Peruphasma marmoratum, Murányi, Dávid, 2007

Murányi, Dávid, 2007, Peruphasma marmoratum, a remarkable new species of high montane Phasmatodea (Pseudophasmatidae: Pseudophasmatinae) from the Venezuelan Andes, Zootaxa 1398, pp. 57-67 : 58-65

Peruphasma marmoratum , sp. n. ( Figs 1–24 )

Type material: Holotype ɗ: VENEZUELA, Mérida state, Andes – Cordillera de Mérida, Mérida, Parque National Sierra Nevada, Pico Espejo, nival region of the peak around the cable car terminal station, N 08º31.854’ W 71º02.707’, 4784m a.s.l., 0 6.04.2005 (locality code: 2005/19), leg. G. Kis, D. Murányi, S. Rózsa ( HNHM). Allotype female (lacks antennae, mouthparts, tarsi, mesofemora and cerci): same locality and date ( HNHM). Paratypes: same locality and date: 1ɗ (lacks head, pronotum and prolegs), 1 immature Ψ, 1 larva ( HNHM), 1ɗ ( ZSMC).

Diagnosis

Medium sized member of the genus. Body dark brown with distinct, marmorated yellow pattern. Tubercles present on the mesonotum. ɗ: poculum slightly bulging, only reaching towards the first quarter of the anal segment. Posterior margin of tergite X has a median protuberance in lateral view. Ψ: Subgenital plate small, only reaching the posterior margin of tergite IX.

Description

ɗ: Medium sized, compact insect, apterous ( Fig 1 ). Legs robust and short, carinated. Body surface granulated and covered with short and thin setae, tubercles present on the mesonotum. General coloration of the body is dark brown with distinct, marmorated yellow pattern on living specimens (become white in alcohol). Legs and antennae dark brown, cerci yellowish. Eyes grey, mandibles, maxilles, labrum and apical segments of palpi yellowish.

Head: Large, slightly longer than wide ( Figs 2–3 ). Oval in cross­section, flattened dorsally and subrectangular in dorsal view. Ocelli absent, eyes prominent, hemispherical. Most of the head dark brown with marmorated yellow pattern arranged in longitudinal lines on the dorsal, irregular on the lateral surface. Frons yellow with a distinct harpoon­like brown mark. Mandible short and wide, lateral margins strongly incurved ( Figs 19–21 ). Incisior lobe with one, molar lobe with three dens, brustia well developed. Antennae short and thick ( Fig 5 ), reaching the abdominal tergite IV. All antennomeres densely covered with fine setae. Scapus 1.5x longer than wide, apical part distinctly flare. Pedicellus longer than wide, club­like, narrower and shorter than scapus. Third antennomere as long as scapus and pedicellus combined, with an incomplete pseudosegmentation in its middle third. Fourth antennomere as long as pedicellus, clubbed. Further antennomeres cylindrical, fifth longer, sixth as long as the fourth, seventh and eight nearly as long as the third, further ones decreasing in lenght. Short and not well defined segments in the apical fifth of the antennae form a flagellum.

Thorax: Oval in cross­section, dorsally flattened. Pronotum ( Figs 6–7 ) as wide as, but one third shorter than head. 1.25x wider than long, sides parallel but with distinct transverse median depression which is closer to the anterior than the posterior margin. Defensive glands well developed. Mesonotom ( Figs 8–9 ) as wide as pronotum but nearly two times longer, slightly broadened towards the posterior margin. Anterior half with five or six short but distinct tubercles arranged in longitudinal line along the lateral sides of a gently commanding anteromedian partion. Metanotum and median segment as wide as the mesonotum but not broadened posteriorly. Metanotum longer than median segment, their combined lenght less than lenght of mesonotum. Transverse fissure between metanotum and median segment indistinct, sinuous. Both dorsal and ventral surface of thorax with distinct, marmorated yellow pattern which is symmetrical to the longitudinal centerline of the body. Pronotum with a transverse yellow band on the anterior margin, more or less complete lateral longitudinal band also present. Vicinity of the defensive glands pale. Dorsal surface with large spots arranged in two C­shaped patterns symmetrical to the longitudinal centerline of the segment. Mesonotum with lateral longitudinal band complete in the first two­third of the segment. Commanding anteromedian partion and lateral sides below the longitudinal band are with small spots, yellow pattern is compiled of larger and longitudinally elongated spots distal to the commanding partion but lacking in the area between the longitudinal band and the commanding partion. Lateral longitudinal band of metanotum and median segment interrupted in the transverse fissure. Dorsal surface with large spots more or less arranged in logitudinal lines. Prosternum with wide lateral bands around the procoxa, large yellow spots becoming smaller and sparse towards the centre of the segment. Mesosternum with small, rounded spots anteriorly to the mesocoxa, lacking in the centerline.

Wide lateral bands present around the mesocoxa, posteromedian part between these bands with only a few small spots. Pattern of the combined metasternum and sternite I similar to the mesosternum, lateral bands end at the transverse fissure.

Legs: All robust and short, carinated, femora slightly granulated ( Fig 4 ). Femora subrectangular, tibiae quadrate in cross­section. Femora and tibiae with setation only along the carinas, tarsal segments densely setated. Spines and teeth are lacking. Profemora straight but clubbed, two times longer than pronotum. Hind legs projecting over the abdomen with one or two tarsal segments. First four tarsal segments decreasing in lenght but pretarsus nearly as long as the first three together. First three tarsal segments flare apically, apical margin undulated, fourth tarsal segment short but ventrally prolonged. Pretarsus subtriangular with a well developed arolium, claws with many setea and an inner carina ( Fig 23 ). First four tarsal segments have a triangular apical field with dense, minute cuticular setae on the ventral surface ( Fig 24 ). Basitarsus 1.5x as long as second segment.

Abdomen: As long as head and complete thorax combined, subcylindrical. Sides of median segment parallel, tergites II–IX broadened towards the posterior margin. Tergites I–VI and IX 1.5x wider than long, tergites VII–VIII shorter. Tergite X subtriangular, slightly longer than wide ( Figs 12–13 ). Posterior margin pointed and with a medial indention as wide as one eight of the tergite’s basal width. Median carina with parallel sides in its posterior half, anterior part triangular. Posterior margin has a median protuberance in lateral view, this protuberance is bulging in caudal view and bear sensilla basiconica ( Fig 22 ). Sternite VIII vestigial, sternite IX simple. Poculum slightly bulging, posterior margin rounded, only reaching towards the first quarter of the anal segment ( Figs 10–11 ). Vomer weakly developed, triangular. Sternite X, paraprocts and epiproct simple. Cerci small, straight, sausage­like, densely setose and with many sensillas. Both dorsal and ventral surface of abdomen with distinct, marmorated yellow pattern besides the mostly dark brown anal segment. Tergites II–IX with complete lateral longitudinal bands. Yellow pattern besides the bands is compiled of spots arranged in eight longitudinal lines. The four inner lines are wider than the lateral four. Tergite X only with a few small spots anteriorly. Sternites II–VII with longitudinal lateral bands, yellow spots arranged in two wide longitudinal lines. Sternite IX with four yellow spots along the anterior margin. Poculum light brown in its anterior third. Two longitudinal yellow bands arise at the anterior third of the lateral margin, nearly reaching the posterior margin while curving inwards. A few small spots present between the bands, lateral areas darker than the central area bordered by the bands. Sternite X lacks yellow pattern.

Penial armature ( Figs 14–15 ): Large, deposited in the segments VII–VIII. Upper penial valves united into a weakly differentiated, membranous sac. Dorsal sclerite of the phallus distinct, anterior part forked, posterior part sinuous and bent around the upper valves. Lower penial valves asymmetrical ( Fig 16 ). Left lower valve has a memranous lower and a sclerotized upper lobe. Right lower valve differentiated into two membranous lobes and a sclerotized, finger­like process with minute spines.

Ψ: Body and extremities generally as in ɗɗ; Because of the very poor condition of the single female, colouration and differences are hard to discuss and only the terminalia described herein.

Terminalia ( Figs 17–18 ): Tergites VIII–IX simple. Tergite X as long as wide, without distinct median carina, posterior margin thickened and straight with two dark patches mediolaterally. Tergite X subtriangular in lateral view. Subgenital plate (operculum) small, only reaching to the posterior margin of tergite IX. Apex pointed, slightly hooked upwards. First valvulae broad, reaching over the tergite IX, blunt. Third valvulae smaller and shorter, end in a blunt tip. Subanal lobe and paraprocts simple. The allotype lack cerci, cerci of the immature female as in ɗɗ.

Nymph: Colouration as in the adults in every aspects. Tibiae and femora more distinctly carinated. Body more slender and legs relatively longer, hind legs of the 13 mm long larva projecting considerably over the apex of the abdomen. Degree of carination and length of the legs more similar to the adults in the 26 mm long immature Ψ, but body still slender.

Egg: unknown.

Affinities

The new species has a rather isolated position within the genus Peruphasma Conle & Hennemann. It can be easily distinguished from all other species of the genus by the presence of tubercles on the mesonotum and the distinct, marmorated yellow pattern on its dark brown body. The very short subgenital plate of the female is also unique for the genus. Regarding to the armature of the mesonotum, the new species also resembles Atratomorpha Conle & Hennemann, 2002 , but differs from this by the lack of a posteromedial tubercle on tergites II–VII, shorter antennae and legs, and mostly cylindrical, not club­like antennomeres.

Ecology and distribution

Peruphasma marmoratum sp. n. was found under stones in the nival belt of the Pico Espejo. This peak is part of the granite chain of the Sierra Nevada and close to the Pico Bolivar (5008 m), the highest point of the Cordillera de Mérida. The habitat of this insect is rather cold and wet, the vegetation consisting of mosses, lichens and a few vascular plants in wind shelters of stones and rocks ( Fig 25 ). The captured specimens were kept alive for a few weeks and were active during the night, drank lots of water but refused to eat. We tried to offer them all of their potential food plants in their habitat (mosses, lichenes, a pigmy carnation and a sedge), as well as Rubus (Rosaceae) and some other plants from the lower regions. It is worth to mention that they never used their well developed defensive glands.

This species seems to be restricted to the highest altitudes, as we could not find it in the upper parámo zone (4000–4300 m) during the three days that we spent there. A single nymph was found in the nival region of the nearby Pico el Toro, but seems to be a distinct species. This peak is separated from the Pico Bolivar and its side­peaks by a 4200 m high pass with parámo vegetation. All this would presume that the insect has a very local distribution, similar to other members of the genus.

Distribution of the genera Peruphasma and Atratomorpha shown on Fig 26 .

Figures

FIGURE 1. Peruphasma marmoratum sp. n. ­ habitus of a living male, photo taken at the type­locality (Pico Espejo)

FIGURES 2 – 5. Peruphasma marmoratum sp. n. – 2: head, dorsal view; 3: head, lateral view; 4: left hind leg, lateral view; 5: antenna, dorsal view – scale 1 mm

FIGURES 6 – 9. Peruphasma marmoratum sp. n. – 6: pronotum, dorsal view; 7: pronotum, lateral view; 8: mesonotum, dorsal view; 9: mesonotum, lateral view – scale 1 mm

FIGURES 10 – 13. Male terminalia of Peruphasma marmoratum sp. n. – 10: ventral view; 11: lateral view; 12: dorsal view; 13: caudal view – scale 1 mm

FIGURES 14 – 16. Penial armature of Peruphasma marmoratum sp. n. – 14: lateral view; 15: ventral view; 16: lower penial valves, ventral view – scale 1 mm

FIGURES 17 – 18. Female terminalia of Peruphasma marmoratum sp. n. – 17: ventral view; 18: lateral view – scale 1 mm.

FIGURES 19 – 24. Peruphasma marmoratum sp. n. – 19: mandible, basal view; 20: mandible, lateral view; 21: mandible, apical view; 22: sensilla basiconica of tergite X; 23: pretarsus of hind leg; 24: apical part of metatarsus, ventral view – scale 1 mm: Figs 19, 21; 0.5 mm: Figs 20, 23; 0.25 mm: Fig 24; 0.2 mm: Fig 22

FIGURE 25. Habitat of Peruphasma marmotratum sp. n.: nival belt of the Pico Espejo (4800 m a. s. l.)

FIGURE 26. Distribution of the genera Peruphasma and Atratomorpha; grey areas are above 2000 m