NAMAINI BOROVEC & MEREGALLI, 2021

Meregalli, Massimo, Borovec, Roman, Cervella, Piero, Santovito, Alfredo, Toševski, Ivo, Ottati, Sara & Nakládal, Oto, 2021, The Namaini, a new weevil tribe with six new genera from South Africa (Coleoptera: Curculionidae: Entiminae), Zoological Journal of the Linnean Society 193, pp. 95-123 : 102-103

NAMAINI BOROVEC & MEREGALLI , TRIB. NOV.

Type genus: Nama Borovec & Meregalli, 2013 , here designated.

Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 944D0242-515B-4A1E-9C2C-62A14267062E

Diagnostic description. Subfamily Entiminae . Small size, 1.4–4.9 mm; body densely squamose, flightless; rostrum short and wide, posteriorly continuous with head; epifrons at base reaching inner margins of eyes, mostly with U- or V-shaped stria on dorsum; frons with a few exceptions densely squamose; antennal sockets in dorsal view hardly visible, furrow-shaped to narrowly reniform, laterally slightly to distinctly enlarged posteriad, directed towards eye or above eye; eyes small to middle sized; antennal scapes mostly robust; anterior margin of pronotum laterally without ocular lobes or vibrissae; elytral humeral calli not developed; metaventral process wide, distinctly wider than transverse diameter of metacoxa; femora unarmed; metatibiae lacking corbels; claws free, distinctly divaricate; Ventrites densely squamose, only exceptionally glabrous; female sternite VIII with long and slender apodeme terminating at base or inside of plate; gonocoxites with apical styli.

Distribution: South Africa (Western and Northern Cape), Namibia (Karas) .

Remarks: The Namaini is a small tribe of entimines, comprising seven genera, six of which are described here. They are native to the south-western part of South Africa and adjacent Namibia. This tribe is clearly delimited by mt-Cox1 sequences, and it can also be characterized by morphological traits. The new tribe underlines the limits of the traditional practice of referring Afrotropical genera to Palaearctic tribes, a procedure that often leads to polyphyletic taxa, particularly in the case of these wingless, highly adapted and scarcely vagile edaphic species.

Because of the free claws and absence of metatibial corbels, the Namaini could be associated with the Oosomini Lacordaire, 1863 , a tribe mainly restricted to South Africa, comprising genera of small- to middlesized weevils. However, at present it is not clearly delimited and in its present composition it seems to be polyphyletic. Therefore, only species belonging to the type genus Oosomus Schoenherr, 1834 , collected in the course of our expeditions, were used for the molecular analysis, and no relationship of this genus with the Namaini was indicated. According to its morphological characters, the Namaini differ from the Oosomini by the following characters: rostrum conspicuously wider than long (either wider than long, or in some genera elongate to a different degree in the Oosomini ), frons densely squamose (glabrous in the Oosomini ), eyes small, often placed in the lower part of head (moderately large, positioned dorsally in the Oosomini ), scapes short, robust (long, slender in the Oosomini ), mesepimera moderately large, subtriangular (small, narrow in the Oosomini ), metacoxae separated by 1.5–2.0 × their width (as wide as width of coxa in the Oosomini ), suture between ventrite 1 and 2 straight, slightly sinuate or deeply arched (straight in the Oosomini ), appressed scales greyish to brownish, always lacking a metallic sheen (with a greenish or bluish sheen in some taxa in the Oosomini ).

The Namaini is easily differentiated from the Embrithini , another Afrotropical entimine tribe with trisetose mandibles. The Namaini has free claws (all genera of the Embrithini have species with connate claws), absence of metatibial corbels (wide or narrow, densely setose or squamose corbels in the Embrithini ) and the rostrum continuous with the head (rostrum separated by a broad depression or a transverse stria in the Embrithini ).

There is a group of genera in the eastern part of South Africa that are provisionally maintained in the tribe Trachyphloeini (see Borovec & Skuhrovec, 2017), because in the absence of molecular data, it is difficult to determine if they really belong to this primarily Palaearctic tribe, showing a disjunct distribution (no species or genus of true Trachyphloeini is known from subtropical and tropical parts of Africa), or if the morphological similarity is due to homoplastic sharing of adaptive characters in edaphic species. However, the Namaini can be distinguished from these genera by the same traits indicated for the Embrithini , except the metatibial corbels, also lacking in the species of these genera.

Alonso-Zarazaga & Lyal (1999) also reported the tribe Otiorhynchini for the Afrotropical region, represented by the genus Sciobius Schoenherr, 1823 , and four other small genera known from South Africa and Madagascar. These five genera differ from the Palaearctic genera referred to the Otiorhynchini and their placement is yet unclear. However, the Namaini differs from these Afrotropical Otiorhynchini by the rostrum not expanded laterally to form pterygia (forming pterygia in the Otiorhynchini ), the squamose frons (glabrous in the Otiorhynchini ), the antennal scapes short and robust (slender and long in the Otiorhynchini ) and the tibiae lacking spur (with spur in all tibiae in the Otiorhynchini ).

The tribe Peritelini includes almost 30 genera and a large number of species in the Palaearctic region, mainly in its south-western part, and these differ from the almost 40 Afrotropical genera referred to the Peritelini known mainly from East Africa. Both groups of this tribe, the Palaearctic as well as the Afrotropical Peritelini , differ from the Namaini by having connate claws, and the Afrotropical genera also by a slender stria separating the rostrum from the head.

SUBCLADE A - GROUP 1