In many groups of different organisms, that deposit their food in order to feed themselves or their spawns, there are some species or even genera of parasites or predators. Such species steal or feed on others deposited food, and often starve to death or kill the host species. They are called cleptoparasitic species. Parasitic apoidea species don’t build nests, don’t collect pollen and nectar reserves for developing a future generation. They usually lay their eggs in the cells of other solitary bee species nests, that is why they are also called cuckoo-bees. Ordinarily cuckoobees fly above the host-bees nests that are building a cell with pollen grain mixed with nectar. When a host-bee is not around the cell, the cleptoparasitic bee pervades in the cell and lays its egg onto pollen grain. The hatched cleptoparasitic larva instantly starts feeding, eating all of the host-larva food, and as a result is developing faster. The host-larva starves to death or is also being ate by the parasite. During the studying of the apoidea species spectrum from the Apoidea superfamily between 1980-1995, 1961 samples were collected. As a result of the samples analysis, for the first time in the Republic of Moldova 68 cleptoparasitic species were indentified and registered. The most cleptoparasitic species belong to their genera or families. This group of cleptoparasitc species differ from their simple relatives: their appearance is similar to hornets, includes colors as black, red, brown, and have a reduced numbers of hairs. Below is a list of cleptoparsitic species from the Republic of Moldova, identified and registered during the study. Halictidae Thoms Family. Sphecodes Latr. Genus includes 10 species of cleptoparasites : Sphecodes albilabris Hagens, S.crasus Thoms. S. cristatus Hagens, S. croaticus Meger, S divisus Kby., S. gibbus L., S. marginatus Hagens, S. monilicornis Kby., S. palucidus Smith., S. scabricolli Wesm. These species parasitize in the nests of species from Halictus Latr. Genus and the Melitturga clavicornis Latr. bee. Mehgachilidae Latr. Family, Stelis Pz. Genus includes 4 species: Stelis breviscula Nyl,. S. ornatula Klug., S odontopyga Nosk., S. punctualatissima Kby. These cleptoparasitic species were observed only at the apoidea species of Lithurgus, Osmia, Chelostoma, Heriades, Anthidium, Anthidielum, Clisodon, certain genera. Megachilidae Latr. Family, Coelioxys Latr. Genus include 10 cleptoparasitic species: Coelioxys afra Lep., C. argentea Lep., C.aff. argentea Lep., C aurolimbata Forst., C. aff. Brevis Eversm., C. elongate Lep., C. inermis Kby., C. ruficaudata Lep., C. obtuse Perez. The hosts of these cuckko-bees are the megachile species from the same family. Coelixys female bees have an oblong, spiked body that helps them in breaking the megachille bee cell wall, to lay their larva. Anthophoridae family includes cleptoparasitic bees from 4 genera: Nomada Scop., Ammobatoides F., Biastez Panz., Melecta Fros. Nomada Scop. genus registers 34 cleptoparasite species: Nomada armata H.-Sch., N. bifida Thoms., N. bispinosa Mocs., N. braunsiana Sch., N. chinobarina F.Mor., N. diversipes Latr., N. goodeniana Kby., N. guttulata Sch., N. incisa Sch., N. emarginata F.Mor., N. fabriciana L., N. flavoguttata Kby., N. favopicta Kby., N. fucata Pz., N. lineola Pz., N. mauritanica Lep., N. mozelere Allken, N. melathoracica lmhoff, N. mutica F-Mor., N. mauptialis Nosc., N. mobilis Schok., N. obscura zett., N. opaca Alfken, N. panurgina F.Mor, N. plativentris F.Mor., N. pusilla Lepeletieri Perez, N rhenana F.Mor., N robusta F Mor., N. rufipes F., N. sexfo Pz., N. signata asciata Jur., N. trispinosa Schmied., N. zonata Pz., N. xanthostica Kby. This complex of cleptoparasitic species have a large circle of host-bee species on which they parasitize, from the following genera: Colletes, Andrena, Halictus, Melitta and Anthophora. Ammobatoides Rad. genus has a single species: A. abdominalis Eversm., that parasitize in the nests of Melitturga clavicornis Latr. Host bees . In Biastes Pz. genus were identified 2 cleptoparasitic species: Biastes brevicornis Pz, and B. emarginatus Sch., that parasitize in the nests of Rophitoides canus Eversm. Bees –the most numerous pollinators of alfalfa seeds. These cuckoo-bees can be also met in nests of the species from the following genera: Systrofa Panz. and Duforea Lep. from Halictidae. Family. In Melecta Latr. Genus were registered 2 species of cleptoparazitic bees: Melecta armada Pz., which parasitize Anthophora acervorum L. species, and Melecta luctuosa Scop. –a parasite of other species of Anthophora. In Apoidae family, Psithyrus Lep genus, were identified 4 species : P. flavidus Eversm., P. rupestris F., P vestalis sithyrus campestris P sylvestris. These species from the Republic of Moldova parasitize in the nests of species from Bombus genus. If the adult insects of this group participate indirectly in the pollinating of the entomophilous , they feed themselves on the pollen and the nectar directly on the flowers, as a result of parasitizing their larvae in others species nests. The interspecific relationships based on trophic links of cleptoparasite apoidea species with their hosts, is a very interesting and poor studied theme. And as it has been found in the period of the last few years, it has a very big practical importance.