Revision of Chinese Phorocardius species (Coleoptera, Elateridae, Cardiophorinae)

Abstract The Chinese species of Phorocardius Fleutiaux, 1931 have been studied and six species are described as new: P.alterlineatus Ruan & Douglas, sp. nov.; P.flavistriolatus Ruan & Douglas, sp. nov.; P.minutus Ruan & Douglas, sp. nov.; P.rufiposterus Ruan & Douglas, sp. nov.; P.yunnanensis Ruan & Douglas, sp. nov.; and P.zhiweii Ruan, Douglas & Qiu, sp. nov. Lectotypes are designated for Cardiophoruscomptus Candèze, 1860, Cardiophoruscontemptus Candèze, 1860, Phorocardiusmagnus Fleutiaux, 1931, and Cardiophorusmanuleatus Candèze, 1888. The holotype is identified for Cardiophorusyanagiharae Miwa, 1927. Phorocardiusflorentini (Fleutiaux, 1895) and P.manuleatus (Candèze, 1888) are newly reported from China; P.comptus (Candèze, 1860) is excluded from the Chinese fauna. A key to the 11 Phorocardius species known from China is given. Phorocardius is newly recorded from deep within the Palearctic Region. The procoxal cavities of P.rufiposterus Ruan & Douglas, sp. nov. are closed, which is different from all other species of Phorocardius. An annotated checklist of the 21 Phorocardius species of the world is provided. Additionally, Phorocardiuscontemptus (Candèze, 1860), comb. nov. is transferred from Cardiophorus to Phorocardius; four species are transferred from Phorocardius to Displatynychus: Displatynychusbombycinus (Candèze, 1895), comb. nov., Displatynychuspakistanicus (Platia & Ahmed, 2016), comb. nov., Displatynychussobrinus (Laporte, 1840), comb. nov., and Displatynychustibialis (Platia & Ahmed, 2016), comb. nov.


Introduction
Phorocardius Fleutiaux, 1931 is a small Asian genus of elaterids with 15 species known previously (Douglas et al. 2018), placed in the subfamily Cardiophorinae Candèze, 1859(Fleutiaux 1931Douglas 2017;Douglas et al. 2018). Fleutiaux (1931) established Phorocardius and its two subgenera for Cardiophorinae with tarsal claws bidentate near their apices. Subsequently, Fleutiaux (1947) revised eight species from French Indo-China (Vietnam, Laos, and Cambodia). Since 1947, only a few new studies have been published: Platia (2015) and Platia and Ahmed (2016) described new species from Pakistan and Maldives respectively; and Douglas (2017) redefined the genus based on a phylogeny using adult morphological characters.
Previously, Phorocardius included a second subgenus: Diocarphus Fleutiaux, 1947. Diocarphus was recognized by the reduced ventral apex of the tarsal claw and more pronounced pronotal lateral carina "sutures inferieures" in comparison to subgenus Phorocardius. However, Douglas (2017) found Phorocardius polyphyletic and elevated Diocarphus to genus status with diagnoses including procoxal cavity closure and female internal genitalic structures.
With only three species previously known (Cate et al. 2007), the Phorocardius fauna of China remained little known. In this paper, we study the taxonomy of Chinese Phorocardius and describe six new species. Additionally, we designate lectotypes for Cardiophorus comptus Candèze, 1860, Cardiophorus contemptus Candèze, 1860, Phorocardius magnus Fleutiaux, 1931, and Cardiophorus manuleatus Candèze, 1888 and the holotype of Cardiophorus yanagiharae  is identified. These were designated (or identified) to fix species concepts and to ensure their universal and consistent interpretation.

Materials and methods
Observations of the habitus and diagnostic characters were made using a NIKON SMZ645 stereo microscope and a NIKON E100 optical microscope. Digital images were taken using a CANNON D800 camera attached to a CANNON MP-E 65 mm Lens or NIKON E100 microscope. Before dissection, dry specimens were submerged in hot water for 10 minutes. Male genitalia were subsequently dissected and glued to card papers pinned under the specimens. Female genitalia were submerged in hot 10% NaOH solution for approximately 1 minute, surrounding tissues were cleared, mounted in glycerin on slides for photography, and then glued to card papers pinned under the specimens. Specimen measurements were made as shown in Fig. 1.
Specimens were identified using species identification keys (e.g., Candèze 1860;Fleutiaux 1947), and additional species descriptions. We were able to examine type material for most species only occurring outside the study area. The remainder were excluded from the Chinese fauna based on literature alone. Details are presented in Results: Checklist and synonymy of world Phorocardius species. bidentate to tridentate; apical palpomere of maxillary hatchet-shaped or polygonal, longer than wide. Labrum evenly convex. Area between each antennal fossa and adjacent compound eye unsculptured, or with groove or pit(s).
Prothorax. Pronotum in dorsal view with sides straight, convex, or sinuate near posterior fourth. Pronotum with punctures circular or oval on dorsal surface, punctures larger and deeper on disc and anterad, sparser and smaller posterad; sublateral incisions and carinae present (with carinae obsolete, see Fig. 1B); posterior edge of pronotum sinuate, with three apices mesally (tridentate antescutellar lobe, i.e., the median basal lobe in Douglas 2003); lateral carina on hypomeron not present (or not distinguishable from hind angle carina); posterior angles not truncate dorsally; hind angle carina not extending anterad beyond posterior third; anterior angles obtuse and not projecting anterad, posterior angles straight-sided, slightly convex or strongly bulged laterally (e.g., Fig. 17C, D), parallel to weakly divergent; hypomeral hind edges rectangularly emarginate (Fig. 12B, indicated by arrow) immediately meso-ventrad of posterior angles. Procoxal cavities open or closed. Prosternum with sides concave in ventral view; anterior prosternal lobe long, covering labium when head is retracted; prosternal process curved dorsad or not, ventral surface convex to flat, carinate laterally or not; prosternal process approximately twice as long as procoxal cavity length.
Legs. Tarsi simple; tarsomere V longest; tarsal claws each with two apices, apices separated in apical half of claw, with ventral surface of claw sinuate basad of ventral apex, ventral apex much smaller than to almost as large as dorsal apex. Metacoxal plate large, covering 1/2-2/3 of metatrochanter with legs withdrawn.
Male genitalia. Urosternite VIII straight to anteriorly pointed, with two lateral posterior lobes, without median posterior lobe; abdominal segment IX with tergite and sternites articulated at sides. Aedeagus: paramere, with or without preapical lateral expansion (Fig. 1G), with preapical ventral (or apical mesal) expansion in some ( Fig. 1H), apical mesal callus (in most oval, disc-like, with sclerotized sharp edge; see Figs 1G, 4G) present or absent, lateral side with two setae near apex; aedeagus with basal strut ca. 0.8-1.0 × median lobe length; in ventral or dorsal view, median lobe tapered, parallel-sided or apically expanded, apex pointed to rounded to blunt; in lateral view, apex of median lobe bent abruptly dorsad in some (e.g., in P. magnus); in lateral view, paramere and median lobe bent 30-45° ventrad near mid-length or apical third.
Female. Body of same or different color as male, some slightly longer and wider than male. Antennae of some shorter than in male. Apex of abdominal ventrite V arcuate to truncate, with deep to shallow incision on each side (Figs 9D,E,20D), or with elongate deep invagination containing slender blade-like projection ( Fig.  15C) (in male: apex of abdominal ventrite V simple, arcuate to slightly sinuate, without incision or invagination). Ovipositor with baculae present; coxites heavily sclerotized. Bursa copulatrix without sclerotized spermathecae; with paired distal and spine-bearing proximal sclerites, proximal sclerites ovoid with emarginate base to elongate and parallel-sided; distal sclerites claw-like and not fused, gradually narrowed to pointed apex; spermathecal gland duct with row of diverticulae in some, base not sclerotized inside bursa (Douglas 2017); anterior end of bursa with a single pedunculate sac.
Checklist and synonymy of world Phorocardius species
Remarks. This species is unlikely to truly belong to Phorocardius because the pronotal lateral carina diverges from the hind angle carina. The distinctive arcuate parameres with bulbous apices distinguish this species from those of any Phorocardius examined by the authors. However, P. maldivianus was not transferred outside Phorocardius because we were unable to make a well-supported generic placement without data from female morphology or DNA.

Distribution. Cambodia (Candèze 1878).
Remarks. Type material examined (RBINS, photograph examined): the head is brown-black, the remainder of the body is brown throughout including the legs and basal four antennomeres (remaining antennomeres are lost), and pronotum with lateral carina diverging from hind angle carina. This species is probably not Phorocardius because of having a pronotal lateral carina. It was not transferred outside Phorocardius because we were unable to make a well-supported generic placement without data from female morphology.

Species transferred from Phorocardius to Displatynychus
The following Phorocardius species are shown, in their original publications (or in the examined type specimens) to have the diagnostic characters of Displatynychus and not Phorocardius. While these species have Phorocardius-like claws, they are shown to have the following diagnostic characters of Displatynychus: pronotal lateral carina distinct from hind-angle carina and hidden in dorsal view by overhanging edge of upper part of pronotum; and female bursa copulatrix with base of spermathecal gland duct sclerotized into complex tube-like structure.
Recently described Phorocardius species from south Asia (P. maldivianus Platia, 2015;P. pakistanicus Platia & Ahmed, 2016;P. tibialis Platia & Ahmed, 2016) could be distinguished from all Chinese Phorocardius species using the species descriptions. We recommend the transfer of P. pakistanicus and P. tibialis to Displatynychus Ôhira, 1987. However, we do not recommend the transfer of P. maldivianus outside Phorocardius because we were unable to make a well-supported generic placement without data from female morphology or DNA. Elytra black, with metallic blue to purple luster; paramere with preapical lateral expansion in ventral view, (Fig. 7E), with sides rounded, facing laterally, without apical mesal callus; prosternal process with outline of ventral apex rounded-rectangular in ventral view (Fig. 25C)  Posterior angle of pronotum with lateral edge convex, strongly bulged laterally in dorsal view (Fig. 17C, D). Median lobe of aedeagus with apex not dilated or bent dorsad in lateral view (Fig. 17G)  Distribution. China (Shaanxi, Hubei, Sichuan, Guangxi). Differential diagnosis. Body length greater than 7.0 mm; integument dark brown (non-metallic), each elytron with three separate yellow stripes along interstriae III, V, and VII. Prothorax: procoxal cavities open. Prosternal process not strongly narrowed posterad to ventral apex in ventral view, with apex truncate to slightly rounded. Pterothorax: scutellar shield with posterior apex pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere without preapical lateral expansion or apical mesal callus. Female: apex of last abdominal ventrite (ventrite V) simple, not emarginate at apex. This species is unique in Phorocardius in its alternating dark and yellow stripes on the elytra, the aedeagus is also unique due to its simple shape: without any preapical lateral expansion (but with ventral hook-like expansion).
Phorocardius alterlineatus Ruan & Douglas, sp. nov. resembles P. flavistriolatus Ruan & Douglas, sp. nov. and P. comptus (Candèze, 1860) in having longitudinal yellow maculation on the elytron, but it could be distinguished from the latter two species by the following characters. In P. alterlineatus Ruan & Douglas, sp. nov., aedeagus gradually narrowed from base to apex in lateral view; apex of median lobe narrowly rounded in ventral view; and each elytron with three slender longitudinal stripes present separately on interstriae III, V, and VII, which partly merged near base and apex; while in P. flavistriolatus Ruan & Douglas, sp. nov., in lateral view, aedeagus with equal breadth from base to apical fifth, only slightly narrowed at apical fifth; apex of median lobe truncate to broadly rounded in ventral view; and each elytron with a single broad stripe covering basal half of interstria IV and interstriae V-VII.
In Phorocardius alterlineatus Ruan & Douglas, sp. nov., the parameres of the aedeagus have apical lateral expansions in dorsal view and lack preapical ventral expansions in  Ruan & Douglas, sp. nov. A male habitus, paratype (Shaanxi, Zhashui County, Niu-bei-liang), dorsal view B female habitus, paratype (Shaanxi, Shan-luo, Zha-shui County, Ying-pan township), dorsal view C female habitus, paratype (same individual as in inset B), ventral view D female abdominal sternite VIII E ovipositor, dorsal view (paratype), arrow indicating coxites F distal (upper side) and proximal sclerites of bursa copulatrix (the two proximal sclerites are viewed from different angles, resulting in different shapes shown above) G aedeagus, dorsal view (paratype, dry), arrow indicating apex of paramere H aedeagus, lateral view (paratype, dry), arrow indicating apex of paramere. I aedeagus (mounted in glycerin), dorsal view (paratype). lateral view; body brown-black; and each elytron with three slender longitudinal stripes present separately on interstriae III, V, and VII, with pale stripes partly joined near base and apex; while in P. comptus (Candèze, 1860), the parameres lack apical lateral expansions in dorsal view and have preapical ventral expansions in lateral view; body black; and a single broad longitudinal stripe covering four interstriae (interstriae V-VIII).
Description. (Based on all type specimens) Body brown-black. Each elytron with three separate longitudinal yellow stripes along interstriae III, V, and VII, partly joined  Ruan & Douglas, sp. nov. A male head, frontal view (paratype) B male pronotum, dorsal view (paratype) C male on foliage (indoors; holotype) D female head, frontal view (paratype) E female pronotum, dorsal view (paratype) F female on foliage (indoors; paratype; collected from Shaanxi, Yan-an). near base and apex; stripes on mid-length of elytron absent or reduced in some females. Elytral stripes pale yellow in most males, orange in females. Antenna brown to dark brown, with first two antennomeres paler. Legs yellow-brown to brown, darker on tarsomere V and tibial apex. Body with yellow pubescence.
Head. Frons and vertex with interspaces between punctures 0.5-1.0 × average puncture diameter; punctures slightly sparser at centre of vertex. Frontal carina convex in frontal view. Distance between eyes to width of eye ratio 4. 2-4.5. Antenna with last antennomere entirely reaching beyond posterior angle of pronotum in male, only reaching to posterior angle in female. Antenna length to body length ratio, in male 0.39-0.41; in female 0.35-0.37. Proportions of antennomere lengths (male): 100 (scape); 53-58; 75-81; 82-83; 81-85; 83-88; 84-86; 85-90; 85-90; 85-90; 100-130. Prothorax. Pronotum in dorsal view: sides evenly convex from anterior edge to constriction near posterior fourth, widest near mid-length; posterior angles with lateral sides almost straight, not bulged; surface with deep punctures, interspaces between punctures 0.5-1.0 × average puncture diameter. In ventral view, ventral surface of prosternal process with sides carinate and slightly and gradually narrow from anterior to posterior end, with apex almost truncate (Fig. 25A). In lateral view, prosternal process with ventral surface curved slightly dorsad; with posterior end (i.e., area between ventral and dorsal apices (sensu Douglas 2011Douglas , 2017) slightly concave to almost straight (  2G); in lateral view slender, gradually narrowing from base to apex. Median lobe in ventral view narrowed from base to mid-length; parallel-sided and slender on apical half, apex narrowly rounded. Median lobe in lateral view gently and evenly curved ventrad from base to apex, apex rounded. Paramere in dorsal view: wide from base to mid-length, gradually narrowed beyond mid-length, angulate at apex; preapical lateral expansion and apical mesal callus absent; width 2.5-3.5 × median lobe width (measured at mid-length of paramere and median lobe respectively). Paramere in lateral view: slender, gradually narrowed and evenly curved ventrad from base to apex; apex with sharp hook-shaped preapical ventral expansion (Fig. 2H, indicated by blue arrow).
Type material. Holotype. ♂ (SZPT), labels: 1) Shaanxi, Yan-an (延安), Yan-an University, Yao-yuan Holiday Hotel, leg. Yongying Ruan et al. 2018-VI-22-23  Remarks. Specimens examined were from low to middle elevations (0-2500 m), temperate to subtropical mountain evergreen forests in central and south China. Specimens of this species were collected at different environments using variable collecting methods, including flight interception trap (in forests), malaise trap (in forests), sweeping (on shrubs), and light trap (near a hill in suburbs of a city). Specimens came to light traps, or were caught by sweep-netting vegetation in daylight. This suggests that this species is nocturnal and diurnal. This species is known from central China (i.e., the boundary between the Palearctic and Oriental Regions), only one specimen examined is from south China (Oriental Region).
In the field, this beetle was spotted running on multiple plants. We have observed one live adult in the field with an aphid in its mouthparts. However, individuals taken back to containers in the laboratory were not observed to feed on live aphids presented there. Further evidence is required to learn the adult and larval feeding habits of this species.
Etymology. The name of this species is derived from the yellow stripes on its elytra. Distribution. Central China (Henan, Shaanxi, Sichuan). Differential diagnosis. Body length 7.0-12 mm; integument dark brown (nonmetallic), each elytron with a longitudinal yellow stripe covering basal half of interstria IV and interstriae V to VII. Prothorax: procoxal cavities open; prosternal process not strongly narrowed from anterior base posterad to ventral apex in ventral view, ventral apex straight to slightly concave. Pterothorax: scutellar shield with posterior apex pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere without preapical lateral expansion, with apical mesal callus present. Female: apex of last abdominal ventrite (ventrite V) simple, not emarginate at apex.
This species is unique in its longitudinal yellow elytral maculation, aedeagus with apical fourth of paramere compressed and gradually narrowing towards apex, and with apical mesal part of paramere turned ventrad (Fig. 6).
Phorocardius flavistriolatus Ruan & Douglas, sp. nov. resembles P. comptus in having a longitudinal yellow stripe on each elytron. They can be separated by the following combination of characters: in P. flavistriolatus Ruan & Douglas, sp. nov., each elytron with a longitudinal yellow stripe covering basal half of interstria IV and interstriae V-VII, interstria VIII is entirely brown-black; female with pronotum not strongly enlarged, sides of pronotum only gently convex, width of pronotum to elytra ratio ca. 0.83-0.85, and proximal sclerites of bursa copulatrix with deep basal emargination; while in P. comptus, each elytron with a longitudinal yellow stripe covering interstriae V-VIII, interstria IV is entirely black; female with pronotum strongly enlarged, sides of pronotum strongly convex, width of pronotum to elytra ratio ca. 0.90-0.92 (measured in two specimens), and proximal sclerites of bursa copulatrix without basal emargination or with emargination narrower than 1/3 width of sclerite. The aedeagus of P. flavistriolatus Ruan & Douglas, sp. nov. has parameres with no apical or preapical expansion, with apical mesal callus present; while P. comptus has acute apical lateral expansions, without apical mesal callus.
Phorocardius flavistriolatus Ruan & Douglas, sp. nov. is similar to P. alterlineatus Ruan & Douglas, sp. nov. in having yellow stripes on the elytra. However, they can be separated by the following characters: in P. flavistriolatus Ruan & Douglas, sp. nov., in lateral view, aedeagus with equal breadth from base to apical fifth, only slightly narrowed at apical fifth; apex of median lobe truncate to broadly rounded in ventral view; and each elytron with a single broad stripe covering basal half of interstria IV and interstriae V-VII; while in P. alterlineatus Ruan & Douglas, sp. nov., aedeagus gradually narrowed from base to apex in lateral view; apex of median lobe narrowly rounded in ventral view; and each elytron with three slender longitudinal stripes present separately on interstriae III, V, and VII, which partly merged near base and apex. Description. (based on all type specimens) Body brown-black, matt; antennae and legs paler, brown to yellow-brown. Head brown-black. Pronotum brown-black, with posterior edge brown. Scutellar shield brown-black. Elytra brown-black, each elytron with a longitudinal yellow stripe covering basal half of interstria IV and interstriae V to VII, epipleura orange at base, dark orange on remainder. Ventral surface entirely brown-black. Body with yellow-grey pubescence.
Head. Frons and vertex punctures with interspaces 0.5-1.0 × average puncture diameter; punctures sparser at centre of vertex. Frontal carina in frontal view convex, not straight. Distance between eyes to width of eye ratio 3.6-3.9. Antenna barely extending beyond posterior angle of pronotum. Antenna length to body length ratio, in male 0.39-0.41, in female 0.36-0.38. Proportions of antennomere lengths: 100 (scape); 52-60; 71-73; 71-73; 72-76; 72-76; 72-76; 73-78; 73-78; 73-78; 90-100. Prothorax. Pronotum in dorsal view: sides evenly convex from anterior edge to constriction near posterior fourth, nearly straight at posterior fourth, widest near posterior third; posterior angles with lateral sides almost straight, not bulged; surface with interspaces between punctures 1-2 × average puncture diameter. In ventral view, ventral surface of prosternal process with sides carinate and slightly and gradually narrow from anterior to mid-length, parallel from mid-length to apex, with apex slightly convex to almost straight. In lateral view, prosternal process with ventral surface curved slightly dorsad; posterior end weakly concave or not ( Robust from ventral and lateral views. Median lobe in ventral view with ridge along midline; narrowed from base to basal third, parallel-sided from basal third to apex, apex broadly rounded to truncate. Median lobe in lateral view curved ventrad from base to apex, apex rounded with angulate dorsal and ventral corners (Fig. 4P). Paramere in ventral view: robust, widest near mid-length, gradually narrowing towards apex, apical part with mesal side turned ventrad in varying degree ( Fig. 6), result in different shapes in ventral view; apex with apical mesal callus present (Figs 4O, 6), without preapical lateral expansion; width 1.5-2.5 × median lobe width (measured at mid-length of paramere and median lobe respectively). Paramere in lateral view ( Fig. 4N): robust; apical fourth compressed and turned ventrad; preapical ventral expansion obtuse, not sharp hook-shaped (Fig. 4P).
Female. Color pattern like male. Apex of abdominal ventrite V convex (Fig. 26B). Proximal sclerites of bursa copulatrix wide and somewhat diamond-shaped (Fig. 4Q), with concave basal edge, flat mesal edge and acute apex; each sclerite with seven or eight large spines arranged along mesal edge, and with 10-15 smaller scattered spines on disc.
Type material. Holotype. male (SZPT), labels: 1) Henan Province, Nan-Yang City, Bao-tian-man National Nature Reserve (  Remarks. Although there are variations in the shape of aedeagi, all the male specimens are identical in color patterns and other external structures. Females are stable in both external characters and the shape of sclerites of bursa copulatrix. Variations are found even in the specimens collected at the same place and time. For instance, Fig. 4G, H shows aedeagi of two externally identical males collected on the same day and same locality in Shi-mian, Sichuan; the two aedeagi are different from each other in the basal width and the shape of the apex of paramere. In Fig. 4J, K, these are aedeagi of two males collected on the same date and same locality in Lu-ding County, Sichuan; the two aedeagi are different from each other in the basal width, median lobe shape, and the shape of the apex of paramere. Additional mitochondrial DNA sequence comparisons would be useful to further test species limits. Variation of the shape of aedeagus: in some cases, the base of the aedeagus is much narrower (e.g., Fig. 4G, J). Variations in the paramere: apical half of paramere of aedeagus compressed; additionally, apical part with mesal side turned ventrad to a varying degree (Fig. 6), resulting in different shapes in ventral view. In ventral view, when the turning is minimal, the apical part of paramere is nearly horizontal to the observers, therefore the paramere apex is broad and gradually narrowed in appearance (e.g., Fig. 4F, G); but, when the turning is stronger, the paramere apex would be nearly vertical to the observers, in which circumstance the paramere apex we see is acute and abruptly narrowed (e.g., Fig. 4K, M). Variations in the median lobe: in ventral view, apex usually truncate, in rare cases broadly rounded (Fig. 4K, L), lateral sides very slightly concave in rare cases (Fig. 4K).
Most specimens of this species were collected from low to middle elevations (ca. 500-2500 m) in central China on the boundary of the Oriental Palearctic Regions.
Based on collecting information, it inhabits mountainous areas with evergreen forest and temperate to subtropical climate. Specimens were collected at light traps, indicating nocturnal activity. Specimens collected by sweep-netting indicate their presence on vegetation during daylight. Differential diagnosis. Body length greater than 7.0 mm; pronotum and hypomeron red, elytra black with metallic blue to purple luster. Prothorax: procoxal cavities open; prosternal process not strongly narrowed from anterior base posterad to ventral apex in ventral view, with apex convex. Pterothorax: scutellar shield elongate, with posterior apex pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere with preapical lateral expansion present, apical mesal callus absent. Female: apex of last abdominal ventrite (ventrite V) simple, not emarginate at apex.

Phorocardius florentini
This species is distinctive for its elytral color: black with metallic blue to purple luster. Phorocardius florentini (Fleutiaux, 1895) resembles P. zhiweii Ruan, Douglas & Qiu, sp. nov. in its entirely red pronotum and metallic elytra. P. florentini (Fleutiaux, 1895) can be easily separated from P. zhiweii Ruan, Douglas & Qiu, sp. nov. by the following characters. In P. florentini (Fleutiaux, 1895): aedeagus strongly narrowed from mid-length to apex in lateral view; in dorsal view, paramere with preapical lateral expansion minute, acute to rounded, facing laterally, with apical mesal callus absent; scutellar shield elongate (width to length ratio: 0.81-0.86); and elytra black, with metallic blue to purple luster; while in P. zhiweii Ruan, Douglas & Qiu, sp. nov., the aedeagus is only slightly narrowed from mid-length to apex in lateral view; in dorsal view, paramere with preapical lateral expansion absent, apical mesal callus present, apex narrow and slightly bent laterad; scutellar shield not elongate (width to length ratio: 1.0); and elytra metallic green with slight purple luster.
Description. (Based on holotype and three non-type specimens examined) Body black, red and metallic blue-purple ( Fig. 7A-D). Pronotum and hypomera red. Elytra black, with metallic blue to purple luster. Head brown-black to black; antennae brownblack. Prosternum red, black or mixed with red and black; meso-and meta-sternum black; abdominal ventrites black; legs brown-black to black. Body with short, yellow pubescence; brown setae also present on disc of pronotum.
Head. Frons and vertex punctures with interspaces 0.5-1 × average puncture diameter; punctures sparser at centre of vertex, with interspaces 1.5-2 × average  (Fleutiaux, 1895 puncture diameter. Frontal carina in frontal view convex, not straight (Fig. 7I). Antenna with last antennomere not reaching beyond posterior angle of pronotum. Distance between eyes to width of eye ratio 3.8-3.9. Antenna length to body length ratio, in male 0.36-0.38; in female 0.37-0.39. Proportions of antennomere lengths (male): 100 (scape); 60-65; 75-83; 75-83; 75-83; 78-85; 81-86; 85-90; 85-90; 81-85; 90-100. Prothorax. Pronotum in dorsal view: sides evenly convex from anterior edge to constriction near posterior end, widest near mid-length; posterior angles with lateral sides almost straight, not bulged; surface with interspaces between punctures 1-2 × average puncture diameter. In ventral view, ventral surface of prosternal process with sides carinate and slightly and gradually narrow from anterior to mid-length, parallel from mid-length to posterior end, with apex convex. In lateral view, prosternal process with ventral surface curved slightly dorsad, posterior end somewhat concave or not ( Robust from ventral and lateral views. Median lobe in ventral view slightly narrowed from base to basal third, parallel-sided from basal third to near apex, apex rounded and very slightly dilated. Median lobe in lateral view wide from base to mid-length, narrow from mid-length to apex; gently and evenly curved ventrad from base to mid-length, straight from mid-length to apex; apex rounded. Paramere in ventral view: wide and equal wide from base to apical third; abruptly narrowed from apical third to apex; preapical lateral expansion present, minute and rounded, facing laterally; apical mesal callus absent; paramere width 3-4 × median lobe width (measured at mid-length of paramere and median lobe respectively). Paramere in lateral view: robust, almost straight from base to mid-length, curved ventrad and narrowed from mid-length to apex; apex with hook-like preapical expansion with barb facing base.
Phorocardius magnus Fleutiaux, 1931 resembles P. unguicularis (Fleutiaux, 1918) in body color and size. They can be separated by the following combination of characters: in P. magnus Fleutiaux, 1931, aedeagus robust in lateral view (more than 4 × thicker at mid-length than at apical 1/5 of parameres); in ventral view, paramere slightly narrowed from base to apical fourth, apical fourth abruptly narrowed to 1/4 width at midlength, with hook-like preapical lateral expansion; pronotum with shallow punctures, interspaces between punctures 1-2.5 × average puncture diameter; and head with frontal carina straight in frontal view; while P. unguicularis (Fleutiaux, 1918) has aedeagus slender in lateral view, in ventral view paramere slightly widened from base to midlength, gradually narrowed from mid-length to apex, apex pointed and without preapical lateral expansion; pronotum with deep punctures, interspaces between punctures 0.3-1 × average puncture diameter; and head with frontal carina convex in frontal view.
Description. (based on photographs of eight type specimens and four non-type specimens) Body robust. Color entirely red-brown to brown throughout, including legs and antennae; pronotum slightly darker than remainder. Integument matt, with yellow pubescence.
Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia. Robust from ventral and lateral views (Fig. 8). Median lobe in ventral view gradually narrowing from base to apical third, parallel-sided near rounded apex. Median lobe in lateral view robust at base, curved ventrad and gradually narrowed from base to apical third, apical third slender, apex globose and recurved dorsad (Fig. 8G, indicated by arrow). Paramere in ventral view: robust, widest near mid-length (4-5 × wider than at apical fifth); width 1.5-2.5 × median lobe width (measured at mid-length part of paramere and median lobe respectively); apical fourth gradually narrowing towards apex, with a secondary lateral bulge present before apex (Fig. 8D-F, indicated by arrow); secondary lateral bulge turned and bent ventrad; preapical lateral expansion small, sharp, hook like; apical mesal callus absent. Paramere in lateral view: robust; parallel from base to mid-length, abruptly narrowed from mid-length to apical fourth, nearly parallel from apical fourth to apex; preapical ventral expansion absent, without hook-shaped structure.
Female. Color like male. Apex of abdominal ventrite V tri-lobed; with shape of middle lobe semicircular to longitudinal with apex rounded; deeply to gently incised between middle and lateral lobes (Fig. 9D-G). [In non-type specimens: proximal sclerites of bursa copulatrix ovoid (Fig. 8I) Fleutiaux, 1931Det. Ruan, 2018 Remarks. This species has the largest body size in Chinese Phorocardius species, with females up to 13.9 mm long and 4.5 mm wide.
Based on specimen information, this species inhabits low to middle elevations (0-1700 m) in south China and throughout Vietnam. It inhabits mountainous areas with subtropical to tropical climates and much rainfall. One specimen was collected in or near to tropical rain forest ("Xi-shuang-ban-na tropical rain forest"). Known from the Oriental Region only. ( (Candèze, 1888) is unique among Chinese Phorocardius species for its variable color pattern. Some individuals are entirely black to black-brown throughout body, resembling P. yanagiharae  and P. yunnanensis sp. nov.

Phorocardius manuleatus
This species can be differentiated from P. yanagiharae by the following combination of characters. In P. manuleatus: in ventral view, parameres of aedeagus with sides gently narrowed from mid-length to apex (not abruptly narrowed from apical third to near apex), with width 1.5-2 × that of median lobe (measured at apical fourth); and in dorsal view, pronotum with lateral sides of posterior angles almost straight, slightly convex (bulged) at posterior half in a few cases (e.g., in Fig. 11A); while in P. yanagiharae, in ventral view, paramere of aedeagus with sides abruptly narrowed from apical third to near apex, with width 2-3 × that of median lobe (measured at apical fourth); and in dorsal view, pronotum with lateral sides of posterior angles strongly bulged and convex (Fig. 18C, D).
This species can be differentiated from P. yunnanensis Ruan & Douglas, sp. nov. by the following combination of characters. In P. manuleatus, in ventral view, paramere of aedeagus narrow and slender near apex, with width to that of median lobe ratio 0.5-0.7 (measured at the area posterior of preapical lateral expansion); legs darker in apical half, not unicolor yellow-brown to brown; while in P. yunnanensis Ruan & Douglas, sp. nov., in ventral view, paramere of aedeagus wide and strong near apex, with width to that of median lobe ratio 1.0-1.2 (measured at the area posterior of preapical lateral expansion); and legs unicolor, entirely yellow-brown.
Distribution. China (Yunnan, new record), Myanmar (Candèze 1888), Laos (Fleutiaux 1931(Fleutiaux , 1947, Vietnam (Fleutiaux 1918(Fleutiaux , 1947. Description. (based on lectotype and 24 non-type specimens) Integument shiny, black with yellow in most, or entirely black to black-brown. Pronotum entirely black or orange with variable median black stripe (Fig. 11E). Ventral side of prothorax yellow, orange, black or orange with black prosternum. Elytra black, yellow, or black with orange spot at elytral bases. Mesosternum brown to black. Metasternum yellow to black. Abdominal ventrites yellow, black, or bicolored (I-IV orange, V yellow). Head red-brown to black. Antennae brown. Legs variably orange to yellow-brown from coxa to mid tibia, yellow-brown to brown from mid tibia to last tarsomere. Body with yellow pubescence.

Abdomen. Serrations on lateral edges of visible abdominal ventrites I-V absent.
Male genitalia. Robust in ventral view, slender in lateral view. Median lobe in ventral view gradually narrowing from base to near apex, then dilated to rounded apex. Median lobe in lateral view curved ventrad at base, straight from basal third to apex; apex broadly rounded. Paramere in ventral view: robust, width 3-4 × median lobe width (measured at mid-length of paramere and median lobe respectively), widest near mid-length; apical fourth gradually narrowing towards apex, with mesal side bent and turned ventrad in varying degree, result in slightly different shapes in ventral view; apex of paramere slender and sharp, with preapical lateral expansion acute, hook-like to rounded, facing laterally (Figs 10F, 11F, indicated by blue arrow), without apical mesal callus. Paramere in lateral view: slender, almost straight from base to mid-length, curved ventrad and gradually narrowed from mid-length to apex; apex obliquely truncate; preapical ventral expansion acute but not hook-like (Figs 10E, 11F, indicated by blue arrows).
Female. Body color like male. Apex of abdominal ventrite V convex, somewhat angulate (Fig. 26E). Proximal sclerites of bursa copulatrix ovoid-triangular shaped (Fig. 10I), basal edge almost without concavity: each with 9-11 large spines mainly on the convex mesal edge, 15-20 smaller spines on disc.  Remarks. This species is unusual for its extensively varied body color. The following three main patterns were found in examined specimens. Color pattern 1 (Fig. 10A, C): black on dorsum, with orange or yellow spot on base of each elytron; venter black before mesocoxae, orange from mesocoxae to abdominal ventrite IV, brown-black on abdominal ventrite V; antenna brown; and leg orange, yellow from coxa to mid-length of tibia in some, brown from mid-length of tibia to apex. Color pattern 2 (Fig. 11E): Figure 11. Phorocardius manuleatus Candèze (1888). A pronotum and scutellar shield, dorsal view B head, frontal view C punctation on disc of pronotum D punctation on vertex of head E color variation between four individuals; insets 2, 4, 6, 8 are the ventral views of 1, 3, 5, 7 F aedeagus, in dorsal view and lateral view, arrows indicating apices of parameres. head black; pronotum with different combinations and proportions of colors, orange at sides in most, black near midline and posterior; elytron black, yellow or mixed with brown and yellow; venter mixed with orange and black; and leg orange or yellow from coxa to mid-length of tibia, brown from mid-length of tibia to apex. Color pattern 3: dorsum and venter entirely black to black-brown, antennae brown, and legs yellowbrown on basal half, brown on apical half.
The aedeagus slightly varied in the apex shapes of the median lobe and parameres. In rare cases, the sides of the pronotum are dramatically wider and more robust (e.g., Fig. 11E 1 ). A comparison of specimens using mitochondrial DNA would be useful to test species boundaries.
Based on specimens from Yunnan, this species inhabits low to middle elevations (ca. 500-1200 m). Yunnan is mountainous, rainy, subtropical to tropical, with subtropical evergreen broad-leaf forest or tropical rain forest. Some of our specimens are collected from Xi-shuang-ban-na tropical rain forest. Known from Oriental Region only.
This species was treated as a subspecies of Phorocardius melanopterus (Candèze, 1878) by Fleutiaux (1931: 311). We have studied the photograph of the single type specimen of P. melanopterus [RBINS, label information: Coll. R. I. SC. N. B., CAMBODGE // Collection E. Candèze // n. sp. Melanopterus cdz., Cambodia // Cardiophorus melanopterus, Cd., dèt. E. Candèze // Type]. In that specimen, the head is brown-black, the rest of the body is entirely brown throughout including legs and basal four antennomeres (all other antennomeres are missing on the type specimen), and the pronotum with lateral carina diverging from hind angle carina. Its color is different from all known color patterns of P. manuleatus. Additionally, P. melanopterus probably does not belong to Phorocardius because of the presence of pronotal lateral carina (see checklist above).
Etymology. This species is named for its small body size. Distribution. China (Inner Mongolia). Differential diagnosis. Body length 5-7 mm. Prothorax: procoxal cavities open; prosternal process gradually narrowed posterad to ventral apex in ventral view, with apex narrowly rounded. Pterothorax: scutellar shield with posterior apex narrowly rounded. Tarsal claw with ventral apex smaller than dorsal apex. Male genitalia: paramere with apex pointed and bent laterad and ventrad, without preapical lateral expansion or apical mesal callus. Female unknown.
Phorocardius minutus Ruan & Douglas, sp. nov. is distinct for its small body size, color, and more robust appendages compared to other Chinese species. Its partly yellow elytra resemble P. flavistriolatus Ruan & Douglas, sp. nov., and P. comptus (Candèze, 1860). This species can be differentiated from P. flavistriolatus Ruan & Douglas, sp. nov. by the following characters: in P. minutus Ruan & Douglas, sp. nov., aedeagus with paramere apex claw-like, produced laterally; males are less than 6.3 mm in body length; and body brown, elytra yellow, with suture and lateral-basal edges near epipleura brown; while in P. flavistriolatus Ruan & Douglas, sp. nov., aedeagus with apex of paramere not claw like or produced laterally; males are longer than 7 mm; body black-brown; and elytra black-brown with two longitudinal yellow stripes.
P. minutus Ruan & Douglas, sp. nov. can be differentiated from P. comptus by the following characters: in P. minutus Ruan & Douglas, sp. nov., males are less than 6.3 mm in body length; and body brown, elytra yellow, with suture and lateral-basal edges near epipleura brown; while in P. comptus, males are longer than 7 mm; and body black, elytra black with two longitudinal yellow stripes.
Description. (Based on all type specimens) Dorsum matt. Head brown, with mouthparts red-brown to pale brown. Antennae pale brown. Pronotum brown, with posterior edge dark brown. Scutellar shield brown. Elytra yellow, with suture and lateral-basal edges near epipleura brown. Ventral surfaces brown, including hypomera. Epipleura brown. Legs pale brown to brown. Body with yellow pubescence.
Legs. Femora and tibiae thick. Length ratio of metatarsomeres I-V (excluding claws): 100; 66-76; 60-63; 45-48; 110-120. Claw with ventral apex much smaller than dorsal apex. Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia. Slender in ventral and lateral views. Median lobe in ventral view gradually narrowed from base to rounded apex. Median lobe in lateral view gently curved ventrad, apex rounded. Paramere in ventral view: wide, width 2-2.5 × median lobe width (measured across the mid-length of paramere and median lobe respectively), widest near apical third, abruptly narrowed near apex; apex pointed, bent laterally; preapical lateral expansion and apical mesal callus absent. Paramere in lateral view: robust, almost straight from base to mid-length; bent ventrad from mid-length to apex; apex pointed and facing ventrad, claw-like, but not hooked.  Remarks. The aedeagus of one paratype collected from 'Ke-you-zhong-qi, Inner mongolia' is slightly different from that of the holotype by being slender in ventral and lateral views (Fig. 11I, J). However, all external characters of this individual (e.g., body color, shape and length, punctures on head and pronotum) are identical with the Holotype. The slight differences in the shape of aedeagus are treated as intraspecific variation here.
Previously, the genus Phorocardius was only known from the Oriental Region. The discovery of P. minutus Ruan & Douglas, sp. nov. from the Palearctic Region indicates that the members of this genus can survive in areas with freezing winter temperatures (in Ke-you-zhong-qi, Inner Mongolia, the minimum temperature is approximately -20 °C in January). Examination of female genitalia or phylogenetic studies would be useful to see how closely this species is related to other Phorocardius. The thick tibiae and ascendant prosternal process of this species are similar to many fossorial elaterids (Douglas 2011), including many species with flightless females. Females of this species are currently unknown.
Phorocardius minutus Ruan & Douglas, sp. nov. is like Diocarphus solitarius (Fleutiaux, 1931) in the ventral apex of the tarsal claw is much smaller than the dorsal apex. However, P. minutus can be easily separated from Diocarphus by its open procoxal cavities and the pronotum without pronotal lateral carina.
Based on specimen information, this species inhabits low elevation areas (ca. 0-500 m) in Inner Mongolia, north China. This area is arid with temperate grassland and shrubland and cold winters. Known only from the Palearctic Region.  Yunnan, Xi-shuang-ban-na, Xiao-meng-yang. Etymology. This species is named after the red-brown color of the posterior half of the body.

Phorocardius rufiposterus
Distribution. China (Yunnan). Differential diagnosis. Body length greater than 7.0 mm; integument black (nonmetallic) anteriorly, fading to red-brown or yellow-brown on posterior half. Prothorax: procoxal cavities closed (narrowly open in a few); prosternal process not strongly narrowed posterad from base to ventral apex in ventral view, ventral apex almost truncate. Male genitalia: paramere acute beyond preapical lateral expansion; with preapical lateral expansion present, without apical mesal callus. Female: apex of last abdominal ventrite (ventrite V) with longitudinal slender blade-shaped projection at middle, deeply emarginate at sides. This species is unique for its closed procoxal cavities. It resembles Phorocardius magnus Fleutiaux, 1931 in the general body shape and the lighter color on the posterior half of body. They can be distinguished by the following characters: in P. rufiposterus Ruan & Douglas, sp. nov., aedeagus with apex of paramere robust (sides convex in dorsal view before large preapical expansion), apex spear-shaped in ventral view with acute tip and triangular preapical lateral expansion; head with frontal carina convex in frontal view; and female with ventrite V deeply emarginate, a slender blade-shaped projection present at middle (Fig. 15C), while in P. magnus, body entirely red-brown to brown throughout, with pronotum slightly darker; aedeagus with paramere narrow and concave before small preapical expansion in ventral view; head with frontal carina straight in frontal view; and female with the apex of abdominal ventrite V tri-lobed, middle lobe semicircular to longitudinal with apex rounded, not slender blade-shaped.
Description. (based on all type specimens) Body black anteriorly, fading to redbrown or yellow-brown on posterior half. Dorsum glabrous and shiny. Head black, with mouthparts red-brown to dark brown. Antennae brown. Pronotum black, with anterior and posterior edge brown. Elytra black to dark red-brown anteriorly, fading to red-brown or yellow-brown posteriorly. Venter black to dark red-brown on anterior half, fading to red-brown or yellow-brown on posterior half. Epipleura red-brown. Legs red-brown to dark red-brown. Body surface covered with yellow-grey pubescence.
Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia. Robust in ventral and lateral views. Median lobe in ventral view gradually narrowed from base to near apex, apex rounded to apically flattened. Median lobe in lateral view curved ventrad, with apex dilated and recurved dorsad. Paramere in ventral view: wide, width 2.5-3.5 × median lobe width (measured at mid-length of paramere and median lobe respectively); widest near mid-length, gradually narrowed and with outer sides evenly convex towards apex; apex spear-shaped, with acute tip and triangular preapical lateral expansion, apical mesal callus absent. Paramere in lateral view: robust, almost straight from base to apical third, gradually narrowed and bent ventrad from apical third to apex; apex slightly recurved dorsad, preapical ventral expansion absent, with an angulate structure near apex (see Fig. 14F), without hook-shaped structure.
Female. Body color like male. Ventrite V deeply emarginate at apex, with longitudinal slender blade-shaped projection at midline (Fig. 15C) (male with ventrite V entirely convex and rounded). Proximal sclerites of bursa copulatrix oval, apex acute ( Fig. 14H): base with without concavity, each with 14-16 large spines occupying twothirds of edges, 9-10 smaller spines on disc.  Remarks. This species is unique for its closed procoxal cavities, which has not been reported in other Phorocardius species. However, other aspects of this species are consistent with generic traits of Phorocardius. These are: characteristic claws and female and male genitalia.
Integument color varies slightly between individuals. However, the gradual change of color from anterior to posterior end of the body can be observed in all specimens.

Phorocardius unguicularis
Differential diagnosis. Body length greater than 7.0 mm; integument brown to dark brown. Prothorax: procoxal cavities open; prosternal process gradually and only slightly narrowed posterad to ventral apex in ventral view, with apex almost truncate. Pterothorax: scutellar shield with posterior apex pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere without preapical lateral expansion or apical mesal callus in any view. Female: apex of last abdominal ventrite (ventrite V) simple, not emarginate at apex. This species is unique among Chinese Phorocardius species by having extremely dense pronotal punctation (interspaces between pronotal punctures 0.3-1 × average puncture diameter).
Phorocardius unguicularis (Fleutiaux, 1918) resembles P. magnus Fleutiaux, 1931 in body color and size. They can be separated by the following combination of characters: in P. unguicularis (Fleutiaux, 1918), aedeagus slender in lateral view (paramere maximum thickness 1/5 paramere length), in ventral view paramere widened from base to mid-length, narrowed from mid-length to apex, apex pointed and without preapical lateral expansion; pronotum with deep punctures, interspaces between punctures 0.3-1 × average puncture diameter; and head with frontal carina convex at middle in frontal view; while in P. magnus Fleutiaux, 1931, aedeagus robust in lateral view (paramere maximum thickness 1/3 paramere length); in ventral view, paramere slightly widened from base to apical fourth, apical fourth abruptly narrowed, with hook-like preapical lateral expansion; pronotum with interspaces between punctures 1-2.5 × average puncture diameter; and head with frontal carina straight in frontal view.
Phorocardius unguicularis (Fleutiaux, 1918) resembles P. yanagiharae  in body color. They can be separated by the following combination of characters. In P. unguicularis (Fleutiaux, 1918), in ventral view, aedeagus with paramere gradually narrowed from mid-length to apex, apex pointed and without preapical lateral expansion; pronotum with deep punctures, interspaces between punctures 0.3-1 × average puncture diameter; and head with frontal carina convex in frontal view; while in P. yanagiharae , in ventral view, aedeagus with paramere, abruptly narrowed from apical third to apex, apex with hook-like preapical lateral expansion; pronotum with shallow punctures, interspaces between punctures 1-2 × average puncture diameter; and head with frontal carina straight in frontal view.
Phorocardius unguicularis is also similar to P. astutus (Candèze, 1888), it differs from the latter based on the following characters: body brown to dark-brown with yellow-brown appendages; legs yellow-brown throughout; proximal sclerites of copulatrix kidney-shaped with slight basal concavity; and parameres of aedeagus without pre-apical lateral expansions. In P. astutus: body brown-black with dark appendages; legs with red-brown joints; proximal sclerites of copulatrix oval, not kidney-shaped, without basal concavity; and parameres wedge-like with pre-apical lateral expansions. Additionally, P. unguicularis has narrower pronotum and body, and larger body length. Further study of these two species would be important to verify their status.
Description. (Based on photographs of the holotype and all examined specimens) Body brown to dark brown (brown-black in a few); legs and antennae brown; pronotum slightly darker than rest (Fig. 16A, B). Integument matt, with yellow pubescence.
Pterothorax (Figs 24H,25H). Mesepisternum in ventral view with antero-mesal angle right-angled ( Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia. Robust from ventral and dorsal views, slender in lateral view. Median lobe in ventral view gradually narrowing from base to near mid-length, apical half elongate with sides parallel-sided to slightly convex, apex narrowly rounded. Median lobe in lateral view almost straight, apex narrowly rounded. Paramere in ventral view: robust, width 3-4 × median lobe width (measured at mid-length of paramere and median lobe respectively), widest near mid-length; gradually narrowing from midlength to apex, apex elongate and needle-like, without preapical lateral expansion or apical mesal callus (Fig. 16E). Paramere in lateral view: slender, gradually narrowing and curved ventrad from base to near apex; preapical ventral expansion absent, without hook-shaped structure.
Differential diagnosis. Body length greater than 7.0 mm; integument red-brown to brown throughout. Prothorax: procoxal cavities open. Pterothorax: scutellar shield with posterior edge pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere with preapical lateral expansion present, without apical mesal callus. Female unknown.
Phorocardius yanagiharae  resembles P. magnus Fleutiaux, 1931 in general body color and shape. They can be separated by the following combination of characters. In P. yanagiharae , in lateral view, aedeagus with median lobe straight at apex, with paramere slender and ca. 1/2 as wide as median lobe (measured near middle part); pronotum narrower than in P. magnus, pronotal width to body width ratio 0.86; and in dorsal view, pronotum with sides of posterior angles strongly bulged and convex (Fig. 18C, D); while in P. magnus Fleutiaux, 1931: in lateral view, aedeagus with median lobe recurved dorsally at apex, with paramere robust and as wide as median lobe (measured near middle part); pronotum wider than in P. yanagiharae, pronotal width to body width ratio 0.90-0.97; and in dorsal view, pronotum with sides of posterior angles not bulged, straight to slightly convex (Fig. 9A).
Phorocardius yanagiharae ) also resembles P. unguicularis (Fleutiaux, 1918) in body color. They can be separated by the following combination of characters. In P. yanagiharae , in ventral view, aedeagus with paramere, abruptly narrowed from apical third to apex, apex with hook-like preapical lateral expansion; pronotum with shallow punctures, interspaces between punctures 1-2 × average puncture diameter; and head with frontal carina straight in frontal view; while in P. unguicularis (Fleutiaux, 1918), in ventral view, aedeagus with paramere gradually narrowed from mid-length to apex, apex pointed and without preapical lateral expansion; Figure 17. Phorocardius yanagiharae . A holotype, habitus, dorsal view B holotype, habitus, ventral view C holotype, habitus, lateral view with specimen labels D claw of holotype E apical part of aedeagus of holotype, ventral view F apical part of aedeagus of holotype, dorsal view G apical part of aedeagus of holotype, lateral view. pronotum with deep punctures, interspaces between punctures 0.3-1 × average puncture diameter; and head with frontal carina convex in frontal view.
Description. (based on holotype) Color entirely red-brown to brown throughout, with legs and antennae yellow-brown to brown; pronotum and venter slightly darker than elytra. Integument matt, with light yellow pubescence.
Measurements. (based on holotype) Body length 9.4 mm. Body width 3.3 mm. Body length to width ratio 2.9. Pronotal width to length ratio 1.1. Pronotal width to body width ratio 0.86. Elytral length to pronotal length ratio 2.6; elytron length to width ratio 4.3.
Head. Frons and vertex with interspaces between punctures 1-3 × average puncture diameter. Frontal carina in frontal view transversely straight. Antenna with apex extending to posterior angle of pronotum. Distance between eyes to width of eye ratio 3.0. Antenna length to body length ratio 0.36.
Prothorax. Pronotum in dorsal view (Fig. 18A): sides strongly convex from anterior edge to posterior fourth, slightly convex from posterior fourth to base of posterior angle, concave at base of posterior angle; widest near posterior third; posterior angles with lateral margin convex, strongly bulged laterally (Fig. 18C, D); surface with interspaces between punctures 1-2 × average puncture diameter.
Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia (only apical third observed in current study, see Fig. 17E-G). Apical third robust in ventral and lateral views. Apical third of median lobe in ventral view (Fig. 17E) narrowing from base to apex, apex rounded. Apical third of median lobe in lateral view bent ventrad (Fig. 17G). Apical third of paramere in ventral view: extremely wide, 2-3 × wider than median lobe (measured at base of apical third), sides convex and narrowed to near apex, preapical lateral expansion triangular, facing laterally (Fig. 17F); apex acute beyond preapical lateral expansion, apical mesal callus absent. Apical third of paramere in lateral view: bent ventrad and gradually narrowed towards apex, preapical ventral expansion absent, without hook-shaped structure near apex.
We have investigated the TARI Elateridae collection. Only one single specimen labeled as "Cardiophorus yanagiharae sp. nov." was discovered, which we have identified as the holotype for the following reasons: 1) it is preserved in the type collection with a circular type label and a rectangular TARI type number label; 2) it has a label indicating "Phorocardius yanagiharae n. sp." in Miwa's handwriting; and 3) it has a label that indicates the specimen locality "車路墘", which is a location in the city "Tainan", which matches the type locality  provided.
We believe Miwa had incorrectly reported the sex of the type as female. Moreover, Miwa implied the collecting date is "21/IV, 1926". However, according to our examination, the date on the label is "27/IV, 1926".
The previous record of Phorocardius yanagiharae from Sichuan province (Jiang 1993;Jiang and Wang 1999) are erroneous. We investigated those specimens the authors used, and they turned out to be a new species (i.e., Phorocardius yunnanensis Ruan & Douglas, sp. nov., see following text).
Based on specimen information, this species inhabits low elevations (below 100 m) in south Taiwan island. The area is rainy, with subtropical to tropical climate. This species is currently considered endemic to Taiwan. Etymology. The name of this species refers to the type locality. Figure 18. Phorocardius yanagiharae . A holotype, pronotum, dorsal view B holotype, head, frontal view C right posterior angle of pronotum, dorsal view D left posterior angle of pronotum, dorsal view.

Phorocardius yunnanensis
Distribution. China (currently endemic to Yunnan). Differential diagnosis. Body length greater than 7.0 mm; integument black and shiny (non-metallic), elytron without yellow stripes, appendages yellow-brown. Prothorax: procoxal cavities narrowly open; prosternal process not strongly narrowed posterad to ventral apex in ventral view, with apex truncate to slightly rounded. Pterothorax: scutellar shield with posterior apex pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere acute in ventral view with small, acute preapical lateral expansion, without apical mesal callus. Female: apex of last abdominal ventrite (ventrite V) truncate to slightly convex, bent dorsad, each side with an incision.
This species is distinctive for having the dorsum entirely black and shiny and legs entirely yellow-brown (except for brown-black coxae).
Phorocardius yunnanensis Ruan & Douglas, sp. nov. is close to P. vicinus in brownblack body color, but distinguishable by the following. In P. yunnanensis Ruan & Douglas, sp. nov., pronotum longer with length of pronotum to elytra ratio 0.37-0.40 (excluding posterior angle) or ca. 0.43 (including posterior angle); antennae, palpi of mouthparts and legs yellow-brown to brown; and proximal sclerites of bursa copulatrix with basal edge concave. According to Kollar (1848) and type material (NHMW), P. vicinus has length of pronotum to elytra ratio only 0.33; appendages brown-black to black; and proximal sclerites of bursa copulatrix not concave at basal edge.
Description. (based on all type specimens (25♂, 24♀)) Dorsum black and shiny, venter brown-black with last 2-3 ventrites yellow-brown. Antennae brown to yellowbrown, with first two antennomeres slightly lighter in color. Legs entirely yellow-brown (except coxae brown-black). Surface of body with yellow pubescence.
Etymology. This species is named after its collector, Mr Zhiwei Dong, who generously provided specimens for this study.
Distribution. China (Yunnan). Differential diagnosis. Body length greater than 7.0 mm; pronotum with integument red, elytra metallic green. Prothorax: procoxal cavities open; prosternal process not strongly narrowed posterad to ventral apex in ventral view, with ventral apex rounded. Pterothorax: scutellar shield with posterior edge pointed. Tarsal claw with ventral apex not smaller than dorsal apex. Male genitalia: paramere without preapical lateral expansion, but with apical mesal callus. Female unknown.
This species is distinct among Phorocardius in its entirely metallic green elytra and red pronotum. It is the second species having metallic color on elytra, as the type species of the genus (i.e., P. florentini (Fleutiaux, 1895)) also has slight blue metallic luster on elytra.
Phorocardius zhiweii Ruan, Douglas & Qiu, sp. nov. resembles P. manuleatus most in body shape and color of leg and prothorax. They can be easily separated by elytral color and aedeagus shape. In P. zhiweii Ruan, Douglas & Qiu, sp. nov., elytra are metallic green with slight purple luster; in ventral view, the aedeagus has apical fourth slightly narrowed, robust in both ventral and lateral views; and the paramere has preapical lateral expansion absent, apical mesal callus present; while in P. manuleatus, elytra are black to yellow, without metallic color; and the aedeagus in ventral view has the apical fourth greatly narrowed. The aedeagus is slender in both ventral and lateral views with parameres lacking acute preapical lateral expansions or apical mesal calli.
Description. (based on holotype) Dorsum shiny. Head black, with mouthparts red-brown to brown. Antennae brown. Pronotum orange, with posterior edge dark brown (Fig. 22A). Scutellar shield black. Elytra entirely metallic green, with purple luster. Hypomera orange; rest of ventral surface black (Fig. 21B). Epipleura metallic  purple. Legs black on coxa, pale brown on femur and basal half of tibia, dark brown from mid-length of tibia to apex. Body with short, yellow-grey pubescence, brown setae also present on disc of pronotum.
Measurements. (based on holotype) Body length 8.0 mm, width 2.8 mm. Body length to width ratio 2.9. Pronotal width to length ratio 1.1. Pronotal width to body width ratio 0.80. Elytral length to pronotal length ratio 2.5; elytron length to width ratio 3.8. Head. Frons and vertex with interspaces between punctures 1-3 × average puncture diameter (Fig. 22C) Prothorax. Pronotum in dorsal view (Fig. 22A): sides slightly convex from anterior edge to concavity near posterior fourth, widest near posterior third; posterior angles with lateral sides almost straight, not bulged; surface with interspaces between punctures 2-2.5 × average puncture diameter. In ventral view, ventral surface of prosternal process with sides carinate and slightly and gradually narrow from anterior to mid-length, parallel from mid-length to near posterior end, apex broadly rounded. In lateral view, prosternal process with ventral surface curved slightly dorsad, posterior end concave (Fig. 24J). Procoxal cavities open.
Abdomen. Lateral edges of visible abdominal ventrites I-V with minute serrations. Male genitalia. Robust in ventral and lateral views. Median lobe in ventral view with sides nearly parallel, slightly narrowed near apex; apex broadly rounded (Fig. 21D). Median lobe in lateral view gently bent ventrad, apex dilated and broadly rounded (Fig. 21F). Paramere in ventral view: wide, widest near mid-length, sides convex to near apex; preapical ventral expansion absent, mesal side of apex with ovoid disc-shaped callus (Fig. 21D, indicated by blue arrow); paramere 2-3 × wider than median lobe (measured at mid-length of paramere and median lobe respectively). Paramere in lateral view: robust, almost straight at basal half, bent ventrad at apical half; preapical ventral expansion hook-like, with acute tip facing ventrad (Fig. 21F  Remarks. This species inhabits middle elevations (around 1500 m) in Yunnan Prov., south China. This area is rainy, subtropical to tropical, with subtropical evergreen broadleaf forest or tropical rain forest. This species is known only from the Oriental Region. There are two undetermined female specimens (SZPT) from Xi-shuang-ban-na (西双版纳), Yunnan that have metallic blue elytra and a black pronotum. One male specimen (SZPT) from Ying-jiang (盈江), Yunnan also has metallic blue elytra and a black pronotum. Its aedeagus is extremely close to that of Phorocardius zhiweii Ruan, Douglas & Qiu, sp. nov. However, it is still not entirely clear whether these are conspecific. More specimens should be studied before a reliable determination can be made. Fig. 28 Cardiophorus comptus Candèze, 1860: 202 Distribution. India (Candèze 1860(Candèze , 1891; Nepal (Ôhira 1978); Sri Lanka (Ôhira 1973). Excluded from China here.

Phorocardius comptus (Candèze, 1860) [removed from distribution of mainland China and Taiwan]
Remarks. Phorocardius comptus was recorded from Taiwan by Miwa ( , 1931. However, Suzuki (1999) considered the record questionable. He excluded P. comptus from Taiwan after studying the specimens that  used for the record. The same specimen was examined in our study (TARI, see Fig. 28F). We agree with Suzuki (1999) that the specimen used by  is one of the "Shiraki specimens". "Shiraki specimens" were originally housed in NHMUK, collected from tropical Oriental countries (e.g., India, Nepal, Borneo, etc.) and shipped to Taiwan by Dr Shiraki in 1916. All specimen labels were then replaced by new labels with several specific localities from Taiwan such as "Rônô", "Kôshun", "Kôtoshô", "Horisha", "Hori", "Musha", etc. (Kurosawa 1980;Chu and Xiao 1981;Chu 2011Chu , 2013. Most of these Taiwan locality names refer to localities in the south and southeast Asia, the codes for these true locality names were documented in a file housed in National Taiwan University, Taipei, which was already lost shortly after world war II (Chu 2011). Additionally, under each of these specimens, there is a typical Shiraki's label with his handwriting and a red circle mark. Therefore, the single P. comptus specimen in TARI is one of these "Shiraki specimens", since it has a locality label indicating "Rônô", and a second label with Shiraki's handwriting and a red circle mark.
Phorocardius comptus was previously recorded by Jiang (1993) and Jiang and Wang (1999) in Hubei Prov., China. We examined the specimens used in those studies and found that these specimens are not conspecific with P. comptus, instead they are described as a new species in this study (i.e., Phorocardius alterlineatus Ruan & Douglas sp. nov. above). We consider P. comptus to be absent from mainland China and Taiwan. Candèze (1860: 202) described Cardiophorus comptus and C. contemptus on the same page and stated that C. contemptus (see Fig. 29) may be a variety C. comptus. The examination of the type material of both species shows that they are similar in female genitalia and external characters (except for the elytral color). It is possible that C. contemptus is a junior synonym of C. comptus. However, as we have not studied any male specimen of C. contemptus, it is treated here as valid.
Three specimens (NHMUK) are designated as lectotype or paralectotypes for the following reasons: 1) they are labeled with "SYNTYPE"; 2) the labels indicate either "S. India" or "Hindoustan", which are consistent with the original description; 3) the collection of Candèze before 1869 had been transferred to the NHMUK (Bousquet 2016); and 4) the type materials are absent in either RBINS or MNHN.  A, B, E, G-I are provided by Ms Karine Savard, Agriculture and Agri-food Canada; insets C, D are provided by Dr Yijie Tong, IZCAS). A lectotype, male, dorsal view B lectotype, male, lateral view C paralectotype, male, dorsal view D paralectotype, female, dorsal view E female, dorsal view (NHMUK, non-type specimen) F female, dorsal view (TARI, used for distributional record by ) G aedeagus of lectotype, dorsal view, arrow indicating apices of parameres and median lobe H aedeagus of lectotype, lateral view, arrow indicating apices of parameres and median lobe I distal (upper side) and proximal sclerites of bursa copulatrix (paralectotype, habitus shown in D).
temperatures near -20 °C. If monophyletic with other Phorocardius, this shows that Phorocardius species can inhabit not only humid tropical rain forest, but also arid and freezing grassland areas. This finding also suggests that at least some species of Phorocardius may not require forest soils, hollow trees, or decaying wood for larval development. The discovery of P. minutus expands the collective distributional records for the genus Phorocardius deep into the Palearctic Region for the first time.
According to specimen records, the highest elevation for Chinese Phorocardius species is 2750 m at the foot of Yu-long-shan Mountain (also know as Yu-long Snow Mountain), with snow present year-round above 3500 m, while the lowest elevation is around 50 m. The strongly sclerotized ovipositors of all Phorocardius species examined here suggests that they can oviposit in dense substrates, such as soils that are not sandy.
Phorocardius zhiweii is the second species described in the genus with metallic coloration on the elytra, with P. florentini also having a slight blue metallic luster on the elytra. There may be additional undescribed metallic species, as we have examined three other undetermined specimens with metallic blue elytra.
We found that using the open procoxal cavities as a generic character, as in Douglas (2017), for Phorocardius is incorrect because the procoxal cavities of P. rufiposterus are closed (Fig. 15E), only narrowly open in rare cases. The degree of the opening of procoxal cavities also slightly varied between individuals of P. magnus Fleutiaux, 1931, with many specimens have nearly closed (narrowly open) procoxal cavities. Douglas (2017) also incorrectly placed Phorocardius in the key to genera among species with the pronotal lateral carina present in the first half of couplet 4. But the proximal sclerites of the bursa copulatrix are ovoid as mentioned there. Users of that key might incorrectly identify Phorocardius specimens as Ryukyucardiophorus based on the pronotal character. However, Phorocardius can be distinguished from Ryukyucardiophorus by its apically split claws (tooth at base in Ryukyucardiophorus) and by having four sclerites in the bursa copulatrix (only two in Ryukyucardiophorus).
The shape of the male genitalia illustrated in this study is highly variable in some species, especially in P. flavistriolatus, P. manuleatus and P. minutus. This may be due to one or more of the following reasons: 3. Mating activity. In a few individuals of P. flavistriolatus (e.g., Fig. 4J), the apical part of the parameres are much more divergent than those in other individuals. This is probably due to the aedeagi being extended at the time of death of the beetle because divergent parameres were found only in specimens preserved with the aedeagus entirely extended from the posterior end of specimens. In Cardiophorinae (and probably Negastriinae), when the aedeagus is extended before copulation, the distal part of parameres diverge from the median lobe (the base of parameres are fused, with the apex flexible, Iablokoff-Khnzorian and Mardjanian 1981;Douglas 2017). We also observed the copulation in Ludioschema obscuripes for comparison. During the copulation, the distal part of the parameres diverges from the median lobe. After copulation, the aedeagus starts to retract back into the body, the parameres gradually move close to median lobe, and when the aedeagus is almost entirely retracted, the parameres return closely to median lobe.
4. Undescribed species diversity. It also remains possible that these species definitions contain undescribed cryptic species, so that further DNA comparisons should be done to test species limits.
This study also first documents that the shape of the apex of abdominal ventrite V in females is highly variable (arcuate, with arcuate median indentation, or with elongate invagination containing slender blade-like projection) between species (see Fig. 26A-H). This character system (first noted in unpublished drawings in specimen drawers in NHMUK by Christine von Hayek) provides a set of powerful diagnostic characters for some species (e.g., P. rufiposterus, P. magnus, and P. yunnanensis). However, in males, the same structure (usually arcuate and simple) is more evenly convex and lacks interspecific variation.