Rhyparus vanuatuensis Skelley & Minkina, 2025

Rhyparus vanuatuensis Skelley & Minkina , new species

Figures 40–45 View FIGURES 40–45

Diagnosis. Rhyparus vanuatuensis is distinguished from other species in the genus by its larger body size, length 5.7–6.6 mm ( Figs. 40–42 View FIGURES 40–45 ). Head with clypeal margin sharply toothed. Pronotum with lateral margin sinuate and weakly lobed; costa low and straight; surface evenly coarsely and densely punctate. Elytra with costae low, somewhat flattened, straight; costae with rows of long setae on each side (rubbed off on a few); intercostal 3 with a basal remnant of a costa; intercostal 3 with reduced third, medial row of punctures; discomedial costa gradually widening at caudal apex, not bulbous; juxtasutural costa in lateral view angled at apex. Abdominal ventrites lacking triangular fossa on each side; female last abdominal ventrite shortened medially; female pygidium depressed into last ventrite, surface weakly carinate medially with acute apex ( Fig. 43 View FIGURES 40–45 ).

Description. Holotype female. Length 5.7 mm, width 1.8 mm. Elongate, parallel sided, flattened, dark brown, surface generally dulled, partly clothed with fine, pale yellow setae on head and all longitudinal costae on pronotum and elytra. Head. Surface glossy, transversely sub-hexagonal. Clypeus trapezoidal in outline, anteriorly truncate in anterior view, concave between teeth in dorsal view; anterior margin upturned with sharp tooth on each side of medial third, lateral thirds concave to obtuse tooth anterior of clypeogenal junction. Gena prominent lobe laterally, distinctly excavated anterior of eyes. Clypeocentral disc convex with two short costae evident only as small tubercles visible in dorsal view; peridiscal impression strong basally, weak anteriorly. Frons with four short, distinct frontodiscal costae. Head covered with moderate to coarse punctures; coarse punctures at base of head, smaller punctures on clypeocentral disc; punctures with short, pale yellow setae. Pronotum. Surface dulled, costae glossy, widest in middle, with paramedian, discolateral, posthumeral, and submarginal costae distinct. Costae on each side with very small punctures bearing very small setae. Paramedian costae complete, most prominent at anterior margin, slightly reducing in prominence at weak constriction near anterior third, distinct and weakly diverging to posterior margin. Discomedian costa nearly straight, distinctly interrupted by fovea on anterior third, present at anterior margin. Submarginal costa complete, sinuate.All costal intervals equally, coarsely, densely punctured; puncture separated by half a diameter or less, rarely with flattened area in between. Lateral margin complete, sinuate with weakly produced anterior and intermediate lobes. Elytra. Surface with costae somewhat glossy, flattened intervals dulled; each elytron with five elevated costae separated by five flattened intervals. Costae moderately convex, low, not sharply convex; on each side with a row of very small punctures bearing long setae. Juxtasutural costa complete from base to apex, prominent behind caudal bulbs, angled ventrally. Discomedian costa straight from base to apex; gradually swelling at apex to small postdiscal bulb that has a weak tuft of setae at dorsal apex. Discolateral and posthumeral costae narrow entire length, curving inward at apex into trichome; basally a short accessory costa over humerus between discolateral and posthumeral costae. Submarginal costa narrow entire length turning inward to caudal bulb. Elytral humerus at base of posthumeral costa bearing punctures with short setae. Striae with large punctures, within a strial punctures separated from each other by a diameter or less, between striae in the flattened interval separated by a puncture diameter or slightly more; punctures weakly crenating costal margins. Costal intervals flattened, dulled, with large strial puncture appearing somewhat rugose; first and second costa interval with two strial puncture rows and few randomly scattered smaller punctures on interval; third costal interval between discolateral and posthumeral costae with two strial puncture rows and a third smaller row on interval, third row begins basally at the remnant accessory costa with punctures becoming gradually smaller as progressing posteriorly nearly to caudal trichomes; fourth costal interval with two strial puncture rows and randomly scattered puncture on interval basally, punctures becoming smaller and stop at apical quarter where interval becomes glossy to trichome. Caudal trichomes small, narrowed. Caudal bulbs large, laterally truncate, transverse, in dorsal view strongly rounded laterally and curving posteriorly to blunt point medially, broadly rounded dorsally in posterior view; upper part of bulb glossy with minute puncture, posteriorly with coarse punctures, surface between bulb and caudal margin strongly alutaceous with large punctures. Venter. Surface weakly glossy, with abdomen dulled. Metaventrite flattened, in the middle with distinct deep longitudinal median impression in posterior third, impression narrowing anteriorly; disc on either side with punctation large and regularly spaced more than one diameter apart, decreasing in size anteriorly and laterally, all punctures bearing short setae. Abdominal ventrites 2–4 with narrow transverse anterior groove that is smoothly margined and lacking large punctures; laterally ventrites lacking triangular depression on each side, rest of surface with scattered moderate punctures bearing short setae. Terminal abdominal ventrite shortened medially, with large anterior groove narrowed medially. Pygidium depressed, held on longitudinal axis with body; with complete central carina, ending with acute, triangular apex. Legs. All femora weakly glossy, with moderately deep, distinct punctures; all punctures bearing very short setae. Mesofemur robust, with posterior margin bearing a single blunt angulation at middle. Metafemur narrow, moderately widened at apical third. Protibial with inner apical tooth not projecting medially. Mesotibia and metatibia lacking inner apical tooth and concave inner margin.

Allotype male. Body length 6.5 mm, width 2.1 mm. Abdominal ventrite 5 (last) as long as preceding two ventrites medially; surface evenly coarsely punctured, punctures separated by one diameter; medially with small carina on anterior half, ending at anterior margin which has a narrow, puncture filled groove extending to lateral margin. Pygidium with central carina weak, but complete, basally with ridges extending laterally to form base of transversely elongate fovea on each side of median carina. Protibia with tridentate apex; inner apical tooth projecting medially; medial margin concave in apical third. Mesotibia with apex truncate; large medially projecting tooth on inner apical angle; inner margin concave in apical third. Metatibia weakly widened to truncate apex; large medially projecting tooth on inner apical angle; inner margin weakly concave in apical third. Mesotarsomere 1 as long as mesotarsomeres 2–4 combined. Metatarsomere 1 as long as metatarsomeres 2–5 combined. Male genitalia with basal piece long ( Figs. 44–45 View FIGURES 40–45 ); parameres short, rounded in caudal view, length a fifth of basal piece length.

Variation. Length 5.7–6.6 mm, width 1.8–2.1 mm. The accessory costa over humerus is obsolete in some, hidden in coarse punctation. The dorsal punctation varies a little in size and number. The pronotal punctation is always dense, coalescing in some.

Distribution. Vanuatu (Espiritus Santo Island).

Material examined. Holotype female and allotype male ( FSCA): “ VANUATU: Espiritus Santo I. / Cumberland Peninsula , / Saratsi Range at 14.9657°S / 166.6521°E. 700m. Flight / intercept FL7A-4. 30.xi-1-xii. / 2006. A.K. Tischenkin, AT827 /” GoogleMaps . Holotype with additional label on red paper “ HOLOTYPE ♀ / Rhyparus / vanuatuensis / Skelley & Minkina” . Allotype with additional label on blue paper “ ALLOTYPE ♂ / Rhyparus / vanuatuensis / Skelley & Minkina” .

Paratypes (24 total). All known specimens were from the same area: VANUATU: Espiritus Santo Island , Cumberland Peninsula, Saratsi Range at 14.9641°S, 166.6479°E, 600 m, 4–6.XI.2006, A.K. Tischenkin AT606, flight intercept FL6B-1 (3 CSCA) GoogleMaps ; [same locality] 4–6.XI.2006, A.K. Tischenkin AT607, flight intercept FL6C-1 (1 BPBM; 2 CSCA) GoogleMaps ; [same locality] 28–29.XI.2006, A.K. Tischenkin AT806, flight intercept FL6A-12 (1 CSCA) GoogleMaps ; [same locality] 30.XI–1.XII.2006, A.K. Tischenkin AT822, flight intercept FL6B-13 (3 CSCA) GoogleMaps ; [same locality] 30.XI–1.XII.2006, A.K. Tischenkin AT823, flight intercept FL6C-21 (1 FSCA) GoogleMaps ; [same locality, different coordinates] at 14.9657°S, 166.6521°E, 700 m, 27–28.XI.2006, A.K. Tischenkin AT801, flight, intercept FL7A-1 (2 CSCA; 1 FSCA) GoogleMaps ; [same locality] 29–30.XI.2006, A.K. Tischenkin AT818, flight intercept FL7A-3 (1 CSCA) GoogleMaps ; [same locality, same data as holotype and allotype] (1 BPBM; 1 CSCA; 2 FSCA; 2 ISEA; 2 NHML) GoogleMaps .

Etymology. Toponymic. Named for the country where this species occurs.

Comments. Rhyparus vanuatuensis belongs to a complex of species readily distinguished from all others by the depressed female pygidium ( Minkina et al. 2022, 2023, 2025). A female holotype was chosen because males are difficult to distinguish. However, both males and females of species in this complex share similar elongate, parallel-sided bodies; dentate clypeus; weakly lobed pronotal lateral margins; low, flattened, straight elytral costae; densely, evenly coarsely punctate pronotal surface; short accessory costae over the elytral humerus; metaventrite lacking discal depressions on each side; abdominal ventrites with narrow anterior grove and small punctures, and lack a lateral triangular fovea on each side. These species differ from each other in details of dorsal punctation, elytral costal development, female pygidial structure and other characters. The majority of species in this complex appear to have speciated on many of the isolated islands or island groups in Indonesia.

Considering all of the species in this group, R. vanuatuensis shares an acute or narrowly rounded apex (not truncate) of the female pygidium with four other species.Three of these species( R. bacanensis Minkina,Anichtchenko, Vasiljeva, & Skelley, 2022 from Moluccas, Bacan Island; R. malaitaensis Minkina, Skelley, Jákl, Král, & Li, 2025 from the Solomon Islands; and R. obiensis Minkina & Jákl, 2024 from Moluccas, Obi Island) have the caudal apex of the discomedian elytral costa rapidly widening, almost bulbous apex, while it is gradually widening to the apex in R. vanuatuensis . The other species, R. argopurensis Minkina & Jákl, 2024 (Java), shares details of the acute female pygidium and gradually swelling discomedian costa with R. vanuatuensis . They differ in having widely separate distributions, and R. vanuatuensis having long setae on the elytral costae, while R. argopurensis has short setae. Additionally, R. vanuatuensis have lateral lobes of pronotum less distinctly sinuate, median caudal bulbs less distinctly developed with no sinuation between median and external caudal bulbs.