Arcanus, Alasmar & Domahovski & Cavichioli, 2025

Alasmar, Luísa, Domahovski, Alexandre Cruz & Cavichioli, Rodney Ramiro, 2025, Morphological-based phylogeny and revision of Ciminius Metcalf and Bruner, 1936 (Hemiptera, Cicadellidae), Arthropod Systematics & Phylogeny 83, pp. 231-285 : 231-285

3.1. 2. Arcanus gen. nov.

Figure 38

Type species.

Arcanus academicus sp. nov.

Diagnosis.

Small sharpshooters, size about 5.5 mm with overall coloration (Fig. 38 A – C ) reddish with several yellowish spots. Head (Fig. 38 A ) moderately produced anterad, subtriangular. Forewing (Fig. 38 B ) with three anteapical cells, middle anteapical cell opened basally, some supranumerary veins on apical portion. Connective (Fig. 38 I ) stem not well sclerotized, articulated with connective. Subgenital plate (Fig. 38 D ), in lateral view, distinctly short, extending to basal third of pygofer. Aedeagus (Fig. 38 G ), in lateral view, symmetrical, with shaft short, without processes, in ventral view (Fig. 38 H ) compressed, apex rounded, opened medially as the gonopore exit. Paraphysis (Fig. 38 I, J ) with ramus long and robust, well sclerotized apically.

Description.

Head and Thorax: Crown (Fig. 38 A, B ), in dorsal view, anterior margin moderated produced, subtriangular, without concavities between ocelli, surface with texture slightly punctate, with fovea between eyes and ocelli, without a carina on transition from crown to face; median length 1 / 3 of transocular width, and 1 ⁄ 2 of intraocular width. Ocelli located before the imaginary line between anterior eye angles, closer to adjacent eye angle than to median line. Frontogenal suture extending to crown, reaching ocelli. Antennal ledge, in dorsal view, not protuberant; in lateral view (Fig. 38 B ), rounded, not carinated. Frons (Fig. 38 B ), in lateral view, slightly oblique, not inflated medially; in frontal view (Fig. 38 C ), texture slightly punctate, muscular impressions distinct; epistomal suture complete. Clypeus, in frontal view, with apical margin rounded; in lateral view, continuing frons contour, without pubescence. Pronotum (Fig. 38 A ), in dorsal view, with width slightly greater than transocular width, anterior third with texture slightly punctate, posterior third transversely rugulose, without pubescence; in lateral view (Fig. 38 B ), dorsopleural carina complete. Mesonotum (Fig. 38 A ), in dorsal view, slightly punctate anteriorly to transverse sulcus and transversely rugulose posteriorly. Forewing (Fig. 38 A, B ) opaque, texture slightly punctate, veins distinct and elevated, membrane distinct with four apical cells, which the base of fourth more proximal to base of third than to clavus apex; with three anteapical cells, middle anteapical cell opened basally; with some supernumerary veins on apical portion; appendix narrow. Hind leg (Fig. 38 B ) with femoral setal formula 2: 1: 1; first tarsomere shorter than combined length of two more distal tarsomeres, with two parallel longitudinal rows of small setae on plantar surface. Sternite II of abdomen with pair of inner small triangular apodemes. — Male terminalia: Pygofer (Fig. 38 D ), in lateral view, moderately produced, without processes; dorsal and ventral margins convergent apically; posterior margin rounded; macrosetae distributed along the entire disk; microsetae along posterior margin. Valve (Fig. 38 E ), in ventral view, slender, anterior margin concave, lateral margins peaked anteriorly. Subgenital plate (Fig. 38 E ), in ventral view, not fused to its counterparts; triangular, narrowing abruptly towards apex; outer margin with uniseriate row of macrosetae, microsetae present basally; in lateral view (Fig. 38 D ), short, extending nearly to pygofer basal third. Style (Fig. 38 F ), in dorsal view, surpassing posteriorly the connective apex; preapical lobe developed and rounded; apex distinctly sclerotized and truncated. Connective (Fig. 38 F ), in dorsal view, V-shaped, as long as wide, arms slender. Stem of connective (Fig. 38 I ) occurring as a separate sclerite, long, not well sclerotized, connecting anteriorly to connective and posteriorly to paraphysis arms. Aedeagus (Fig. 38 G ), in lateral view, symmetrical, directed posteroventrally, without processes; shaft slightly curved ventrally; apex expanded, rounded; in caudoventral view (Fig. 38 H ), expanded preapically; apical third heart-shaped, with gonopore exit. Paraphysis (Fig. 38 I ), in lateral view, large, extending nearly to pygofer apex, with a pair of symmetrical arms directed dorsally, articulated with a long robust ramus directed posterodorsally; in dorsal view (Fig. 38 J ), wide basally and narrowing gradually to an acute and well sclerotized apex.

Female terminalia.

Unknown.

Etymology.

The genus name Arcanus (a neutral noun) is derived from Latin, meaning “ mysterious ” and “ secret. ” This name alludes to the difficulty of collecting specimens and their remarkable, unique morphological characteristics.

Remarks.

Arcanus gen. nov. shares similarities with Ciminius and Tylozygus , especially in the male terminalia, such as: (1) pygofer moderately produced, with macrosetae distributed along the entire disk, (2) subgenital plates triangular, short, not extending posteriorly to pygofer basal third (3) styles short with apex truncate (4) stem of connective occurring as a separated sclerite. Although, the new genus can be promptly differentiated from Ciminius and Tylozygus by the combination of characters below: (1) body somewhat flattened dorsoventrally; (2) head moderately produced, with anterior margin subtriangular; (3) forewings with three anteapical cells, median one opened basally; and (4) paraphysis large and well sclerotized. Until the present moment, Arcanus gen. nov. is known only for its type location.

Figures

Figure 38. Arcanus academicus gen. et sp. nov., male holotype. A habitus, dorsal view; B habitus, lateral view; C head, frontal view; D pygofer, valve and subgenital plate, lateral view; E valve and subgenital plates, ventral view; F connective and style, ventral view; G aedeagus, lateral view; H aedeagus, caudoventral view; I connective, stem and paraphysis, lateral view; J paraphysis, dorsal view. Scale bars in mm.