Penia inopinata Arimoto, 2023

Arimoto, Kôichi, 2023, Taxonomic revision of the genus Penia Laporte (Coleoptera, Elateridae, Dendrometrinae) from Taiwan, Zootaxa 5375 (3), pp. 301-335 : 315-318

Penia inopinata Arimoto , sp. nov.

( Figure 10 , 11 )

Penia takasago Kishii, 1997: 12 (original description; type locality: Taiwan, Nantou County, Sungkang ) [partim].

Etymology. Specific epithet derived from the circumstances of the discover of the species.

Type material. Holotype. Female, Taiwan, Chiayi County, Zhuqi Township , Fenqihu, 4 V 1970 (as 8 V 1970 in original description of Penia takasago ), Y. Kiyoyama leg. [ OMNH; 6349]. Verbatim label data ( Fig. 10A ). “Female symbol”; “6349”; “PARATYPE”; “FUNCHIFO/ FORMOSA / 4. V. 1970 / Y. KIYOYAMA”; “ Penia / takasago/ KISHII, sp. n. / Det. KISHII, ’92”.

Female. Diagnosis. This species is characterized by the following features: eyes 0.25 x longer than interocular distance in dorsal view; antennae extending beyond pronotum posterior lateral apices by antennomere VII; antennomeres III distinctly longer than II; IV 1.2 x longer than III, 0.8 x longer than II – III combined; apical maxillary palpomere 2.1 x longer than wide, almost as long as maximum length of eye; pronotum straightly and slightly narrowed ahead of hind angles; posterior edge of pronotum with sublateral incisions; hind angles of pronotum broad, not protruding laterally beyond pronotal side; hypomeron with slight mesial projection; anterior angle of hypomeron rounded; hind angle of hypomeron broadly triangular; scutellar shield almost as long as wide; mesosternal process between mesocoxae a little higher than mesocoxae, visible in lateral view; posterior edge of mesosternal process 0.15 x wider than total width of mesosternum; elytron 3.4 x longer than wide, 2.7 x longer than pronotum length; abdominal ventrite V semicircular, rounded apically; spiculum ventrale 5.45 x longer than length of sternite VIII; ovipositor longer than length of abdomen.

This species is more similar to P. babai than to P. takasago in the eye size, the relative length of the basal antennomeres, the length-to-width ratios of the apical maxillary palpomere, scutellar shield and elytron, the shapes of the hind angle of the hypomeron and abdominal ventrite V, and the lengths of the spiculum ventrale and ovipositor. It is distinguished from P. babai by the following contrasting characteristics ( P. babai in parentheses): apical maxillary palpomere almost as long as maximum length of eye (apical maxillary palpomere shorter than maximum length of eye); hind angles of pronotum not protruding laterally beyond pronotal side (hind angles of pronotum weakly protruding posterolaterad); anterior angle of hypomeron rounded (anterior angle of hypomeron nearly right angle); hypomeron with slight mesial projection (hypomeron with distinct mesial projection); mesosternal process between mesocoxae a little higher than mesocoxae (mesosternal process between mesocoxae distinctly higher than mesocoxae); posterior edge of mesosternum between mesocoxae 0.15 x wider than total width of mesosternum (posterior edge of mesosternum between mesocoxae 0.2–0.25 x wider than total width of mesosternum).

Measurements. BL: 8.96, BW: 3.63, MAE: 1.54, MBE: 1.02, OI: 151, PL: 2.30, PML: 1.80, PW: 2.77, PAW: 1.72, PLI: 83.3, PWI: 161, EL: 6.17, EW: 1.83, EI: 336, BI: 268.

Description. Body broad, widest around elytral midlength ( Fig. 10B ); surface generally smooth; interspaces between punctures distinctly larger than fine puncture diameter ( Fig. 10B, C ). Color. Body, antennae and legs reddish brown. External edge of mandible, posterior edges of prosternum and anterior edge of scutellum black. Body covered with long yellow setae.

Head. Frons flatted medially ( Fig. 10D, E ); frontal carina not complete ( Fig. 10D ); frontal margin hexagonal, almost straight apically in dorsal view ( Fig. 10E ); frontoclypeal region protruding beyond base of labrum. Eyes relatively normal in convexity, 0.25 x longer than interocular distance in dorsal view ( Fig. 10E ). Antennae extending beyond pronotum posterior lateral apices by antennomere VII; antennomeres longer than wide; II obconical, shortest, 1.5 x longer than wide; III weakly serrated, 2.7 x longer than wide, 2.1 x longer than II; IV –XI filiform; IV 3.2 x longer than wide, 1.2 x longer than III, 0.8 x longer than II – III combined ( Fig. 10F ); V 3.4 x longer than wide, almost as long as IV; right antennomeres II –XI and left antennomeres IX–XI lost in holotype ( Fig. 10B ). Mandible bidentate ( Fig. 10D ). Apical maxillary palpomere semicircular ( Fig. 10G ), 2.1 x longer than wide, almost as long as maximum length of eye; anterior edge rounded .

Prothorax. Pronotum hexagonal, 0.8 x longer than wide, roundly widening anteriorly, widest around midlength, and then straightly and slightly narrowed ahead of hind angles ( Fig. 10A ), tallest just behind midlength ( Fig. 10H ), without median longitudinal depression posteriorly; anterior edge strongly concave; anterior angles simple, acute; punctate lateral ridge extending from anterior angles to hind angles ( Fig. 10B ); hind angles simple, broad, not protruding laterally beyond pronotal side; posterior edge with a sublateral incision near each hind angle, without carinae next to sublateral incisions ( Fig. 10B ). Hypomeron with slight mesial projection ( Fig. 10I : arrow); anterior angle rounded; mesial edge slightly rounded; mesial and posterior margins with impunctate ridge ( Fig. 10I ); posterior margin with rectangular projection between two large emarginations; hind angle broadly triangular. Prosternum weakly incurved ventrally in lateral view; anterior lobe weakly protruding beyond prosternal ventral line in lateral view ( Fig. 10H ); anterior edge broadly rounded in ventral view ( Fig. 10C ). Prosternal process broad, 2.1 x longer than procoxal cavity length, concave between procoxae, strongly curved dorsad from the middle of procoxal cavities in lateral view ( Fig. 10H ), without subapical tooth; dorsal lobe abruptly narrowed posterad near apical region in ventral view ( Fig. 10J ); ventral lobe roundly expanded near base and then abruptly narrowed posterad in ventral view ( Fig. 10J ); ventral margin roundly and medially expanded in lateral view ( Fig. 10J ); apex rounded in lateral and ventral views ( Fig. 10J, H ). Pronotosternal sutures not grooved ( Fig. 10I ), weakly sinuate in ventral view ( Fig. 10C ), slightly opened anteriorly. Scutellar shield tongue-shaped ( Fig. 10K ), almost as long as wide, widest anteriorly, slightly constricted near base and then narrowed posterad, flat, inclined anterior-downwards, not visible in lateral view ( Fig. 10H ); anterior edge broadly rounded and slightly protruding medially; posterior edge rounded. Mesosternum: borders of mesosternal cavity slightly rounded and then curved obtusely ventrad in lateral view ( Fig. 10H ); mesosternal process between mesocoxae higher than mesocoxae, visible in lateral view ( Fig. 10H : white arrow); posterior edge 0.15 x wider than total width of mesosternum, straight ( Fig. 10L ). Mesepisternum reaching mesocoxal cavity ( Fig. 10L ). Metasternum sulcate medially and ahead of metacoxal cavities ( Fig. 10B ). Metacoxal plate narrowed toward outer side, becoming like a parallel-sided bar at its outer 1/ 4 in ventral view ( Fig. 10C ). Elytron broadly moderately convex, but with outer margin widely depressed, widest around midlength, 3.4 x longer than wide, 2.7 x longer than pronotum length; apex rounded; elytral striae defined by lines of elongated punctures. Hind wings fully developed. Tibiae with paired spurs; relative tarsomere lengths: IV<III II<V<I; tarsomeres III and IV with lobe ventrally ( Fig. 10M ).

Abdomen. Ventrite V wide semicircular, rounded apically ( Fig. 10C ), 0.4 x longer than wide. Tergite and sternite VIII yellow. Terigite VIII semicircular, almost as long as wide; sternite VIII (between base of spiculum ventrale and apex) semicircular, 0.8 x longer than wide ( Fig. 11A ; the pregenital segments of holotype had been mounted in balsam on slides and were distorted by the pressure exerted by the coverslip, Fig. 11B, C ); spiculum ventrale 5.45 x longer than length of sternite VIII ( Fig. 11C ). Ovipositor 1.2 x longer than length of abdomen; coxites two segmented at ventral side, with three setae each dorsally, ventrally, and apically; stylus with several setae around apex ( Fig. 11D ). Vagina and bursa copulatrix lost in holotype ( Fig. 11C ).

Male. Unknown.

Discussion. Four female types were assigned to P. takasago in the original description ( Kishii, 1997). However, the paratype (6349) is distinguished from the holotype and other two paratypes of P. takasago by the following contrasting characters (the holotype and other two paratypes in parentheses): eyes 0.25 x longer than interocular distance in dorsal view (eyes 0.4 x longer than interocular distance in dorsal view); apical maxillary palpomere almost as long as maximum length of eye (apical maxillary palpomere shorter than maximum length of eye); pronotum slightly and straightly narrowed ahead of hind angles (pronotum strongly and straightly narrowed ahead of hind angles); hind angles of pronotum broad, not protruding laterally beyond pronotal side (hind angles of pronotum acute, strongly protruding posterolaterad); hypomeron with slight mesial projection (hypomeron with moderate mesial projection); hind angle of hypomeron broadly triangular (hind angle of hypomeron claw-like shaped); mesosternal process between mesocoxae higher than mesocoxae, visible in lateral view (mesosternal process between mesocoxae lower than mesocoxae, not visible in lateral view); ovipositor longer than length of abdomen (ovipositor shorter than length of abdomen). Moreover, the paratype is different from the other Taiwanese congeners (see diagnosis). Therefore, the paratype was determined to be a new species.

Distribution. Taiwan: Chiayi County ( Fig. 1 ).

Figures

FIGURE 1. Map of Taiwan. A: location of Taiwan; B: the collection sites of the material used in this study.

FIGURE 10. Penia inopinata, holotype, female (6349) (= paratype of Penia takasago). A: labels; B: habitus, dorsal side; C: habitus, ventral side; D: head, anterior view; E: head, dorsal view; F: basal antennomeres of left antenna; G: left maxillary palp, dorsal side; H: head, prothorax and mesothorax, lateral view (black arrow: the direction perpendicular to the base of ventral lobe of prosternal process, white arrow: the direction perpendicular to the mesosternal process between mesocoxae); I: left hypomeron (arrow: hypomeron with slight mesial projection); J: prosternal process from the direction perpendicular to base of ventral lobe (black arrow of figure 10H); K: scutellar shield; L: mesothorax from the direction perpendicular to mesosternal process between mesocoxae (white arrow of figure 10H); M: left mid tarsus.

FIGURE 11. Penia inopinata, holotype, female (6349) (= paratype of Penia takasago). A: pregenital segments, ventral side; B: slide; C: pregenital segments and ovipositor, ventral side; D: coxites, ventral side.