Alphinellus Bates, 1881

Santos-Silva, Antonio, Botero, Juan Pablo & Pérez-Flores, Oscar, 2024, New species, new geographical records and taxonomical notes on North and Central American Cerambycidae and Disteniidae (Coleoptera, Chrysomeloidea), Contributions to Entomology 74 (2), pp. 199-216 : 199-216

Alphinellus Bates, 1881

Figs 25–28

Alphinellus Bates, 1881: 153; Monné 2023 b: 12 (cat.).

Material examined.

Alphinellus minimus – MEXICO • Campeche (new state record): Hwy. 261, 5 km N Hopelchén , beating in burn, 1 female, 13. VI. 2005, F. W. Skillman Jr. leg. ( FWSC) . GUATEMALA (new country record), Suchitepéquez: Los Tarrales Nature Reserve, Patulul , at UV and metal halide lights, 1 male, 26. VIII. 2008, C. W. & L. B. O’Brien & Fred Skillman leg. ( MZSP) .

Alphinellus carinipennis – MEXICO • 1 specimen, former J. Flohr collection, no more data ( MZSP) .

Remarks.

Bates (1881) described Alphinellus as follows (translated): “ Body small, oblong, convex. Head very concave between antennae. Antennae filiform, slightly longer than body, nor ciliated, scape short, gradually widened just from base, slightly sinuous below, apex subacute; antennomere III twice as long as scape, IV slightly shorter, V – XI shorter. Thorax [prothorax] subquadrate, dorsally [pronotum] anteriorly very gibbose, the sides a little before posterior margin sharply spinosus or obtusely protruding [lateral tubercles of prothorax]. Elytra subcylindrical, distinctly sloping posteriorly, very shortly truncate apically, dorsally with three longitudinal carinae and bicostate toward sides [inner longitudinal carina divided into three short carinae and outermost longitudinal carina divided into two short carinae]. Legs short, femora clavate; metatarsomere I triangular. Prosternal process narrow, coxae globose, protruding; procoxal cavities closed laterally [It is not clear to us whether he was actually describing the side of the procoxal cavities or the posterior region. However, in both cases the cavities are closed]. ” Still according to him: “ The form of the scape is unlike that of any other genus of Acanthocinini, approaching nearest that of Alphus . ”

Separation between some tribes of Lamiinae is practically impossible. However, true Acanthocinini have a notably elongated scape. This feature alone allows excluding Alphinellus from Acanthocinini. Among the American tribes of Lamiinae , based on the tarsal claws divaricate and scape proportionally short, Alphinellus is better included in Desmiphorini or Acanthoderini . Again, separation between some genera of these two tribes is problematic. However, as the typical genera of Acanthoderini have the scape clavate, we think that Alphinellus agrees better with Desmiphorini . Although some genera currently included in Desmiphorini have distinctly long scape, the scape in Alphinellus is similar to that in many genera of this tribe, as for example, in Parablabicentrus Dalens, Touroult & Tavakilian, 2009 . Therefore, we are transferring this genus from Acanthocinini to Desmiphorini .

Although the definition of Acanthocinini by Linsley and Chemsak (1995) is problematic for part of genera not occurring in North America, the description of the length of the scape agrees well with the other American Acanthocinini: “ scape elongate, slender … ” Linsley and Chemsak (1984) considered Estolini as distinct from Desmiphorini . However, the features used by him to separate these two tribes from Acanthocinini are not reliable when genera of Desmiphorini from Central and South Americas are considered.

Lacordaire (1872) separated Desmiphorini from Acanthocinini and Acanthoderini by the shape of the mesocoxal cavities: closed in the two later; open in the former. However, the mesocoxal cavities are not different in these three tribes. Therefore, the key and definition of these tribes in Lacordaire (1872) is not reliable.

In his key to tribes of Lamiinae from the Iberian region, Vives (2000) also separated Acanthocinini from Desmiphorini by the shape of the mesocoxal cavities: closed in Acanthocinini; open in Desmiphorini . However, even in the type genus of Desmiphorini , Desmiphora Audinet-Serville, 1835 , the procoxal cavities are equal to that in Acanthocinini.

Villiers (1980) separated Desmiphorini (listed as Estolini) from Acanthocinini in his alternative of couplet “ 10: ” Scape bulged, shorter than the pronotum, leading to Desmiphorini ; scape gradually widened from base to apex, longer than the pronotum, leading to Acanthocinini. Although the scape in Acanthocinini is variable and may or may not to be longer than the prothorax, it is always distinctly elongated. However, there are genera in Desmiphorini also with elongate scape, making the key not useful. It is interesting to report that Villiers (1980) considered correctly the shape of the mesocoxal cavities equal in these two tribes. Furthermore, in the redescription of Acanthocinini he reported, partially contradicting his key (translated): “ scape very long, often longer than the pronotum. ”

Therefore, although it is not possible to separate the genera of Acanthocinini and Desmiphorini based on the length of the scape, it is possible to exclude the genera with proportionally short scape from Acanthocinini. It is possible that genera of Desmiphorini with long scape belong to Acanthocinini. Despite these problems, we consider that, in light of current knowledge, if the length of the scape is excluded as a basic feature of Acanthocinini, there will be no morphological features left capable of maintaining the stability of the tribe. In fact, it seems to us that it is Desmiphorini that is in a somewhat chaotic situation, due to the absence of stable morphological features, and not Acanthocinini. This is when Acanthocinini is compared with Desmiphorini and not with some other tribes of Lamiinae such as, for example, Colobotheini .

Alphinellus is not the only American genus wrongly included in Acanthocinini (see Eugamandus Fisher, 1926 ). However, it would be necessary to examine the species of this genus to allocate it correctly (it is possible that its species belong to more than one tribe).

Currently, Alphinellus includes four species ( Monné 2023 b; Tavakilian and Chevillotte 2023):

A. carinipennis Bates, 1885 (see photographs in Monné et al. 2020), known from Mexico (Veracruz);

A. gibbicollis Bates, 1881 (see photographs on Bezark 2023), type species, known from Guatemala (Sacatepéquez);

A. minimus Bates, 1881 (Figs 25–28 ), known from Mexico (Quintana Roo) and Guatemala (Escuintla);

A. subcornutus Bates, 1881 (see photographs on Bezark 2023), known from Guatemala (Alta Verapaz), Honduras (Atlántida), and Costa Rica.

Figures

Figures 25–28. Alphinellus minimus Bates, 1881, male from Guatemala: 25. Dorsal habitus; 26. Ventral habitus; 27. Lateral habitus; 28. Head, frontal view.