Tyrinthia frontalis ( Guérin-Méneville, 1855 )

Galileo, Maria Helena M., Mcclarin, Jim & Santos-Silva, Antonio, 2017, The genus Tyrinthia Bates, 1866 in Ecuador (Coleoptera, Cerambycidae, Lamiinae, Hemilophini), Zootaxa 4362 (3) : -

Tyrinthia frontalis ( Guérin-Méneville, 1855)

( Figs 1–10 )

Hemilophus frontalis Guérin-Méneville, 1855: 601 .

Tyrinthia frontalis ; Bates, 1866: 372; Lacordaire, 1872: 887 (note); Gemminger, 1873: 3209 (cat.); Bates, 1881: 305 (list); Aurivillius, 1923: 586 (cat.); Blackwelder, 1946: 623 (checklist); Gilmour, 1965: 634 (cat.); Martins & Galileo, 1991: 814; Monné & Giesbert, 1994: 289 (checklist); Monné, 1995: 10 (cat.); 2005: 503 (cat.); Martins & Galileo, 2014: 188; Monné, 2017: 444 (cat.).

Redescription. Male ( Figs 1–5 ). Integument mostly yellowish-orange; anteclypeus reddish-brown; mandibles orange on basal 2/3 (more brownish at inferior margin of outer side), black on distal third; mouthparts orange except brownish labial palpomere II and maxillary palpomere III, and black last palpomeres; labrum black basally, gradually reddish-brown toward apex; apex of genae brownish toward ventral side, reddish-brown toward upper side; apex of antennal tubercles black; area behind eyes with black, transverse spot, gradually brownish toward prothorax; scape and pedicel black except orangish ventral side of scape; antennomere III black except yellowishorange basal ring; antennomere IV yellowish-orange except black distal ring; antennomere V black and remaining gradually dark brown; pronotum with central, triangular, large black maculae, not reaching distal margin (paler toward narrower area); sides of prothorax with wide, longitudinal, dark brown band, widened basally, reddishbrown between this band and pronotum; mesanepisternum, mesepimeron and metanepisternum dark brown, almost black, especially the latter; metaventrite black except yellowish-orange centro-basal area; each elytron dorsally with wide, longitudinal black band, somewhat narrowed on distal quarter, but widened and reaching suture close to apex; tibiae yellowish-orange on basal third, gradually black toward apex (light area reaching distal third ventrally); tarsi black; abdominal ventrites with dark brown, irregular, wide, longitudinal band on each side, somewhat fused at apex of ventrites II and III.

Head. Frons convex, with conical tubercle on each side of median groove between lower eye lobes; finely, shallowly, sparsely punctate; with yellowish-white pubescence not obscuring integument (silvery depending on angle of light source), interspersed with a few long, erect, yellowish-white setae close to lower eye lobes. Area between conical tubercles and upper eye lobes depressed; finely, shallowly punctate (punctures coarser, more distinct than on frons); with yellow pubescence not obscuring integument (longer, more distinct than on frons). Area of vertex between posterior margin of eyes and prothoracic margin not depressed, moderately finely, shallowly, sparsely punctate; with yellow pubescence not obscuring integument. Median groove distinct from clypeus to prothoracic margin. Antennal tubercles minutely, abundantly punctate, interspersed with fine punctures; with yellowish-white pubescence not obscuring integument, gradually sparser toward apex, and absent on centrodorsal area. Area behind upper eye lobes with dark pubescence close to eyes, partially obscuring integument, gradually yellower toward prothorax. Area behind lower eye lobes with yellowish-white pubescence not obscuring integument (silvery depending on angle of light source). Genae with pubescence as behind lower eye lobes, interspersed with long, erect yellowish-white setae toward ventral side, except glabrous, narrow distal area. Gulamentum smooth, glabrous, except distal area with nearly indistinct yellowish-white pubescence. Labrum coplanar with anteclypeus on basal 2/3, strongly inclined on distal third; finely, abundantly punctate; with long, erect brownish setae. Distance between upper eye lobes 0.37 times length of scape; in frontal view, distance between lower eye lobes 0.75 times length of scape. Antennae 2.15 times elytral length, reaching elytral apex at basal quarter of antennomere VI. Scape distinctly clavate, curveted basally; ventrally with erect, sparse yellowish setae. Antennomere III not widened, with long, erect, moderately abundant brownish setae ventrally; antennomere IV with long, erect, moderately sparse yellowish setae ventrally (brownish on distal dark area); remaining antennomeres with short, erect, sparse brownish setae ventrally. Antennal formula (ratio) based on length of antennomere III: scape = 0.47; pedicel = 0.10; IV = 0.65; V = 0.40; VI = 0.34; VII = 0.30; VIII = 0.29; IX = 0.27; X = 0.26; XI = 0.31.

Thorax. Prothorax 1.34 times wider than long; sides rounded widened near middle. Pronotum with 3 gibbosities, one centrally, more distinct, subtriangular, placed on basal half, one subcircular, less distinct, placed on each side of middle; moderately finely, sparsely punctate centrally (denser basally), sparser, shallower laterally; with longitudinal, moderately wide white pubescent band on each side; remaining surface with yellow pubescence not obscuring integument, more brownish, less distinct on base of black area. Sides of prothorax moderately coarsely and abundantly punctate; with yellowish-white pubescence not obscuring integument. Ventral side of meso- and metathorax with yellowish-white pubescence not obscuring integument (silvery depending on angle of light source, especially on dark areas), except nearly glabrous central area of metaventrite; prosternal process narrow between coxae; margins distinctly elevate. Mesoventral process concave, about as wide as 1/4 of mesocoxae. Mesanepisternum and mesepimeron finely, sparsely punctate. Metanepisternum coarsely, sparsely punctate, interspersed with finer punctures. Metaventrite coarsely, moderately abundantly punctate laterally. Scutellum with yellowish pubescence partially obscuring integument. Elytra. Moderately coarsely, abundantly punctate; with slightly distinct, longitudinal striae dorsally; humeral carina moderately distinct from humerus to at about middle; with yellow pubescence not obscuring integument on light areas, and yellowish-white pubescence not obscuring integument on dark areas; with moderately short, erect, sparse yellowish setae; apex subtruncate. Legs. Procoxae distinctly conical. Femora with yellowish-white pubescence not obscuring integument (silvery depending on angle of light source).

Abdomen. Ventrites with yellowish-white pubescence not obscuring integument (silvery depending on angle of light source); apex of ventrite V truncate, slightly elevated centrally.

Female ( Figs 6–10 ). Area behind upper eye lobes entirely black; conical tubercles on frons only indicated; scape entirely black; sides of prothorax with transverse band black; antennae 1.43 times elytral length, reaching elytral apex at apex of antennomere VIII; antennomere III somewhat widened, with long, erect, dense black setae throughout, except basally with yellowish pubescence; abdominal ventrites II–IV entirely black except yellowishwhite sides; abdominal ventrite V entirely black; apex of abdominal ventrite V emarginate.

Dimensions (mm), male/female. Total length, 11.25/11.70; prothoracic length, 1.84/1.67; basal prothoracic width, 2.25/2.52; distal prothoracic width, 1.91/2.02; central prothoracic width, 2.47/2.38; humeral width, 3.15/ 3.46; elytral length, 8.41/9.13.

Material examined. ECUADOR, Napo: Cosanga (in Clibadium sp. ( Asteraceae )), 1 male, 1 female, 15.IX.2016, J. McClarin col. (respectively, QCAZ; MZSP).

Remarks. The type locality of Tyrinthia frontalis is uncertain, because Guérin-Méneville (1855) gave no precise locality of collection. Based on the title of the work where the species was described, it is only possible to say that the specimen is from some place in Ecuador, Peru or Brazil: “…sur les bords du Napo et de l’Amazone.” According to Papavero (1973) on Gaetano Osculati’s travel: “After traversing the Isthmus of Panama he went to Guayuaquil and Quito, Ecuador. Crossing the Andes, he followed the Rio Napo from its sources to its mouth in the Amazonas, and through the later went to Belém…” Osculati (1850) gave no indication of where the holotype could have been collected.

According to Martins & Galileo (2014) (translated): “ LACORDAIRE (1872: 887) cited Tyrinthia frontalis for Amazonas. MARTINS & GALILEO (1991e: 814) mentioned it from Ecuador.” Apparently Lacordaire (1872) really listed Tyrinthia frontalis as from “ Amazone ”. Nevertheless, the citation by Lacordaire (1872) is completely chaotic and difficult to understand, because he used commas, semicolons and dashes without any sense: “ Hem. frontalis, Guér. -Ménev. Verhandl. d. Zool.-Bot. Ver. in Wien, V, p. 601; Amazone.— Cyphom. infacetus , Brésil; Lacordairei, Colombie; J. Thomson. Loc. Cit. p. 193.” However, as Cyphometopus infacetus Thomson, 1868 was described from “Brasilia”, without additional place, it makes more sense to assume that Lacordaire (1872) was recording H. frontalis from “ Amazone ” and not C. infacetus . Gemminger (1873) also recorded “Amazon” as the place where T. frontalis would occur. Bates (1881) was the first to record the species from Ecuador, and was followed by all authors until now, as from Napo or “bords du Napo ” in this country ( Monné 2017).

Only the examination of the labels of the holotype may provide a detailed place in northern South America. Thus, for the time being, the type locality of T. frontalis should be considered as “northern South America”.

Tyrinthia frontalis can be easily separated from the other species of the genus by the dark longitudinal band on the elytra (not forming longitudinal band in the other species).

Although Guérin-Méneville (1855) did not record the sex of the holotype, now we know it is a male, due the length of the antennomeres III–IV (the only remaining in the specimen), and also by the kind of pubescence on antennomere III (not covering the antennomere throughout), as well as not wider than IV. Formally, the couple described here are the only known specimens other than the holotype. According to Guérin-Méneville (1855) (translated): “Antennae dark at base, yellow from antennomere IV, with the apex of each antennomere dark”; and “Legs yellow with tibiae and tarsi dark.” Unfortunately, the holotype has only the first four antennal segments.

Thus, it is not possible to know if the original description is correct regarding antennomeres V–XI. As the antennal length was not recorded, it is not possible to know if they existed when the species was described. As for the color of the tibiae, it is possible to see in the photograph of the holotype (available at Bezark 2017) that at least the right mesotibia is light on base.

Figures

FIGURES 1–10. Tyrinthia frontalis. 1–5, male:1, dorsal habitus; 2, ventral habitus; 3, lateral habitus; 4, head, frontal view; 5, frontal tubercles and scape. 6–10, female: 6, dorsal habitus; 7, ventral habitus; 8, lateral habitus; 9, head, frontal view; 10, frontal tubercles and scape.