Larinus planus (Fabricius) sensu Germar, 1824 (Germar 1824: 389) is not Curculio planus Fabricius, 1792. However, during the examination of Fabrician Lixinae types by Gültekin (2006a) it became evident that Larinus planus (Fabricius, 1792) is identical with the well known Palaearctic species Larinus rusticanus Gyllenhal, 1835, and that the current synonymy of Larinus planus with L. carlinae (Olivier, 1807) is based on a misidentified Larinus planus (Fabricius) sensu Germar, 1824, not Larinus planus (Fabricius, 1792).
Gültekin (2006a), while placing Larinus planus (Fabricius, 1792) in synonymy of Larinus rusticanus Gyllenhal, 1835, considered it to be a nomen oblitum but failed to give the evidence requested by Art. 23.9.2. The fact that the taxon was misidentified does not invalidate the use of the name, since it has been used as a valid name after 1899 (ICZN, Art. 23.9.1.1). For this reason, Larinus planus (Fabricius, 1792) becomes the correct name for Larinus rusticanus Gyllenhal, 1835. This species is closely related to Larinus tenuicorpus Ter-Minasian, 1962 but the latter differs by its flatter body and shorter rostrum.
Larinus carlinae (Olivier, 1807) is a well known Palaearctic species introduced also into North America. Its senior synonym Curculio ebeneus Marsham, 1802, has not been used as valid since 1899, so Gültekin (2013a) declared it nomen oblitum, while Larinus carlinae was declared nomen protectum according to ICZN Art. 23.9.1.
Zicha O, Hrb J, Maňas M, Novák J, and BioLib contributors. BioLib.cz: Taxonomic tree of plants and animals with photos. 1999 - 2019, https://www.biolib.cz/en/main/ (Link)
It is hard to accept this name change. I have realized it some months ago, but decided not to adopt it. "Larinus planus" should have been conserved.
1) The "types" of the "Fabricius collection" have to be regarded critical; on several occasions it was detected that "type material" was not original material.
Probably, later curators added to the collection, and this is long time forgotten.
2) Curculio planus Fabricius: "immaculatus" does not really apply planus auct. (abraded specimens only) - but the patria "Germania" safely excludes the possibility
being identical with L. rusticanus (not present N of Alps).
3) Lixus carlinae Olivier, 1807: Olivier indicated possible synonymy: https://www.biodiversitylibrary.org/item/125992#page/292/mode/1up and tells for the species "toute la France" and "sur les fleurs de differents chardons" - biological note, and this not being a common species, exclude Larinus pollinis (brevis auct.) - but name is not well chosen (Carlina possible host, but inter alia)
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
Gültekin 2006 paper:
https://www.researchgate.net/publication/258885589_Gultekin_L_2006_On_some_Lixinae_types_of_J_C_Fabricius_Coleoptera_Curculionidae_Fragmenta_entomologica_381_111-133
Fabricius' original description of planus:
https://www.biodiversitylibrary.org/item/213305#page/756/mode/1up
It is hard to accept this name change. I have realized it some months ago, but decided not to adopt it. "Larinus planus" should have been conserved.
1) The "types" of the "Fabricius collection" have to be regarded critical; on several occasions it was detected that "type material" was not original material.
Probably, later curators added to the collection, and this is long time forgotten.
2) Curculio planus Fabricius: "immaculatus" does not really apply planus auct. (abraded specimens only) - but the patria "Germania" safely excludes the possibility
being identical with L. rusticanus (not present N of Alps).
3) Lixus carlinae Olivier, 1807: Olivier indicated possible synonymy: https://www.biodiversitylibrary.org/item/125992#page/292/mode/1up
and tells for the species "toute la France" and "sur les fleurs de differents chardons" - biological note, and this not being a common species, exclude Larinus pollinis (brevis auct.) - but name is not well chosen (Carlina possible host, but inter alia)
4) Gültekin & Perrin (2011) tell nothing about possible type material:
https://www.researchgate.net/publication/258885598_Gultekin_L_Perrin_H_2011_Study_of_a_part_of_the_A_G_Olivier_Lixini_collection_Coleoptera_Curculionidae_lectotype_designations_new_synonymies_and_nomenclatural_acts_Zootaxa_2943_45-57
5) Others also seem to have problems: https://www.zin.ru/Animalia/Coleoptera/rus/larcarts.htm