Abstract
The plant Jurinea cyanoides (L.) Reichenbach (Asteraceae), protected under the European Commission Directive on the conservation of natural habitats and of wild fauna and flora (92/43/EEC), is critically endangered in Central Europe. The centre of its continuous range of distribution is in Ukraine and in a part of European Russia.
Natural isolated populations have refugial distribution in the Czech Republic and Germany. Interactions of insects from different feeding guilds (i.e., phytophages, pollinators, parasitoids, predators) with J. cyanoides were studied in central Ukraine, Czech Republic and Germany.
The insect community identified on J. cyanoides and differences in its composition on robust populations of plant in contrast to sparsely populated periphery of its range are discussed. Altogether 78 species belonging to six orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Neuroptera) were recorded.
Larvae of the pyralid moth (genus Dioryctria), tephritid fruit flies (Acanthiophilus helianthi), and several polyphagous Heteroptera species are identified as main taxa feeding on inflorescences and seeds of J. cyanoides, with a potential to reduce the plant's sexual reproduction. The impact of phytophagous insects is, however, considered only a secondary reason for the decline of the Czech populations of J. cyanoides on which a fairly low number of insect species were recorded in comparison with Ukraine and Germany; habitat loss and inbreeding effect are probably major negative factors.
Several new host plant-insect and host-parasitoid associations are reported for insects on J. cyanoides.