Pristiphora bifida ( Hellen , 1948)

Prous, Marko, Vikberg, Veli, Liston, Andrew & Kramp, Katja, 2016, North-Western Palaearctic species of the Pristiphora ruficornis group (Hymenoptera, Tenthredinidae), Journal of Hymenoptera Research 51, pp. 1-54 : 22

Pristiphora bifida ( Hellen, 1948)

Nematus (Pristiphora) bifidus Hellén, 1948: 116-117. Lectotype ♀ (http://id.luomus.fi/GL.5214; here designated) in MZH, examined. Type locality: Malla, Kilpisjärvi, Enontekiö, Finland.

Similar species.

Externally, perhaps the most similar species is P. frigida , from which it can be distinguished by having pale hind trochanters, trochantelli, and tibiae (black or brown in P. frigida ). In addition, antennae of males have numerous and clearly visible stout black setae among finer paler ones (Fig. 36 ), while in P. frigida there are only a few barely visible ones (Fig. 35 ). The lancets (Figs 70-71 ) and penis valves (87-88) are also different. Apical serrulae are somewhat shorter and more protruding and the tangium of the lancet tends to be longer and narrower (Fig. 70 ) than in P. frigida (Fig. 71 ). The penis valve lacks (Fig. 87 ) a membranous fold near the tip of the ventro-apical spine (present in P. frigida ; Fig. 88 ) and the pseudoceps has a distinct dorsal depression in the middle or basal part (absent in P. frigida ).

Genetic data.

Based on COI barcode sequences, P. bifida belongs to the same BIN cluster (BOLD:AAG3568) as P. aphantoneura , P. confusa , P. luteipes , P. opaca , P. pusilla , P. staudingeri , and P. subopaca (Fig. 1 ). The nearest neighbour (BOLD:AAQ2302, P. armata and P. leucopus ) is 2.76% different. Only one partial TPI sequence (sequencing of the first exon and part of the following intron failed apparently because of intron length polymorphism) of P. bifida is available, which can be distinguished from other species (Fig. 2 ).

Host plants.

Salix viminalis L. ( Liston and Burger 2009). In Kilpisjärvi (Finland) some other species must be the host, as S. viminalis does not occur there.

Distribution and material examined.

Western Palaearctic. Specimens studied are from Finland, Germany, Norway, and Sweden. According to the BOLD database, this species may also be present in North America. The identifications of North American specimens falling within BIN cluster BOLD:AAG3568 are however uncertain.

Figures

Figure 1. Maximum likelihood tree of Pristiphora ruficornis group based on cytochrome oxidase subunit I (COI) sequences (1078 bp). Specimens that had at least the full barcode sequence (658 bp) were included in the analysis. Branches with multiple specimen identification labels represent identical sequences, only one of which was used in the analysis. Numbers on the nodes show approximate likelihood-ratio test (aLRT) support values and bootstrap proportions (%, BP). Support values for weakly supported branches (aLRT <0.9 and / or BP <70) are not shown. The inset shows the tree with outgroup species. The scale bar shows the number of estimated substitutions per nucleotide position. An asterisk (*) indicates the specimens that we have not studied. AUT, Austria; CAN, Canada; CHN, China; DEU, Germany; ESP, Spain; EST, Estonia; FIN, Finland; FRA, France; GBR, United Kingdom; ITA, Italy; MAR, Morocco; NOR, Norway; PRT, Portugal; SWE, Sweden; USA, United States of America. NUMTs?, possible nuclear mitochondrial pseudogenes.

Figure 2. Maximum likelihood tree of Pristiphora ruficornis group based on triose-phosphate isomerase (TPI) sequences (alignment length 842 bp). Branches with multiple specimen identification labels represent identical sequences, only one of which was used in the analysis. Numbers on the nodes show approximate likelihood-ratio test (aLRT) support values and bootstrap proportions (%, BP). Support values for weakly supported branches (aLRT <0.9 and / or BP <70) are not shown. The scale bar shows the number of estimated substitutions per nucleotide position.

Figures 18 - 36. 18 P. albitibia DEI-GISHym 31514, thorax in lateral view 19 P. luteipes DEI-GISHym 80038, thorax in lateral view 20 P. astragali holotype, thorax in lateral view 21 P. leucopus DEI-GISHym 31556, lateral 22 P. leucopus DEI-GISHym 4989, lateral 23 P. luteipes DEI-GISHym 80038, lateral 24 P. luteipes DEI-GISHym 80038, flagellum 25 P. ruficornis DEI-GISHym 31185, flagellum 26 P. armata DEI-GISHym 11092 27 P. subopaca holotype, pterostigma (arrow) 28 P. opaca holotype, pterostigma (arrow) 29 P. ruficornis DEI-GISHym 31185, pterostigma (arrow) 30 P. appendiculata DEI-GISHym 31500, claw 31 P. opaca holotype, claw 32 P. subopaca holotype, claw 33 P. armata DEI-GISHym 11554, claw 34 P. bifida DEI-GISHym 31507, claw 35 P. frigida NHRS-HEVA 000005006, flagellum with barely visible stout black setae (arrows) 36 P. pusilla DEI-GISHym 80050, flagellum with clearly visible stout black setae.

Figures 70 - 72. Lancets of Pristiphora aphantoneura subgroup and P. frigida. 70 P. bifida PR. 408 VV 71 P. frigida NHRS-HEVA 000003873 72 P. pusilla PR. 369 VV.

Figures 87 - 96. Penis valves of Pristiphora ruficornis group. 87 P. bifida DEI-GISHym 80000 (arrow indicates a dorsal depression of the pseudoceps) 88 P. frigida NHRS-HEVA 000003861 (arrow indicates a membranous fold near the tip of the ventro-apical spine) 89 P. confusa DEI-GISHym 31265 90 P. confusa PR. 460 VV 91 P. subopaca DEI-GISHym 80030, left penis valve 92 P. subopaca paratype http: // id. luomus. fi / GL. 5203 93 P. pusilla DEI-GISHym 80029, left penis valve with strong dorsal depression of the pseudoceps (arrow) 94 P. pusilla DEI-GISHym 80029, right penis valve with weak dorsal depression of the pseudoceps 95 P. opaca PR. 459 VV 96 P. opaca http: // id. luomus. fi / GL. 5206, paratype of P. amaura Lindqvist.