<i>Deroceras panormitanum</i> and congeners from Malta and Sicily, with a redescription of the widespread pest slug as <i>Deroceras invadens</i> n. sp.

Abstract

The name Deroceras panormitanum is generally applied to a terrestrial slug that has spread worldwide and can be a pest; earlier this tramp species had been called Deroceras caruanae. Neither name is appropriate. The taxonomic descriptions apply to a species from Sicily and Malta. This true D. panormitanum and the tramp species are distinct in morphology and mating behaviour. For instance, the penial caecum of D. panormitanum is more pointed, everting faster at copulation. The size of the penial lobe varies considerably in preserved specimens but is always prominent at copulation. D. panormitanum is distinct from the Maltese endemic Deroceras golcheri, but a phylogeny based on mtDNA COI sequences implies that they are more closely related than is the tramp species. D. golcheri has a still closer counterpart on Sicily, but we leave the taxonomy of this "species X" unresolved. In interspecific crosses, D. panormitanum may transfer sperm to the partner's sarcobelum whereas the partner fails to evert its penis (D. golcheri) or to transfer sperm (the tramp species). Names previously applied to the tramp species originally referred to D. panormitanum or are otherwise invalid, so it is here formally redescribed as D. invadens. Deroceras giustianum Wiktor, 1998 is synonymised with D. panormitanum.

Terrestrial molluscs of the Province of Newfoundland and Labrador,&nbsp;Canada. Part 1: Boettgerillidae

“…The first serious collections of terrestrial molluscs on the Island of Newfoundland were made, somewhat incidentally, by Philadelphia botanist Bayard Long, who Reise et al (2011), andin Forsyth (2014). This collection is significant, since it constitutes only the second outdoor record of D. invadens for eastern Canada.…”

First record of Deroceras invadens Reise, Hutchinson, Schunack &amp; Schlitt, 2011 (Gastropoda: Pulmonata: Agriolimacidae) from the island of Newfoundland, Canada

“…Deroceras invadens Reise, Hutchinson, Schunack & Schlitt, 2011 was recently described for a species of terrestrial slug that has previously been called D. panormitanum (Lessona & Pollonera, 1882) or Agriolimax caruanae (Pollonera, 1891). Neither of these names is applicable to the invasive species that presumably originated from the Mediterranean region but now has an almost worldwide distribution (Reise et al 2006(Reise et al , 2011.…”

“…Neither of these names is applicable to the invasive species that presumably originated from the Mediterranean region but now has an almost worldwide distribution (Reise et al 2006(Reise et al , 2011.…”

“…The penis of D. invadens is strongly and equally bilobed. Between the lobes of the penis, there is a cluster of usually 4-6 finger-like glands (Forsyth 2004;Grimm et al 2010;Reise et al 2011) (Figure 1). Partial or total loss of the male reproductive organs is common for D. laeve, but when a penis is present, it is a long, somewhat contorted structure with a twisted terminal gland (Pilsbry 1948;Wiktor 2000).…”

An invasion from Germany: Deroceras invadens (Pulmonata: Agriolimacidae) and other synanthropic slugs in the southwest corner of Poland

“…Deroceras invadens Reise, Hutchinson, Schunack et Schlitt, 2011 (previously known as Deroceras pa normitanum (Lessona et Pollonera, 1882): Reise et al 2011) is a slug that has spread from southern Italy across much of the world over the last century (hutChinson et al 2014). However, in central Europe it has been slow to colonise further east than Germany.…”