Alphinellus Bates, 1881

Monné, Miguel A., Santos-Silva, Antonio & Monné, Marcela L., 2020, Key to Mexico and Central America genera of Acanthocinini (Coleoptera Cerambycidae, Lamiinae) without erect setae on elytral surface, excluding the Caribbean Islands, Zootaxa 4861 (3), pp. 301-337 : 308

Alphinellus Bates, 1881

( Figs. 5–7 )

Alphinellus Bates, 1881: 153 .

Type species— Alphinellus gibbicollis Bates, 1881 (designation by Monné 1995: 104).

Diagnosis. Scape gradually expanded, ventrally flexuose, reaching about middle of prothorax; prothorax subquadrate, gibbose anteriorly; sides with prominent acute tubercle placed in the posterior third or lacking lateral tubercle; elytra marked with short elevated lines arranged in rows. Number of species currently included: 4 (all in Mexico and Central America ).

Remarks. Bates (1881) described Alphinellus as follows (translated): “Body small, oblong, convex. Head between antennae distinctly concave. Antennae filiform, scarcely longer than body, not ciliated, scape short, dilated after the base, slightly sinuous ventrally, apex subacute; antennomere III twice the length of the scape, IV slightly shorter [than III], and remaining antennomeres shorter [than III and IV]. Thorax subquadrate, pronotum gibbous anteriorly, sides of the prothorax with acute spine or with obtuse protuberance slightly before base. Elytra subcylindrical, abruptly sloping, apex shortly truncate toward suture, dorsal surface with three separated carinae aligned, and sides bicarinate. Legs short; femora clavate; metatarsomere I short, triangular. Prosternal process narrow, coxae globose, exposed; procoxal cavities closed behind.” Additionally, he commented: “Three extremely small species at present constitute this very distinct genus, which resembles Leiopus and Lepturges in the form of the prosternum and anterior coxae, but differs wholly from them in its convex oblong body, with gibbous thorax and elytra marked with short elevated lines arranged in rows. The thoracic lateral spines existing in two of the species are similar to those of the genus Dectes ; but in a third species, very similar to the other two, these spines are absent. The form of the scape is unlike that of any other genus of Acanthocinini , approaching nearest that of Alphus .”

In fact, Alphinellus lacks the most reliable feature of Acanthocinini : the long scape. Accordingly, we believe that this genus does not belong to this tribe. The general appearance, especially the prothorax and elytra (including the sculpturing) resembles the species of Eupromerini , but the profemora not expanded excludes this genus from this tribe.

Alphinellus can be included in both Desmiphorini and Pogonocherini . This is because the characters currently used to separate these two tribes are very fragile and, quite often, completely false. Unfortunately, we only examined one species of this genus. Therefore, for now, we prefer not to transfer Alphinellus to another tribe.

Apparently, Alphinellus is composed by species belonging to more than one genus. However, we only examined specimens of A. carinipennis Bates, 1885 , being impossible to be sure about the true characterization of this genus.

Figures

FIGURES 1–14. 1) Acanthocinus (Acanthocinus) aedilis, female, dorsal habitus. 2–3) Acanthocinus (Acanthocinus) spectabilis (LeConte, 1854), male: 2) Dorsal habitus; 3) Lateral habitus. 4) Alcathousiella polyrhaphoides, male, dorsal habitus. 5–7) Alphinellus carinipennis Bates, 1885: 5) Dorsal habitus; 6) Ventral habitus; 7) Lateral habitus. 8) Amniscites pictipes, female, dorsal habitus (from Santos-Silva et al. 2019). 9–10) Anisopodus arachnoides, male: 9) Dorsal habitus; 10) Lateral habitus. 11–13) Apteralcidion lapierrei, male: 11) Dorsal habitus; 12) Ventral habitus; 13) Lateral habitus. 14) Atrypanius conspersus, female, dorsal habitus.