Detection of an invasive species Arion vulgaris Moquin-Tandon, 1855 (Mollusca: Gastropoda: Arionidae) in the Republic of North Ossetia-Alania

Arion vulgaris Moquin-Tandon is a serious agricultural pest. Its rapid spread started in the middle of the twentieth century. Currently, its range covers almost all of Western Europe and it is rapidly expanding to the east. A. vulgaris has been recorded in the Baltics, Ukraine, and central Russia; it is also found in the Faroe Islands. In 2009, it was discovered in Russia in the commercial greenhouses of Tver. Now it has spread in the suburbs and Moscow. On the 6th of August 2019, a population of this species was found in the arboretum of Vladikavkaz, North Ossetia which is the first record of A. vulgaris in the Caucasus. Description of the slug’s genitalia is given.

The first records of an invasive land snail Cepaea nemoralis(Stylommatophora: Helicidae) in Central and Southern Ukraine

Two colonies of an invasive West European land snail Cepaea nemoralis are reported from Kyiv region of Ukraine, as well as a third locality where snails were present in 2019, but no living individuals were found in 2020. One more locality is reported from Odessa City in Southern Ukraine. These localities are the most south-eastern ones for the range of C. nemoralis and are the first known records of this species in Ukraine outside its western regions, with closest previously published confirmed colonies in more than 400 km. Distribution of this species in Eastern Europe is discussed, it is argued that invasion ofC. nemoralis is probably driven by the same processes as invasion of the Spanish slug, Arion vulgaris, that invaded Eastern Europe during the last decades.

Draft Genome Sequences of Two Listeria monocytogenes Strains Isolated from Invasive Snails (Arion vulgaris) in Austria in 2019

We report the draft genomes of two Listeria monocytogenes strains that were isolated from the invasive alien snail species Arion vulgaris in Austria in 2019.

Experimental indications of gardeners’ anecdotes that snails interfere with invasive slugs

The invasive Spanish slug (Arion vulgaris) is an important pest species in agriculture and horticulture in Europe. In the last decades it has spread across the continent where it outcompetes native slug and snail species, thus posing a threat for biodiversity. A popular anecdote suggests to promote Roman snails (Helix pomatia) in gardens because they are able to control A. vulgaris. We examined a potential interrelationship between these two species using a mesocosm experiment with lettuce plants. 13C-15N stable isotope labelling of lettuce allowed us to investigate interactions between Helix and Arion on weight gain/loss and herbivory. Additionally, we wanted to know whether different watering regimes (daily vs. every 3rd day watering of weekly amount) and earthworms alter these interactions. Egg predation of Helix on Arion eggs was further tested in a food-choice experiment. Arion showed a five times higher herbivory per body mass than Helix in a single-species setting. However, in mesocosms containing both species percentage of herbivory per body mass was significantly lower than in Arion-only mesocosms, especially when watered every three days. Overall isotope uptake via eaten lettuce was unaffected by the presence of the other species. Only very little predation (three out of 200 eggs) of Helix on Arion eggs was observed. Our results provide no evidence for a clear dismissal or confirmation of the popular gardener’s anecdote that Helix snails have a negative effect on Arion abundance or herbivory.

Survival of animal and human associated Listeria monocytogenes in drinking water and biofilms

Land slugs are occasionally observed as contaminants in groundwater wells and drinking water treatment plants including storage tanks. Slugs may feed on carrion and feces, and they are potential vectors of pathogens such as Listeria monocytogenes. We isolated L. monocytogenes from the pest slug Arion vulgaris and examined persistence and survival of human and slug derived L. monocytogenes in groundwater-based drinking water and biofilms. L. monocytogenes survival was evaluated using cultivation and cultivation-independent techniques. L. monocytogenes remained culturable for 35–47 days in drinking water with first order decay rates between 0.314 and 0.457 h−1 (T99 ≥10 days). Attachment of L. monocytogenes to filter sand delayed washout from drinking water filters and increased persistence 2–3-fold. Indigenous biofilms stimulated initial surface attachment 10–100 fold but L. monocytogenes declined more rapidly in drinking water biofilms compared to virgin filters not colonized by microorganisms. Grazing by protozoa likely attenuated L. monocytogenes survival in some drinking water biofilms. A comparable survival pattern was observed for L. monocytogenes and the fecal indicator bacterium E. coli. The study suggests that live L. monocytogenes can persist for weeks as sessile organisms in groundwater-based drinking water supplies and may subsequently be released to the drinking water.

Plži Obory Hvězda, Petřína a Vyšehradu v Praze [Gastropods of the Hvězda Game Reserve, Petřín and Vyšehrad in Prague]

Mollusc fauna of three protected areas in the capital of the Czech Republic, Prague, was revised after 25 years (Hvězda Game Reserve, Petřín) or studied for the first time (Vyšehrad). In total, 56 molluscs species were found and the survival of endangered species Vertigo angustior and Nesovitrea petronella in the Hvězda Game Reserve was verified. Generally, some sensitive species in well-preserved localities are being replaced by weed species, including non-indigenous ones such as the invasive Arion vulgaris, and the southern element Monacha cartusiana. On the other hand, some woodland species such as Arianta arbustorum, Urticicola umbrosus, Eucobresia diaphana, Arion silvaticus and Lehmannia marginata apparently spread in Prague.

Arion vulgaris (Spanish slug).

The invasiveness of A. vulgaris is related to several factors. Its ability and readiness to colonize humanly-disturbed environments is of major importance. Proschwitz (1997) observed that 99% of Swedish records were from synanthropic habitats and only 1% from natural woodlands. With a proximity to humans, comes the possibility of passive dispersal through trade, particularly in living plants. The garden centre trade and horticulture are particularly implicated (Weidema, 2006). In Poland, there is evidence from studies of molecular diversity that A. vulgaris has originated from repeated, separate introductions from other parts of Europe (Soroka et al., 2007). The ability of A. vulgaris to utilize a great variety of food sources and types has been well-documented and must aid dispersal and colonization. Other than its country of origin (France), it is considered to be invasive across western and central Europe, from the Pyrenees to eastern Poland and from southern France to north Italy, Austria and Slovakia and within an isolated range in eastern Bulgaria.

Analysis of the adventitious fauna of terrestrial molluscs in the centre of the Russian Plain

The terrestrial mollusc fauna of the central part of the Russian Plain has been analysed with respect to its species composition and the proportion of adventitious species. The classification of adventitious species follows that accepted in Russia. Considerable changes in the fauna took place in the period 2016–2020. Helix lucorum Linnaeus and Cornu aspersum (O. F. Müller) were added to the terrestrial malacofauna of the area. Within the last four years, Arion vulgaris Moquin-Tandon colonised anthropogenic habitats and its spread continues. Krynickillus melanocephalus Kaleniczenko, Arianta arbustorum (Linnaeus), and Helix pomatia Linnaeus are now firmly established in natural ecosystems. Populations of A. vulgaris, K. melanocephalus, and A. arbustorum have become so abundant that now they cause significant damage to agricultural crops. In both natural and anthropogenic habitats K. melanocephalus and A. arbustorum displace Succinea putris (Linnaeus), Deroceras laeve (O. F. Müller), D. sturanyi (Simroth), D. invadens Reise, Hutchinson, Schunack et Schlitt, 2011, D. agreste (Linnaeus), D. reticulatum (O. F. Müller), Fruticicola fruticum (O. F. Müller) and Euomphalia strigella (Draparnaud). Interactions between invasive species are discussed. The proportion of alien species in several European countries and in Central Asia is compared.

Обзор методов борьбы с инвазивными видами животных в применении к остановке инвазии испанского слизня вида Arion vulgaris

В статье представлен обзор самых неординарных и в то же время действенных методов борьбы с различными инвазивными видами животных, а также перечислены факторы, без учѐта которых прекращение инвазии было бы невозможно. Подобные методы могут служить примером действий при разработке стратегии борьбы с Испанским слизнем, который входит с список наиболее опасных инвазионных видов России