North-Western Palaearctic species of the Pristiphora ruficornis group (Hymenoptera, Tenthredinidae) Author Prous, Marko https://orcid.org/0000-0002-5329-7608 Senckenberg Deutsches Entomologisches Institut, Eberswalder Strasse 90, 15374 Muencheberg, Germany & Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia mprous@ut.ee Author Vikberg, Veli Liinalammintie 11 as. 6, FI- 14200 Turenki, Finland Author Liston, Andrew Senckenberg Deutsches Entomologisches Institut, Eberswalder Strasse 90, 15374 Muencheberg, Germany Author Kramp, Katja Senckenberg Deutsches Entomologisches Institut, Eberswalder Strasse 90, 15374 Muencheberg, Germany text Journal of Hymenoptera Research 2016 2016-08-29 51 1 54 http://dx.doi.org/10.3897/jhr.51.9162 journal article http://dx.doi.org/10.3897/jhr.51.9162 1314-2607-51-1 B3D68EDB9CF844A3BC43E9C2D6626BD7 FFCF966B691BFFC1FF950C14486D5B5D 147922 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 Laen ( Bohuslaen ), Stockholm, and Skane , 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 .