Pristiphora cadma Wong & Ross, 1960

Prous, Marko, Kramp, Katja & Liston 1, Veli VikbergAndrew, 2017, North-Western Palaearctic species of Pristiphora (Hymenoptera, Tenthredinidae), Journal of Hymenoptera Research 59, pp. 1-190 : 83

Pristiphora cadma Wong & Ross, 1960 Figs 51, 331-337

Pristiphora cadma Wong & Ross, 1960: 198. Holotype ♀ was not found in CNC. Type locality: Meadow Lake, Saskatchewan, Canada.

Similar species.

Females of P. cadma could most likely be confused with P. bufo or P. conjugata . Completely or nearly completely pale mesepisternum (Fig. 336) and sometimes extensively pale dorsal part of thorax (Fig. 51) distinguish cadma from conjugata . Claws with large subapical tooth (Fig. 335) can be used to distinguish cadma from bufo (which has a small subapical tooth, Fig. 22). Additionally, the serrulae of lancet of cadma are more protruding than in bufo and conjugata . Penis valves of cadma (Fig. 337) are most similar to P. nigricans and P. pallidiventris , but completely or nearly completely pale mesepisternum (Fig. 336) of cadma distinguishes it from the two species (mesepisternum is at most partly pale in some P. pallidiventris ). The head and dorsal part of thorax of two studied European females (Estonia and Sweden) are distinctly paler than three studied Canadian females (which fit the original description). However, it is quite likely that these characters vary continuously, as for example in P. bufo and P. paralella . Small differences in the lancet (Figs 331, 333) (shape of the basal sutures of the annuli and tip of the lancet) are probably not reliable either. According to the original description, the holotype female is 8 mm long, but the studied females from Canada (5.9-6.5 mm) are in the same size range as the European specimens (6.1-6.5 mm).

Genetic data.

Based on a single COI barcode sequence (TUZ615726), P. cadma forms its own cluster (no BIN number has been assigned yet) (Fig. 5). Based on nuclear data (one specimen and both genes combined), the nearest neighbour is 1.0% different ( P. testacea ).

Host plants.

Betula papyrifera Marshall (based on label data of five reared specimens from Canada) and probably some other Betula species ( B. papyrifera occurs naturally only in northern North America).

Distribution and material examined.

West Palaearctic, Nearctic. Specimens studied are from Canada, Estonia and Sweden.