Insects, snails and slugs

Norwegian Print

Most alien invertebrates have been unintentionally introduced to Norway with import of timber, garden plants, or fruit and other food. Increasing numbers of insects and arachnids (spiders) are being imported for use in the biological control of pests in agriculture and horticulture, and sometimes as pets.

Leopard slug

Leopard slug is one of the alien slugs that have established populations in Norway. Photo: Sissel Rübberdt

Some of the invertebrates that are imported survive to become part of the Norwegian fauna. Hundreds of insect species and dozens of species of snails and slugs have been imported. Because our knowledge of the indigenous invertebrate fauna is incomplete, we know far too little about how many, and which, species have been imported.

Examples of non-native insects that have become established in Norway

Scientific name	Place of origin	Year/period introduced
Megastigmus spermotrophus	North America
Gilletteella cooleyi	North America	1959
Dreyfusia(=Adelges) nordmanniana	Probably Caucasus	Uncertain
Aphrastasia pectinata	Uncertain	Uncertain
Pristiphors erichsonii	North America	19th century
Pristiphora wesmaeli
Pristiphora laricis
Adelges laricis
Coleophora laricella

Examples of non-native snails and slugs that have become established in Norway

Common name	Scientific name	Place of origin	Year/period introduced
European red slug	Arion rufus	Central Europe	1853
Spanish slug	Arion lusitanicus	South Europe	1988
Leopard Slug	Limax maximus	Central Europe	18th century
Roman snail	Helix pomatia	South-, Central-, East-Europe	1952
Hairy snail	Trichia hispida	Uncertain	18th century
Black-keeled slug	Milax gagates	Mediterranian area	2001
Nettled slug	Deroceras reticulatum	Central- and West-Europe	Uncertain

Source: Norwegian Institute for Nature Research (NINA)