Arion vulgaris
(Spanish slug)

Pictures

Picture	Title	Caption	Copyright
Title Ova Caption Egg mass of A. vulgaris in soil. Copyright B. Speiser/FiBL Switzerland	Ova	Egg mass of A. vulgaris in soil.	B. Speiser/FiBL Switzerland
Title Colour morphs Caption Two differently coloured juvenile A. vulgaris. Note the dark lateral bands on the slugs. Copyright B. Speiser/FiBL Switzerland	Colour morphs	Two differently coloured juvenile A. vulgaris. Note the dark lateral bands on the slugs.	B. Speiser/FiBL Switzerland
Title Adult Caption Adult A. vulgaris in copula. Copyright B. Speiser/FiBL Switzerland	Adult	Adult A. vulgaris in copula.	B. Speiser/FiBL Switzerland
Title Adult Caption Adult A. vulgaris fully extended. Copyright B. Speiser/FiBL Switzerland	Adult	Adult A. vulgaris fully extended.	B. Speiser/FiBL Switzerland
Title Field damage Caption Lettuce damaged by A. vulgaris (a) and undamaged (b). Copyright B. Speiser/FiBL Switzerland	Field damage	Lettuce damaged by A. vulgaris (a) and undamaged (b).	B. Speiser/FiBL Switzerland
Title Field damage Caption Bean plant damaged by A. vulgaris. Copyright B. Speiser/FiBL Switzerland	Field damage	Bean plant damaged by A. vulgaris.	B. Speiser/FiBL Switzerland
Title Field damage Caption Pumpkin damaged by A. vulgaris. Note extensive damage (arrowed) to pumpkin skin and additional damage to stalk. Copyright B. Speiser/FiBL Switzerland	Field damage	Pumpkin damaged by A. vulgaris. Note extensive damage (arrowed) to pumpkin skin and additional damage to stalk.	B. Speiser/FiBL Switzerland
Title Juvenile Caption Juvenile of pale phase. Starcross, England. Copyright Roy Anderson	Juvenile	Juvenile of pale phase. Starcross, England.	Roy Anderson
Title Brown and black variants Caption Brown and black variant of dark phase. Antrim, Co. Antrim, Ireland. Copyright Roy Anderson	Brown and black variants	Brown and black variant of dark phase. Antrim, Co. Antrim, Ireland.	Roy Anderson
Title Juvenile Caption Juvenile of dark phase. Honau, Germany. Copyright Roy Anderson	Juvenile	Juvenile of dark phase. Honau, Germany.	Roy Anderson
Title Red form Caption Red form of dark phase, in copula. Note dark underlying pigment in pneuostome (arrowed). Honau, Schwäbiacher Alb, Germany. Copyright Roy Anderson	Red form	Red form of dark phase, in copula. Note dark underlying pigment in pneuostome (arrowed). Honau, Schwäbiacher Alb, Germany.	Roy Anderson
Title Pale phase Caption Pale phase in copula. Starcross, Devon, England. Copyright Roy Anderson	Pale phase	Pale phase in copula. Starcross, Devon, England.	Roy Anderson

Identity

Preferred Scientific Name

• Arion vulgaris Moquin-Tandon 1855

Preferred Common Name

• Spanish slug

Other Scientific Names

• Arion lusitanicus Mabille 1868

International Common Names

• Spanish: babosa lusitana
• French: arion rouge; limace ibérique; limace noire; limace rouge

Local Common Names

• Germany: Spanische Wegschnecke

EPPO code

• ARIOLU (Arion lusitanicus)

Summary of Invasiveness

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.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Mollusca
•             Class: Gastropoda
•                 Subclass: Pulmonata
•                     Order: Stylommatophora
•                         Suborder: Sigmurethra
•                             Unknown: Arionoidea
•                                 Family: Arionidae
•                                     Genus: Arion
•                                         Species: Arion vulgaris

Notes on Taxonomy and Nomenclature

This species is best known as the Lusitanian slug Arion lusitanicus J Mabille 1868. However, the name lusitanicus can no longer be applied. A re-description of lusitanicus sensu Mabille, based on topotypes from its type locality at Setubal, Serra da Arrábida, Portugal (Castillejo, 1997, 1998) has shown that Portuguese lusitanicus has a very different spermatophore and internal morphology from the central and west European species to which this name was applied by Altena (1956) and then by subsequent authors. The distinction between topotypic Arion lusitanicus and Arion ‘lusitanicus’ from north-west Europe has been confirmed by phylogenetic analysis (molecular studies) through ITS1 sequencing (Quinteiro et al., 2005; Colomba et al., 2007). Falkner et al. (2002) proposed that the pest species in north-west Europe is called vulgaris Moquin-Tandon, 1855 as this appears to be the first available name that can be unambiguously applied. This is possible because Moquin-Tandon (1855), unusually among early authors, figured the highly diagnostic spermatophore in his description.

British authors, including Quick (1960), have confused vulgaris with Arion flagellus Collinge, a large Arion that inhabits the British Isles and northern Iberia, but has not so far been found elsewhere in Europe nor further afield. Some of Quick’s drawings of ‘lusitanicus’, particularly of the spermatophore (p. 142), actually relate to flagellus. This has clearly been a source of confusion and the reader is directed to Davies’ (1987) paper that first resolved the problem and gives a very detailed account of the distinguishing features and reproductive biology of flagellus and vulgaris (as lusitanicus).

Description

Pneumostome located on the right-hand side of the mantle and near the front margin; keel absent; mantle granular. Foot fringe broad, heavily lineolated, similar in colour to that of the back. Juveniles have dark lateral bands with paler ‘shadow’ bands on the sides above these – compare juvenile Arion rufus and juvenile and adult Arion subfuscus. Sides below the bands are pale. Colour is variable - yellowish, greyish, chocolate, reddish, brownish (never greenish). The adults are normally unbanded, colour of the upper surface a uniform yellowish-brown, brown, reddish-brown or dark-brown, rarely black. Eggs are white, slightly transparent, soft-shelled, ca 2 mm in diameter. 

Hatchlings are ca 5 mm long when stretched out. The adults are 6-12 cm long and normally weigh 5-15 g (extremes: 3-27 g) (Briner and Frank, 1998).

Distribution

Moquin-Tandon’s description of A. vulgaris relates to a species inhabiting southern France (Moquin-Tandon, 1855). Arion lusitanicus sensu Mabille, on the contrary, is restricted to Portugal (Quinteiro et al., 2005). In addition, there is no evidence to suggest that vulgaris occurs on the Iberian peninsula outside the southern Pyrenees of Catalunya (Chevallier, 1981; Castillejo, 1998; Quinteiro et al., 2005). Theories for its area of origin range from southern Europe (Schmid, 1970) to the Alpine Region (SM Davies, [address available from CABI], personal communication, undated). Chevallier (1981) gives a map showing its French range, which is mainly Pyrenean rather than alpine.

A. vulgaris has been spread by international trade from central and south France, and can now be found throughout much of central, northern and eastern Europe. In many regions it is well-established and has partly replaced the native large arionids: Arion rufus and Arion ater, especially in anthropogenic habitats, to become a serious pest (Fechter and Falkner, 1990; Turner et al., 1998). It appears to be uncommon at higher altitudes, at least in the Alps (ca. 1600 m above sea level) (Turner et al., 1998) although this may not apply to the Pyrenees (Chevallier, 1981).

Extensions in its range have been recorded in a number of countries since 2000. It is now confirmed from Ireland (Anderson, 2010), where it was earlier confused with other taxa. It has recently been found in Iceland for the first time. There is a single unconfirmed report from Cornell University in the USA (October 1998).

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

In the modern era, A. vulgaris was first recognised in the UK and France in the early 1950s (Winter, 1989; Kerney, 1999), in Switzerland in 1955 (Turner et al., 1998), in Germany in 1965 (Schmid, 1970 cited in Briner and Frank, 1998), in Belgium in 1974 (Winter, 1989), in the Netherlands in 1988 (Winter, 1989) and in Austria in 1972 (Fischer and Reischütz, 1998). Before German unification in 1990, A. vulgaris was well-established in West, but not in East Germany (von Proschwitz, 1997). The first record for the former East Germany is from 1994 (von Proschwitz, 1997). In Sweden, A. vulgaris was first recorded in 1975, but from 1987 onwards populations exploded and the species spread rapidly to new sites. Of all the records in Sweden, 99% are from anthropogenic and only 1% from natural woodlands (Proschwitz, 1997). 

Outside Europe, there is a suspected occurrence in the Falkland Islands (Proschwitz, 1988). This report has not been confirmed because the specimen involved was badly damaged. There is also an unconfirmed report from Cornell University in the USA (October 1998). 

In addition to the information provided in the History of Introduction table, A. vulgaris has been confirmed from Ireland. Kerney (1999), in his atlas of non-marine Mollusca, shows A. lusitanicus (=vulgaris) as an Irish species. However, subsequent research indicates that Kerney’s records are probably in error. The species has since been unequivocally recorded in Ireland by Anderson (2010).

Introductions

Risk of Introduction

It is likely that A. vulgaris will continue to spread northwards and especially eastwards in Europe, to the Baltic States and Russia (Proschwitz, 1997). It may be expected to turn up eventually in the Antipodes and in North America.  

A survey of introduced slugs in California, USA, in which ITS sequencing based on UK material of the species was used, found only Arion rufus (R McDonnell, UCLA, personal communication, 2008).  

Many authors refer to its propensity for transport with plant materials through the horticultural trade and the gardening trade.

Habitat

A. vulgaris is most frequent in agricultural and horticultural habitats with permanent, dense vegetation, such as grassland, fallows and gardens, and is abundant in compost heaps. In low numbers, it is present in most agricultural and horticultural land, and also increasingly in natural habitats (Fechter and Falkner, 1990; Turner et al., 1998).
 

Habitat List

Hosts/Species Affected

A. vulgaris is a serious pest of diverse vegetable crops (especially Brassicaceae, lettuce, cucurbits), vegetable seedlings, arable crops (Triticaceae), ornamental plants, low-growing fruits (strawberries) and herbs within gardens in Central Europe, regularly causing severe losses. In the early stages of arable crop development (after seedling emergence or after planting), the plants are seriously defoliated or completely destroyed. The leaves, flowers or fruit may be damaged with feeding holes, and the potential harvest devalued. In Austria, serious damage to arable agriculture has been reported (Reischütz, 1984). In Poland, A. vulgaris was found to feed on a wide range of plants, including arable crops and commonly occurring weeds. Slug damage was found on 103 plant species (including wild species) and preferred crops including Brassica napus (Kozlowski and Kaluski, 2004; Kozlowski, 2005).

Host Plants and Other Plants Affected

Growth Stages

Symptoms

Copious deposits of slime and slime trails leading from damaged site indicate activity. 

Damage only within 1-5 m from the field edge, next to an area with dense, undisturbed vegetation, for example, grassland, fallow, scrub and garden.

Surface damage to large plants or plant parts specifically indicates the presence of this species. Complete removal of plants may occur.  

No damage occurs below ground with this species.

List of Symptoms/Signs

Biology and Ecology

Genetics

A. vulgaris shows comparatively little genetic variation through its central European range (Quinteiro et al., 2005). Material from Britain, France and Italy gives no genetic indication of hybridisation with Arion ater or A. rufus. However, data on metabolic rates of individuals of these species from Sweden (Hagnell et al., 2003) appear to suggest hybridisation between A. vulgaris and A. rufus. 

Interpretation of these data is complicated by the suggestion (Chevallier, 1981; SM Davies, [address available from CABI], personal communication, 2008) that the A. ater complex in Europe comprises species additional to those presently recognized, i.e. A. ater, A. rufus and A. vulgaris. 

Reproductive Biology

A. vulgaris has an annual life cycle (Davies, 1987). In the British Isles, mating takes place between late July and early September. Courtship starts after sunset and copulation may take between 2 and 3 hours (Davies, 1987). The eggs are laid between September and November and the adults then die off. The juveniles appear in spring (March/April) and grow rapidly to maturity in June/July. 

It has been suggested that two generations can occur in especially favourable (warm, moist) environments.  

Physiology and Phenology

Due to the recent expansions in the range and the difficulty in distinguishing A. vulgaris from related species, few observations on regional phenotypic variability are reported. 

Chevallier (1977) noted a tendency for dark-coloured individuals to occur at higher altitudes in the species native range in France, and for brighter, reddish coloured individuals to predominate in warmer regions and at lower altitudes.  

Climate

Latitude/Altitude Ranges

Natural enemies

Notes on Natural Enemies

No natural enemies have yet been shown to substantially reduce the populations of A. vulgaris. 

Means of Movement and Dispersal

Very little is known about the rates of spread of this species. The first dates of when it was recorded in various countries are given in the Distribution table. 

An introduction to new areas is always accidental and appears to occur with the movement of plant materials including garden and horticultural waste.

Pathway Causes

Pathway Vectors

Impact Summary

Economic Impact

No overall assessment of the economic consequences of A. vulgaris has been made, but the species contributes to damage on several horticultural crops (Fischer and Reisschütz, 1998). Strawberry growers in Norway have reported more than 50% loss in yield due to A. vulgaris, but proper economic assessments have not been conducted yet (Weidema, 2006).

Environmental Impact

Impact on Habitats

A. vulgaris can be a significant cause of defoliation of wild plants and even trees (Proschwitz, 1997). However, these effects are likely to be short-lived and the severity of defoliation will be dependent upon a number of environmental variables controlling slug breeding success. 

Impact on Biodiversity

The main impact on biodiversity noted by authors has been the decline in numbers and disappearance of Arion rufus in areas where A. vulgaris is abundant and invasive (Fischer and Reischütz, 1998).

Social Impact

The use of toxic baits could have health impacts on children in gardens and on predators that may accumulate poisons. The volume of sales of garden slug killers in central Europe has been linked to the prevalence of this species (Weidema, 2006).

Risk and Impact Factors

• Proved invasive outside its native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Tolerant of shade
• Capable of securing and ingesting a wide range of food
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential
• Reproduces asexually

• Changed gene pool/ selective loss of genotypes
• Negatively impacts agriculture
• Negatively impacts livelihoods
• Threat to/ loss of native species

• Competition - monopolizing resources
• Hybridization
• Interaction with other invasive species

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect in the field
• Difficult/costly to control

Uses List

General

• Laboratory use
• Research model

Detection and Inspection

The occurrence of A. vulgaris in transported plant materials may involve the adults, juveniles or eggs. 

The adults and juveniles are active after dark and may be detected in the evening or early morning, or by inspecting plant materials stored under cover. Like Deroceras reticulatum, all stages hide in leaf whorls, under debris, stones and wood and occasionally in the soil around root systems. 

The eggs are deposited on the soil, under dead leaves or other surface debris and are not buried in the soil. 

Traps containing molluscicides (metaldehyde, carbamate, iron pyrophosphate hydrate) may be used to collect material, but hand collecting is often just as efficient and avoids the risk of contaminating produce.

Similarities to Other Species/Conditions

A. vulgaris belongs to a clade of large round-back slugs inhabiting central, western and southern Europe. These include Arion rufus, which has been dispersed with trade to western North America. A. vulgaris and A. rufus are closely related and able to hybridize (Hagnell et al., 2003). 

Unfortunately, it is very difficult to distinguish between these two species based on external morphology. Reliable methods of discrimination include: dissection of the proximal genitalia in mature individuals; the use of ITS1 sequencing data based on known reference material. The spermatophores exchanged during sexual intercourse are highly diagnostic, but they are unlikely to be available routinely. A summary of the internal and external characteristics of A. vulgaris are given by Davies (1987). Quick (1960) provides a useful summary for A. rufus.  

There are two colour phases: a dark phase and a light phase, which can occur mixed in populations. 

The dark phase (red-brown, black body colours) of A. vulgaris has a sub-dermal black pigment masked by an overlying reddish pigment. The red pigment responds to environmental conditions and varies from bright red-brown (warm, dry conditions) to dark-brown or black (cold conditions) (Chevallier, 1977). Colour can alter within a generation if specimens are transplanted from warm to cold areas e.g. an increase in altitude or movement further north (R Anderson, [address available from CABI], personal communication, 2008). The foot fringe colour matches the overall body colour in the dark phase. In the dark phase of A. rufus there is no indication of contrasting pigment layers in the dermis. In addition, the foot fringe is brighter, yellow or red to orange, usually contrasting markedly with (duller) body colours that may include grey or pure black. 

The pale phase of A. vulgaris (yellowish to pale-brown body colours) lacks the contrasting dark subdermal pigment and the skin layers are uniform in colour. The pale phase is difficult to distinguish from A. rufus although the latter still tends to have brighter red to orange, contrasting foot fringes, whereas in A. vulgaris the foot fringe and body colours match better.   

Populations of A. vulgaris reproduce more by sexual means than by selfing. This is in contrast to other large Arions such as A. rufus, which commonly self. Discovery of copulating individuals, particularly during daylight hours, would tend to indicate A. vulgaris rather than A. rufus or Arion ater. 

Resting individuals of A. rufus, when stimulated by stroking the back firmly, will often react by rolling the body from side to side while in the contracted position. This reaction is extremely rare or non-existent in A. vulgaris (see Davies, 1987).

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Early Warning Systems

No warning system is available for A. vulgaris. However, in habitats that have been undisturbed for at least 2 years, A. vulgaris often occurs in high numbers and is likely to cause damage.

Cultural Control

Ploughing and other methods of soil cultivation significantly reduce slug populations, and the removal of vegetation deprives A. vulgaris of shelters. In recent years the establishment of fallows has been encouraged in many European countries as part of government-subsidized set-aside programmes. Along with grassland, fallows and other undisturbed habitats are excellent habitats for A. vulgaris. In these habitats, A. vulgaris builds up large populations and migrates into adjacent crops, often completely destroying the nearest few metres of the field. Thus, crops sensitive to slug feeding should not be sown or planted next to undisturbed habitats and undisturbed habitats should not be created next to a slug sensitive crop.

Biological Control

The nematode Phasmarhabditis hermaphrodita (Rhabditidae) is an effective biocontrol agent for many slug species (Wilson et al., 1993; Glen et al., 1996). Juvenile A. vulgaris are highly susceptible to P. hermaphrodita, but larger specimens are not susceptible (B Speiser, FiBL, Frick, Switzerland, unpublished data).

Chinese ducks are successfully used to control slugs in horticultural crops (B Grimm, Institute of Zoology, Graz, Austria, personal communication; B Speiser, FiBL, Frick, Switzerland) but their use is limited by the labour requirement of herd management. If ducks swallow A. vulgaris, they need access to water to clean their beaks (Sulzberger, 1996). The successful use of ducks for control of snails is described by Sakovich (1996).

Chemical Control

For chemical control of A. vulgaris, bait pellets are normally used. These contain either metaldehyde or a carbamate as active ingredient. The pellets are broadcast on the soil. If A. vulgaris migrates into the crop from an adjacent habitat, it may be sufficient to treat a narrow strip (0.5 m) with twice the dosage recommended for broadcast application (Friedli and Frank, 1998).

Host Resistance

There is little scope to reduce damage by A. vulgaris through the use of resistant varieties.

Gaps in Knowledge/Research Needs

Quantification of economic impacts is missing from almost all evaluations and should be followed up. 

The status of A. vulgaris in the USA is unclear. Apart from an uncorroborated report on the internet (October 1998) for Cornell University, USA, no evidence for its occurrence there has been adduced. Despite this, almost the whole of continental USA falls within the latitudinal and climatic parameters suitable for this species. The relevant authorities are aware of the potential problem, but more studies addressing the identity of introduced large arionids in the USA are required. It has been established by a molecular study in California, USA (R McDonnell, UCLA, personal communication, 2008) that the invasive, large arionids in that area at least, are attributable to Arion rufus. 

References

Altena CORvan, 1956. [English title not available]. (Notes sur les limaces, 3. (Avec la collaboration de Mm. Aten et A. Schouten) Sur la présence en France de'Arion lusitanicus Mabille) Journal de Conchyliologie, 95:89-99.

Anderson R, 2010. The invasive pest slug Arion vulgaris Moquin-Tandon (=A. lusitanicus Mabille) (Mollusca: Arionidae) confirmed for Ireland, with an appeal for records. Irish Naturalists' Journal, 31(1):69-70. http://www.habitas.org.uk/inj/

Backhuys W, 1975. Land and freshwater molluscs of the Azores. Amsterdam, Netherlands: Backhuys and Meesters.

Briner T; Frank T, 1998. Egg laying activity of the slug Arion lusitanicus Mabille in Switzerland. Journal of Conchology, 36:9-15.

Briner T; Frank T, 1998. The egg-laying activity of the slug Arion lusitanicus (Mabille). Journal of Conchology,London, 36:9-15.

Castillejo J, 1997. [English title not available]. (Babosas del Noroeste Ibérico) . Santiago, Spain: Universidad de Santiago de Compostela.

Castillejo J, 1998. [English title not available]. (Guia de las Babosas Ibéricas) . Santiago, Spain: Real Academia Gallega de Ciencias.

Cejka T; Dvorák L; Horsák M, 2006. New records of mollusc species for Slovakia during the last 25 years. Malakologický Bulletin, 14 August 2006. http://mal-bull.blogspot.com

Cesari P, 1978. [English title not available]. (Nota preliminare sulla diffusione in Italia e l'esplosione demografica nel Veneto di Arion lusitanicus Mabille) Lavori,Società veneziana di Scienze naturali., 3-7.

Chevallier H, 1977. [English title not available]. (Observations sure le polymorphisme des limaces rouges (Arion rufus Linné et Arion lusitanicus Mabille) et de l'escargot petit-gris (Helix aspersa Müller)) Haliotis, 6:41-48.

Chevallier H, 1981. [English title not available]. (Taxonomie des "Limaces rouges" (genre Arion, sous-genre Arion s., Mollusca, Pulmonata)) Haliotis, 11:87-99.

Colomba M; Backeljau T; Gregorini A; Jordaens K, 2007. Chromosome numbers and chromosomal evolution in the land snail genus Arion (Gastropoda, Pulmonata). In: Proceedings of the World Congress of Malacology, Antwerp, Belgium, 15-20 July 2007, 40.

Davies SM, 1987. Arion flagellus Collinge and A. lusitanicus Mabille in the British Isles: a morphological, biological and taxonomic investigation. Journal of Conchology, 32:339-354.

Dvorák L; Horsák M, 2003. [English title not available]. (Soucasné poznatky o plzáku Arion lusitanicus (Mollusca: Pulmonata) v Ceské republice) Casopis Slezskeho Musea v Opave, 52:67-71.

Falkner G; Ripken TEJ; Falkner M, 2002. Mollusques continentaux de France. Liste de Référence annotée et Bibliographie. Patrimoines Naturels. Paris, France: Museum d'Histoire Naturelle.

Fechter R; Falkner G, 1990. Weichtiere. München, Germany: Mosaik Verlag.

Fischer W; Reischütz PL, 1998. General aspects of the slug pest. (Grundsätzliche Bemerkungen zum Schadschneckenproblem) Die Bodenkultur, 49:281-292.

Friedli J; Frank T, 1998. Reduced applications of metaldehyde pellets for reliable control of the slug pests Arion lusitanicus and Deroceras reticulatum in oilseed rape adjacent to sown wildflower strips. Journal of Applied Ecology, 35(4):504-513.

Glen DM; Wilson MJ; Hughes L; Cargeeg P; Hajjar A, 1996. Exploring and exploiting the potential of the rhabditid nematode Phasmarhabditis hermaphrodita as a biocontrol agent for slugs. Slug & snail pests in agriculture. Proceedings of a Symposium, University of Kent, Canterbury, UK, 24-26 September 1996., 271-280.

Grimm B, 2002. Effect of the nematode Phasmarhabditis hermaphrodita on young stages of the pest slug Arion lusitanicus. Journal of Molluscan Studies, 68(1):25-28.

Hagnell J; Schander C; Proschwitz TVon, 2003. British Council for Crop Protection Symposium Proceedings., 221-226.

Ingimarsdóttir M; Ólafsson E, 2005. [English title not available]. (Spánarsnigilin finnst á Íslandi, því miður) Náttúrufræðingurin, 73:75-78.

Kerney MP, 1999. Atlas of the land and freshwater molluscs of Britain and Ireland. Colchester, UK: Harley Books.

Kerney MP; Cameron RAD; Jungbluth JH, 1979. Die Landschnecken Nord- und Mitteleuropas. Hamburg, Germany: Paul Parey.

Kozowski J, 2007. The distribution, biology, population dynamics and harmfulness of Arion lusitanicus Mabille, 1868 (Gastropoda: Pulmonata: Arionidae) in Poland. Journal of Plant Protection Research, 47(3):219-230. http://www.ior.poznan.pl/Journal/

Kozlowski J, 2005. Host plants and harmfulness of the Arion lusitanicus Mabille, 1868 slug. Journal of Plant Protection Research, 45:221-233.

Kozlowski J; Kaluski T, 2004. Preferences of Deroceras reticulatum (O. Müller), Arion lusitanicus Mabille and Arion rufus (Linnaeus) for various weed and herb species and winter oilseed rape (II group plants). Folia Malacologica, 12:173-180.

Kozlowski J; Kornobis S, 1995. [English title not available]. (Arion lusitanicus Mabille, 1868 (Gastropoda: Arionidae) w Polsce oraz nowe stanowisko Arion rufus (Linnaeus, 1758)) Przeglad Zoologiczny, 39:79-82.

Laznik Z; Ross JL; Trdan S, 2010. Massive occurrence and identification of the nematode Alloionema appendiculatum Schneider (Rhabditida: Alloionematidae) found in Arionidae slugs in Slovenia. Acta Agriculturae Slovenica, 95(1):43-49. http://aas.bf.uni-lj.si/februar2010/06laznik.pdf

Ludwig A; Reise H; Hutchinson JMC, 2015. The slug fauna of gardens in the town of Görlitz (Saxony, Germany). (Die Nacktschneckenfauna in Gärten der Stadt Görlitz (Sachsen, Deutschland).) Berichte der Naturforschenden Gesellschaft der Oberlausitz, 23:43-57. http://www.naturforschende-gesellschaft-der-oberlausitz.de/Publikationen

Moquin-Tandon A, 1855. Histoire naturelle des mollusques terrestres et fluviatiles de France. Paris, France: Baillière.

Noble LR, 1992. Differentiation of large arionid slugs (Mollusca, Pulmonata) using ligula morphology. Zoologica Scripta, 21(3):255-263.

Proschwitz TVon, 1988. Arion lusitanicus (?) on the Falkland Islands. Journal of Conchology, 33:49.

Proschwitz TVon, 1989. [English title not available]. (Arion lusitanicus Mabile - en för Sverige ny snigelart) Göteborgs Naturhistoriska Museum Årstryck., 43-53.

Proschwitz TVon, 1997. Arion lusitanicus Mabille and A. rufus (L.) in Sweden: A comparison of occurrence, spread and naturalization of two alien slug species. Heldia, 4:137-138.

Proschwitz TVon; Winge K, 1994. [English title not available]. (Iberiaskogsnegl- en art pa spredning i Norge) Fauna, 47:195-203.

Quick HE, 1960. British slugs (Pulmonata: Testacellidae, Arionidae, Limacidae). Bulletin of the British Museum (Natural History) Zoology, 6:1-226.

Quinteiro J; Rodríguez-Castro J; Castillejo J; Iglesias-Piñeiro J; Rey-Méndez M, 2005. Phylogeny of slug species of the genus Arion: evidence of monophyly of Iberian endemics and of the existence of relict species in Pyrenean refuges. Journal of Zoological Systematics and Evolutionary Research, 43(2):139-148. http://www.blackwell-synergy.com/servlet/useragent?func=showIssues&code=jzs

Rabitsch W, 2006. Arion vulgaris. Delivering Invasive species entries for Europe. http://www.europe-aliens.org/images/pdficon_small.gif.

Reischütz P, 1984. [English title not available]. (Zur Schadenwirkung der "Kapuzines-schnecke" Arion lusitanicus Mabille in Alpengebiet) Heldia, 1:39.

Sakovich NJ, 1996. An integrated pest management (IPM) approach to the control of the brown garden snail, (Helix aspersa) in California citrus orchards. In: Henderson IF, ed. Slug & Snail Pests in Agriculture. Farnham, UK: British Crop Protection Council, 283-287.

Schmid G, 1970. [English title not available]. (Arion lusitanicus in Deutschland) Archiv für Molluskenkunde, 100:95-102.

Soroka M; Kaluski T; Kozlowski J; Wiktor A, 2007. Molecular diversity among populations of the terrestrial slugs Arion lusitanicus and Arion rufus (Mollusca, Pulmonata, Arionidae) in Poland. In: Proceedings of the World Congress of Malacology, Antwerp, Belgium, 15-20 July 2007, 211 pp.

Stranc P; Vasák J; Becka D; Stranc D, 2006. Alternative methods for slug and arion control in winter rapeseed (Brassica napus L.). Scientia Agriculturae Bohemica, 37(3):104-107.

Sulzberger R, 1996. Wenn Schnecken zur Plage werden. München, Germany: BLV.

Turner H; Kuiper JGJ; Thew N; Bernasconi R; Ruetschi J; Wuthrich M; Gosteli M, 1998. Atlas of the Mollusca of Switzerland and Liechtenstein. Atlas der Mollusken der Schweiz und Liechtensteins., 527 pp.

Valovirta I, 1995. [English title not available]. ("Tappajaetana" on mainettaan säyseämpi) Helsingin Sanomat, 8.7.2005, B18 (interview).

von Proschwitz T, 1997. Arion lusitanicus Mabille and A. rufus (L.) in Sweden: A comparison of occurrence, spread and naturalization of two alien slug species. Heldia, 4:137-138.

von Proschwitz T, 1997. Erstnachweis von Arion lusitanicus Mabille in Mecklenburg-Vorpommern. Schriften zur Malakozoologie, 10:21-22.

Weidema I, 2006. Nobanis invasive alien fact sheet: Arion lusitanicus. htttp://www.nobanis.org /files/factsheets /Arion_lusitanicus.pdf.

Wiktor A, 1983. The slugs of Bulgaria (Arionidae, Milacidae, Limacidae, Agriolimacidae - Gastropoda Stylommatophora). Annales Zoologici, 37:71-206.

Wilson MJ; Glen DM; George SK, 1993. The rhabditid nematode Phasmarhabditis hermaphrodita as a potential biological control agent for slugs. Biocontrol Science and Technology, 3(4):503-511.

Winter AJDe, 1989. Arion lusitanicus Mabille in Nederland (Gastropoda: Pulmonata: Arionidae). Basteria, 53:49-51.

Distribution References

Anderson R, 2010. The invasive pest slug Arion vulgaris Moquin-Tandon (=A. lusitanicus Mabille) (Mollusca: Arionidae) confirmed for Ireland, with an appeal for records. Irish Naturalists' Journal. 31 (1), 69-70. http://www.habitas.org.uk/inj/

Backhuys W, 1975. Land and freshwater molluscs of the Azores. Amsterdam, Netherlands: Backhuys and Meesters.

CABI, Undated. Compendium record. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

Cejka T, Dvorák L, Horsák M, 2006. New records of mollusc species for Slovakia during the last 25 years. In: Malakologický Bulletin. http://mal-bull.blogspot.com

Cesari P, 1978. [English title not available]. (Nota preliminare sulla diffusione in Italia e l'esplosione demografica nel Veneto di Arion lusitanicus Mabille). Lavori, Società veneziana di Scienze naturali. 3-7.

Chevallier H, 1981. [English title not available]. (Taxonomie des "Limaces rouges" (genre Arion, sous-genre Arion s., Mollusca, Pulmonata)). Haliotis. 87-99.

Davies S M, 1987. Arion flagellus Collinge and A. lusitanicus Mabille in the British Isles: a morphological, biological and taxonomic investigation. Journal of Conchology. 339-354.

Dvorák L, Horsák M, 2003. [English title not available]. (Soucasné poznatky o plzáku Arion lusitanicus (Mollusca: Pulmonata) v Ceské republice). Casopis Slezskeho Musea v Opave. 67-71.

Fischer W, Reischütz P L, 1998. General aspects of the slug pest. (Grundsätzliche Bemerkungen zum Schadschneckenproblem). Bodenkultur. 281-292.

Kerney M P, 1999. Atlas of the land and freshwater molluscs of Britain and Ireland. Colchester, UK: Harley Books.

Kerney MP, Cameron RAD, Jungbluth JH, 1979. (Die Landschnecken Nord- und Mitteleuropas)., Hamburg, Germany: Paul Parey.

Laznik Ž, Ross J L, Trdan S, 2010. Massive occurrence and identification of the nematode Alloionema appendiculatum Schneider (Rhabditida: Alloionematidae) found in Arionidae slugs in Slovenia. Acta Agriculturae Slovenica. 95 (1), 43-49. http://aas.bf.uni-lj.si/februar2010/06laznik.pdf

Ludwig A, Reise H, Hutchinson J M C, 2015. The slug fauna of gardens in the town of Görlitz (Saxony, Germany). (Die Nacktschneckenfauna in Gärten der Stadt Görlitz (Sachsen, Deutschland).). Berichte der Naturforschenden Gesellschaft der Oberlausitz. 43-57. http://www.naturforschende-gesellschaft-der-oberlausitz.de/Publikationen

Moquin-Tandon A, 1855. Histoire naturelle des mollusques terrestres et fluviatiles de la France contenant des études générales sur leur anatomie et leur physiologie et la description particulière des genres, des esp. Paris, France: J. B. Baillière. 646 pp.

Proschwitz T Von, 1989. [English title not available]. (Arion lusitanicus Mabile - en för Sverige ny snigelart). In: Göteborgs Naturhistoriska Museum Ǻrstryck, 1989 43-53.

Proschwitz T Von, 1997. Arion lusitanicus Mabille and A. rufus (L.) in Sweden: A comparison of occurrence, spread and naturalization of two alien slug species. Heldia. 137-138.

Proschwitz T Von, Winge K, 1994. [English title not available]. (Iberiaskogsnegl- en art pǻ spredning i Norge). Fauna. 195-203.

Schmid G, 1970. Arion lusitanicus in Germany. (Arion lusitanicus in Deutschland). Archiv für Molluskenkunde. 95-102.

Slotsbo S, 2014. Nobanis invasive alien fact sheet: Arion lusitanicus. In: Nobanis invasive alien fact sheet: Arion lusitanicus, https://www.nobanis.org/globalassets/speciesinfo/a/arion-lusitanicus/arion_vulgaris1.pdf

Štranc P, Vašák J, Bečka D, Štranc D, 2006. Alternative methods for slug and arion control in winter rapeseed (Brassica napus L.). Scientia Agriculturae Bohemica. 37 (3), 104-107.

Turner H, Kuiper J G J, Thew N, Bernasconi R, Ruetschi J, Wuthrich M, Gosteli M, 1998. Atlas of the Mollusca of Switzerland and Liechtenstein. (Atlas der Mollusken der Schweiz und Liechtensteins.). In: Atlas der Mollusken der Schweiz und Liechtensteins. Neuchâtel, Switzerland: Centre Suisse de Cartographie de la Faune (CSCF). 527 pp.

Valovirta I, 1995. [English title not available]. ("Tappajaetana" on mainettaan säyseämpi). In: Helsingin Sanomat,

Wiktor A, 1983. The slugs of Bulgaria (Arionidae, Milacidae, Limacidae, Agriolimacidae - Gastropoda Stylommatophora). Annales Zoologici. 71-206.

Winter A J De, 1989. Arion lusitanicus Mabille in Nederland (Gastropoda: Pulmonata: Arionidae). Basteria. 49-51.

Links to Websites

Organizations

Europe: DAISIE - Delivering Alien Invasive Species Inventories for Europe, Web-based service, http://www.europe-aliens.org

UK: Malacological Society of London, Canterbury Christ Church University , Kent, CT1 1QU, http://www.malacsoc.org.uk/

Contributors

07/04/2008 Updated by:

Roy Anderson, Consultant, UK

Distribution Maps