Kerasellum, Vlasak & Botero & Santos-Silva & -, 2025

Kerasellum gen. nov.

( Fig. 1-8)

ZooBank:https://zoobank.org/ 36C38EBA-C0F5-4299-9B16-B1A63639B71C

Type species. – Kerasellum afasciatum sp. nov., here designated.

Etymology. – The name Kerasellum comes from Greek “κέρας” (“keras,” meaning horn of an animal) with diminutive Latin suffix “ellum.” Alluding to the centrobasal crest of the elytra, which resembles a small horn. Neuter gender.

Description

Female. – Small-sized body, somewhat ant-shaped. Body, antennae, and legs with long,erect, light-color setae.Head not retractile; frons distinctly transverse; maxillary palpomere IV and labial palpomere III securiform; antennaltubercles slightly elevated,wellseparated;genae abouthalf maximum lengthof lower eye lobe in frontal view; antennae 11-segmented, slightly surpassing elytral apex; basalflagellomeres nottumidand without apical spine;distal antennomeresnot strongly widened toward their apices; antennomere III shorter than scape, slightly shorter than V; upper eye lobes absent; lower eye lobes with small projection upward posterodorsally. Prothorax strongly narrowed posteriorly; pronotum densely, longitudinally vermiculate; prosternal process strongly narrowed centrally, moderately triangularly widened apically; procoxal cavities slightly openposteriorly. Elytra, inlateralview, depressed aboutmiddle, strongly elevated andconvex onposteriorhalf;apex rounded,unarmed;centrobasalcrest elevated, narrow, C-shaped; withouttransverselight integumentalband.Femora pedunculate-clavate; metatarsomere I slightly longer than II-III together.

Remarks. –Among the genera of Tillomorphini without distinct upper eye lobes ( Licracantha Lingafelter, 2011 ; Pentanodes Schaeffer, 1904 ; and Gourbeyrella Lane, 1959 ), Kerasellum gen. nov. is similar to Pentanodes , but differs as follows: elytra without eburneous or yellowish transverse band; centrobasal crest of elytra C-shaped; and apex of prosternal process slightly widened, making procoxal cavities slightly open. In Pentanodes , the elytra have eburneous or yellowish transverse band (except in P.albofasciatus Fisher, 1932 , provisionally kept in the genus by Heffern et al. (2020)), the centrobasal crest of elytra is longitudinal, from distinct to practically absent, and the apex of the prosternal process is strongly widened, making the procoxal cavities distinctly closed posteriorly. From Gourbeyrella , the new genus differs by the prothorax not subcylindrical (subcylindrical in Gourbeyrella ), and elytra with C-shaped centrobasal crest (centrobasal crest absent in Gourbeyrella ); and from Licracantha it differs by the antennomeres III-V without apical spine (present in Licracantha ), elytra without eburneous or yellowish transverse band (present in Licracantha ), and the centrobasal of elytra C-shaped (longitudinal and slightly tumid in Licracantha ).

Vitali (2011) transferred Eudereces elachys Martins & Galileo, 2013 ) to Tillomorphites Vitali,2011 .However,thisspecies has noupper eye lobes ( Martins & Galileo 2013; one paratype male examined by us). The illustrations of the type species of the genus ( Vitali2011, 2017), T. robustus Vitali, 2011 , and of T. otiliae Vitali, 2017 (see original description) clearly show that both species have distinct upper eye lobes.Therefore, we think thatthe transference of Euderces elachys to Tillomorphites was a mistake. A more detailed study will be necessary to correctly allocate Euderces elachys , which differs from Kerasellum by the absence of spine on the basal flagellomeres (present in Tillomorphiteselachys).

On the tribal allocation of Kerasellum . – According to Martins (1975) (translated): “The systematic of the subfamily Cerambycidae at tribal level is almost incomprehensible and, in the groups related to Tillomorphini (sensu Lacordaire, 1869) , seems to me to be one of the most chaotic, needing urgently a broad-spectrum review. One of the main confusions arises from the genus Tillomorpha , type of Tillomorphini ; the type species of Tillomorpha , T. lineoligera Blanchard (by monotypy and later designation by Thomson 1860:229) [sic] deviates greatly from the tribal concept defined by Lacordaire (1869:88); in this species, the procoxal cavities are widely open behind and the mesocoxal cavities are visibly open laterally. Now, Lacordaire himself states that the Tillomorphini are a dismemberment of the Clytini , separable by the closed mesocoxal cavities, but, “il est, très-difficile de trouver une ligne de démarcation entre eux et ceux des groupes suivants ( Cleomenini , Rhopalophorini , etc.) qui présentent le même caractère” [it is very difficult to find a line of demarcation between them and those of the following groups [ Cleomenini , Rhopalophorini , etc.] which present the same feature] (p. 88).”

More recently, Heffern et al. (2020), reported: “The characteristics mentioned by diverse authors to separate Tillomorphini from Anaglyptini (and also Neocorini ) appear not to be useful (see, for example, Lingafelter 2011). Thus, future studies to separate these tribes should be done.”

Whether the new genus belongs to Tillomorphini or Anaglyptini (or even another tribe) remains opened. However, based on the general appearance much more similar to genera currently included in Tillomorphini , we prefer to include the new genus in this tribe.

Kerasellum afasciatum sp. nov.

( Fig. 1-8)

ZooBank:https://zoobank.org/ AA5A7415-501D-4F39-AEDD-ADB403722A78

Holotype, ♀, ECUADOR, Napo: Pacto Sumaco , 0°40'10"S 77°35'42"W, 23 Nov 2022, J. Vlasak leg. ( MZSP, formerly JVCO). GoogleMaps

Paratype, 1 ♀, same data as holotype ( JVCO) GoogleMaps .

Description of the holotype ( Fig. 1-7)

Coloration. – Integument mostly blackish; ventral mouthparts dark brown on mentum and basal area of labium, reddish brown on remaining segments, except extreme apex of maxillary palpomeres I-III and labial palpomeres I-II, and apical 2/3 of maxillary palpomere IV and labial palpomere III yellowish-brown; anteclypeus and labrum partially dark brown; mandible partially dark reddish brown between basal 2/3 and apical fourth; scape and pedicel dark brown except dark reddish-brown apex of dorsal surface; antennomere III reddish brown except dark-brown inner dorsal apex; antennomeres IV-V reddish brown except apical quarter mostly dark brown; antennomeres VI-VIII reddish brown except apical quarter; antennomeres IX-XI reddish brown basally, dark brown on remaining surface. Coxae mostly dark brown; trochanters mostly reddish brown; femora reddish brown, except dark-brown dorsal surface of femoral club; tibiae reddish brown basally and apically, dark brown on remaining surface; tarsomeres mostly reddish brown with irregular brown areas.

Head. – Frons densely rugose with sparse, coarse punctures interspersed; frontoclypeal sulcus deep, arched; with very sparse, short, erect white setae, and a few long, erect, thick yellowish-brown setae, especially laterally. Vertex and area behind antennal tubercles with sculpturing as on frons; with a few short, erect whitish setae and a few long, erect, thick yellowish-brown setae laterally between antennal tubercles, glabrous on remaining surface. Area behind lower eye lobes slightly rugose close to eye, subsmooth close to prothorax; glabrous. Genae slightly rugose except smooth apex; with a few short, erect whitish setae toward ventral surface and long, erect, thick yellowish-brown setae, smooth area glabrous. Wide central area of postclypeus finely rugose; with short, bristly, sparse whitish setae and one long, erect, thick yellowish-brown seta on each side. Sides of postclypeus partially smooth, glabrous. Labrum coplanar with anteclypeus, finely, transversely striate on posterior third, inclined, subsmooth on remaining surface; glabrous on posterior third, with sparse, short, bristly whitish setae on central third, with long, erect yellowish setae interspersed, abundant, short light yellowish-brown setae on center of anterior third, glabrous on sides of anterior third. Posterior 2/3 of outer surface of mandibles coarsely rugose-punctate; with sparse, shortwhitishsetae and long, erect, thick yellowish setae interspersed; apical third smooth, glabrous. Antennal tubercles with sculpturing as on frons except subsmooth apex; with sparse whitish setae. Posterior 2/3 of gulamentum smooth, glabrous; anterior third transversely striate-punctate; with a few long, erect lightyellowish-brownsetae. In frontal view, distance between lower eye lobes 0.61 times distance between outer margins of eyes. Antennae 1.7 times elytral length, surpassing elytral apex on basal quarter of antennomere XI. Scape very finely, irregularly striate, except smooth dorsal apex; sparsely, moderately coarsely punctate, except on dorsal apex; dorsal and lateral surfaces with a few short, decumbent white setae and long, erect, thick yellowish-white setae interspersed except glabrous dorsal apex; ventral surface withlong, erect whitish setae on basal 2/3 and long, erect yellowish-white setae on apical third, yellowish-white setae longer than whitish setae.Pedicel minutely striate on basal 3/4, smooth on apical quarter; with a few short, decumbent whitish setae dorsally between middle and apical quarter, and long, erect whitish setae on apical half, except on smooth apical area. Antennomeres III-X gradually widened toward apex, more distinctly from IV to VIII; XI subcylindrical with narrowed, rounded apex. Antennomeres III-VI with moderately abundant whitish pubescence not obscuring integument, except glabrous base, and long, erect whitish setae ventrally and on apex of dorsal and lateral surfaces; with a few short, erect light yellowish-brown setae interspersed dorsally, setae gradually more abundanttoward VI.Antennomeres VII-XIwithabundantwhitish pubescence not obscuring integument, gradually denser toward XI, and short, erect yellowish setae interspersed throughout; VII-VIII with a few long whitish setae on apex of dorsal surface; VII with a few long erect whitish setae on apex of ventral surface.

Antennal formula (ratio) based on length of antennomere III:

– Scape = 1.50. – Pedicel = 0.45. – IV = 1.10. – V = 1.30. – VI = 1.05. – VII = 1.00. – VIII = 0.95. – IX = 0.90. – X = 0.70. – XI = 0.95.

Thorax. – Sides of prothorax rounded from anterolateral angles to posterior sixth, then parallel-sided toward posterolateral angles.Anterior 5/6of pronotum densely, irregularly, longitudinally vermiculate, with coarse punctures interspersed; sides of posterior sixth transversely striate, less so toward posterolateral angles, central area rugose; anterior 5/6 with sparse, long, erect, thick yellowish-brown setae, sparser centrally; posterior sixth glabrous. Sides of prothorax withsculpture similar to that onwide centralarea of pronotum, but punctures more abundant, except subsmooth area close to anterior and posterior margins; with sparse, long, erect, thick light yellowish-brown setae on wide central area, especially anteriorly. Anterior 1/3 of prosternum transversally striate with sparse grayish-white pubescence centrally. Posterior 2/3 of prosternum moderately abundantly, coarsely punctate laterally, densely, finely, transversely striate-punctate centrally; sides with moderately sparse grayish-white pubescence and central area with sparse, long, erect, thick yellowish-white setae. Prosternal process with sides elevated; apex slightly rounded; finely rugose-punctate centrally, smooth laterally; glabrous; narrowest area 0.13times procoxal width. Sides of anterior half of centralarea of mesoventrite densely, finely, obliquely striate, glabrous; remaining surface of anterior half finely rugose, glabrous; posterior half of central area sparsely, coarsely punctate, with a few, both short and long, erect yellowish setae; sides with abundant whitish pubescence obscuring integument, except glabrous apex. Mesoventral process with sparse, long, erect yellowish setae. Mesanepisterna finely rugose; with a few long, bristly yellowish-white setae close to central area of mesoventrite and dense whitish pubescence close to elytra. Mesepimera glabrous. Metanepisterna mostly glabrous on anterior 3/4 and dense whitish pubescence over most of posterior quarter. Metaventrite with dense whitish pubescence close to metacoxal cavities, and a few long, erect, thick yellowish setae on remaining surface. Scutellum minutely striate, glabrous, with rounded apex.

Elytra. – Abundantly, coarsely punctate on anterior quarter, punctures sparser, finer on remaining anterior half, and very sparse and fine on posterior half; with sparse, long, erect, thick yellowish-brown setae, setae slightly more abundant on anterior quarter, and abundant, long, erect yellowish setae on sides and apex of posterior quarter.

Legs. – Femora abundantly, minutely striate on dorsal and lateral surfaces of femoral club; sparsely, coarsely punctate throughout; with a few short, decumbent yellowish setae throughout, and sparse, long, erect, thick yellowish-white setae throughout. Tibiae abundantly, minutely striate, dorsal and lateral surfaces with moderately abundant, long, erect, thick yellowish-white setae; ventral surface with sparse yellowish-white setae, setae gradually longer toward area near apex, except apex with abundant, bristly yellowish-brown setae. Dorsal surface of tarsomeres with whitish pubescence not obscuring integument and long, erect setae of same color interspersed.

Abdomen. – Ventrites verysparselyand finelypunctate; with a few,both short, decumbent whitish setae and more abundant, long, erect yellowish setae, and yellowish-brown on sides of ventrite 5; apex of ventrite 5 rounded.

Dimensions (mm) (holotype ♀ – paratype ♀)

– Total length, 5.10-5.40;

– Prothoracic length, 1.35-1.55;

– Anterior prothoracic width, 0.90-0.95;

– Posterior prothoracic width, 0.75-0.85;

– Maximum prothoracic width, 1.25-1.35;

– Humeral width, 1.30-1.45;

– Elytral length, 3.00-3.20.

Etymology. – The name “afasciatum ,” from Latin “fasciatus” (banded), with a prefix “a” (without) alludes to the lack of the eburneous transverse band, which is present in most species of Tillomorphini .

Remarks. – See remarks in the description of the genus.