Taxonomical revision of the Longitarsus atricillus species group with resurrection of Longitarsus nigricollis (Foudras) (Coleoptera: Chrysomelidae: Galerucinae)

The Longitarsus atricillus species group, which includes L. atricillus (Linnaeus 1761), L. aeneicollis (Faldermann 1837), L. nigricollis (Foudras 1860), L. apicalis (Beck 1917), L. danieli Mohr 1962, L. idilphilus Biondi 1984, L. atlanticus Döberl 2002 has been investigated in depth by the study of a large number of specimens. As a result, L. nigricollis, previously a synonym of L. aeneicollis, has been resurrected based on clear morphological differences. The lectotypes of L. aeneicollis and L. nigricollis have been designated and compared with one another; the main comparative features, as well as several new collecting localities of the two species, are reported. The neotype of L. apicalis has been designated. Two new synonymies are proposed: L. rubenticollis (Allard 1860) = L. cribripennis (Abeille 1909) = L. nigricollis (Foudras 1860). The synonymy L. atricillus var. similis Weise 1893 = L. atricillus (Linnaeus 1761) is confirmed. L. bedelii (Uhagón 1887) has been here considered “taxon dubium”. L. danieli is new to Portugal. Action is required (namely an application to the International Commission on Zoological Nomenclature) to fix the problem of L. atricillus, whose type might be unsuitable to represent the species. A determination key for the whole group has been included.