none. Scambus pomorum (Ratzeburg) is a well known ectoparasitoid of the larva of the apple blossom weevil Anthonomus pomorum (L.) (Coleoptera, Curculionidae), which lives concealed in a unopened flower bud, the capped blossom. It also parasitises the pear bud weevil A. piri Kollar. Several authors described the biology of the parasitic juvenile stages, but failed to keep adults alive after emergence and mating (Imms, 1918; Speyer, 1926). In our research, we succeeded in completing the life cycle of the species. We collected parasitised A. pomorum and emerged adults were kept in cages in an outdoor insectary. Mating occurred from the day of emergence. All males died within a few weeks, despite the presence of honeywater as food. Females, under these conditions, lived longer. They were offered, besides honeywater as carbohydrate source, various insect larvae. Larvae of the related strawberry blossom weevil A. rubi Herbst were not accepted by the females, nor were exposed caterpillars of several Lepidoptera. On the concealed larvae of some leaf miners, however, a typical behaviour was observed. After the female found a leaf mine, the ovipositor was pierced into the larva at once, through the epidermal layer on either side of the leaf. Holding the larva in position with the ovipositor, the leaf epidermis was scraped off with the mandibles. The female subsequently fed from the haemolymph that emerged from the larva, sometimes after damaging the larval skin with the mouthparts. The feeding period was quite variable and often took about 20 minutes, during which the wasp was not readily disturbed. S. pomorum appears to be a polyphagous predator. Leaves of various plants and trees containing mines of different species were offered to the wasp. Larvae of the same leaf miner genus, Phyllonorycter spp. (Lepidoptera, Gracillariidae), on leaves of 4 different tree families, were all accepted as prey. Mining larvae belonging to different insect orders, Diptera, Lepidoptera and Hymenoptera, on the same tree species (Malus sylvestris Miller or Alnus incana (L.) Moench) were also accepted. In general miners on trees were attacked, and on herbs were not. Females fed this way through summer were dissected and their ovaries appeared to be as undeveloped as they were at emergence. Before winter, the adult females were provided with small conifers (Chamaecyparis sp.) in their cages. Hidden in these trees, the females overwintered. They were again observed in a sunny corner of the cage in March. In a laboratory experiment it was found that after winter females fed on both host (A. pomorum) and non-host (Phyllonorycter blancardella (Fabricius) larvae. Females provided with either prey were ready to lay eggs after 5 days at 16°C, on A. pomorum only, whereas females provided only with honey water needed another 5 days of host-feeding to mature their ovaries. In conclusion, feeding on leaf miners does not result in ovarial development until after hibernation. Oviposition is restricted to host larvae, that also become available after winter. So no second generation is passed in the year of emergence and feeding on leaf miners can be regarded as true predation, in contrast to host-feeding. The detailed results of this study are currently prepared for publication. Anthonomus pomorum; HYMENOPTERAN-PARASITES; Scambus pomorum; Parasite life cycle & development; NETHERLANDS-; Hymenopteran parasite life cycle & development Scambus pomorum; DORMANCY-; Hibernation, female ovarian development relations; INSECT-PREY; Female prey preferences & feeding behaviour; FOOD-PREFERENCES; Female preferences; FORAGING-; Female searching behaviour; OVARY-; Female ovarian development, hibernation relations; LIFE-CYCLE; Female annual cycle; COLEOPTERAN-HOSTS; Anthonomus pomorum; Parasitoid life cycle & female ovarian development; NETHERLANDS-; Female life cycle & development, coleopteran hosts & insect prey INSECTA-; INSECT-PREDATORS; Scambus pomorum (Hymenoptera); Predator life cycle & feeding behaviour; NETHERLANDS-; Hymenopteran predator life cycle & feeding behaviour