The description of [taxon-name: Tipula stackelbergi] ([taxon-name: Diptera], [taxon-name: Tipulidae]) was based on male holotype collected from Russian East Siberia (^{Alexander 1934}). Later this species was also recorded from the Russian Far East (^{Savchenko 1961}; ^{Pilipenko 2009}). ^{Savchenko (1961)} considered [taxon-name: Tipula stackelbergi] as a subspecies of [taxon-name: Tipula pruinosa] Wiedemann, based on the small structural differences between the two taxa. He also transferred [taxon-name: Tipula stackelbergi] to the subgenus [taxon-name: Tipula] ([taxon-name: Yamatotipula)] Matsumura. In the same publication, Savchenko suggested two synonyms for [taxon-name: Tipula stackelbergi], namely [taxon-name: Tipula usuriensis] Alexander, 1925 and [taxon-name: Tipula subpruinosa] Mannheims, 1954. However, both synonyms were uncertain because Savchenko did not examine the type material of these two species. The description of [taxon-name: Tipula usuriensis] was based on male holotype, collected from Siberia (exact locality uncertain) and the description of [taxon-name: Tipula subpruinosa] was based on two females, collected from northern Finland (holotype) and Sweden (paratype) (^{Alexander 1925}; ^{Mannheims 1954}). Since the taxonomic treatment by ^{Savchenko (1961)}, both species have remained synonyms of [taxon-name: Tipula stackelbergi] (e.g. ^{Oosterbroek and Theowald 1992}) and apparently the type material has remained unstudied. In addition, [taxon-name: Tipula stackelbergi] has been used as an example of a tipulid (sub)species with a large but disjunct range in the Palaearctic region (^{Oosterbroek et al. 2001}).

Subspecies are traditionally held as geographically separate and genetically distinct populations within the species’ range, permitting gene flow in the area of contact (^{Wilson and Brown 1953}; ^{O’Brien and Mayr 1991}; ^{Patten and Unitt 2002}). Despite possible interbreeding between subspecies, subspecies may retain differences in respective life cycles or other traits (^{Hewitt 2002}; ^{Kothera et al. 2009}). Among birds, high subspecies richness was associated with large breeding ranges, island dwelling, inhabiting montane regions, habitat heterogeneity and low latitude; on the other hand, species phylogenetic age was a poor predictor of subspecies richness (^{Phillimore et al. 2007}). Definition of subspecies, and propensity of naming subspecific taxa, vastly differs among taxonomic groups. High proportions of higher plants, mammals and birds have subspecies, less so compared to invertebrates (^{Haig et al. 2006}). New molecular methods have revolutionized subspecific classifications: i) formerly held subspecies gain no support at all, ii) subspecies are proposed to be valid species or iii) their status as operational evolutionary units is supported (^{Ball and Avise 1992}; ^{Patten and Unitt 2002}; ^{Tsao and Yeh 2008}; ^{Miller et al. 2011}). Despite problems in correct recognition and delineation of subspecies, subspecific taxa are seen as powerful tools in conservation and as meaningful biological entities (^{Haig et al. 2006}; ^{Phillimore and Owens 2006}).

In crane flies ([taxon-name: Diptera], [taxon-name: Tipuloidea]) subspecific ranks are not uncommon. For example, out of 493 and 168 Palaearctic [taxon-name: Tipulidae] taxa described by C.P. Alexander (1889–1981) and E.N. Savchenko (1909–1994), respectively, 24 and 26 taxa are currently ranked as subspecies (data from ^{Oosterbroek 2011}). However, the recent tendency has been to elevate former subspecies to valid species (^{Starý 2006}; ^{Salmela and Autio 2009}; ^{Starý and Brodo 2009}). In these cases, former subspecies are clearly separated upon differences in male and female hypopygial structures. In addition, due to the improved faunistic knowledge, range-sizes of former subspecies are in reality much larger than was previously known. On the other hand, some western Palaearctic (sub)species are most probably recent origin of Pleistocene glacial and interglacial periods; examples of such species are present in especially in the Iberian peninsula and Asia minor (^{Oosterbroek 1980}). In general, tipuloid subspecies are elusive and very poorly known, and no rigorous assessment on the suitability of subspecific rank among crane flies has been carried out. Based on subjective opinion, perhaps a majority of the current Palaearctic tipuloid subspecies are in fact valid species. Furthermore, most allopatric or parapatric crane fly populations, that are genetically distinct from nominotypical (sub)species, are still to be found by biologists. Based on above mentioned references, subspecies should not be proposed on exiguous basis, relying on a small number of studied specimens and subtle differences in coloration or other structures. Instead, an interdisciplinary approach (genetics, ecology, taxonomy) is suggested if subspecific ranks are to be on a solid ground.

In this article I present the results of an examination of all available type material of [taxon-name: Tipula stackelbergi], [taxon-name: Tipula usuriensis] and [taxon-name: Tipula subpruinosa]. I propose changes to the nomenclature of these species and I also review the morphology of [taxon-name: Tipula pruinosa] and [taxon-name: Tipula stackelbergi], with an emphasis on male and female genitalia. In addition, female genitalia of [taxon-name: Tipula (Yamatotipula) freyana] are illustrated and a key to [taxon-name: Tipula (Yamatotipula) freyana] and females of [taxon-name: Tipula (Yamatotipula) chonsaniana] and [taxon-name: Tipula (Yamatotipula) moesta] are provided.

The morphological terminology used here mainly follows ^{Alexander and Byers (1981)}. Terminology of some special parts of male genitalia was taken from ^{Frommer (1963)} or is explained in the figures. The following acronyms for museums and collections are used in the text: MZHF – Finnish Museum of Natural History (Zoological Museum), University of Helsinki, Helsinki, Finland; PVM – Private Collection of V.-M. Mukkala, Kaarina, Finland; USNM – Smithsonian Institution, National Museum of Natural History, Washington DC, USA; ZMUC – Zoological Museum, University of Copenhagen, Copenhagen, Denmark; ZMUT – Zoological Museum, University of Turku, Turku, Finland; ZISP – Zoological Institute Russian Academy of Sciences, St. Petersburg, Russia. Due to the courtesy of Valentin Pilipenko (Moscow State University, Russia), I was able study high quality digital photos of male hypopygium of [taxon-name: Tipula (Yamatotipula) pruinosa] (Russia: Moscow, 1 male, Altay, 1 male) and [taxon-name: Tipula (Yamatotipula) stackelbergi] (Russia: Primorski kray, 1 male).

Layer photos were taken using an Olympus SZX16 stereomicroscope attached to an Olympus E520 digital camera. Digital photos were captured using the programmes Deep Focus 3.1 and Quick PHOTO CAMERA 2.3. Layer photos were finally combined with the program Combine ZP.

In the present paper I suggest three changes to the nomenclature of Palaearctic [taxon-name: Tipulidae]: i) [taxon-name: Tipula (Yamatotipula) stackelbergi] is a valid species, not a subspecies of [taxon-name: Tipula (Yamatotipula) pruinosa] ii) [taxon-name: Tipula usuriensis] is neither a valid species nor a synonym of [taxon-name: Tipula (Yamatotipula) stackelbergi], it is instead a junior synonym of [taxon-name: Tipula (Yamatotipula) pruinosa] and iii) [taxon-name: Tipula subpruinosa] is not a synonym of [taxon-name: Tipula (Yamatotipula) stackelbergi], it is a junior synonym of [taxon-name: Tipula (Yamatotipula) freyana]. It remains questionable whether [taxon-name: Tipula (Yamatotipula) pruinosa sinapruinosa] is a valid subspecies. Based on the original description (^{Yang and Yang 1993}) it is likely that Chinese specimens are conspecific with other eastern Palaearctic [taxon-name: Tipula (Yamatotipula) pruinosa] specimens. If these eastern Palaearctic specimens are to be ranked as subspecies below [taxon-name: Tipula (Yamatotipula) pruinosa], [taxon-name: Tipula usuriensis] is the oldest available name for the taxon. However, as discussed above, subspecies should be delineated through several criteria, e.g. ecology and genetics. More data on Asian [taxon-name: Tipula (Yamatotipula) pruinosa] populations should be available for the assessment of speciation and reliable use of subspecific rank.

[taxon-name: Tipula (Yamatotipula) pruinosa] and [taxon-name: Tipula (Yamatotipula) stackelbergi] are closely related but valid species. The species pair is well separated due to the differences in male genitalia (see the key to the species), but less so regarding female genitalia. More females of [taxon-name: Tipula (Yamatotipula) stackelbergi] should be studied in order to firmly validate the diagnostic differences presented here. [taxon-name: Tipula (Yamatotipula) stackelbergi] is a very rarely collected species, known only from East Siberia and the Russian Far East (^{Alexander 1934}; ^{Savchenko 1961}; ^{Pilipenko 2009}).

[taxon-name: Tipula subpruinosa], described from Finland and Sweden, was thought to be a synonym of [taxon-name: Tipula (Yamatotipula) stackelbergi] (^{Savchenko 1961}; ^{Oosterbroek and Theowald 1992}). Due to this tentative synonymy, [taxon-name: Tipula (Yamatotipula) stackelbergi] was erroneously thought to be present in Fennoscandia. However, examination of the holotype of [taxon-name: Tipula subpruinosa] revealed that the species is a junior synonym of [taxon-name: Tipula (Yamatotipula) freyana], not [taxon-name: Tipula (Yamatotipula) stackelbergi]. Hence, [taxon-name: Tipula (Yamatotipula) stackelbergi] should be removed from the list of European crane flies. It should be noted that the description of [taxon-name: Tipula subpruinosa] was very short and lacking any figures; it is not surprising it led to fallacious interpretation. In a similar vein, [taxon-name: Tipula usuriensis] was also tentatively synononymized by ^{Savchenko (1961)} with [taxon-name: Tipula (Yamatotipula) stackelbergi]. In his description of [taxon-name: Tipula usuriensis]^{Alexander (1925)} provided figures depicting male 9^th tergite and lateral view of hypopygium, but these figures can now be considered too general to discriminate between [taxon-name: Tipula (Yamatotipula) pruinosa] and [taxon-name: Tipula (Yamatotipula) stackelbergi].

Compared to [taxon-name: Tipula (Yamatotipula) stackelbergi] and [taxon-name: Tipula (Yamatotipula) pruinosa], [taxon-name: Tipula (Yamatotipula) freyana] is phylogenetically rather distant to these two species, being instead close to [taxon-name: Tipula (Yamatotipula) moesta] Riedel and [taxon-name: Tipula (Yamatotipula) chonsaniana] Alexander (e.g. ^{Salmela and Autio 2009}). Although illustrations of male hypopygium, or parts of it, of [taxon-name: Tipula (Yamatotipula) freyana] have been provided by several authors (see ^{Salmela and Autio 2009}), no figures of female terminalia have been hitherto published. A key to the females of [taxon-name: Tipula (Yamatotipula) chonsaniana], [taxon-name: Tipula (Yamatotipula) freyana] and [taxon-name: Tipula (Yamatotipula) moesta] explains the diagnostic differences between these three species (see above). Figures of female genital forks of [taxon-name: Tipula (Yamatotipula) moesta] and [taxon-name: Tipula (Yamatotipula) chonsaniana] were provided by ^{Salmela and Autio (2009)}.

I am indebted to the following persons for information and/or the loan of specimens: Nikolai Paramonov (St. Petersburg), Pekka Vilkamaa (Helsinki), Jon Gelhaus (Philadelphia), David G. Furth, Patricia Gentili-Poole (Washington), Thomas Pape (Copenhagen), Valentin Pilipenko (Moscow) and Veli-Matti Mukkala (Kaarina). Julia Kuosmanen and Liisa Puhakka (Turku) are thanked for translations of Russian texts. Constructive comments by Fenja Brodo (Ottawa) and John Kramer (Leicester) improved the manuscript.