Identification of beetles (Coleoptera)

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23.07.2015 21:51, Barnaba

without a detailed examination of the incisions, the drug paramer and the torn pygidium, in my opinion, it is generally rotten to determine them.

Not exactly. Most of the signs are still external, many are visible without special tricks, and in some cases their combinations are unique. Often you can do without paramer preparations, especially since the differences in them are no more obvious than many external ones. I do not know any fully genital species. So, in the Mordella genus in Southern Russia, there may not be so many species with such a combination of traits in males, visible in the photo below:
size more than 6-7mm;
black iridescent elytra with V-shaped light pubescence;
completely black (or at least dark) appendages, including the anterior tibiae;
male antennal segments enlarged from the 5th, 6-10 longitudinal, slightly elongating to the 10th;
anterior tibiae slightly curved;
pygidium with white pubescence at the base, long, but not needle-shaped.
This is enough to suggest M. aculeata. Of course, without confidence, since other signs are not available.
Another thing is that the group has not been studied enough, so the keys may be incomplete or not work somewhere. Interesting works with keys based mainly on external morphology were published by V. K. Odnosum (attached).

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23.07.2015 23:49, Fornax13

Not exactly. Most of the signs are still external, many are visible without special tricks, and in some cases their combinations are unique. Often you can do without paramer preparations, especially since the differences in them are no more obvious than many external ones. I do not know any fully genital species. So, in the Mordella genus in Southern Russia, there may not be so many species with such a combination of traits in males, visible in the photo below:
size more than 6-7mm;
black iridescent elytra with V-shaped light pubescence;
completely black (or at least dark) appendages, including the anterior tibiae;
male antennal segments enlarged from the 5th, 6-10 longitudinal, slightly elongating to the 10th;
anterior tibiae slightly curved;
pygidium with white pubescence at the base, long, but not needle-shaped.
This is enough to suggest M. aculeata. Of course, without confidence, since other signs are not available.

Nenene, you really can't do that with them... ) In the photo, beetles from two genera - massive from Mordella, slender - from Mordellistena. Without paramers, only the most characteristic animals can be identified offhand. Mordell, in principle, can be determined by external signs, but for this it is better to first gut a dozen beetles of each species (perhaps only velutina is easily recognizable). By the way, M. aculeata in the Ul. region is a very infrequent animal, I have only from the forests of the north of the region. holomelaena and brachyura are much more common. As for mordellisten, such beasts are quite at the seams )

This post was edited by Fornax13-24.07.2015 02: 00

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24.07.2015 3:07, Barnaba

Nenene, you really can't do that with them... ) In the photo, beetles from two genera - massive from Mordella, slender - from Mordellistena. Without paramers, only the most characteristic animals can be identified offhand. Mordell, in principle, can be determined by external signs, but for this it is better to first gut a dozen beetles of each species (perhaps only velutina is easily recognizable). By the way, M. aculeata in the Ul. region is a very infrequent animal, I have only from the forests of the north of the region. holomelaena and brachyura are much more common. As for mordellisten, such beasts are quite at the seams )

I still believe that the photo shows beetles of the same species, with a female in the foreground and a male in the background (see the shape of the last segment of tentacles). The differences are partly due to their usual dimorphism, and partly apparent due to perspective and different angles. And this, imho, is Mordella, both in terms of habit and size. A few Mordellistena of comparable size differ in color and habit, while the rest would be entirely located on two adjacent flowers from the inflorescence. M. aculeata is a trans-palearctic species, south to Primorye, north. Kazakhstan and the Caucasus, there are in the Ciscaucasia and, in particular, in the Stavropol region (for example, in the ROC. Pyatigorsk). In the Rostov region. in some places it is common. But I will not argue, there is little accurate data, and there is no way to check, as I understand it.

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