Müller-Kroehling discusses this in detail:

https://www.researchgate.net/publication/273139530_Muller-Kroehling_S_2013_Zum_Vorkommen_der_bisher_meist_verkannten_Amara_pulpani_KULT_1949_und_Amara_makolskii_ROUBAL_1923_in_Waldern_Bayerns_-_Angewandte_Carabidologie_10_35-40

Best, Rudolf

Article Müller-Kroehling, S. (2013): Zum Vorkommen der bisher meist ...

Das scheint mir eine ökologische Rasse.

I think, that morphological difference are so small. I never seen A. pulpani. May be it is absent in N Poland and Belarus. 

 Dear Janis, you can try to use Paill's paper for identification. I think it will be useful.

Best regards

Research Amara pulpani Kult, 1949 - eine valide Art in den Ostalpen (...

What I can suggest is to check on-line gene banks and barcoding banks. These can be (hopefully) some valuable data available which may highlight phylogenetic relationships between two taxa

Thank You for all answers and opinions!

I read carefully the papers on Amara pulpani (by W.Paill) and pulpani + makolskii (By Mueller -Kroehling.and i'm sure that the morphological characters they found are clear and acceptable. Nevertheless, many authors are doubtful about the existence of a three species communis group. The pulpani-makolskii existence poses a fundamental question: has somebody found the two/three forms syntopic, i. e. co-existing in the same habitat or pitfall trap? I don't know. But I know that also in Carabid species some ecomorphotypes (ecological forms, ecotypes) are known, even if not so well studied. For example, I collected a population of Trechus quadristriatus in a doline of the Karst near Trieste, where all specimens where brachypterous. This population was highly isolated from all other living in the same area. Dr. Deb Boer in the Netherlands found that in more wet habitats Pterostichus oblongopunctatus had a trychobothrium more on each elytra, and he distinguished between "High and low pitters". In my lab 40 years ago I reared Carabus creutzeri and were able to produce blue/black forms at higher temperatures (20°C or more) and copper brilliant specimens at lower temperatures (research interrupted because of money shortage...).

To solve the question, I suggest that people interested in it try to find coexisting populations of the two forms or to begin with genetic analyses.

Whatever anybody thinks, the question of those forms or species is of great importance for a deeper insight in the problems of carabid adaptation and speciation processes.

Dear Pietro! Thank You for very interesting answer!

Hello Janis (and to all other contributers),

Schmidt (2004) found A. pulpani sympatrically with A. communis and A. convexior ("Amara pulpani Kult, 1949 und Amara nitida Sturm , 1825 (Col., Carabidae) kommen auch an der deutschen Ostseeküste vor"). A. pulpani prefers drier habitats (in this case dry sandy grasslands, in other known locations calcareous grasslands or heath). I have some specimens collected from sandy heath near "Märkisch Buchholz" in East Germany (not far from the Polish border). A. makolskii seems to prefer bog-forests and birch forests - though no specimens are known to me. A. communis - as you know - is rather eurytopic and often found in rather humid habitats. So all three species are distinguishable from thier ecological preferences as well as (as Pietro mentioned) from morphological characters. Nevertheless, Firtz Hieke had some doubts and only mentionned that some regard them as three different species and some do not.  In my opinion, more sympatric populations of these species could give some more evidence. Yet, we have to remember that evolution is a continuing process and while some species are very well differentiated from each other while others (because of their evolutionary history) are still very close to each other, so the differences might be rather small.

Thank's Fabian!

Hello Janis (and all other contributers),

I can confirm the observations of Fabian Boetzl. I found pulpani very rare in very dry grassy (Calamagrostis) biotops, and makolski only in very wet bog areas with some trees. Makolski microsculpture is very different, usually the look is different at first sigth.  

I cannot remember to ever have sampled them together with either communis or convexior, but the both latter species are widespread and eurytopic, so its likely to find them also alltogether.

I can remember a private talk with Dr. Hieke (maybe in 2010), well after the publication of the second edition of FHL volume 2 in 2004, where ive learned that he started to accept pulpani and makolskii as separate taxa as well.

Best wishes

Ingo

Hello,

I never seen any specimens of A. pulpani and A. makolski from Belarus and Poland. I'm collecting Carabidae from any biotops last 40 years. There are a lot of very morphology different specimens of A. communis in my collection. That is all.

Hello dear colleagues,

Of course there are lot of morphological variations within the A. communis as well as A. convexior, but what exactly? Which characters are overlapped and which are certain? I think it is important to know and morphometric analysis should be very needful on these group.

Best regards

Vytautas