Forum Entomologi Italiani

See http://publication.nhmus.hu/pdf/folento ... _61_95.pdf

I tried to search in that publication for the nigratus ♂ species, but I found nothing !
That is not surprising because (p.124) lines 104(103) to 107(108) are missing or incomplete.
These lines concern the species: nigratus , haematodes & nigrominutus.
- nigrominutus is a Hungarian endemic [see http://publication.nhmus.hu/pdf/folento ... 59_131.pdf.]
- nigratus & haematodes , to differentiate them I used the keys of Zhelokhovtsev 1988 [in Medvedev (Ed.) - Keys ... USSR. III. Hym. Part 6 Symphyta (Translation in English 1994)].
The difference is as follows :
- nigratus : The last Tergit is bordered by a membranous zone starting from the apex of the Tergit and extending at least 3/4 of the height of Tergit towards its base
... [see fig.]
- haematodes : The membrane zone is absent or extends at most 1/3 of the height of the Tergit.