I had earlier taken into consideration the synonymy proposed here (Jaschhof & Jaschhof 2009). I assume that Berest (1991 a) simply ignored the existence of A. halteratus when she introduced A. giganteus. Her differential diagnosis, which gives importance to the large body size and to the peculiar gonostylus of A. giganteus, makes reference to the A. flavidus (Winnertz, 1870) group of species, but not explicitly to A. halteratus, known at that time as A. flaviventris (Winnertz, 1870). A description of A. flaviventris was published in Edwards’s (1938 b) revision of British Lestremiinae, but the figure therein of the male genitalia of this species (fig. 17 h–i) is not really characteristic. An informative genital illustration of A. halteratus was presented only several years after the publication of A. giganteus (Jaschhof 1998). Berest’s (1991 a: fig. 2–3) and Jaschhof’s (1998: fig. 159 a–c) illustrations clearly depict one and the same species.