Invasive alien species in Switzerland - Schweizer ...

An inventory of alien species and their threat to biodiversity and economy in Switzerland FOEN 2006 76
establishment in Switzerland are natural phenomena and not mediated by human
activity. A few species whose invasive status is in doubt are included in the list, such as
the geometrid Eupithecia sinuosaria, a European species for which the spread through
Central Europe has been particularly well studied (Rezbanyai-Reser et al., 1998).
Similarly, Caradrina ingrata is a noctuid of eastern Mediterranean origin and is increasingly
observed in urban areas, where it could have become established in warmer
microclimates (Rezbanyai-Reser et al., 1997; Whitebread, 1997).
Many Lepidoptera of exotic origin are primary or secondary pests. Among the bestknown
exotic species are several leaf miners in the family Gracillariidae, which all
invaded Europe in the last 30 years. Leaf miners are easily introduced into new areas
because the mines on fresh or dead leaves are often inconspicuous and readily carried
over long distances. In addition, several species pupate in or near the leaf mine, and
these stages are less vulnerable to adverse conditions. The horse chestnut leaf miner,
Cameraria ohridella, is a moth of unknown origin that was first found in Macedonia in
1984 and in Switzerland in 1998 (Kenis and Forster, 1998; see also Fact Sheet). In less
than 20 years, it has invaded most of Europe. The rapid spread of the moth in Europe is
explained by the transport of adults and dead leaves containing pupae in or on vehicles.
It causes severe defoliation to horse chestnut (Aesculus hippocastanum L.) trees in
urban areas in most European regions as well as to indigenous horse chestnut stands in
the Balkans, where it represents a threat to the survival of the tree species in the wild.
The North American species Phyllonorycter robiniella and Parectopa robiniella mine
leaves of their original host, the North American black locust Robinia pseudoacacia L.
(see Fact Sheet in the plants chapter). Phyllonorycter platani, a moth originating from
the Balkans and Asia Minor, is commonly found on Platanus trees. Phyllonorycter
leucographella, also of eastern Mediterranean origin, has spread all over Europe and
feeds on Pyracantha and Crataegus. Another gracillariid, the eastern Asian Caloptilia
azaleella, mines on Rhododendron in greenhouses. Ornamental Cupressaceae in Europe
are attacked by another North American leaf miner, the yponomeutid Argyresthia
thuiella.
The arctiid moth Hyphantria cunea is another interesting case of an invasive Lepidoptera.
Originating from North America, H. cunea arrived in the 1940s in Hungary, from
where it spread to most of Europe. It was first found in the Ticino in 1991 (Jermini et
al., 1995; see also Fact Sheet). This polyphagous defoliator is considered a serious pest
of forest and ornamental trees and shrubs in some eastern European countries and
eastern Asia, where it was also introduced. Cydia molesta is an Asian species present
in orchards in Switzerland where it feeds on various fruit trees. The noctuid Helicoverpa
armigera is a cosmopolitan, polyphagous pest, probably of African origin,
which occurs in Switzerland mainly in greenhouses. It is now also regularly found
overwintering in the Tessin, where it probably arrived by itself. Another greenhouse
pest of African origin is the banana moth, Opogona sacchari, which feeds on various
woody and perennial ornamentals.
Several exotic moths are pests of stored products in Switzerland. Most of them have
been introduced with commodities into most parts of the world. The pyralid Plodia
interpunctella is a major pest of stored products in warehouses, grain elevators and