Identification of beetles (Coleoptera)

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31.03.2016 4:51, Barnaba

23-26. 08. 2014-Ukraine, Transcarpathian region, Khust district, Shayan village outskirts, beech forest, Barber traps. L = 22 mm
Ocypus (Ocypus) olens (O. Muller, 1764)?????
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O. tenebricosus. In general, it is not harmful to dream

and in the north of Poland - it is banal-I caught it myself, but in Russia and the former states of the USSR, it is replaced by similar species, including in the Crimea. It can only be, probably, in the far north-west and in Transcarpathia in Ukraine - but even then I do not have reliable data.

Of course, I'm not an expert, but there are doubts that the photo shows O. tenebricosus. It is difficult to judge from such a photo at all, but it may be O. biharicus, which is just known from those places. And O. tenebricosus, as I recently read here, is generally not reliably known either from the Ukrainian Transcarpathia, or from the adjacent regions of Hungary and Slovakia, or even from all of Romania.
As for O. olens, I don't have any points from Transcarpathia. To the east, its range is unclear, but to the south it goes far, it is reliably known from southern Romania, including the Romanian Dobruja, from Bulgaria, including the Bulgarian Dobruja, from the European territory of Turkey and from Greece (reliably to the south at least to the vicinity of Thessaloniki). I had copies of the Soviet era, which I thought was quite typical olens from the extreme south-west of Ukraine, from the vicinity of Izmail. Unfortunately, they are lost. This year I brought something quite deer-like, horse-sized, from Cyprus, but I haven't really looked at it yet. They were active in early January. It is possible that this is O. curtipennis, which is also found in the south of the Crimea. It seems that this species in the Crimea is rather a relatively recent invader from the main part of its range, rather than a "replacement" O. olens species in the sense of geographical vicariation.
There is also a certain quirk with defining features that are now used in Russia, judging by the well-known note by K. A. Grebennikov. There, in the "step-by-step instructions" in step 4, it says: "Step 4. Just in case, carefully consider the last segment of the maxillary palps (under magnification of at least x20; look very carefully-the pubescence is thin, short and pressed, but clearly visible on the outside in the basal part of the segment). If it is thinly pubescent (also compare with the photo) - we are definitely looking at the real O. olens. If completely naked, this is probably a rare case of a completely black large O. ophthalmicus." It is difficult to see the details in the photos of O. olens palps, there are no bristles, and some small hairs may be visible. Photos for other types are not provided. Meanwhile, both species belong to the same subgenus Ocypus s. str., which, according to the diagnosis of Smetana (SMETANA & DAVIES, 2000), is characterized by a naked ("asetose") last segment of maxillary palps, in contrast to the subgenus Matidus. Smetana's article does not contain a photo of the maxillary palpate of O. olens, but there are very high-quality photos of those of other representatives of both subgenera, and no fine pubescence can be detected on them - either there are sets or not. In this connection, it is not entirely clear what K. A. means. Grebennikov, and it can be assumed that all specimens without visible bristles were identified by him as O. ophthalmicus. Where would O. olens come from then? I would be grateful if any of the experts would comment on this.
In fact, among the external characters of O. olens and O. ophthalmicus, they should differ only in color and, possibly, in the character of the dotted head and prsp, but the variability of both characters, to put it mildly, has not been sufficiently studied. I personally can't tell them apart from the Aedeagus images.

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31.03.2016 20:52, Barnaba

Thank you very much for such a meaningful answer and for a possible definition. I will try to take better photos today and post them for the final definition. Maybe you need to take a picture of some distinguishing feature to be sure?

I don't think that makes sense. The main signs relate to such structures that it is better for you to look directly at the beetle. I attach a recent paper on the ocipuses of Romania and surrounding countries, and there is a key at the end. Unfortunately, there is no O. tenebricosus in the key, as it was not found in the studied material from Romania. But there are drawings of a number of aedeagus species, including O. tenebricosus and O. biharicus, and detailed descriptions of all Romanian species. Unfortunately, I am not aware of any other contemporary work on this genus in the region.

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01.04.2016 0:06, Barnaba

Barnaba, what's wrong with Quaffe's capital summary? There are types of ocipus there. Yes, the taxonomy may be outdated in some places, but it is still relevant

Well, I'm not an expert, but first of all, I don't like the Quaffe approach itself, which is based mainly on comparing aedeagus without seriously studying the scope of their variability with an insufficiently standardized approach to determining the states of traits. As a result, this approach often seems inconsistent, one-sided, and subjective. In many cases, it turned out that the states of aedeagus traits described by him for different taxa occur in the same population. A significant number of taxa have been described and are now synonymous. On the other hand, as an amateur, it is difficult for me to use these works for definition. The nomenclature and data collected (on distribution, etc.) are certainly very outdated at the moment. Over the years, new species have been described and restored, diagnoses have been corrected, synonymy has been revised, and a large amount of faunal material has been collected. It is another matter how much use can be made of many even relatively recent (20-30 years old) faunal data in terms of the accuracy of definitions, which are often made provisionally due to the lack of reliable manuals.
The main thing is that after the works of A. Smetana (the quintessence is attached), which are currently taken as a basis, as I understand it, by most specialists in the family, the set of features used and the general approach to the taxonomy of staphylinins have fundamentally changed. Yes, the signs have become more complex, but they are defined more clearly, and the approach is more comprehensive. It is more convenient to work with them. In general, the morphology of the group and the variety of combinations of traits are studied at a much deeper level. For many features, dichotomously branching state trees are practically built, which ensures key stability. Of course, many questions remain. In practical terms, there is no major summary of at least the Palearctic at the level of species-subspecies. In theoretical terms, the question of the relationship of the system with the phylogeny of the group is open. The monophyly of the distinguished subgenera and groups within them is not at all obvious to me. I believe that the next stage will involve the use of molecular methods, cladistic analysis, analysis of areas from a paleogeographic point of view, and the formation of at least some concept of the phylogeny of the group.

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