Piestus chullachaqui Pérez, Rodríguez & Asenjo, 2017

Pérez, Luis, Rodríguez, Maryzender & Asenjo, Angélico, 2017, A new Peruvian species and new records of the genus Piestus Gravenhorst (Coleoptera: Staphylinidae), Zootaxa 4303 (3), pp. 417-426 : 418-422

Piestus chullachaqui Pérez, Rodríguez & Asenjo , sp. nov.

( Figs. 1–14 )

Type material (3♂♂, 1♀). Holotype: PERU: ♂, labeled “ PERU: CU[department of Cuzco], Echarate, 579 m [meters of altitude in relation to sea level]// 11°57’16.30”S [ South ]/ 73°1’23.94”W [West], // 29.v [may].2016. Under bark. // L. Pérez [leg.]”; “ HOLOTYPE [red label]// Piestus chullachaqui // Pérez, Rodríguez & Asenjo // Desig. L. Pérez et al. 2017” ( MUSM) . Paratypes (3): 2♂♂, 1♀, labeled: “ PERU: CU[department of Cuzco], Echarate, 579 m [meters of altitude in relation to sea level]// 11°57’16.30”S [ South ]/ 73°1’23.94”W [West], // 29.v [may].2016. Under bark. // L. Pérez [leg.]”; “ PARATYPE [yellow label] // Piestus chullachaqui // Pérez, Rodríguez & Asenjo // Desig. L. Pérez, et al. 2017” (1♂ and 1♀ MUSM; 1♂ FMNH) .

Diagnosis. Piestus chullachaqui sp. nov. is similar to P. capricornis but can be differentiated by the following characters: basal distance between frontal processes about 4 times ( P. chullachaqui sp. nov.) ( Fig. 1–2 ) or 3 times ( P. capricornis ) (Fig. 64: Caron et al. 2012) the basal width of each one; left mandible with trifurcate ( P. chullachaqui sp. nov.) ( Fig. 6 ) or bifurcate ( P. capricornis ) apex (Fig. 119: Caron et al. 2012); scape with 3 ( P. chullachaqui sp. nov.) ( Fig. 2 ) or 2 ( P. capricornis ) (Fig. 64: Caron et al. 2012) long setae at middle of dorsal face; aedeagus much longer ( P. chullachaqui sp. nov.) ( Fig. 11 ) or slightly longer ( P. capricornis ) (Fig. 166: Caron et al. 2012) than median lobe in lateral view, internal sclerites for P. chullachaqui sp. nov. ( Fig. 11–12 ) different of P. capricornis (Fig. 166–167: Caron et al. 2012); spermathecal duct around 3 times ( P. chullachaqui sp. nov.) ( Fig. 14 ) or 2 times ( P. capricornis ) (Fig. 253: Caron et al. 2012) the length of spermatheca and sclerotized in its half ( P. chullachaqui sp. nov.) ( Fig. 14 ) or third ( P. capricornis ) (Fig. 253: Caron et al. 2012) basal.

Description. Holotype male (BL=9.15, BW=2.64). Body flattened dorsoventrally. Body, antennae, mouthparts and legs reddish brown. Dorsal integument of head and pronotum with inconspicuous fine punctures and some moderately sized punctures distributed on pronotal disc, undulate microstriae only on lateral regions; neck with undulate microstriae only in lateral margin; striae of elytra with moderately sized punctures ( Fig. 1 ).

Head hexagonal, wider than long (HW/HL=2.32); eyes medium size and positioned posteriorly; two parallel frontal processes, shorter than scape, and basal distance between processes approximately four times basal width of each one; V-shaped frontal sulcus incomplete, curved arms not joined medially; one minor macrosetae and one major macrosetae near to edge of eye, one major macrosetae posterior to edge of eye ( Fig. 2 ). Antennae almost reaching apex of abdomen, scape with three long setae at middle of dorsal face; antennomere 1 (scape) longer than wide (AW/AL=0.40), antennomere 2 (pedicel) (AW/AL=0.53) and antennomere 3(AW/AL=0.34) longer than wide, inverted piriform, with several macrosetae near apex, antennomeres 1-3 without microtrichae, antennomeres 4-11 oblong shape, the same width from the base to the apex, with microtrichae and several macrosetae, antennomere 4 (AW/AL=0.37), antennomere 5 (AW/AL=0.37), antennomere 6 (AW/AL=0.36), antennomere 7 (AW/AL=0.36), antennomeres 8 (AW/AL=0.36), antennomere 9 (AW/AL=0.39), antennomere 10 (AW/AL=0.39), antennomere 11 (AW/AL=0.27). Labrum transverse, anterior margin emarginate, six setae in the middle and each lateral third with two macrosetae apical and two macrosetae subapical ( Fig. 3 ). Epipharynx with one lobe at each side, length around 2.5 times the median length of labrum. Mandibles with trifurcate apex ( Fig. 6 ), dorsal teeth little shorter than ventral teeth; right mandible with small depression in dorsal tooth and with three setae, left mandible with two setae in a small depression; internal border asymmetrical, in right mandible with an area that resemble a tooth, absent in left mandible ( Fig. 6 ). Maxillary palpus with palpomere 4 shorter than 2 and 3 combined ( Fig. 5 ). Mentum two times wider than long and with five setae in each lateral side ( Fig. 4 ). Neck narrower than head.

Pronotum wider than long (PW/PL=1.79) anterior angles projected forward; longitudinal median sulcus conspicuous; basal constriction represent one-quarter the pronotum length, with small acute projection in the basal constriction; apical three-quarters with parallel sides; slight margination anterior to each abrupt basal constriction with one setae; anterior and posterior margin with microtrichae, one setae near to anterior margin equidistant to longitudinal median sulcus and lateral margin, one setae near to anterior angle in anterior margin, three setae in the anterior angle projected, one setae in the middle lateral margin, one setae near to anterior angle, one setae in slight margination and one in the basal constriction ( Fig. 2 ).

Scutellum visible, developed and triangular in shape, basal portion with fine punctures. Elytra wider than long (EL/EW =1.14). Elytrum with seven striae, sixth stria incomplete; seven setae near to lateral margin, two setae near anterior margin, one in second stria and other in fifth stria, one setae near posterior margin in fourth striae ( Fig. 2 ); posterior margin emarginated. Epipleural carina present.

Legs. Protrochantin transverse; procoxal cavities open and contiguous; procoxae transverse, protrochanter small and subtriangular; profemur robust, base flattened, with several robust short microsetae in base of groove in dorsal view; in ventral view five setae near to anterior margin, two setae near to apex in posterior margin and microtrichae near to base; protibia elongated, apex wider than base, one longitudinal row of robust truncate spines in apical half of external margin, one longitudinal row of setae from apex to two-thirds tibia in margin dorsal, one longitudinal row of setae in internal margin with many setae in third apical, two longitudinal rows of setae from base to two-thirds tibia in ventral margin, crown of six short spines and one medium spine in the apex in ventral view one robust spine on the internal margin of apex, reaching apex tarsomere 2; tarsomeres 1–4 subequal in length with several long ventral setae, tarsomere 1 (TW/TL=1), tarsomere 2(TW/TL=1), tarsomere 3(TW/TL=0.83), tarsomere 4 (TW/TL=0.57), tarsomere 5 (TW/TL=0.30) as large as tarsomeres 1-4 together, pair of claws simple, empodium and pair of empodial setae. Mesotrochantin visible, mesocoxal cavities separated; mesocoxa globose; mesotrochanter small and triangular shape; mesofemur robust; mesotibia elongated, two longitudinal rows of setae in dorsal margin, two longitudinal rows of setae in margin external, one longitudinal row of small setae from middle to apex in internal margin, two longitudinal rows of small setae in ventral margin; six short spines and two medium spines in apex in ventral view; tarsomeres 1–4 subequal in length with several long ventral setae, tarsomere 1 (TW/TL=0.71), tarsomere 2 (TW/TL=0.71), tarsomere 3 (TW/TL=0.71), tarsomere 4 (TW/TL=0.57), tarsomere 5 (TW/TL=0.30) as large as tarsomeres 1–4 together, pair of claws simple, empodium and pair of empodial setae. Metacoxa trapezoidal shape; metatrochanter triangular shape; mesofermur robust; metatibia elongated; two longitudinal rows of setae in dorsal margin, one longitudinal row of setae in ventral, several setae in internal margin, five short spines and two medium spines in ventral view; tarsomeres 1–4 subequal in length with several long ventral setae, tarsomere 1 (TW/TL=0.63), tarsomere 2 (TW/TL=0.63), tarsomere 3(TW/TL=0.63), tarsomere 4 (TW/TL=0.50), tarsomere 5 (TW/TL=0.27) as large as tarsomeres 1–4 together.

Abdomen. Tergites III–VII with punctures only in anterolateral regions, one pair of paratergites; tergites IV–VI with one long setae on each lateral third; sternites IV–VII with six short setae, each lateral third with 3 oblique setae, which start from inferior corner. Tergite VIII slightly curved in apical margin with ten short setae in the apical half ( Fig. 7 ); sternite VIII slightly curved in apical margin with ten long setae in the apical half ( Fig. 8 ); tergite IX in dorsal view divided by tergite X in two equal parts with two long setae in apical half ( Fig. 9 ); tergite IX in ventral view with six setae in apical half; tergite X with two long setae and two short setae on apex ( Fig. 9 ); sternite IX with two short setae in apex ( Fig. 10 ). Median lobe of aedeagus curved ( Fig. 12 ) with bulbous base ( Fig. 11 ), parameres much longer than median lobe in lateral view ( Fig. 11 ), internal sclerites as in Figs. 11–12 .

Female. Similar to male, except apex of sternite VIII slightly acute, gonocoxites divided longitudinally ( Fig. 13 ). The distal plates are small and slender each with a pair of microsetae; the proximal plates are bigger than distal plates with the apex acute ( Fig. 13 ). Spermathecal duct around 3 times the length of spermatheca, duct sclerotized from the base to middle region ( Fig. 14 ).

Habitat. According to the collection labels, the specimen was collected under bark in undisturbed forest.

Distribution. Only known from type locality, Echarate at 579 m of altitud.

Etymology. The specific name “ chullachaqui ” is a Quechua word. “Chulla” means backwards and “chaqui” means foot. The chullachaqui is a character from Peruvian Amazon myths and represents a guardian of the forest. The name is a noun in apposition.

Figures

FIGURES 1 – 6. Piestus chullachaqui sp. nov., holotype male. 1, habitus, dorsal aspect; 2, setae arrangement of head, pronotum and elytra; 3, labrum, left epipharynx and right setae removed; 4, labium; 5, maxilla; 6, mandibles. Scale bars: 2 mm (1 – 2), 0.2 mm (3), 0.4 mm (4 – 6). Dotted areas represent membranous areas.

FIGURES 7 – 14. Piestus chullachaqui sp. nov., holotype male (7 – 12), paratype female (13 – 14). 7, male tergite VIII (T 8); 8, male sternite VIII (S 8); 9, male tergite IX (T 9) and tergite X (T 10), left tergite IX removed; 10, male tergite IX (T 9) and sternite IX (S 9), right tergite IX removed; 11, aedeagus, lateral view; 12, aedeagus, dorsal view; 13, gonocoxites of female, right tergite IX removed; 14, spermatheca. Scale bars: 0.4 mm. Dotted areas represent membranous areas.