Plistonax ariasi ( Chemsak & Hovore, 2002) Silva Júnior & Haseyama & Souza, 2021

Silva Júnior, José O., Haseyama, Kirstern L. F. & Souza, Diego de S., 2021, Phylogenetic approach redefines Plistonax (Coleoptera, Cerambycidae, Lamiinae) with new combinations and a new genus of flat-faced long-horned beetles, Organisms Diversity & Evolution (New York, N. Y.) 21 (2), pp. 491-520 : 508-510

Plistonax ariasi ( Chemsak & Hovore, 2002) , comb. nov.

( Figs. 10e , 13a, b, c, d, e, f, g)

Acanthoderes ariasi Chemsak and Hovore (2002): 11 , fig. 6.

Acanthoderes (Acanthoderes) ariasi Monné (2005): 160 (cat.); Swift et al. (2010): 44 (distr.); Taboada-Verona and Botero (2019): 599 , fig. 13 (distr.); Monné (2021) (cat.).

Type locality: holotype (male) – Panama, Panamá, Bayano ( EMEC) ( Fig. 10e ) .

Diagnosis. Vertex with one pair of oval brown stains (Fig. 13a, c). Pronotum with short lateral tubercle ( Figs. 2a , 10e , 13a, c). Humerus and anterior elytral margin with distinct black stain ( Figs. 10e , 13a, c).

Redescription. Female (♀) (Fig. 13a–b). General surface covered with decumbent light-brown setae, merged with yellowish and grizzly setae. Head. Large punctures. Gena subequal in length to lower ocular lobe. Frons and margin of eyes with yellowish setae. Antenna. Pedicel about 1/3 length of scape; antennomere III about 1.3 length of scape; antennomere IV subequal to scape; antennomeres V–XI gradually decreasing in length. Antennomeres V–VI each with two dark-brown stains, one near base and other subapical; antennomeres VII–XI each with only one dark-brown subapical stain; dark-brown stains intercalated by yellowish stains. Inner surface without black setae on antennomeres IX–XI, with distinct erect setae on antennomeres I–VII. Antenna reaching elytral apex at antennomere IX. Prothorax. Pronotum covered by yellowish setae; median tubercles slightly elevated; one pair of median-longitudinal black bands at level of median tubercles. Prosternal process with lateral margin straight. Mesothorax. Scutellum mostly covered by black setae, with a median-longitudinal yellowish band. Mesoventral process width shorter than diameter of mesocoxa; one pair of antero-lateral tubercles little distinct. Elytra. Median-basal crest starting from base, reaching third apical, curved and with small ridges on anterior region. One pair of longitudinal short white stain on center-median region; white stain on center-basal region; two pairs of curved black setae on post-median region; short transversal black stains anteriorly, located between crests and elytral suture; vertical short white stains on elytral slope; other white and black stains sparse; margin with yellowish stain. Internal semierect setae in punctures white, long and slim, tapered at apex, with near sulci each other (Fig. 13g). Elytral apex truncate. Legs. Femora covered with brown setae, with yellowish setae forming small clusters. Tibiae slightly expanded towards apex, with two dark-brown stains, intercalated by yellowish stains. Tarsomerus I covered with white setae, tarsomeres II– V mainly covered with dark-brown setae. Abdomen. Entirely covered with decumbent yellowish setae, sparser at median region.

Male (♂) ( Figs. 10e , 13c–d). Differs from female in the following: presence of black setae on inner surface of antennomeres IX–XI; antenna longer, reaching elytral apex at antennomere XIII. Male terminalia ( Fig. 14a, b, c, d, e, f ). Tegmen ( Fig. 14a ). Ringed part slightly convex, with anterior region sclerotized in both margins, stronger in inner margin; remaining surface membranous; apex rounded, with slight median reentrance. Paramere with uniform sclerotization, narrowed towards apex; basal region expanded laterally, with row of short setae; apex entirely covered by long setae; remaining surface with sparse and very short setae. Endophallus ( Fig. 14b–c ). Median lobe strongly curved in lateral view, with dorsal lobe indistinguishable; ventral lobe entirely sclerotized, stronger at lateral margins; apex slightly narrowed, with median deep invagination. Median strut membranous, smooth, with apex rounded. Internal sac with one pair of sclerotized curved structures anteriorly. Ventral arc ( Fig. 14d ). Membranous, with stem strongly curved at apex; width uniform in stem and lateral projections. Tergites ( Fig. 14e–f ). Tergites VII and VIII longer than wider, both covered with short setae posteriorly, entirely sclerotized, with apex truncate. Tergite VII with base rounded. Tergite VIII with base slightly concave, with membranous apophysis.

Variation. Gena may be larger in length than lower ocular lobe; antennomeres V–VI may present only one dark-brown stain; lateral margin of prosternal process may be convex; pair of black stains on third apical of elytra may be connected or distinctily disconnected; elytral apex may present a slight projection at outer margin.

Measurements (mm). Total length (9.5–12.9); elytral length (6.8–9.1); pronotum length (1.9–2.4); humeral width (3.9–5); pronotum width (3.2–4.2).

Distribution. Colombia [Atlántico n.rec., Antioquia, Bolívar n.rec., Cundinamarca n.rec., Magdalena n.rec.], Costa Rica [Cartago, Limón, San José n.rec.], French Guiana n.rec., Panama [Bocas del Toro, Chiriquí, Coclé, Colón, Los Santos, Panamá, Panamá Oeste] (Fig. S4b).

Remarks. The main redescription provided here is based on a female because that specimen is more consistent with the original description of the species. Chemsak and Hovore (2002) discussed the difficulties in allocating new species to Acanthoderes and Plistonax because those genera do not have reliable diagnostic features. In spite of that, they decided to describe the species as Acanthoderes ariasi . The new combination proposed here is present in the database of Tavakilian and Chevillotte (2020), conflicting with the catalogue of Monné (2021), and there is no previous publication formalizing this nomenclatural act. According to ICZN (1999) (articles 8.5.2 and 8.5.3), the publication by Tavakilian and Chevillotte (2020) is not effectual. The new combination Plistonax ariasi is then formalized here. This species is very similar to P. rafaeli and P. bialbomaculatus but may be differentiated from the former by the elytral pattern and from the latter by the pronotum with short lateral tubercle and the presence of white semierect seta in the elytral punctures. The new records for Colombia (Atlántico and Bolívar departments) were determined through corrections of previous records defined as P. bialbomaculatus ( Galileo and Martins 1999; García et al. 2019).

Figures

Fig. 10 Holotypes of some species of Plistonax: a Plistonax multipunctatus Thomson, 1864 (=P. albolinitus). b Plistonax albituberculatus Silva Júnior & Souza, 2019. c Acanthoderes albolinitus Bates, 1861 (=P. albolinitus). d Plistonax antonkozlovi Santos-Silva, Nascimento & Silva Júnior, 2020. e Acanthoderes ariasi Chemsak & Hovore, 2002 (=P. ariasi comb. nov.). f Acanthoderes bialbomaculata Zajciw, 1964 (=P. bialbomaculatus). g P. senecauxi

Fig. 2 Character photographs: a 2:0 frons with small punctures (anterior view, Aegomorphus jaspideus). b 2:1 frons with large punctures (anterior view, A. travassosi). c 21:0 mesoventral process with antero-lateral tuber- cles slightly elevated (lateral view, Plistonax albolinitus). d 21:1 mesoventral process with antero-lateral tubercles very ele- vated (lateral view, Acanthoderes (Acanthoderes) daviesii). e 4:1 male’s antennomeres VI–XI with tubercles in the inner surface and 11:1 male’s antennomeres IX–XI with black setae in the inner sur- face (lateral view, male of P. albolinitus). f 6:1 antennomere III with darker stain near apex, 7:1 antennomere III with darker stain near base, 8:1 antennomere IV with darker stain near base, 9:0 antennomeres IV–XI with darker stain near apex in subapical posi- tion, and 10:1 antennomeres III– VII with erect setae in the inner surface (dorsal view, P. rafaeli). g 9:1 antennomeres IV–XI with darker stain near apex in apical position (dorsal view, P. insolitus). White dashed lines highlight the character states 2:0 and 2:1; blue arrows highlight the character states 6:1, 7:1, 8:1, 9:0, and 9:1; red arrows highlight the character state 10:1. Scale bars: 1 mm

Fig. 14 Male terminalia: Plistonax ariasi (a–f): a tegmen (ventral view); b endophallus (ventral view); c endophallus (lateral view); d ventral arc (ventral view); e tergite VII (dorsal view); f tergite VIII (dorsal view). P. difficilis (g–l): g tegmen (ventral view); h endophallus (ventral view); i endophallus (lateral view); j ventral arc (ventral view); k tergite VII (dorsal view); l tergite VIII (dorsal view). Points and gray shapes represent sclerotized structures. Scale bars: 0.5 mm