Phytophagous arthropod fauna of Chinese Mugwort Artemisia verlotiorum, Lamotte, 1877 (Asteraceae) in Central Europe, particularly the Lake Constance region.
In Central Europe, the Asian Artemisia verlotiorum, Lamotte, 1877 (Asteraceae) is becoming increasingly invasive and may in future - forced by climate change - cause problems in nature conservation and agriculture. To estimate its ecological role as a host plant, its phytophagous arthropod complex was analysed. The analysis is based on field surveys, primarily in the Lake Constance area, as it is an "old" stronghold of the alien herb. A total of 55 sites were investigated in 2007, of which 26 are lake shore sites and 23 ruderal or segetal sites nearby. Other (ruderal) sites are near Mainz (Germany: Rheinland-Pfalz, 4 sites), Heidelberg (Germany: Baden-Württemberg, 1 site) and Locarno (Switzerland, Ticino, 1 site). The sites on Lake Constance were investigated four times a year to capture various phytophagous guilds (e.g. external feeders, leaf miners, stem and rootstock inhabitants). The phytophagous insect complex as studied here encompasses 30 species (12 Homoptera, 6 Lepidoptera, 6 Diptera, 5 Heteroptera and 1 Coleoptera) and is consequently significant pourer than that of the native A. vulgaris (181 sp.). 43.3% of these are polyphagous, 30.0% oligophagous (i.e. restricted to Asteraceae), 6.6% are second degree monophagous (i.e. restricted to the genus Artemisia) and 20.0% were found only on A. vulgaris before (first degree monophagous). More than half the species (55.2%) are sap-suckers, while the rest chew on plant tissue. Epiblema foenella (Torticidae), Phytomyza artemisivora (Agromyzidae) and Trypeta artemisiae (Trypetidae) are the most abundant chewing species. The stem borer E. foenella in particular can have a noticeable effect on the vitality of the plants. Macrosiphoniella artemisiae, M. oblonga and Pleotrichophorus glandulosus are locally abundant aphid species (Aphididae).