Insect community in maturing capitula of dandelion (Tavaxacum officinale)

In 2000-2003, arthropods colonizing the capitula of dandelion (Taraxacum officinale agg.) before seed dispersal were sampled at weekly intervals, from April to November. In each sample 50 - 150 capitula were removed and individuals of all species were recorded. In total at least 24 species of 9 orders were established. Abundant seed consumers were Olibrus bicolor (Coleoptera, Phalacridae) larvae, Glocianus punctiger (Coleoptera, Curculionidae) larvae, and Thrips hukkineni (Thysanoptera, Thripidae) larvae and adults. Dry biomass of these species was greatest (ca. 4.0 mg capitulum(-1)) from mid-May to early June. During the season O. bicolor produced 58% of total biomass, G. punctiger 37% and T. hukkineni 5%. Biomass production may indicate the extent of seed damage caused by particular species. Rare phytophagans were Cnephasia oxyacanthana (Lepidoptera, Tortricidae) and Ensina sonchi (Diptera, Tephritidae) larvae. Phytophagans were followed by predators, of which the most abundant were Syrphidae spp. (Diptera) larvae (not identified to species) and Orius (Heteroptera, Anthocoridae) adults and larvae (4 species). Larvae of Tachyporus sp. (Coleoptera, Staphylinidae) and Malthodes sp. (Coleoptera, Cantharidae) were found regularly. Several species occasionally sheltered inside the capitula. The period of species occurrence was similar but their abundance varied between years.