Invasive alien species in Switzerland - Schweizer ...

4 > Insects – Insecta 83
4.8 Dictyoptera
At least five exotic cockroach species are known to be established in Switzerland.
Others may be introduced occasionally with imported goods. Unlike the native cockroaches,
the exotic species are synanthropic, i.e. they are always found in association
with humans. These cockroaches are of tropical and subtropical origin but they now
occur worldwide. Some species, such as Blatta orientalis and Periplaneta americana,
have been cosmopolitan for such a long time that their origin is uncertain. B. orientalis,
P. americana, P. australasiae and B. germanica have been established in Switzerland
for a long time, whereas Supella longipalpa is a recent introduction.
All these species are considered as serious urban pests. They are gregarious, nocturnal,
and difficult to eradicate in houses. They can eat almost anything, e.g. human food and
animal feed, bookbindings, wallpaper, excrement, leather products, etc. They can carry
organisms causing human diseases, have a repulsive odour, and can cause allergic
reaction and anxiety in some individuals. In Switzerland, the most problematic species
are B. germanica, S. longipalpa and B. orientalis, whereas Periplaneta spp. are of
minor importance (Landau et al., 1999).
4.9 Isoptera
There is no record of establishment of exotic termites in Switzerland. However, in
recent years, subterranean termites of the genus Reticulitermes have invaded new areas
(see Fact Sheet). The North American R. flavipes (Kollar) is introduced in some German
and Austrian cities. The southern European R. grassei Clément occurs now in
southern England and R. santonensis de Feytaud, a species of uncertain origin (and
perhaps synonymous with R. flavipes) has spread from south-western to northern
France. These termites undoubtedly have the potential to invade the warmest areas in
Switzerland. They live in colonies in the soil, mainly in urban areas. They are particularly
harmful to wooden elements in building but can also attack living trees. The
spread of subterranean termites in France is causing major concern. New regulations
have been set up to limit the spread.
4.10 Thysanoptera
Many exotic thrips species are found, regularly or occasionally, in Switzerland in
greenhouses. However, it is not always clear whether they are firmly established in the
country. At least four species are considered permanently established, mainly in greenhouses.
Three of them, Frankliniella intonsa, F. occidentalis and Heliothrips haemorrhoidalis
are polyphagous, cosmopolitan pests on ornamentals, vegetables, and fruits.
F. occidentalis, the western flower thrips, is among the most destructive greenhouse
pests in Switzerland (Ebener et al., 1989; Schmidt and Frey, 1995). It is also a vector of
various viruses. The pest status of F. occidentalis is relatively recent. It occurs naturally
in North America on wild flowers and emerged as a greenhouse pest in the Neth-