This paper presents the trophic relations that exist among the aphids (Aphididae) which attack some species of grassy plants and their primary parasitoids (Aphidiidae) and hyper parasitoids (Charipidae, Pteromalidae, Megaspilidae and Encyrtidae). The biological material of study was collected from grassy plants from six localities that are situated on the territories of Iasi and Vaslui counties. BR Parasites diseases and disorders. Parasites. Insect parasites. Hosts. Insect hosts. Land zones. Palaearctic region. Eurasia. Europe. Aphididae (Aphidoidea): Host, Parasite; Syrphophagus aphidivorus (Encyrtidae): Parasite; Pachyneuron aphidis (Pteromalidae): Parasite; Charips leunisii (Cynipidae): Parasite; Aphidiidae (Ichneumonoidea): Host, Parasite; Dendrocerus carpenteri (Ceraphronidae): Parasite. Aphididae: Hymenopteran parasites, Aphidiidae, Pathology, prevalence, Plant hosts, Grass plants, Romania, Iasi and Vaslui counties; Aphidiidae: Hymenopteran parasites, Dendrocerus carpenteri, Pachyneuron aphidis, Syrphophagus aphidivorus, Charips leunisii, Hyperparasitism, in hemipteran host, Hemipteran hosts, Aphididae, Pathology, prevalence, Romania, Iasi and Vaslui counties; Charips leunisii, Dendrocerus carpenteri, Pachyneuron aphidis, Syrphophagus aphidivorus: Hymenopteran hosts, Aphidiidae, Hyperparasitism, Romania, Iasi and Vaslui counties. ST Animalia, Arthropoda, Insecta, Hemiptera, Homoptera, Sternorrhyncha, Aphidoidea; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Chalcidoidea, Encyrtidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Chalcidoidea, Pteromalidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Cynipoidea, Cynipidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Ichneumonoidea; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Proctotrupoidea, Ceraphronidae. Arthropods; Hymenopterans; Insects; Invertebrates; True Bugs. none2006