First records of alien crayfish of the Procambarus acutus species complex in Belgium

We present the first Belgian records of potentially invasive alien crayfish of the Procambarus acutus species complex, including the first confirmed record of P. acutus acutus. The species complex was observed at four different sites in three provinces in the north of the country. Only at one site the presence of a form I male specimen made identification to species level possible, based on gonopod morphology. The other three observations are considered as belonging to the P. acutus species complex. Procambarus acutus acutus is the fifth alien crayfish species known to Belgium. In Europe, it was previously only known as an established alien species from the Netherlands and Great Britain

Cabomba caroliniana Gray (Cabombaceae) invades major waterways in Belgium

Recently, unattached viable stem fragments of the invasive macrophyte Cabomba caroliniana Gray were found at several locations in two canals in northern Belgium. A subsequent survey of the canal Zuid-Willemsvaart revealed one site with rooted plants and the presence of floating stem fragments along the entire length of the canal (25 km). These findings indicate that C. caroliniana is already well established in the Zuid-Willemsvaart and probably considerably more widespread than previous records from isolated lentic water bodies indicate. We have summarised the new records and discuss the potential spread and risks associated with further establishment and spread of C. caroliniana in Belgium

Beetles (Coleoptera) of wetlands and other aquatic habitats in the Polish part of the Polesie region found during the Balfour-Browne Club Meeting 2016

A total of 27 sites in the Polish part of the Polesie region were investigated for aquatic and wetland-associated beetles during the field sessions of the Balfour-Browne Club Meeting (23-30.05.2016). These comprised a mixture of fens and Sphagnum peat bogs, ditches draining fens, oxbow lakes of the Bug River, and sand excavations. A total of 408 species, belonging to all three sub-orders of beetle and 34 families were captured, including 351 species related to the aquatic environment (true water beetles – 157, phytophilous water beetles – 32, facultative water beetles – 1, false water beetles – 156, shore beetles – 157). Numerous rare, protected, species and those endangered in Poland or neighbouring countries were found. Information on three species (Agabus pseudoclypealis, Hygrotus polonicus and Berosus geminus) is important for our understanding of their geographical range limits. In the case of B. geminus, new data, in conjunction with information from Ukraine, points to the existence of an isolated island of occupancy in Polish and Ukrainian Polesie. Analysis of the material collected also reveals the high value of the study area, both nationally and internationally, for the protection of wetland beetle biodiversity

Na Chinese wolhandkrab bedreigt ook Amerikaanse kreeft het leven in onze rivieren: “Nóg agressiever”

We zaten in Vlaanderen al erg verveeld met de Chinese wolhandkrab, en nu bedreigt ook de gestreepte Amerikaanse rivierkreeft in massale aantallen het leven in onze rivieren. “Deze exotische kreeft – waarvan er vermoedelijk intussen miljoenen in onze rivieren zitten – is bovendien een grotere bedreiging voor onze natuur dan de wolhandkrab, wegens veel agressiever dan de wolhandkrab”, zegt Kevin Scheers van het Instituut voor Natuur en Bosonderzoek (INBO).status: Published onlin

De komst van de gestreepte Amerikaanse rivierkreeft in Vlaanderen, een streep door de rekening voor de Vlaamse natuur?

status: Published onlin

Gestreepte Amerikaanse rivierkreeft slecht nieuws voor Vlaamse natuur

(Belga) De gestreepte Amerikaanse rivierkreeft blijkt al in drie provincies in Vlaanderen aanwezig te zijn. Dat zegt Kevin Scheers van het Instituut voor Natuur- en Bosonderzoek in een bijdrage op de website van Natuurpunt. "Dat deze soort nu ook bij ons opduikt (...), is allesbehalve goed nieuws", zegt hij.status: Published onlin

Honderden marmerkreeften vreten grachten kaal bij de Antwerpse begraafplaats Schoonselhof

Bij begraafplaats het Schoonselhof in Antwerpen is opnieuw een exotische rivierkreeftensoort opgedoken. De marmerkreeft eet alles wat hij tegenkomt. Daardoor wordt het water troebel en is er een gevaar voor de biodiversiteit. "Het is onmogelijk om elk diertje te pakken te krijgen. Het is dweilen met de kranen open", zegt Kevin Scheers van het Instituut voor Natuur- en Bosonderzoek.status: Published onlin

Neoclypeodytes Young from Panama, with description of two new species (Coleoptera: Dytiscidae: Hydroporinae: Bidessini)

Scheers, Kevin, Hájek, Jiří (2020): Neoclypeodytes Young from Panama, with description of two new species (Coleoptera: Dytiscidae: Hydroporinae: Bidessini). Zootaxa 4890 (2): 245-256, DOI: https://doi.org/10.11646/zootaxa.4890.2.

Mislabelling may explain why some prohibited invasive aquatic plants are still being sold in Belgium

In Belgium, a voluntary code of conduct intended to prevent introduction of invasive plants through the horticultural trade has been implemented since 2009. European Regulation 1143/2014 that imposes legal bans on a number of plant taxa entered into force in 2015. However, studies regarding the presence of invasive plants in the Belgian horticultural trade remained scarce. In 2016–2017 and in 2020, we surveyed a total of 11 garden centres specialized in water gardening and compiled a list of 285 aquatic plant taxa that were being traded. In 2020, four Belgian Consensus List species and one Communication List species were still offered for sale. Also, three species of Union Concern were still being sold in 2020. The plants of the Belgian Lists that were still being sold in 2020 and all except one of the European Union List plants were mislabelled, either because of misidentification or because a taxonomic synonym was used. Mislabelling may explain why some prohibited plants were still in trade. Therefore, retailers and plant producers should be encouraged to correctly identify the plants that are being traded. Our study illustrates that regular surveys are essential to assess the effectiveness of voluntary codes of conduct and legal trade bans