South Korea.

This paper reports the most westerly record of Cymatia rogenhoferi in the UK to date and considers the potential importance of contributing environmental factors to its expanding distribution. Although C. rogenhoferi is likely a neonative species, its arrival and range expansion across Europe should be monitored and tracked. More detailed sampling and research is required to identify its current distribution, habitat preferences and potential for future range expansion in the UK and more widely across north-west Europe. Morphological features are provided to aid identification in the UK for future monitoring and research programmes.

A non-native planarian of the family Dendrocoelidae, provisionally assigned following previous literature reports to the Ponto-Caspian species Dendrocoelum romanodanubiale and recorded here as D. cf. romanodanubiale, has been recorded for the first time in Great Britain. From January 2022 to July 2023 a total of 21 specimens were found at 12 locations on the River Thames. The stretch concerned runs for approximately 36 km, from Sunnymeads in Berkshire to immediately downstream of the tidal limit at Teddington Weir in Greater London. Two exemplar specimens were used for nanopore sequencing of nearly full-length 18S and 28S rDNA amplicons. These sequences, representing the first molecular data obtained for this invasive species, confirm the status of the specimens as sister-group to the congener Dendrocoelum lacteum. Further research is required to confirm the taxonomic status of this invasive species using histological sectioning, and to characterise the nature of the invasion using population genetic markers.

The estuarine bivalves of the species complex Mytilopsis cf. sallei are currently distributed worldwide, but are native from the Caribbean, and belong to different lineages. One of these lineages has been introduced in the northeastern Brazil, in the states of Paraíba, Pernambuco and Alagoas, and in the southeastern Brazil, in the Estuary of Santos (São Paulo state). We present a new record of such lineage, in the Bahia state, which is the largest state of NE Brazil and comprises the largest shoreline of the country. In a fieldwork conducted in 2024, we sampled M. cf. sallei in the cities of Ilhéus (Cachoeira River, based only on empty shells) and Canavieiras (Pardo River, based on live specimens). A mitochondrial COI gene analysis confirmed the presence of a single lineage of the species complex in the Pardo River. Probable vectors for the introduction of M. cf. sallei in both estuaries comprise local ports and aquaculture (shrimp farms), in addition to the possible role of small boats as local-scale dispersers.

The present study updates the status about the geographic distribution of the giant river prawn Macrobrachium rosenbergii in the wild and exotic environments. So far, this species has been formally recorded in 26 countries and 1 island. For the first time, we validated the occurrence of giant river prawn in exotic environments across the ecoregions: Honshu–Shikoku–Kyushu (Japan), Western Taiwan, Eastern Taiwan (Taiwan), Guianas, Puerto Rico–Virgin Islands, and Windward and Leeward Islands (Martinique), besides new records in Ganges Delta and Plain, Northern Deccan Plateau, Western Ghats, Southeastern Ghats (India), Ganges Delta and Plain (Bangladesh), Chao Phraya, Mae Khlong (Thailand), Southern Central Sumatra, Southern Sumatra–Western Java, Malukku, Lesser Sunda Islands, New Guinea North Coast, Southwest New Guinea–Trans-Fly Lowland (Indonesia), Malay Peninsula Eastern Slope, Northern Central Sumatra–Western Malaysia, Northwestern Borneo (Malaysia), New Guinea North Coast, Southwest New Guinea–Trans-Fly Lowland (Papua New Guinea), Kimberley, Arafura–Carpentaria, Lake Eyre Basin (Australia), Amazonas Estuary and Coastal Drainages, Northeastern Caatinga and Coastal Drainages (Brazil). In addition, we confirmed the first occurrence of this species in exotic areas along the Northeastern Caatinga and Coastal Drainages ecoregion in the state of Ceará, northeastern Brazil.

There is a large information gap on the occurrence of non-native species and their impacts on native biodiversity in southeastern Mexico; this region is a focal point for biodiversity conservation efforts due to its high concentration of species and habitats, including those facing threats. We recorded the occurrence of non-native invasive species in two Ramsar sites in Mexico that are habitat of the endemic and endangered fish Tlaloc hildebrandi (Miller, 1950). Data from museum specimens during different collection periods were used. A total of eight non-native species were documented, including four new records of species that had not been previously cited in the San Cristobal basin: two fish species (Astyanax aeneus (Günther, 1860) and Poeciliopsis hnilickai Meyer & Vogel, 1981), the American bullfrog (Lithobates catesbeianus (Shaw, 1802)), and the red swamp crayfish (Procambarus clarkii (Girard, 1852)). We also confirmed the presence of the rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)), the common carp (Cyprinus carpio Linnaeus, 1758), the largemouth bass (Micropterus salmoides (Lacepède, 1802)) and the Asian fish tapeworm (Schyzocotyle acheilognathi (Yamaguti, 1934)), which had been previously recorded in the study area. The presence of non-native species in this important conservation area could impact biodiversity and ecosystem functions through repressing or excluding native species, either directly by out-competing them for resources or indirectly by changing the way nutrients are cycled through the system.

The first occurrence of a channel catfish (Ictalurus punctatus) in Atlantic Canada is reported. The single specimen, an adult male of 430 mm total length, was taken on 7 June 2023, by commercial gaspereau fishers in Grand Lake, New Brunswick. Grand Lake drains through the Wolastoq (Saint John) River, which stretches about 800 km from its headwaters in Maine (USA) to the Bay of Fundy. Although studies of the invasive potential of the channel catfish seem to be limited, where non-native and established, the species is often considered problematic. Grand Lake supports a relatively diverse native fish fauna, as well as a variety of native aquatic species of conservation concern. Whether the single channel catfish collected to date is representative of an established population is unknown, but the introduction is believed to be the result of an intentional, unsanctioned, effort to establish a recreational fishery for the species in Grand Lake.

Northern snakehead Channa argus (Cantor, 1842) is an aquatic invasive fish species in the United States with first documented occurrence in the wild in the 2000s. Management efforts to control their populations in the eastern United States are ongoing. In the Mississippi River basin, limited resources have been allocated to control its distribution, after initial detection and rapid response in Arkansas were unsuccessful. Northern snakehead distribution in the Mississippi River basin was limited to Arkansas and Mississippi until 2019 when a single northern snakehead was detected on the southern border of Missouri in the Saint Francis River drainage, the furthest northern detection. Described here are additional northern snakehead detections following public reports and subsequent monitoring in the Mingo basin of the Saint Francis River drainage, a historical braided channel and floodplain habitat of the Mississippi River with intermittently flooded bottomland hardwood forests and wetlands, and other consistent aquatic habitats. These increasing captures document the recent range expansion of northern snakehead. Most of the 11,300 ha Mingo basin consists of Mingo National Wildlife Refuge and Duck Creek Conservation Area; these areas are protected aquatic ecosystems possessing sensitive species and serve as a potential example of prioritized areas for northern snakehead control efforts. Additionally, we highlight the significance of these detections in the Mingo basin which is connected via the Castor River water-control structure to the Upper Mississippi River and may facilitate further range expansion.

The invasive Indo-Pacific lionfish (Pterois volitans) has been spreading rapidly across the Atlantic Ocean, causing significant ecological impacts. This study reports the first known record of a lionfish larva from the Amazon Continental Shelf off Northern Brazil which expands on existing knowledge of lionfish establishment in the region. The specimen, collected during the AMAZOMIX survey, was identified using DNA barcoding: a technique that analyzes a fragment of the COI gene for precise species identification. The larva was found near the coast of the Brazilian state of Amapá and presented characteristics typical of the genus Pterois, including the development of the fins and its distinctive pigmentation patterns. This finding, together with the previous records of adult individuals in the region, indicates local breeding in an established population. The phylogenetic analysis revealed that the COI haplotype of the larva matches one recorded previously in the Amazon region, which reinforces the hypothesis of an invasion through the Caribbean, followed by migration and the expansion of the range of this invasive species. These findings highlight the effectiveness of DNA barcoding for the reliable identification of fish larvae and underscore the need for further studies on the dynamics of lionfish populations established in Brazilian waters to support the development of management measures and effective control strategies.

All species of the family Testudinidae are listed in the CITES Appendices and are traded under international trade regulations. In this study, we report a sighting of Stigmochelys pardalis (Bell, 1828) in the wild in South Korea. The individual was identified based on both morphological characteristics and genetic analyses. It exhibited carapacial scute pyramiding, suggesting that it had been kept under inadequate captive conditions before being abandoned. Although this species is non-native, its occurrence in the wild underscores the challenges of managing the exotic pet trade and highlights the importance of responsible captive care.

Budgerigar (Melopsittacus undulatus), a small parrot species native to Australia, is widely kept as a companion bird and has established feral populations in various parts of the world. In May 2025, we recorded the first observation of M. undulatus in the wild on Jeju Island, South Korea. The individual was identified as an adult female based on plumage pattern, iris coloration, and cere characteristics. A review of records from the national citizen science platform Naturing confirmed the absence of previous sightings of this species on the island. Although this observation does not indicate population establishment, it demonstrates the potential for short-term survival and highlights the possibility of naturalization in a temperate island ecosystem. Jeju Island’s mild oceanic climate, abundant grass seeds, and urban green spaces may offer favorable conditions for survival. We also discuss climate change as a driver of range expansion in exotic parrots. This case underscores the importance of early detection and rapid response strategies in insular ecosystems and suggests the need for a monitoring framework that integrates citizen science observations with expert validation.