not in Young Iolana iolas is a Mediterranean and sub-Mediterranean butterfly that is closely tied to its larval foodplant, bushes of the genus Colutea. Its caterpillars are exclusively carpophagous, penetrating the Colutea pods immediately after birth, where they feed on the plant's seeds. Both the plant and the butterfly require open sunny habitats, for example road margins, and open forests at altitudes between 100 and 800 m a.s.l., although specimens have been found up to 1,300 m a.s.l. In Catalonia the adults fly from April to June, with .a peak in the second half of May. The majority of the known Catalan populations are found in the mountains of the Serralada Prelitoral, above all in its central section, although a few populations exist in the pre-Pyrenees and Pyrenees. The butterfly has never been recorded from Andorra or the Balearic Islands. It is probably extinct in the comarca of Barcelones, where a good number of populations were known in the past. The species has been foun! d in 24 10 x 10 UTM squares, although in only 18 have there been records since 1975. Almost all the populations known from Catalonia fly in extremely low densities and depend on a very small number of hostplants. Thus, we consider that this is a vulnerable species in Catalonia and suggest a number of ways in which it could be protected. Given the controversy regarding the species' taxonomy, myrmecophily, length of diapause and voltinism, we review the biological data and the taxonomic hypotheses found in the literature. Camponotus cruentatus (Formicidae); Myrmica (Formicidae); Tapinoma erraticum (Formicidae); Cotesia specularis (Braconidae): Parasite; Anisobas cephalotes (Ichneumonidae): Parasite; Iolana iolas (Lycaenidae): Host. Anisobas cephalotes, Cotesia specularis: Lepidopteran hosts, Iolana iolas, Spain, Catalonia; Camponotus cruentatus, Myrmica, Tapinoma erraticum: Mutualism, Iolana iolas (Lepidoptera), Spain, Lepidopteran mutualists, myrmecophily; Iolana iolas: Conservation measures, Conservation recommendations, Food plants, Colutea, Life cycle, Phenology, Mutualism, Camponotus cruentatus (Hymenoptera), Myrmica (Hymenoptera), Tapinoma erraticum (Hymenoptera), Hymenopteran parasites, Anisobas cephalotes, Cotesia specularis, Spain, Hymenopteran mutualists, myrmecophily, Catalonia. Arthropods; Hymenopterans; Insects; Invertebrates; Lepidopterans. none2008checked