Biraidion, Galileo, Maria Helena M. & Santos-Silva, Antonio, 2016

Galileo, Maria Helena M. & Santos-Silva, Antonio, 2016, New genus and new species of Neoibidionini from the Neotropical region (Coleoptera, Cerambycidae, Cerambycinae), Zootaxa 4137 (3), pp. 391-404 : 392

Biraidion gen. nov.

Etymology. This genus is named after the late Ubirajara R. Martins de Souza (Bira) for his enormous contribution to the knowledge of Cerambycidae , with Greek diminutive “idion”. Neuter gender.

Type species. Biraidion martinsi sp. nov., present designation.

Description. Antennal tubercles elevated, subacuminate at apex. Eyes not divided; upper eye lobes narrow, with 5 rows of ommatidia; distance between upper eye lobes about 2.5 times width of one lobe. Antennae 12- segmented in both sexes; in male about much longer than body (1.8 times in type species); in female shorter than in male (about 1.4 times body length in paratypes of type species); antennomere III not carinate; antennomeres III– XII filiform, moderately flattened dorsoventrally, slightly narrowed on outer side than inner side, not tumid on basal antennomeres in both sexes; scape subpiriform, obliquely sulcate dorsally; antennomere IV shorter than III and V. Prothorax cylindrical, notably longer than wide in both sexes. Pronotum not microsculptured, with 5 distinct tubercles, pubescent. Procoxal cavities open behind. Prosternum entirely pubescent. Elytra entirely pubescent; elytral carina slightly marked, mainly in female. Profemora fusiform; meso- and metafemora clavate; apex of femora without spine or projection; apex of metafemora not reaching elytral apex. Metatibiae not carinate, slightly longitudinally sulcate on inner side. Metatarsomere I about as long as II+III in male, slightly longer in female.

Remarks. Four genera of Neoibidionini have antennae 12- segmented: Dodecaibidion Martins, 1962 (Compsina) ; Homaloidion Martins, 1968 (Tropidina) ; Perissomerus Gounelle, 1909 (Tropidina) ; and Tetraopidion Martins, 1960 (Neoibidionina) . Biraidion gen. nov. belongs to Tropidina. Thus, it differs from Dodecaibidion and Tetraopidion by the subtribal features: procoxal cavities open behind (closed in Dodecaibidion ); scape subpiriform and antennomere IV not notably shorter than III and V (respectively cylindrical and distinctly shorter in Tetraopidion ). It differs from Homaloidion as follows: antennae 12- segmented in both sexes; lower eye lobes rounded nearest margin of ventral side of head; pronotum not microsculptured and pubescent; pronotum distinctly tuberculate; elytra with carina slightly marked, mainly in female. In Homaloidion the antennae in female are 11- segmented, the lower eye lobes is truncate nearest margin of ventral side of head, the prothorax is distinctly microsculptured, the pronotum is not pubescent and has not distinct tubercles, and each elytron has a distinct longitudinal carina. It can be separated from Perissomerus mainly by the antennomere III not dorsally carinate (carinate in Perissomerus ), by the antennal tubercles acute at apex (rounded in Perissomerus ). Additionally, all known species of Perissomerus have not the pronotum and elytra notably pubescent, while they are so in Biraidion .

Biraidion gen. nov. can be included in the alternative of couplet “2” to Tropidina, from Martins & Galileo (2007) (translated; modified):

2(1) Apex of antennal tubercles rounded; antennomere III carinate dorsally..................... Perissomerus Gounelle, 1909 - Apex of antennal tubercles acute; antennomere III not carinate dorsally......................................... 2’ 2’(2) Pronotum densely microsculptured, without distinct tubercles; elytra carinate; antennae 11- segmented in female...........

.............................................................................. Homaloidion Martins, 1968 - Pronotum not microsculptured and with distinct tubercles; elytra not carinate; antennae 12- segmented in female...........

..................................................................................... Biraidion gen. nov.