Arianta arbustorum is a medium-sized species of land snail, sometimes known as the "copse snail", a terrestrial pulmonate gastropod mollusk in the family Helicidae. Subspecies Several subspecies are recognized by some authors: Arianta arbustorum alpicola Férussac, 1821 Arianta arbustorum arbustorum (Linnaeus, 1758) Arianta arbustorum canigonensis (Boubée, 1833) Arianta arbustorum picea Arianta arbustorum pseudorudis (Schlesch, 1924) Arianta arbustorum repellini (Reeve, 1852) Arianta arbustorum styriaca (Frauenfeld, 1868) Arianta arbustorum vareliensis Ripken & Falkner, 2000 Distribution This species is native to Europe: North-western and central Europe with Alps and Carpathians Netherlands Austria Czech Republic Slovakia Poland Switzerland. One of the most frequent species of land snails in Switzerland, can be very abundant, up to 20 adults per square meter. eastern Pyrenees, Spain Norway Iceland Faroe Islands the British Isles: Great Britain and Ireland In Britain the species suffered slightly from intensive farming and the continuous destructions of suitable uncultivated refuges. It is rare in Ireland. Kaliningrad Finland. In Finland, it has become so common in the Porvoo region east of Helsinki, that it is locally called the "Porvoo snail". Estonia Latvia scattered to Serbia Bulgaria It is rare in Bulgaria. western Ukraine Arianta arbustorum is introduced to North America, but is only known from Canada, where established populations are known from Newfoundland, New Brunswick, Ontario, and Prince Edward Island. This species has not yet become established in the US, but it is considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national quarantine significance in the USA. Description The shell is usually brown with numerous pale yellowish rows of spots and usually with a brown band above the periphery, occasionally yellowish, reddish or with greenish hue, weakly striated and with fine spiral lines on the upper side. The shell has 5-5.5 convex whorls with deep suture. The last whorl is slightly descending near the aperture. The aperture is with prominent white lip inside. The apertural margin is reflected. Umbilicus is entirely covered by the reflected columellar margin. The width of the shell is 18–25 mm. The height of the shell is 12–22 mm. Dimensions are locally variable. The shell shape is globular in most present-day populations, but originally is believed to have been depressed in the Pleistocene, before lowlands were invaded and shells became globular, re-invading mountain