Pristiphora armata (Thomson, 1863)

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 : 19-21

Pristiphora armata (Thomson, 1863)

Nematus crassicornis Hartig, 1837: 204-205. Primary homonym of Nematus crassicornis Stephens, 1829 [= Cladius (Cladius) pectinicornis (Geoffroy, 1785)]. 3 ♀♀ and 13 ♂♂ possible syntypes belonging to P. armata and P. leucopus in ZSM, examined. Type locality: Germany according to the title of the publication.

Nematus armatus Thomson, 1863: 619. Seven possible female syntypes belonging to P. armata and P. leucopus in MZLU, examined. Type locality: Bohus Län ( Bohuslän), Stockholm, and Skåne, Sweden.

Nematus crataegi Brischke, 1883: pl. I(7), 6. Syntype(s) possibly destroyed ( Blank and Taeger 1998). Type locality: not stated, but probably in former East Prussia (now Kaliningrad Oblast of Russia, or Poland).

Nematus Fletcheri [sic!] Cameron, 1884: 26. Syntype(s) possibly in BMNH, not examined. Type locality: Worcester and Clydesdale, United Kingdom.

Nematus melanostomus Zaddach in Brischke, 1884: 140-141. Holotype ♀ possibly destroyed ( Blank and Taeger 1998). Type locality: Bautzen, Saxony, Germany.

Nematus ensicornis Jacobs, 1884: XXIII. Syntype(s) ♀ possibly in IRSNB, not examined. Type locality: near Brussels, Belgium.

Nematus nigricollis Cameron, 1885: 66. Syntype(s) possibly in BMNH, not examined. Type locality: Worcester, United Kingdom.

Similar species.

The most similar species is P. leucopus . Differences between these two species were extensively discussed by Grearson and Liston (2012). Briefly, specimens, both male and female, with completely or nearly completely pale metafemur (Fig. 22 ) belong to P. leucopus , but specimens with black or mostly black metafemur (Fig. 21 ) cannot be distinguished externally. Unfortunately, differences in lancets (Figs 54-57 ) and penis valves (Figs 83-86 ) are also small and might not always be detectable. According to Grearson and Liston (2012), the general proportions of the lamnium of P. armata (Figs 56-57 ) are wider than that of P. leucopus (Fig. 54 ), but this does not always work, because P. leucopus can have a distinctly wider lamnium than P. armata , though serrulae are in this case somewhat weaker (Fig. 55 ). Males can perhaps be distinguished through small differences in penis valves (Figs 85-86 and Figs 9-10 in Grearson and Liston 2012), as described by Grearson and Liston (2012): "In P. armata , the outer edge of the spine has a short straight section near the apex, termi nated ventrally by a marked angle and below this a second section which is almost straight; there is a noticeable narrowing of the width of the spine at this point. In P. leucopus , the spine is almost parallel with a smoothly-curved outer edge and only a slight narrowing near the base". Unfortunately, the differences are not always evident (Figs 83-84 ). Females might be confused also with some specimens of P. confusa (if they have completely smooth mesepisternum), the only differences perhaps being the colour of pterostigma (uniformly dark brown in P. armata , usually basally dark brown and apically brown in P. confusa ) and small differences in the lancet (ctenidia tend be more distinct in P. confusa ; Figs 62-63 ). Differences in host plant use are the only reliable way to separate P. armata from P. leucopus that have a black metafemur ( Crataegus in P. armata , Tilia in P. leucopus ). Because of difficulties separating these species, we refrain from selecting lectotypes (in agreement with Grearson and Liston 2012) for Nematus crassicornis Hartig and Nematus armatus Thomson at this stage.

Genetic data.

Based on COI barcode sequences, P. armata belongs to the same BIN cluster (BOLD:AAQ2302) as P. leucopus (Fig. 1 ). The nearest neighbour (BOLD:AAG3568) is 2.76% different. BOLD:AAG3568 includes P. aphantoneura , P. bifida , P. confusa , P. luteipes , P. opaca , P. pusilla , P. staudingeri , and P. subopaca . Although we have only one TPI sequence of P. armata , it also does not allow separation of P. armata from P. leucopus (Fig. 2 ). The single P. armata sequence would be identical to the single available P. leucopus female sequence when ambiguous positions due to heterozygosity are excluded. Examination of all the six heterozygous sites (double peaks in chromatograms) in P. leucopus revealed that all of them include also the nucleotide found in P. armata , possibly indicating haplotype sharing between these two taxa.

Host plants.

Crataegus species ( Brischke 1883; Grearson and Liston 2012).

Distribution and material examined.

Western Palaearctic. Specimens studied are from Finland, France, Germany, Italy, and Sweden.

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 54 - 57. Lancets of Pristiphora armata subgroup. 54 P. leucopus PR. 393 VV, summer morph 55 P. leucopus PR. 467 VV reared ex larva from Tilia sp. 56 Nematus armatus Thomson syntype specimen 8 (X 112) 57 P. armata DEI-GISHym 20366.

Figures 77 - 86. Penis valves of Pristiphora ruficornis group. 77 P. appendiculata DEI-GISHym 31555 78 P. albitibia DEI-GISHym 20956 79 P. ruficornis PR. 462 VV 80 P. melanocarpa PR. 425 VV 81 P. ruficornis DEI-GISHym 19636 82 P. melanocarpa PR. 409 VV 83 P. armata PR. 465 VV 84 P. leucopus PR. 466 VV reared ex ovo from Tilia sp. 85 P. armata DEI-GISHym 80020 86 P. leucopus GBIF-GISHym 3246 (syntype of Nematus crassicornis Hartig).

Figures 3 - 17. 3 Pristiphora bifida DEI-GISHym 31507, sawsheath with large scopa (arrows) in dorsal view 4 P. appendiculata DEI-GISHym 80025, sawsheath with large scopa (arrows) in apical view 5 P. albitibia DEI-GISHym 31514, head in dorsal view showing short postocellar area (lines and arrows) 6 P. geniculata DEI-GISHym 20961, head in dorsal view showing long postocellar area (lines and arrows) 7 P. appendiculata DEI-GISHym 31500, smooth mesopostnotum (arrow) 8 P. albitibia DEI-GISHym 31516, matt mesopostnotum (arrow) 9 P. ruficornis DEI-GISHym 31185, dorsal view 10 P. subopaca DEI-GISHym 20899, dorsal view 11 P. ruficornis DEI-GISHym 31185, lateral view 12 P. subopaca DEI-GISHym 20899, lateral view 13 P. beaumonti DEI-GISHym 20766, lateral view 14 P. melanocarpa DEI-GISHym 21031, abdomen in lateral view 15 P. luteipes DEI-GISHym 18872, abdomen in lateral view 16 P. armata DEI-GISHym 11092, tergum 8 in dorsal view with apical projection (arrow) 17 P. subopaca DEI-GISHym 31560, tergum 8 in dorsal view without apical projection.

Figures 62 - 65. Lancets of Pristiphora aphantoneura subgroup. 62 P. confusa holotype 63 P. confusa PR. 544 VV reared ex larva from Salix caprea 64 P. opaca DEI-GISHym 80032 (presence of a fold is indicated by an arrow) 65 P. opaca PR. 389 VV.