Pericalus formosanus, Dupuis, 1913

Hunting, Wesley & Yang, Man-Miao, 2019, A taxonomic review of the pericaline ground-beetles in Taiwan, with descriptions of new species (Coleoptera, Carabidae, Lebiini), ZooKeys 816, pp. 1-164 : 139-142

Pericalus formosanus Figs 104A, B, 105 A–D, 106, 110A

Pericalus formosanus Dupuis, 1913: 83; Csiki 1932: 1369; Jedlička 1963: 379; Fedorenko 2017: 311.

Pericalus ornatus formosanus Dupuis: Shi and Liang 2018: 36.

Types and other material examined.

Holotype (male) labeled "Chip Chip/ II Formosa/Sauter 07-09"; “TYPUS” [rectangular, red paper]; " Pericalus formosanus Dupuis/Dupuis det. "; “Syntypus”; "DEI Coleoptera /# 200415". Five paratypes and 151 other specimens of P. formosanus : 75 males and 76 females. For further details see EH Strickland Virtual Entomology Museum Database.

Type locality.

Taiwan. Kaoshiung County, “Hoozan” = Fengshan City.

Taxonomic notes.

In a recent paper Shi and Liang (2018) considered P. formosanus to be a subspecies of Pericalus ornatus Schmidt-Goebel, 1846. While these taxa are similar, we have deduced that there are sufficient differences to maintain the species status of P. formosanus . Along with differences in the hind angles of the elytra, and number of discal setae (one in P. formosanus and two in P. ornatus ), there are slight but consistent differences in the genitalic characteristics. Females of P. formosanus have a spermathecal gland duct that is longer and a spermathecal gland (Fig. 110B) that is larger than seen in specimens of P. ornatus . Males of P. formosanus have a phallus with ostium more dorsally situated than in members of P. ornatus and an endophallus that is obviously narrower in form and has only one prominent endophallic lobe (Fig. 108A), located more basally than the most basal endophallic lobe of specimens of P. ornatus .

Shi and Liang observed that Fedorenko (2017), recorded P. formosanus from Vietnam based on misidentification of P. acutidens . After examining his images of the everted endophallus, it is clear that it was a mistaken identity. Pericalus formosanus is restricted to Taiwan and allopatric with all other species of Pericalus .

Diagnosis.

Specimens of this species are easily distinguished from other Taiwanese pericalines by having smooth tarsal claws, two pairs of supraorbital setae, two pairs of latero-marginal setae on the pronotum and a black dorsal coloration with eight maculae on the disc of the elytra.

Redescription.

OBL 7.67 - 11.33 mm. Length (n = ten males, ten females): head 0.92 - 1.24, pronotum 1.28 - 2.12, elytra 4.33 - 6.33, metepisternum 1.04 - 1.40 mm; width: head 2.14 - 3.10, pronotum 3.33 - 4.67, elytra 3.33 - 4.67, metepisternum 0.56 - 0.84 mm.

Body proportions. HW/HL 2.24 - 2.58; PWM/PL 1.45 - 1.58; EL/EW 1.25 - 1.46; ML/MW 1.40 - 1.94.

Color. Fig. 104A, B. Various. Dorsum of head piceous, clypeus piceous with rufo-brunneous apical edge, antennae and palpi rufo-brunneous, scape sometimes darker; pronotum piceous; elytral disc piceous, with eight testaceous maculae, two in basal 1/3, two near mid-length, and four in apical 1/3, basal macula somewhat dentate, from interval 3 or 4 to interval 6 or 7, always closest to base in interval 5 and closest to apex in interval 4, mid-length macula from interval 4 to interval 5 or 6, apical macula with small patch from interval 2 to 3 and small patch in interval 7; ventral surface rufo-piceous to piceous; legs rufo-brunneous, tibia darker.

Microsculpture. Head with microsculpture almost isodiametric to isodiametric; pronotum with microsculpture shallow, somewhat transverse to transverse; elytra with sculpticells transverse, single row of isodiametric cells down center of each stria; ventral surface with transverse to almost isodiameteric microsculpture.

Macrosculpture and pilosity. Dorsum of head and base of clypeus rugulose, surface with very fine, scattered, setigerous punctures, hardly visible at 50 ×; pronotum disc faintly rugulose centrally, more so along lateral margins, surface with very fine, scattered, setigerous punctures; elytral intervals convex, interval 7 slightly more raised than others in apical 1/3, entire dorsal surface with fine, scattered setigerous punctures, punctures hardly visible but setae easily viewed in lateral view at 50 ×, striae impunctate; ventral surface of head rugulose to gula suture, remaining ventral surface with randomly scattered setigerous punctures.

Fixed setae. Two pairs of supraorbital setae; clypeus with two long, lateral setae; labrum with six setae along apical margin; one pair of suborbital setae; pronotum with two pairs of setae, one at base of lateral margin, one on lateral margin at pronotum max width; 24 - 25 lateral (umbilical) setae in interval 9; elytra with interval 3 with one seta in basal 1/6 (See also, variation); ventral surface with two setae on each of abdominal sterna III to VI; four setae along apical margin of sternum VII.

Variation.

of 151 specimens observed only one was observed to have two setae in interval 3, the typical apical setae and one at mid-length; see Fig. 104A (two setae) vs. Fig. 104B (one seta).

Luster. Dorsal surface moderately glossy; ventral surface glossy.

Head. Mandibles long, left mandible with distinctive notch on inside and dorsal surface in apical 1/3; labrum deeply bilobed, mentum without tooth; eyes large, convex; palpi cylindrical and elongate and with fine setae.

Pronotum. Lateral margins explanate, with margins curved slightly upwards, anterior transverse impression moderately shallow, posterior transverse impression deep, median longitudinal impression moderately deep, apico-lateral margins broadly and distinctly lobed, posterio-lateral margins sinuate, right-angled.

Elytra. Hind angles slightly sinuate, apex of lateral margin with distinctly sharp edge, pointed.

Hind wings. Macropterous.

Legs. Tarsal claws smooth, rather long and slender, males with adhesive vestiture ventrally, two rows squamo-setae on tarsomeres 1-3 of fore-leg.

Male genitalia. Fig. 105 A–D. Length 1.80 - 2.06 mm. Ostium catopic, open slightly more on the left side. Phallus cylindrical, widest at mid-length, apex short, rounded at tip; endophallus relatively long and narrow along length, with single distinctive lobe (el) at base.

Female genitalia. Fig. 110A. Width 1.15 - 1.30 mm. Gonocoxite 2 (gc2) distinctively long and narrow, relatively uniform in width along length; three lateral ensiform setae spaced widely apart (les), one dorsal ensiform seta. Sensory furrow, furrow pegs, and associated nematiform setae not observed. One spermatheca present (sp1), elongate and cylindrical, expanding slightly in apical half; one spermathecal accessory gland (sg), associated spermathecal gland duct (sgd), with attachment site just before widening of spermatheca.

Habitat, habits, and seasonal occurrence.

The known elevational range of P. formosanus is from 500 to 2095 meters with the majority of adults being collected between 1800 and 2000 meters. Adults of this species are crepuscular and are found in mixed primary and secondary forest of montane areas, typically in moist areas. They can be found inside and under deadwood during the day and on deadwood at night. Specimens are easily captured as they do not run or fly when illuminated. Specimens have been collected throughout the year with most collected from May to July. Methods of collecting include light trap on ground, u.v. light sheet, pitfall trap, and hand collecting.

Geographical distribution.

Pericalus formosanus is known only from Taiwan. See Figure 106.