Glomibidion trinidadense ( Gilmour, 1963 ) Galileo & Nascimento & Santos-Silva, 2018

Galileo, Maria Helena M., Nascimento, Francisco E. De L. & Santos-Silva, Antonio, 2018, Transference and new records in Neoibidionini (Coleoptera, Cerambycidae), Zootaxa 4457 (3), pp. 481-486 : 481-482

Glomibidion trinidadense ( Gilmour, 1963) , comb. nov.

Phormesium trinidadensis Gilmour, 1963: 93 ; Ruette, 1970: 21 (type).

Engyum trinidadense ; Martins, 1970: 927; Chemsak et al., 1992: 50 (checklist); Monné, 1993: 55 (cat.); Monné & Giesbert, 1994: 78 (checklist); Monné, 2005: 366 (cat.); Monné & Hovore, 2006: 96 (checklist).

Compsibidion trinidadense ; Martins, 2009: vi; Monné, 2018: 511 (cat.).

Taxonomic history. Gilmour (1963) described his new species in Phormesium Thomson, 1864 . Several years later, Martins (1970:923) synonymized Phormesium with Engyum Thomson, 1864 (translated): “The name Engyum has priority over the name Phormesium ; the former was established for the female of E. quadrinotatum Thomson (1864: 216) , and the latter for the male of eudesmoides Thomson (= fusiferum Serville), (1864: 217).” The correction is regarding the synonymy proposed by Lacordaire (1868), who considered Engyum as a junior synonymy of Phormesium . Still, according to Martins (1970: 929), who provisionally considered P. trinidadense as belonging to Engyum (translated): “The allocation of trinidadense in Engyum is provisional and can only be clarified when it is possible to examine material in natura.” Some conclusions can be extracted from the detailed description: the procoxal cavities “moderately widely open posteriorly” move the species to the Division IV [currently Neoibidionina]. Actually, the kind of pubescence of the pronotum, the number of longitudinal rows of piliferous punctures on each elytron, and the dimensions (10-11.2 x 2.1-2.3 mm) relatively large, appear to exclude it from Engyum and similar genera, despite the shape of antennomere III. Once located in Division IV, trinidadense could be included in Compsibidion and would constitute a separate grouping, next to the group sphaeriinum: upper eyes lobes "rather small and narrow", with three rows of ommatidia; antennomere III thickened and not carinate in the antennae of males. The representatives of this group, however, have sparse pubescent pronotum, prosternum without sericeous pubescence, elytra bispinose and uniform coloring. Finally, Martins (2009: vi) transferred Phormesium trinidadensis to Compsibidion Thomson, 1864 (translated): “ Phormesium trinidadensis is transferred to the genus Compsibidion Thomson, 1864 , treated in volume nine of this series ( Martins & Galileo, 2007). Because it has procoxal cavities open posteriorly, it seems to us more appropriate to transfer it to Ibidionina, and in this subtribe, the most appropriate genus for receiving it is Compsibidion . A more precise transfer, however, will only be possible when the holotype is examined.”

Napp & Martins (1985) described Glomibidion for their new species, G. tumidum ( Figs 1–4 ), from Brazil (Sinop, Mato Grosso). Glomibidion was characterized as follows (translated): “Frons flat; frontoclypeal suture moderately marked. Maxillary palpi slightly longer than labials ones, the apical palpomeres securiform. Antennal tubercles slightly elevated, rounded and distant from each other at the base. Eye normal, the upper eye lobes with four rows of ommatidia. Antennae 11-segmented, longer than body; scape cylindrical, slightly thickened toward apex, without basal sulcus, longer than antennomere IV; the III strongly thickened (male), not carinate; antennomeres IV–XI normal and carinate, the IV distinctly shorter than III and V. Prothorax cylindrical-elongate, slightly constricted basally and distally. Pronotum not microsculptured, shining, with basal tubercles slightly distinct. Elytra shining, without pubescence; punctation and setae restricted to five longitudinal rows of piliferous punctures; apex curved notched, with short spine at outer angle. Femora nearly clavate, without basal depression, unarmed. Tibiae with carinae slightly distinct at basal half.”

Transference. Reading the original description of Phormesium trinidadensis , it is possible to see the following points that allow the inclusion of the species in Glomibidion : “Elytra glabrous and nitid except for about five sublinear rows of erect ferruginous setae”; “Head with frons a little transverse, with a short median sulcus, extending between antennal tubercles, almost plane, with a strong semicircular sulcus anteriorly, curving round on the inner side of the eyes”; “antennal tubercles rather strongly raised, broadly concave between, widely separated”; “Palpi with apical segments large, broad, strongly obliquely truncate apically”; “Eyes… isthmus to upper lobe about three facets wide”; “Antennae only about a seventh longer than the body; scape rather robust, moderately swollen, moderately long, extending past the pronotal base; third segment extremely enlarged and swollen, subdepressed, about twice as long as scape; fourth segment short, about two thirds as long as scape, about a third as long as third segment; fifth segment about one and three-quarters as long as fourth, slightly longer than scape”; “segments [antennomeres] four to about eight, feebly longitudinally carinate above”; “Pronotum subcylindrical, elongate, one and a half times as long as broad”; “which [elytra] have the marginal angle somewhat attenuate and strongly spinose, inwardly obliquely truncate, sutural angle broadly rounded”; “each elyton [sic] with four rows of widely spaced setigerous punctures on anterior half and five rows on posterior half”; “profemora clavate, the others more gradually subpedunculo-clavate, the posterior least swollen”; “tibiae rather feebly longitudinally carinate above and below.”

Since all these features agree exactly with the original description of Glomibidion , Phormesium trinidadensis should not be excluded from Glomibidion . Additionally, antennomere III in males of Compsibidion are never as thickened as in Glomibidion .

Remarks. Apparently, the only reliable difference between G. tumidum and G. trinidadense is the size of the anterior pale yellow macula of the elytra. Gilmour (1963) examined two specimens with very broad anterior macula, while Napp & Martins (1985) examined three specimens with proportionally much smaller anterior maculae. Even comparing Gilmour’s detailed description with a paratype of G. tumidum deposited at MZSP collection, we did not find any other consistent differences (see photographs of the holotypes at Bezark 2018). Thus, these two species may eventually be synonymized. Females of both species remain unknown. However, as occurs in other species of Neoibidionini in which the males have the antennomere very tumid, the female probably has narrow and cylindrical antennomere III. Furthermore, as antennomere IV in both species is carinate, antennomere III of the female may also be carinate.

Figures

FIGURES 1–4. Glomibidion tumidum, paratype male: 1, Dorsal habitus; 2, Ventral habitus; 3, Lateral habitus; 4, Head, frontal view.