none The quinolizidine alkaloids (QA) of golden rain, Laburnum anagyroides , and those of phytophagous insects associated with the plant, as well as of parasitoids of the latter, were analyzed by capillary GLC and GLC-MS. The alkaloid content in samples of vegetative plant parts was high at the beginning of the season, then decreased, while that of reproductive organs was high throughout flowering, pod formation, and maturation. The analyses showed that the QA of the plant passed through two higher trophic levels (herbivorous insects and their parasitoids) and that the alkaloid pattern changed little during the passage. The alkaloids were present in two phytophagous insect species associated with golden rain: the predispersal seed predator, Bruchidius villosus (5-13 mu g/g fresh weight (fw)), and Aphis cytisorum (182-1012 mu g/g fw), an aphid that feeds on shoots, leaves, and inflorescences. Biochemistry; Nutrition; Diet; Associations; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Trophic structure; Land and freshwater zones; Palaearctic region; Europe Bruchidius villosus (Bruchidae); Biochemistry; Food plants; Laburnum anagyroides (golden rain); Hymenopteran parasites; Chalcidoidea & Triaspis thoracicus; Food webs; Hungary; Quinolizidine alkaloids from food plant, passage in food chain Triaspis thoracicus (Braconidae ); Chalcidoidea; Biochemistry; Coleopteran hosts; Bruchidius villosus; Quinolizidine alkaloids from food plant; Food webs; Hungary; Quinolizidine alkaloids, passage in food chain Formicidae; Biochemistry; Food webs; Hungary; Quinolizidine alkaloids, passage in food chain Formica cunicularia; Formica rufibarbis; Lasius niger (Formicidae ); Mutualism; Aphis cytisorum (Hemiptera); Quinolizidine alkaloids from food plant, passage in food chain; Hungary Aphis cytisorum (Aphidoidea); Biochemistry; Food plants; Laburnum anagyroides (golden rain); Mutualism; Formicidae (Hymenoptera); Food webs; Hungary; Quinolizidine alkaloids from food plant, passage in food chain