Life History of Passaloecus pictus Ribaut, 1952 (Hymenoptera, Pemphredonidae)

The nesting of Passaloecus pictus Ribaut, 1952 was observed in Kowalewo Pomorskie (northern Poland). The nests were built in trap nests that were placed on a windowsill facing southwest. The females used resin from Picea pungens Engelm., located 5 m away, to build the cell walls. The tunnel consisted of 1-7 cells. The females provided provisions for two to three cells per day. The frequency with which a female brought aphids to a nest cell varied from 1 to 7 min. No males were observed near the nest. A total of 42 cells were examined (consisting of 31 female cells and 11 male cells). On average, a female brought about 33 aphids to the female cells and 21 aphids to the male cells. The prey were Macrosiphoniella millefolii (De Geer, 1773), Dysaphis crataegi (Kaltenbach, 1843), Macrosiphoniella persequens (Walker, 1852) and Uroleucon achilleae (Koch, 1855). The nest parasites were Melittobia acasta (Walker, 1839). The occurrence of a second generation has been confirmed.