Photinopygus Chatzimanolis 2021
Creators: name: Chatzimanolis, Stylianos
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Photinopygus

description: Photinopygus Chatzimanolis, 2021
(Figs. 1–234)
Photinopygus Chatzimanolis, 2021: 97.
Type species: Staphylinus calidus Erichson, designated by Chatzimanolis 2021.
Species included: P. akrodontis, P. alloportokalis, P. apicalis, P. assingi, P. calidus, P. chapareanus, P. chryselytros, P. chrysopygus, P. chrysurus, P. cotopaxi, P. corcovadoensis, P. cyanelytrius, P. cyanipennis, P. dimidiatus, P. faustus, P. haemorrhoidalis, P. hilaris, P. iopterus, P. janthinipennis, P. koptopeos, P. mexicanus, P. mirabilis, P. morosus, P. punctatus, P. rufipennis, P. sapphirinus, P. schedonapicalis, P. tepidus, P. thafmasios, and P. viridipennis.
Diagnosis: Modified from Chatzimanolis 2021. Photinopygus can be distinguished from all other genera in Xanthopygina based on the combination of the following characteristics: head shape rectangular; posterior margin of head slightly extended posteriad on each side of the neck (except in P. corcovadoensis, P. mirabilis and P. thafmasios, with posterior margin of head more or less at the same level with neck border); antennomeres 1–5 elongate (except in P. tepidus antennomeres 4–5 quadrate, and in P. akrodontis and P. chrysurus, antennomere 5 subquadrate); labial palpomere 3 not securiform; medium size eyes (eye length between 1/2 and 3/4 length of head); superior marginal line of pronotal hypomeron not continuing to anterior margin; postcoxal process present; pronotum with sparse micropunctures but no microsculpture of transverse lines visible at 70x magnification; mesoscutellum without dense micropunctures; mesoventral process narrow and rounded; metatarsi with setose dorsal surface; tergites 3–4 (at minimum, some species 3–5) with arch-like carina; and sternite 7 in males with emargination at posterior margin. While this may seem like a complex and large combination of characters, there are multiple species in Oligotergus Bierig, Styngetus Sharp, Xenopygus Bernhauer, and Zackfalinus Chatzimanolis that can be confused with Photinopygus. Species currently in Photinopygus used to be in Xanthopygus sensu Herman 2001, and perhaps there is still some confusion among rove beetle taxonomists on how to tell these two genera apart. Chatzimanolis (2021) provided a detailed comparison between these two genera (see table 2 in Chatzimanolis 2021) but most species of Photinopygus can be easily distinguished from Xanthopygus by the shape of the head (posterior margin of head slightly extended posteriad on each side of the neck; in Xanthopygus posterior margin of head more or less at the same level with neck boarder) and the teeth on the left mandible (one bicuspid tooth; in Xanthopygus left mandible with two teeth separated by deep emargination). From a citizen science point of view (i.e., iNaturalist), almost all Xanthopygina with black/dark brown head and pronotum and vivid metallic blue-green elytra are Photinopygus, but of course one should check the characters above to be certain.
Description. Habitus as in Figs. 7, 15, 23, 31, 40, 48, 56, 64, 71, 78, 86, 94, 101, 109, 116, 124, 131, 139, 146, 153, 161, 169, 177, 184, 191, 198, 206, 213, 220, 227. Body medium-sized, forebody 4.7–8.9 mm, without long bristle-like setae. Head shape rectangular; head shorter than pronotum. Eye size medium, between 2/5 and 2/3 length of head. Postclypeus, in comparison to frons, not deflexed; anterior margin more or less straight. Middle of epicranium impunctate but with microsculpture. Postmandibular ridge present laterally; with deep punctures demarcating raised postmandibular ridge present. Gular sutures not joined before neck, extended close to each other at base of head capsule. Posterior margin of head slightly extended posteriad on each side of the neck (except in P. corcovadoensis, P. mirabilis and P. thafmasios). Nuchal ridge incomplete dorsally. Neck disc without or with sparse punctures.
Antennae (Figs. 10, 18, 26, 34, 43, 51, 60, 67, 74, 82, 89, 97, 104, 112, 119, 127, 134, 142, 149, 157, 164, 172, 180, 187, 194, 201, 209, 216, 223, 230) with relative width of antennomere 1 equal or slightly wider than 2; antennomere 1 in comparison to antennomere 2 twice as long or longer.Antennomeres 3 2.5 times as long as wide or less; antennomere 3 with tomentose pubescence absent (except P. corcovadoensis); antennomere 4 with tomentose pubescence present (faint in P. mirabilis, P. thafmasios); antennomeres 4–10 cylindrical in shape; antennomeres 5–10 without club; antennomeres 7–10 symmetrical, transverse or subquadrate; antennomere 6–10 with curved, distinctly longer and thicker subapical setae than other macrosetae, forming a circlet; antennomere 11 in males subequal to 10.
Mouthparts with labrum having broadly U-shaped emargination, lobes strongly separated. Mandibles (Figs. 1–2) with relative length typical (i.e., closed mandible not extending beyond margin lateral margin of head); without asymmetrical torsion. Mandibles in dorsal view curved from apical half; in lateral aspect straight; left mandible with bicuspid tooth (except single tooth in P. haemorrhoidalis); right mandible with one tooth. Maxilla (Fig. 3) with galea much shorter than palpus; maxillary palpus with palpomere 3 shorter than 2; palpomere 4 longer than 3; palpomere 4 not dilated. Labial palpus (Fig. 4) with palpomere 3 widest before apex; palpomere 3 without long dense setae on entire lateral sides. Ligula small, entire. Mentum with alpha seta present; hypostomal cavity present; moderately delimited.
Pronotum with shape of lateral margins in dorsal view posteriad of midpoint varied; 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 pattern variable; with sparse micropunctures but without transverse lines of microsculpture; without coarse punctures impressed in flange at posterior angle of pronotum. Hypomeron with superior marginal line not 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. Superior and inferior marginal lines produce anterolateral angles parallel to one other. Postcoxal process present. Basisternum (Fig. 5) slightly longer than furcasternum; basisternum with pair of macrosetae, situated far from anterior margin of prosternum.
Elytra not reduced; hind wings present; hind wing venation with veins CuA and MP4 fused in one vein. Elytra setae not reduced, easily seen at low magnification; without patches of white setae. Elytra without contiguous polygon-shaped meshed microsculpture. Mesoscutellum with dense cluster of punctures medially, without dense micropunctures. Mesoventrite (Fig. 6) with apex of intercoxal process narrow and rounded. Metepisternum covered with punctures or impunctate area less than 1/3 (except P. mirabilis, P. thafmasios).
Legs 5-5-5; profemora without lateroventral apical spines; protarsi with modified pale (adhesive) setae ventrally; protarsi with tarsomeres 1–4 dorsoventrally flattened. Mesocoxae strongly separated, intercoxal area on approximately same plane as both meso and metaventrital processes. Metacoxae without coxal shield; with 4 or less spines on posterior surface. Metatibia without thick and long apical spurs but smaller spurs present; with spines. Meso/metatarsi without asymmetrically lobed tarsomeres 1–4; tarsomeres 3–5 of metatarsi dorsally setose (setae not restricted to marginal series). Pretarsal claws with empodial setae.
Abdomen with lateral sides in dorsal view more or less parallel-sided; protergal glands with well-developed acetabula. Anterior basal transverse carina on tergites 3 and 4 without pair of accessory ridges; tergite 3 without posterior basal transverse carina; tergites 3–4 (some species 3–5) with curved carina (arch-like) on disc; tergite 5 without pair of accessory ridges on anterior basal transverse carina; center of tergite 5 with punctation; posterior half of tergite 5 in lateral view not appearing bulging. Sternite 3 with straight to arcuate basal transverse carina medially; basal transverse carina laterally not sinuate. Sternite 4 without basal transverse carina medially. Males with secondary sexual structures (medial emargination) present on sternites 7 and 8; with or without porose structure. Aedeagus with long median lobe and single paramere; paramere with sensory peg setae. Spermatheca not sclerotized.
Informal species groups
I do not designate formal species groups since there is not a comprehensive phylogeny for the genus (see Discussion for more details). Species were kept in alphabetical order below but for the ease of identification, the following informal species groups are proposed:
1. Convex pronotum species group.
In this group the lateral margins of pronotum in dorsal view posteriad of midpoint are convex. Species included: P. apicalis, P. calidus, P. cyanipennis, P. hilaris, and P. schedonapicalis.
2. Concave pronotum species group.
In this group the lateral margins of pronotum in dorsal view posteriad of midpoint are concave. Species included: P. chryselytros, P. chrysopygus, P. cotopaxi, P. cyanelytrius, P. haemorrhoidalis, P. iopterus, P. janthinipennis, P. mexicanus, P. punctatus, P. sapphirinus, and P. viridipennis.
3. Narrow pronotum species group.
In this group the lateral margins of pronotum in dorsal view posteriad of midpoint are strongly converging. Species included: P. akrodontis, P. alloportokalis, P. assingi, P. chapareanus, P. chrysurus, P. dimidiatus, P. faustus, P. koptopeos, P. morosus, P. rufipennis, and P. tepidus.
4. Mirabilis species group.
In this group, the species can be readily identified by the rainbow-like coloration of the elytra. Species included: P. mirabilis and P. thafmasios.
5. Corcovadoensis species group.
Species included: P. corcovadoensis.
description: Published as part of Chatzimanolis, Stylianos, 2023, A revision of the genus Photinopygus Chatzimanolis (Staphylinidae: Xanthopygina), pp. 1-100 in Zootaxa 5292 (1) on pages 7-9, DOI: 10.11646/zootaxa.5292.1.1, http://zenodo.org/record/7959518