Peripus, Chatzimanolis and Hightower, 2019

Chatzimanolis, Stylianos, 2019, Peripus, a new genus of Xanthopygina (Coleoptera: Staphylinidae) from South America, Zootaxa 4648 (2), pp. 371-383 : 372-375

Peripus, Chatzimanolis and Hightower , new genus

( Figs. 1–33 )

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Type species. Peripus monodontus , new species, here designated.

Diagnosis. Peripus belongs to the Isanopus group of genera of Xanthopygina ( Chatzimanolis & Brunke 2019) based on the following characteristics: antennomeres 8–10 elongate or quadrate ( Fig. 12 ); basal transverse carina of sternum 3 ( Fig. 17 ) acutely pointed medially; mesocoxae moderately to strongly separated ( Fig. 16 ); lack of dense meshed microsculpture anteriolaterally on sterna 5–7 ( Figs. 18–19 ). The sister group relationship between Zackfalinus and Peripus is supported by these characteristics: anterior margin of postclypeus slightly emarginate; basal transverse carina of sternum 4 ( Fig. 17 ) produced medially; sterna 5–7 ( Figs. 18–19 ) anteriorly with longitudinally elongate punctures and posteriorly with rounded punctures; labial P 3 dilated (securiform). The following two characteristics can distinguish Peripus from Zackfalinus and are putative synapomorphies for Peripus : basal transverse carina of sternum 5 ( Fig. 18 ) medially produced (not seen in the species of Zackfalinus examined); and securiform labial P 3 with unique sensory setae orientation: distally with 2–3 rows of setae (as in Zackfalinus ) but proximally expanding to 4–6 rows ( Fig. 11 ). Additionally, male Zackfalinus specimens can be easily distinguished from male Peripus specimens based on the elongate 11 antennomere seen in Zackfalinus . Distinguishing female specimens of Peripus and Zackfalinus can be slightly more challenging, especially from Peru, where species belonging in these genera tend to have the same coloration. Besides the characters given above, Zackfalinus species tend to be slightly larger and more robust than those of Peripus .

Description. Habitus as in Figs. 1–4 . Body medium-sized, forebody 4.2–5.5 mm long; without long bristle-like setae. Coloration of head and pronotum dark metallic blue purple or brown-blue purple; elytra metallic brown-green or blue-green; ventral forebody brown.

Head ( Figs. 5–8 ) shape rectangular; head length in comparison to pronotum shorter to subequal. Eye size large, more than 3/4 length of head. Postclypeus, in comparison to frons not deflexed; anterior margin slightly emarginate. Middle of epicranium impunctate but with microsculpture. Postmandibular ridge laterally; with deep punctures demarcating raised postmandibular ridge dorsolaterally present. Gular sutures not joined before neck, extended close to each other at base of head capsule. Nuchal ridge incomplete dorsally. Neck disc punctures absent or sparse.

Antennae ( Fig. 12 ) with antennomere 1 same width or slightly wider than 2. Antennomeres 3: three times as long as wide; antennomere 4 with tomentose pubescence; antennomeres 4–10 cylindrical in shape; antennomeres 4–7 longer than wide; antennomeres 8–10 symmetrical in shape, quadrate to elongate (longer than wide); antennomere 6 with curved, distinctly longer and thicker subapical setae than other macrosetae, forming circlet. Antennomeres 5–10 without club; antennomere 11 in males slightly longer than 10.

Mouthparts with labrum ( Fig. 14 ) having broad U-shaped emargination, lobes strongly separated. Mandibles ( Figs. 9–10 ) with relative length typical (i.e. closed mandible not extending beyond lateral margin of head); without asymmetrical torsion. Mandibles in dorsal view curved from apical half; in lateral view straight; left and right mandibles each with one tooth. Maxilla ( Fig. 13 ) with galea much shorter than palpus; maxillary palpus with P 3 distinctly shorter than P 2; P 4 distinctly longer than P 3; P 4 not dilated. Hypopharynx and labial palpus as in Fig. 11 ; labial palpus with P 3 securiform, starting with 2–3 rows of setae as in Zackfalinus but expanding to 4–6 rows; P 3 without long dense setae on lateral sides. Ligula shape small, entire. Mentum with alpha seta present; hypostomal cavity present, moderately delimited.

Pronotum ( Figs. 5–8 ) with shape of lateral margins in dorsal view posteriad of midpoint straight to sinuate; anterior angles in dorsal view not strongly acuminate and produced laterad.

Pronotum near anterolateral angles without raised impunctate spots; anterolateral corners with punctation; disc of pronotum with punctation beyond midlength; punctation various but with multiple rows of large punctures; with microsculpture; without coarse punctures impressed in flange at posterior angle of pronotum; impunctate area in middle expanded. Hypomeron ( Fig. 15 ) with superior marginal line continuous to anterior margin; superior marginal line without distinct deflection under anterior angles in ventral view; inferior marginal line of hypomeron continued as separate entity beyond anterior pronotal angles and curving around them. Postcoxal process absent. Basisternum slightly longer than furcasternum; basisternum with pair of macrosetae situated far from anterior margin of prosternum; furcasternum with medial elongate carina pointed vertically.

Elytra ( Fig. 20 ) without contiguous polygon-shaped meshed microsculpture or with patches of white setae. Elytral setae not reduced, easily seen at low magnification. Mesoscutellum with dense cluster of punctures medially. Mesoventrite ( Fig. 16 ) with anterior margin forming “lip”; with median carina and mesoventral process triangular; process extended distally to distance about 2/5 between mesocoxae. Metaventrite ( Fig. 16 ) with large punctures; metaventral processes, small, rounded, triangular, extended to beginning of metacoxae.

Legs with tarsal segmentation 5-5-5; profemora without lateroventral apical spine; protarsi with modified pale (adhesive) setae ventrally; tarsomeres 1–4 of protarsi dorsoventrally flattened. Mesocoxae ( Fig. 16 ) strongly separated, intercoxal area on approximately same plane as both meso and metaventrital processes; metatibiae with spines. Metacoxae without coxal shield; metatibia without thick and long apical spurs but smaller spurs present; tarsomeres 3–5 of metatarsi with chaetotaxy developed only at margins of dorsal surface, dorsal surface of tarsomeres glabrous along midline. Pretarsal claws with empodial setae.

Abdomen ( Figs. 17–19 ), with protergal glands having well-developed acetabula. Anterior basal transverse carina on terga 3 and 4 without pair of accessory ridges; tergum 3 without posterior basal transverse carina and without curved (arch-like) carina on disc; tergum 5 without pair of accessory ridges on anterior basal transverse carina; center of tergum 5 punctate; posterior half of tergum 5 in lateral view not appearing bulging. Sternum 3 with acutely pointed basal transverse carina medially; basal transverse carina laterally not sinuate. Basal transverse carina point- ed medially on sterna 4 and 5. Sterna 5–7 anteriorly with longitudinally elongate punctures and posteriorly with rounded punctures; polygon-shaped microsculpture present in grooves of longitudinally elongate punctures. Males with secondary sexual structures (emargination medially) on sterna 7 and 8; without porose structure on sternum 7. Females without obvious secondary sexual structures.

Aedeagus as Figs. 21–32 ; with long median lobe and single paramere; paramere with sensory peg setae; median lobe with single or pair of subapical teeth; median lobe without apical tooth, carina or paired apex. Spermatheca not sclerotized.

Etymology. The name is derived from the Greek word “περίπου” (about), and refers to the fact that the first author of this paper thought for a long time that Peripus is about the same as Zackfalinus . The name is masculine.

Habitat. Collected in lowland tropical rainforests (elevations 5–600 m) using flight intercept and malaise traps.

Figures

FIGURES 1–4. Habitus photographs of species of Peripus Chatzimanolis & Hightower. 1. The holotype of P. brunkei Chatzimanolis & Hightower. 2. Peripus madrededios Chatzimanolis & Hightower. 3. Peripus didontus Chatzimanolis & Hightower. 4. Peripus monodontus Chatzimanolis & Hightower. Not to scale.

FIGURES 5–8. Heads and pronota of Peripus Chatzimanolis & Hightower. 5. Peripus brunkei Chatzimanolis & Hightower. 6. Peripus didontus Chatzimanolis & Hightower. 7. Peripus madrededios Chatzimanolis & Hightower. 8. Peripus monodontus Chatzimanolis & Hightower. Not to scale.

FIGURES 9–14. Peripus monodontus Chatzimanolis & Hightower. 9. Dorsal view of left mandible, scale bar = 0.5 mm. 10. Dorsal view of right mandible, scale bar = 0.5 mm. 11. Hypopharynx and labial palps, scale bar = 0.35 mm. 12. Antenna, scale bar = 0.57 mm. 13. Maxilla, scale bar = 0.32 mm. 14. Labrum, scale bar = 0.4 mm.

FIGURES 15–20. Peripus monodontus Chatzimanolis & Hightower. 15. Oblique view of prosternum and pronotal hypomeron, scale bar = 0.78 mm. 16. Meso- and metaventrite, scale bar = 1.19 mm. 17. Abdominal terga 3 and 4, scale bar = 1.15 mm. 18. Abdominal terga 5 and 6, scale bar = 1.06 mm. 19. Abdominal terga 7 and 8, scale bar = 0.90 mm. 20. Elytron, scale bar = 1.25 mm.

FIGURES 21–23. Aedeagus of P. brunkei Chatzimanolis & Hightower. 21. Dorsal view. 22. Lateral view. 23. Detail of paramere, ventral view.

FIGURES 24–26. Aedeagus of P. didontus Chatzimanolis & Hightower. 24. Dorsal view. 25. Lateral view. 26. Detail of paramere, ventral view.

FIGURES 27–29. Aedeagus of P. madrededios Chatzimanolis & Hightower. 27. Dorsal view. 28. Lateral view. 29. Detail of paramere, ventral view.

FIGURES 30–32. Aedeagus of P. monodontus Chatzimanolis & Hightower. 30. Dorsal view. 31. Lateral view. 32. Detail of paramere, ventral view.

FIGURE 33. Distribution map of Peripus Chatzimanolis & Hightower: P. brunkei Chatzimanolis & Hightower (squares); P. didontus Chatzimanolis & Hightower (stars); P. madrededios Chatzimanolis & Hightower (circles); and P. monodontus Chatzimanolis & Hightower (triangles).