Striduloselymbria cabofrioensis, Sanborn, 2024

Striduloselymbria cabofrioensis View in CoL gen. nov., sp. nov. ( Fig. 1 View Figure 1 )

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Type material: Holotype. “ Ilha de Cabo Frio / Cabo Frio – RJ / 24–27/I/84 / Carvalho/Sampaio / Kosawa ” ♂ ( DZRJ) .

Etymology. The name is a combination of cabofrio - (Cabo Frio, island where the type specimen was collected) and - ensis (L., suffix denoting place, locality) in reference to the site where the holotype originated.

Diagnosis. Striduloselymbria cabofrioensis gen. nov., sp. nov. can be distinguished from all other species of the tribe by the stridulatory apparatus on the dorsolateral mesothorax. No other species currently classified in the tribe possess an accessory sound structure.

Remarks. The mesonotal stridulatory apparatus quickly distinguishes the specimen from all other species of Selymbriini . Fore wing morphology is another means to distinguish the species quickly from other members of the tribe.

Description. Ground color testaceous marked with castaneous and piceous. The ground color is probably green in fresh specimens.

Head. Head wider than mesonotum, not as wide as lateral angles of pronotum, transverse piceous fascia across dorsal head between eyes on most of vertex and frons, ground color anterolateral corner of vertex, medioposterior corner of supra-antennal plate, anteromedial frons, and epicranial suture posterior to median ocellus, piceous posterior to eye. Ocelli red, eyes fuscous. Short silvery pile on dorsum, denser short and long silvery pile posterior to eye. Gena ground color with transverse piceous fascia connecting to piceous mark ventral to eye, lorum ground color except castaneous posterior half of anteromedial margin, mark expanding onto posterior end of lorum, gena and lorum covered with short silvery pile and radiating long silvery pile. Postclypeus apex smoothly rounded anteriorly, wide but shallow central sulcus on ventral side, twelve transverse grooves, ground color with piceous triangular mark on dorsum and castaneous fasciae within transverse grooves, fascia only in medial portion of posterior seven ventral grooves, castaneous within sulcus, short silvery pile laterally. Anteclypeus ground color with castaneous lateral margin, transverse fascia posterior to anterior margin, and longitudinal fasciae on either side of posterior half of carina midline, covered with short silvery pile, radiating sparse long silvery pile. Mentum ground color, labium ground color medially, castaneous becoming piceous distolaterally with piceous tip, reaching to middle trochanters, radiating silvery pile. Scape and proximal pedicel ground color, remaining antennal segments castaneous.

Thorax. Thorax ground color marked with castaneous and piceous. Pronotum ground color, light castaneous longitudinal fascia extending onto disc from middle of paramedian fissure, small, light castaneous spots at medial end of paramedian fissure, small, transverse fascia on each side of dorsal midline anterior to ambient fissure. Pronotal collar ground color, lateral part of pronotal collar adpressed with dark castaneous lateral margins. Pronotum short silvery pile in ambient fissure, sparse, longer pile radiating from pronotal collar lateral angle. Mesonotum ground color, castaneous mottling in lateral sigillae, castaneous fascia between lateral sigillae and stridulatory apparatus, castaneous spot on lateral margin at posterior stridulatory apparatus, castaneous fascia extending from anterior margin along anteromedial margin of lateral sigilla, longitudinal castaneous fascia on anterior half of lateral margin, longitudinal fascia on posterior dorsal midline beginning at posterior end of submedian sigillae expanding posteriorly between anterior arms or cruciform elevation extending on midline to middle of cruciform elevation, scutal depressions castaneous, cruciform elevation ground color, wing groove ground color. Stridulatory apparatus at base of fore wing, constructed of 22 ridges decreasing in size anterolaterally, ground color with depressions between posterior 10 ridges marked with castaneous. Mesonotum with silvery pile around posterolateral curve, and between anterior arms of cruciform elevation, wing groove radiating long silvery pile. Metanotum ground color with large piceous spot anterolaterally, small piceous spot on dorsolateral surface. Metanotum with sparse, long, silvery pile. Ventral thoracic plates ground color, except castaneous spots on either side of midline of basisternum 2 and 3, and dark castaneous fascia along lateral aniepisternum 2, covered with short and radiating long white pile.

Wings. Fore wings and hindwings hyaline, with eight and six apical cells respectively. Venation ground color basally becoming lightly castaneous distally in apical cells, pterostigma present, extending distally to level of radial crossvein, light infuscation in basal clavus and a few spots anterior to anal cell vein 2+3. Basal cell hyaline, greater than 4.35 times longer than wide. Basal membrane reddish-orange. Proximal costal margin thickened, costa arching producing expanded radial cell, ulnar cell 1 narrowest of ulnar cells and of intermediate length, ulnar cell 2 shortest but of intermediate width, ulnar cell 3 longest and widest ulnar cell, medial cell elongated, sinuate with narrow proximal end, cubitus posterior+anal vein 1 distinctly arched forming expanded cubital cell. Hindwing venation ground color basally becoming lightly castaneous distally except castaneous spot on base next to cubital cell 1, anal vein 3 short, about half the length of anal vein 2 with curved terminus. Basal half of anal cell 3 extending about three fourths distance to distal terminus along wing margin and anal vein 3 white marked with reddish-orange margined with infuscation centrally, anal cell 2 along anal vein 3 to distal curve and along proximal half of anal vein 2.

Legs. Ground color, castaneous spots on anterior, medial, and lateral base of hindcoxae, distal tibiae and distal pretarsi castaneous, pretarsal claws with piceous tips, covered with short silvery pile, radiating long silvery pile from legs. Fore femora with proximal spine widest, triangular, slightly angled, secondary spine longest, finger-like, upright, tertiary spine shortest, narrow, parallel to primary spine. Spines ground color with castaneous tips. Tibial spurs and tibial combs castaneous. Male meracanthus greenish-ground color with castaneous spot on medial base, triangular, pointed, reaching posterior margin of medial operculum.

Opercula. Male operculum ground color, castaneous spot in anterolateral extension, not covering tympanal cavity reaching anterior margin of sternite II posteriorly, not covering tympanal cavity anteromedially or posterolaterally, lateral rectangular extension at base, lateral margin straight to obtusely angled posterolateral corner, straight posterior margin, approximate right angle to straight medial margin just past medial meracanthus, anteromedial margin angled mediad surrounding meracanthus. Operculum with short white pile, radiating long silvery pile from margin.

Abdomen. Abdominal tergites ground color marked with piceous and castaneous. Abdominal tergite 1 ground color with anterolateral piceous spot anterior to timbal, tergite 2 piceous anteriormedially, anterior piceous spots at medial opening of timbal cavity and in middle of timbal cavity, tergites 3–8 with piceous anterior margin and pair of lateral castaneous spots, larger spot dorsal to smaller spot, larger spot with castaneous more intense posteriorly forming a crescent shape, tergites covered with sparse, short, silvery pile. Timbal cover absent, timbal semi-transparent with castaneous margins, with six long ribs, intercalary ribs absent. Sternite I ground color, sternite II ground color, castaneous along midline, on posterior tympanal cavity margin, on auditory capsule, and transverse fascia on posteromedial margin, sternite III with transverse castaneous fascia on anterior midline, castaneous spot surrounding spiracle, sternites III–VII ground color with light castaneous hue transversely on posteromedial sternites, male sternite VIII ground color with castaneous spot on anterolateral angle and posteromedial terminus, open U-shaped notch posteriorly, epipleurites ground color, sternites with short white and radiating long white pile, denser laterally and on epipleurites.

Genitalia. Pygofer ground color with castaneous spots on ventrolateral corner at proximal basal pygofer lobe, lateral base, and on midline anterior to dorsal beak, a pair of small castaneous fasciae on lateral surface, dorsal beak light castaneous, straight but slightly bent ventrally, about as long as dark castaneous anal styles, anal tube ground color. Upper pygofer lobe triangular, curved mediad at distal terminus of basal pygofer lobe giving the appearance of absent upper pygofer lobes. Pygofer basal lobe well developed, extending more than half the length of the pygofer, with central groove on ventral side and triangular terminus. Uncus lobes dark castaneous, large, flattened dorsally, recurving laterally to support aedeagus under proximal half of uncus, distal terminus reducing to a point, uncus radiating long silvery pile. Aedeagus castaneous, tubular, with small lobes distally, conjunctival claws and pseudoparameres absent. Female unknown.

Measurements (mm). Length of body: 19.20; length of fore wing: 23.10; width of fore wing: 8.20; length of head: 2.65; width of head including eyes: 6.30; width of pronotum including suprahumeral plates: 6.35; width of mesonotum: 5.65.

Distribution. The new species is known only from the holotype specimen collected on Ilha de Cabo Frio in the state of Rio de Janeiro, Brazil. Ilha de Cabo Frio is currently recognized by UNESCO as part of the Atlantic Forest Biosphere Reserve and is located at 22.995°S, 41.989°W. The protected status as a biological reserve should prevent local extinction of these new taxa.

Discussion

The new taxon is another example of the pleasant surprises awaiting discovery in the undetermined material deposited in research collections. This new species waiting to be described for more than 40 years after it was collected. The shortage of classical taxonomists is continuing to impact our abilities to comprehend the true diversity of various faunae.