Invasion Potential of Ornamental Terrestrial Gastropods in Europe Based on Climate Matching

Invasive species are one of the main causes of biodiversity loss worldwide. Pet trade is a well-known pathway for the introduction of non-native species. Prevention is the most effective, least time-consuming, and least financially demanding way to protect biodiversity against the spreading of invasive species. The main part of prevention is the early detection of a potentially high-risk species, as well as the successful implementation of prevention strategies in legislation and practice. This study summarizes the pre-introduction screening of pet-traded terrestrial gastropod species and their potential occurrence in the EU territory. Based on the list of species traded in the Czech Republic, one of the most important global hubs of the pet trade, 51 species (49 snails and 2 slugs) were analysed. Due to a lack of certain native occurrence data, only 29 species (28 snails and 1 slug) from 10 families were modelled using MaxEnt software. Twenty species from seven families have potential occurrence in the EU territory. Based on MaxEnt modelling, we considered the following species to be high-risk candidates for the EU: Anguispira alternata, A. strongylodes, Laevicaulis alte, Megalobulismus oblongus, Rumina decollata, and R. saharica. Based on this estimation, we present considerations with which to further improve the risk assessment and recommend continuous monitoring of the pet trade market.

Distribution patterns of established alien land snail species in the Western Palaearctic Region

Established alien land snail species that were introduced into the Western Palaearctic Region from other regions and their spread in the Western Palaearctic are reviewed. Thirteen of the 22 species came from North America, three from Sub-Saharan Africa, two from the Australian region, three probably from the Oriental Region and one from South America. The establishment of outdoor populations of these species was usually first seen at the western or southern rims of the Western Palearctic. Within Europe, the alien species usually spread from south to north and from west to east. The latitudinal ranges of the alien species significantly increased with increasing time since the first record of introduction to the Western Palearctic. The latitudinal mid-points of the Western Palaearctic and native ranges of the species are significantly correlated when one outlier is omitted. There is a general trend of poleward shifts of the ranges of the species in the Western Palaearctic compared to their native ranges. There are three reasons for these shifts: (1) the northward expansion of some species in Western Europe facilitated by the oceanic climate, (2) the impediment to the colonisation of southern latitudes in the Western Palaearctic due to their aridity and (3) the establishment of tropical species in the Mediterranean and the Middle East. Most of the species are small, not carnivorous and unlikely to cause serious ecological or economic damage. In contrast, the recently introduced large veronicellid slugs from Sub-Saharan Africa and the giant African snail Lissachatina fulica could cause economic damage in irrigated agricultural areas or greenhouses in the Mediterranean and the Middle East.

Identification problems of travelling snail species-new exotic introductions to tropical greenhouses in Gothenburg, Sweden (Gastropoda: Achatinellidae, Strobilopsidae, Helicarionidae)

Three previously unreported species of tropical land snails were found in the greenhouses of the Gothenburg (Göteborg) Botanical Garden and the Public Science Center Universeum in Gothenburg. For Tornatellides cf. boeningi (Schmacker & Boettger, 1891) and Ovachlamys fulgens (Gude, 1900) this is the first observed occurrence in a European greenhouse, while Discostrobilops hubbardi (Brown, 1861) was first reported very recently in the Vienna Botanical garden. Tornatellides and Discostrobilops seem to be spread with orchid culture and trade. Identification of the Tornatellides species proved extremely difficult and a genetic sequence-based approach completely failed due to the unavailability of reference data. This was unexpected considering the importance of these introduced species in horticultural trade. A broader assessment of available sequence data for genetic identification based on COI or 16S for other snail species reported from horticultural facilities showed that such reference data in GenBank are still scarce and only for a limited number of species this approach would support identification.

Fermenting Bread Dough as a Cheap, Effective, Nontoxic, and Generic Attractant for Pest Snails and Slugs

Simple Summary

Snails and slugs are key pests of crops but control options are limited with an overreliance on molluscicides, which have variable efficacy. Thus, there is an urgent need to improve the performance of these pesticides, and one option is to identify more efficacious attractants for incorporation into baits and/or use in traps. Our results showed that a simple bread dough (flour, water, and yeast) was highly attractive to six invasive pest gastropod species in both laboratory and field trials in Hawaii, Oregon, and Montana. The dough remained attractive for at least 8 days and was significantly more attractive than a widely used toxic bait (Deadline^® M-Ps™). Given its simplicity, low cost, and the ready availability of its ingredients, the dough has potential to be used in developing countries where access to commercial molluscicides is limited by cost. In addition, a premixed dry formulation of flour and yeast, where water simply needs to be added to activate the bait, would likely have an indefinite shelf life and be readily shippable, both highly desirable properties for an operational lure. Thus, bread dough constitutes a nontoxic, generic, and effective tool that could be used in the detection and management of pest gastropods worldwide.

Abstract

Invasive slugs and snails are among the most damaging pests of agriculture in temperate and tropical regions of the world. Control options, however, are limited and there is a heavy reliance on chemical molluscicides of variable efficacy. There is an ongoing need to improve management methods. Here, we show that a simple fermenting bread dough formulation (flour, water, and yeast) was effective in attracting pest mollusk species in laboratory tests, and in multiple replicated field trials in Hawaii, Oregon, and Montana. The dough attracted substantially more terrestrial pest gastropods, including invasive species of major economic importance such as Cornu aspersum, Deroceras reticulatum, Ambigolimax valentianus, Xerolenta obvia, Lissachatina fulica, and Parmarion martensi, than water controls. The dough remained attractive for at least 8 days and was significantly more attractive than a widely used metaldehyde-based bait, Deadline^® M-Ps™. Thus, fermenting bread dough represents a nontoxic, generic, and effective tool to aid in managing pest gastropod infestations, either using baited traps or in attract-and-kill approaches. Given its simplicity, low cost, and the ready availability of its ingredients, the dough also has potential to be used in developing countries where access to commercial molluscicide baits is limited by cost.

Malacological news from the Czech and Slovak Republics in 2015–2019

Since the last comprehensive overview of the Czech and Slovak mollusc fauna, released in 2013, several records of species new for the countries or particular regions have appeared. In this paper, we summarize all such records and news collected in 2015–2019, including those affecting nomenclature and the national Check-lists made in 2013 and 2014. The rules for the selection of the records are: (i) the first record in Bohemia, Moravia or Slovakia, (ii) regionally important new records, (iii) records of species listed in NATURA 2000 and the national Red-lists as either critically endangered or endangered species, and (iv) currently spreading non-native species. New records are briefly commented and summarized for each species separately. Location data are published with all details in a supplementary table and are freely accessible.