Thistles (Asteraceae: Carduoideae) are permanent or biennial (up to perennial) weeds, which are highly competitive and invasive, and well spread in the whole area of the Czech Republic. Despite the thistles are relatively adequately armoured by spines, they support a rich and varied fauna of insect herbivores with their associated predators and parasitoids. Herbivores can significantly reduce reproductive potential of the host plant.
Flower heads of thistles contain the most varied, specific and well-known insect fauna of any part of the plant. They are rich source of food, packed with achenes, and their inhabitants are protected from vertebrate predators by the tough spiny bracts (Redfern 1995).
We have studied associations of pre-dispersal predators with 32 plant species in the Czech Republic and 6 species in U.S.A. from the following genera: Arctium, Carduus, Carlina, Centaurea, Cirsium, Cyanus, Echinops, Onopordum and Serratula.
Presented data are for now only from a few literature sources. Next data and also our observations will be refilled as soon as possible, probably in a new version of database, where will be presented also source of literature.