Embrithini

Borovec, Roman & Oberprieler, Rolf G., 2013, Afrophloeus, a new genus of African weevils of the tribe Embrithini (Coleoptera: Curculionidae: Entiminae), with description of a new species and notes on the composition of Embrithini, Zootaxa 3693 (3), pp. 365-378 : 367

Tribe Embrithini Marshall

Embrithini Marshall, 1942: 3 .

Type genus: Embrithes Schoenherr, 1842 .

Diagnosis. Entiminae with short to long rostrum dorsally separated from head by broad V-shaped depression or sharp V-shaped sulcus (sometimes obscured by vestiture); trisetose mandibles; glabrous, often posteriorly sharply carinate epistome; bare or squamose frons; usually dorsolaterally placed scrobes but with antennal sockets visible in dorsal view, only occasionally concealed by lateral edges of epifrons ( Glyptosomus , Peritelomus Faust ), sometimes entirely dorsally placed (e.g., Ellimenistes , Sympiezorhynchus , Zeugorygma ); usually 7-segmented funicles (6- to 4-segmented in some Afrophloeus , Heisonyx , Lalagetes , Bryochaeta Pascoe , Syntaphocerus J. Thomson ), segment 2 often the longest; protruding to flat eyes; laterally straight anterior pronotal margin, not extended into ocular lobes; elytra with 10 distinct, regular striae or with 12 or more irregular ones; wingless (hence scutellar shield and humeri absent); tibiae without spurs, with short mucro (sometimes not protruding out of fringing setae) or no mucro (mainly genera with multistriate elytra); metatibial apices with narrow or broad, densely setose (rarely squamose) corbel; tarsal claws connate in basal half, usually subparallel, occasionally single ( Heisonyx ).

Remarks. Although the tribe Embrithini is at present not satisfactorily delimited by any unique character(s), this diagnosis serves to distinguish it from all tribes of Entiminae in Africa as these are currently conceived. From all “brachyderine” tribes ( Blosyrini , Brachyderini , Cneorhinini , Dermatodini , Tanymecini ), “leptopiines” ( Afroleptops Oberprieler , Leptostethus Waterhouse , Spartecerus Schoenherr ), Sitonini and the “otiorhynchine” tribes Ectemnorhinini , Episomini and Otiorhynchini it is most readily distinguishable by its trisetose mandibles, and from the other tribes with trisetose mandibles ( Cyphicerini , Oosomini , “ Peritelini ”, Tanyrhynchini and Trachyphloeini ) it differs in having metatibial corbels and/or connate claws. In line with this diagnosis and in order to constitute the tribe in a more natural way, we here transfer to Embrithini the genera Bryochaeta , Cosmorhinus , Cycliscus , Glyptosomus , Porpacus — whose claws Marshall (1942) mistakenly interpreted as being separate — and Syntaphocerus from Oosomini and Bicodes , Goniorhinus , Holorygma , Lecanophora Aurivillius , Neobicodes Hustache , Sympiezorhynchus and Zeugorygma from Myorhinini , where they were respectively listed by Alonso- Zarazaga & Lyal (1999). All these genera have ten elytral striae. Two genera listed in Embrithini by Alonso- Zarazaga & Lyal (1999) do not accord with this diagnosis and are therefore here excluded from this tribe: the South African Epibrithus Marshall , which has no metatibial corbels and the rostrum not dorsally separated from the head ( Marshall 1955), and Rhyncholobus Gahan from Christmas Island ( Australia) in the Indian Ocean, which has multisetose mandibles and quite a different configuration of rostral structures. The tribal placement of these genera in Entiminae remains uncertain for the moment. Together with Afrophloeus , the new genus described below, the tribe Embrithini now comprises 67 genera, 49 with ten elytral striae and 18 with more. A proper separation of such two groups is, however, unwarranted, as e.g. Amphitmetus Kolbe, with ten striae, is in other characters much more similar to multistriate genera such as Dicasticus Pascoe , Entypotrachelus Kolbe and Peritmetus Kolbe than it is to other (mainly southern African) genera with ten striae. As indicated by Oberprieler (1995), a number of other Africa genera may belong in Embrithini as well, but the tribe is in need of a thorough taxonomic and phylogenetic study to delineate it as a natural (monophyletic) group and determine all its constituent genera.