Acythopeus glyptorhis Prena, 2021

Prena, Jens, 2021, Acythopeus glyptorhis, a new gall-inducing weevil (Coleoptera, Curculionidae Baridinae) damaging gac vines in Southeast Asia, Zootaxa 4981 (2), pp. 388-392 : 388-390

Description of Acythopeus glyptorhis Prena , sp. n.

Diagnosis. Of the 17 Asian species of Acythopeus (Carpobaris) in the sense of Thompson (1973) presently known to me, only three have distinct premucrones in both sexes. All three are undescribed and occur in Southeast Asia, particularly Vietnam. Acythopeus glyptorhis is in the size range of the melon weevil, A. curvirostris , and can be recognized by a conspicuous sulcus along the base of the rostrum ( Fig. 3 ). The other two species are smaller, lack the sulcus, and one has basally separate tarsal claws.

Description. Total length (without rostrum) 3.6–4.9 mm, standard length (without head) 3.5–4.7 mm; integument black, glabrous except for erect setae ventrally on femur and tibia and small, appressed setae in pits on venter and legs. Head punctate, transition to rostrum transversely sulcate, eyes oblong ovate, dorsally separated by width of rostrum; rostrum male 1.10–1.12×, female 1.14–1.15× as long as pronotum, moderately thick at base and gradually narrowed toward apex, middle section with feeble ventrolateral edge, base coarsely punctate and with transverse, dorsally visible sulcus in front of eye, dorsal ridges absent, prorostrum male 0.33–0.34×, female 0.37–0.40× as long as rostrum, with punctation increasingly subtle toward apex, mandibles decussate; antenna not sexually dimorphic, scape straight, not quite reaching transverse sulcus in repose, funicle with 7 articles, distal articles increasingly wider, with almost gradual transition to compact club. Prothorax laterally convex, pronotal base bisinuate, punctation dense, generally separate but occasionally irregularly spaced or confluent in apical constriction and dorsomedially, postocular lobes subtle, prosternum with 2 inconspicuous grooves in subapical constriction, not channeled or otherwise modified, fore coxae separated by slightly less their own width, basal lobe slightly prominent but unmodified. Elytra with base wider than pronotum, sides gradually narrowed in middle third, apices almost conjointly rounded, striae wide and deep particularly near base and apex, interstrial pits variable, often transverse or in pairs near base and more subtle in apical half, interstrial ridges absent, subapical callosity moderate. Legs with femora ventrally flat to shallowly sulcate, edentate, without subbasal constriction, tibiae in both sexes with premucro adjacent to ventrodistal spine, tarsal claws flat and basally subconnate. Male with pygidium almost vertical, locked by narrow process of ventrite 5, stridulation device absent, aedeagus ( Fig. 4 ) with body of penis 3× as long as wide, apodemes excluding hyaline connection 4× longer and reaching into mesothorax, endophallus with slight narrow dorsomedian sclerotization, flagellum not detected, tegmen with basal apodeme as long as body of penis, parameroidal lobes well-developed. Female with pygidium shorter and oblique, ventrite 5 unlocked.

Distribution. The species is known at present from Taiwan and Hainan ( China) and four sites in northern Vietnam.

Material studied. Holotype male, labeled “TAIWAN: Luye Township , Taitung County, 22.9405N 121.1223E, 19.VIII.2019, Shu-Jen Tsai”, “ HOLOTYPE, Acythopeus glyptorhis Prena, 2021 ”, “ on Momordica cochinchinensis (Cucurbitaceae)” ( TARI) . Paratypes 24 (13 males, 11 females): TAIWAN. Same series as holotype ( CMNC 1 , IZCAS 1 , JPPC 2 , TARI 2 ); Luye Township , Taitung County, 22.9889N, 121.1403E, 240 m, 11.IX.2020, on Momordica cochinchinensis, Po-Cheng Huang ( NTUC 13 ) . CHINA. Insel Hainan, 10.–25.III.[19]09, H. Schoede S[tudien-] G[esellschaft] ( MNKB 1 ) . VIETNAM. Bắc Kạn Province : mountains 50 km N of Thai-Nguen [Thái Nguyên], 300 m, 27.VII.1963, O.N. Kabakov ( ZIN 1 ) . Hanoi: Hanoi, 14.II.1989, on Momordica cochinchinensis, E.S. Sugonyaev ( ZIN 1 ). Lang Son Province: Than-Moi [Thanh M ọi, Ðống Mỏ], Juni – Juli [1900], H. Fruhstorfer ( MNKB 1 ). Ngh ệ An Province: mountains N of Kua-Rao [Cửa Rào], 500 m, 30.IX.1962, O.N. Kabakov ( ZIN 1 ) .

Derivation of name. The specific epithet is a composite noun in apposition derived from Ancient Greek γλυπτός (glyptos = carved) and ῥίς (rhis = snout).

Figures

FIGURES 1–4. Acythopeus glyptorhis, length 4.8 mm. 1, dorsal view; 2, lateral view; 3, detail of rostrum showing basal sulcus in front of eye; 4, aedeagus, dorsal view.