Yagder serratus, Grebennikov & Anderson, 2021

Grebennikov, Vasily V. & Anderson, Robert S., 2021, Yagder serratus, a new eyeless weevil from Mexico and the non-monophyly of Brachycerinae, the evolutionary twilight zone of true weevils (Coleoptera: Curculionidae), Acta Entomologica Musei Nationalis Pragae 61 (2), pp. 363-374 : 372

Yagder serratus sp. nov.

( Figs 1 , 2 , 4 , 6 )

Type locality. Mexico, Puebla, 5 km SW Hueytamalco, N 19.911° W 97.328°, 1370 m a.s.l.

Material examined. Hඈඅඈඍඒඉൾ: female, ‘ MEXICO, Puebla, 19.911 -97.328, 1370m, 13.vi.2019, sift., J.Longino 10670’, ‘CNCCOL- VG00010339’ (deposited in the Canadian Museum of Nature, Ottawa, Canada). The holotype is missing both hind legs (one used for sequencing), the right middle leg and right front tarsus.

Description. Body size large, 3.8 mm in length (excluding rostrum and deeply inserted head). Rostrum with pterygia very widely exposed in dorsal view ( Fig. 2A ), apical two antennomeres of funicle longer than wide ( Fig. 1C ). Pronotal and elytral contour in dorsal view with large saw-like serrations especially evident towards elytral apex ( Fig. 2J ). Abdomen with ventrites I and II densely deeply punctate. DNA: MW201355 (COI), MW201457 (ITS2) and MW201468 (28S).

Biology. A single female was sifted from leaf litter in primary mountain forest. Multiple samples taken at the same time and location by J. T. Longino and M. G. Branstetter failed to produce additional specimens.

Etymology. The species name is the Latin adjective meaning “serrated, toothed like a saw”.

Distribution. This species is known only from the type locality.

Figures

Fig. 1. Yagder serratus gen. & sp. nov., habitus, dorsal (A), ventral (B) and left fronto-lateral (C).

Fig. 2. Yagder serratus gen. & sp. nov., details. A–C – rostral apex, dorsal (A), left lateral (B), ventral (C); D – head, left lateral; E–F – left antenna, lateral (E), distal part magnified (F); G–I – tarsi, left front leg (G–H), left middle leg (I); J – elytral apex; K–L – dissected female abdominal apex, ventral (K) and right latero-ventral (L).

Fig. 4. Eyeless and nearly eyeless brachycerine weevils, habitus.A tip of a regular mechanical pencil with a 0.5 mm lead is added for size comparison. All images are to scale.

Fig. 6. Maximum Likelihood inference phylogram positioning Yagder serratus gen.& sp. within non-monophyletic Brachycerinae. Note non-monophyly of Raymondionymini. Black lines denote eyeless or nearly eyeless terminals and clades. Digits at internodes are bootstrap values>85%.