Invasive alien species in Switzerland - Schweizer ...

4 > Insects – Insecta 71
4 > Insects – Insecta
Prepared by Marc Kenis
4.1 Introduction
Insects probably represent the most numerous exotic organisms in Switzerland. A list
of insects that are considered to be of exotic origin has been drawn up, with the help of
specialists (see Tables 4.1–4.6). It includes 311 species of exotic origin that have
certainly or probably been introduced into Switzerland or neighbouring countries by
human activities. It does not include species that are spreading naturally into Switzerland,
unless they were first introduced into neighbouring countries. This list is by no
means complete, but it will be maintained and new records will be added when data
become available. In collaboration with taxonomists for the various insect groups, we
also intend to publish this list in peer-reviewed journals, with more details on the
occurrence, distribution and biology of the exotic species. The two published lists of
alien organisms in Austria and Germany (Essl and Rabitsch, 2002; Geiter et al., 2002)
have been of great help in the construction of the Swiss list.
Many problems were encountered in drawing up the list, the main ones being detailed
below.
> There is an obvious lack of information sources in Switzerland. Up-to-date, published
checklists are available for a few insect groups only (e.g. Diptera, Orthoptera,
Odonata). The ‘Centre Suisse de Cartographie de la Faune’ (CSCF) is maintaining
incomplete lists with the input of Swiss taxonomists, and several lists of other important
insect groups are in the process of being completed (e.g. Coleoptera, Lepidoptera,
Aphidoidea, etc.). The CSCF and individual taxonomists were very cooperative
in helping us check and complete the list of exotic insects; nevertheless, it
has been a rather difficult task. For some groups, there is presently little expertise in
Switzerland, and no recent checklist is available (e.g. most primitive orders and
Mallophaga, which are therefore not included in the list, and also parts of the Hymenoptera,
Heteroptera, etc.). Additionally, it must be noted that in the few checklists
published, the origin of the species is often not clearly indicated. For future
checklists, we suggest including the ‘exotic character’ and the area of origin in the
data set.
> Many alien insects in Switzerland originate from the Mediterranean region. Some of
these species, particularly Hemiptera, were evidently introduced with their host
plants, which are often planted as ornamentals or crops in Switzerland. However, for
other species, it is not clear whether they were introduced by human activities or
arrived naturally (e.g. the Heteroptera Arocatus longiceps and Deraeocoris fla-