A SECOND GENUS AND SPECIES OF TERUELPHASMINI YONG, 2017 (PHASMIDA: PHASMATIDAE: CLADOMORPHINAE), FROM THE HIGH MOUNTAINS OF CENTRAL CUBA

A new genus and species of stick insects (Phasmida: Phasmatidae: Cladomorphinae: Teruelphasmini) are herein described based on several adults collected at Pico San Juan (Cienfuegos Province), the highest mountain in central Cuba. Guamuhaya prodita n. gen., n. sp. is the second phasmid genus and species described in the tribe Teruelphasmini and the fourth genus endemic from this island, all belonging to Cladomorphinae. The new genus and species are described and illustrated in detail, including photographs of habitus, morphologically diagnostic characters and habitat.


Introduction
The monotypic tribe Teruelphasmini Yong, 2017 was described very recently from the coastal desert of Guantánamo (southeastern Cuba), to accommodate the single genus and species Teruelphasma stridulus Yong, 2017. This phasmid possesses a very peculiar combination of diagnostic characters, one of the most important being that both tegminae and alae are extremely reduced and strongly modified into a complex stridulatory organ, which produces a clearly audible hissing sound. As described by Yong (2017: 228), this sound is produced by rubbing the pars stridens (gearwheel-like alae stumps) sideways against the immobile plectrum (small triangular tegminae).
In 2015, the author conducted two field trips to survey the orthopteroid fauna of Pico San Juan (1,140 m a.s.l.), the highest mountain of central Cuba, located in the Guamuhaya Massif. Amongst other interesting phasmids, eight specimens of a very peculiar stick-insect were collected; its posterior study revealed it to represent an undescribed genus and species, and more important, the second discovered member of the so far monotypic tribe Teruelphasmini.
The new genus and species are formally described in this paper, which includes a thorough photographic complement. Also, the diagnosis of the tribe is updated accordingly, a necessary step to accommodate its second member.
The most obvious characters that distinguish Guamuhaya n. gen. from Teruelphasma are as follows: 1) sexual dimorphism well-marked, i.e., male much smaller and more slender, cylindrical-bodied and less sculptured than female; 2) completely different habitus, e.g., larger size and a very different coloration, essentially monochromatic and only irregularly spotted; 3) body surface much less sculptured, covered only by small round granules and blunt tubercles, and with minute setiferous tubercles restricted to antennae, maxillary palps, legs and abdomen terminalia; 4) both sexes with pronotum longer than wide, mesothorax very long and slender, and metathorax much longer and more slender; 5) probasitarsus longer and dorsally rounded to vestigially angulose; 6) female with anal segment laterally expanded, operculum wider, and epiproct longer; 7) tegument delicate, thin and only weakly sclerotized; 8) male genitalia with the same basic structure but conspicuously simpler, e.g., poculum less sculptured, vomer much less curved, and cerci less angulose in cross-section; 9) gula apparently present in females only.
As opposite, in Teruelphasma: 1) sexual dimorphism is only subtle, i.e., male smaller and more slender than female; 2) size is smaller and coloration is patterned with parallel stripes of vivid colors, e.g., yellow, white and black; 3) body surface is much more sculptured, covered by large spines and sharp tubercles, and with minute setiferous tubercles covering all cuticular surfaces including membranes; 4) both sexes have pronotum wider than long, mesothorax robust and inflate fusiform, and metathorax much shorter and more robust; 5) probasitarsus is shorter and dorsally lacks any traces of angles or carinae; 6) female has abdomen progressively and evenly narrower distally, operculum narrower, and epiproct shorter; 7) tegument is rough, thick and heavily sclerotized; 8) male genitalia with the structure more complex, e.g., poculum more strongly sculptured, vomer much more curved, and cerci strongly angulose in cross-section; 9) gula apparently present in both sexes.
Distribution. Monotypic genus, known only from top of Pico San Juan, the highest mountain of the Central Cuba ( fig. 10).

Diagnosis. See genus diagnosis above.
Etymology. The selected epithet is a Latin adjective that literally means "revealed, discovered, disclosed". It alludes to the unexpected discovery of this second member of Teruelphasmini in the rainforests of the highest mountain of central Cuba.

Description of adult male holotype
Medium-sized (total length 38.00 mm), slender, cylindrical, micropterus. Legs long, slender, unarmed and strongly carinated. Coloration. Base color pale brownish to silver-gray, without vivid colors and largely immaculate except as follows: whole body with all major tubercles and granules blackish, antennae with flagellar segments irregularly annulated with dark brown, head and prothorax laterally with an irregular but wide, dark brown to blackish stripe on each side, legs diffusely and irregularly infuscate. See figures 1-7 and table 1. Head ( fig. 2). 1.4 times longer than wide, subpentagonal in dorsal view, with genae parallel-sided. Tegument thin and weakly sclerotized, rugose, with small and medium-sized blunt tubercles scattered. Vertex shallowly convex, with a pair of large supra-antennal spines covered by small tubercles. Eyes small, prominent, spherical, occupying 1/4 of genae length; ocelli absent. Genae with exactly the same sculpture as the rest of the head. Antennae filiform, slightly longer than head + thorax, with 18/12 segments which are apically shorter than the others and moderately covered by minute setiferous tubercles; scapus depressed and expanded, two-times longer than wide, oval in cross-section, with two large, deep, parallel furrows all along ventral surface; pedicel cylindrical, half the length of scapus; third segment longer than scapus + pedicel, 16.5 times longer than wide. Gula apparently absent (see detailed discussion in General Remarks section below). Thorax. Tegument thin and weakly sclerotized. Prothorax (fig. 2) subcylindrical and clearly shorter than head. Pronotum longer than wide; anterior margin shallowly concave, lateral margins shallowly concave, posterior margin shallowly convex; median longitudinal and transversal sulci deep and narrow; tegument rugose, with some blunt tubercles scattered and two pairs of large but blunt spines along median longitudinal sulcus: a pair near of the anterior margin and a pair near of the posterior margin, the latter much larger than the anterior pair. Prosternum ( fig. 2, 5) semicircular to crescent-shaped, sensorial area of profurcasternum totally absent. Mesothorax ( fig. 3) elongate cylindrical. Mesonotum 7.3 times longer than wide and 2.8 times longer than head + pronotum; lateral margins straight in dorsal view, anterior margin shallowly concave, posterior margin convex; projecting slightly over metanotum and with a pair of small scale-like tegminae (plectrum); tegument rugose, with abundant small tubercles scattered all over, mediodorsal carina weakly marked, with a pair of large, thick, digitiform tubercles along posterior margin, which are divergent and evenly curved downwards. Metathorax subrectangular ( fig. 4-5), half of mesothorax length, lateral margins concave in dorsal view. Metanotum paraboloid and very short, 10.0 times shorter than mesonotum, with a weak median sulcus; anterior margin basically straight and slightly concealed below posterior margin of mesonotum, with alae modified into a gearwheel-like pars stridens, posterior margin strongly convex; tegument rugose. Meso-and metapleurae essentially with the same sculpturing as mesoand metanotum. Meso-and metasternum rugulose and with some small tubercles scattered.
Legs ( fig. 1, 9). Tegument thin and weakly sclerotized. Procoxae without dorsal spine, with small blunt tubercles scattered. Profemur slender, slightly shorter than mesonotum, conspicuously compressed and basally curved, unarmed, rectangular in cross-section; anterodorsal, posterodorsal, anteroventral and posteroventral carinae strong, straight and each with a row of minute setiferous tubercles all along, medioventral carina raised and with a row of minute setiferous tubercles all along. Protibiae very slender, straight, unarmed, rectangular in cross-section; anterodorsal, posterodorsal, anteroventral, and posteroventral carinae strong, straight and each with a row of minute setiferous tubercles all along, medioventral carina strong and with a row of minute setiferous tubercles all along. Meso-and metafemora slightly narrower basally, similar to profemora in structure. Mesofemora essentially reaching mid length of abdominal segment III. Meso-and metatibiae similar to protibiae in structure. Basitarsus of all legs slightly shorter than the remaining three tarsomeres altogether and dorsally rounded to vestigially angulose. Abdomen (figs. 6-7). Subcylindrical and slightly depressed, tegument thin and weakly sclerotized, rugose, with granules and tubercles arranged into four parallel longitudinal rows. Median segment essentially rectangular, 3.0 times longer than wide and 3.9 times longer than metanotum; anterior margin strongly concave, lateral margins shallowly concave, posterior margin shallowly convex and with a pair of small tubercles. Segments II-V quite homogeneous in size and shape, with anterior and posterior margins straight to shallowly convex, 1.6-2.0 times longer than wide, with two pairs of small tubercles near posterior margin, the submedian pair slightly longer. Segment VI slightly narrower, with lateral margins straight and divergent backwards. Segments VII-IX progressively shorter, wider than long. Segment VIII trapezoidal in dorsal view and weakly carinate; anterior and posterior margin shallowly convex, lateral margins slightly divergent backwards. Segment IX shorter than previous segments, convex dorsally and with anterior and posterior margin noticeably convex. Anal segment tectiform in dorsal view, with a strong, coarse mediodorsal carina and lateral longitudinal carinae well defined but weaker than mediodorsal carina; anterior margin shallowly convex, lateral margin straight and posterior margin symmetrically bilobed, curved downwards, highly sclerotized and irregularly but weakly toothed; ventral surface concave, with a coarse, crescent-shaped, subapical transverse carinae medially raised into a sharp, narrow, symmetrical lobe which projects beyond posterior margin. Vomer well-developed, moderately sclerotized, subtriangular and asymmetrically curled like a corkscrew tip: left lateral margin straight to slightly convex, right lateral margin moderately concave, apex weakly curved first rightwards and then upwards as a thick, pointed hook. Cerci long, slightly projecting beyond tip of anal segment, densely covered by minute setae and simply shaped: digitiform, weakly angulose in cross-section and slightly depressed. Poculum strongly elevated and subtriangular in lateral view, with anterior margin straight and posterior margin strongly produced into a paraboloid lobe.

Description of adult female paratype
Size much larger than male (total length 53.85 mm including subgenital plate), micropterus.
Coloration. Similar to male, but conspicuously darker and with extensive irregular infuscation all over, operculum with distal half yellowish-brown and a diffuse, wide, blackish longitudinal stripe all along median line. See figures 1-7 and table 1.
Head ( fig. 2). 1.4 times longer than wide and more strongly sculptured, roundly subpentagonal in dorsal view, with genae parallel-sided. Tegument thin and weakly sclerotized, rugose, with small and medium-sized tubercles scattered. Vertex shallowly convex, with a pair of medium supra-antennal spines and with some tubercles scattered. Eyes small, prominent, spherical, occupying 1/4 of genae length; ocelli absent. Genae with exactly the same sculpture as the rest of the head but without tubercles. Antennae filiform, shorter than head + thorax, with 19/17 segments which are apically shorter and densely covered by short setae and minute setiferous tubercles; scapus subrectangular, globose, with external margin essentially straight and internal margin convex; pedicel cylindrical, oval in cross-section, about 1/2 the length of scapus; third segment almost as long as scapus + pedicel. Gula apparently present (see detailed discussion in General Remarks section below). Thorax (figs. 2-4). Tegument thin and weakly sclerotized, rugose, with blunt tubercles scattered. Prothorax (figs. 2) moderately depressed and slightly shorter than head. Pronotum clearly longer than wide; anterior margin shallowly concave, lateral and posterior margins shallowly convex; median longitudinal and transversal sulci deep and narrow, median longitudinal sulcus basically straight and median transversal sulci U-shape. Pronotum with two pairs of tubercles, each near both anterior and posterior margins, the posterior pair clearly larger than the anterior pair. Prosternum semicircular to crescent-shaped, sensorial area of profurcasternum ( fig. 5) absent. Mesothorax (fig. 3) elongate fusiform and moderately robust; tegument rugose, with small tubercles scattered. Mesonotum 4.7 times longer than wide and 2.9 times longer than head + pronotum; anterior margin shallowly concave, lateral margins shallowly convex in dorsal view, posterior margin convex, with two large, blunt tubercles projecting slightly over metanotum and with a pair of small scale-like tegminae (plectrum). Metathorax ( fig. 4) sub-rectangular. Metanotum 8.3 times shorter than mesonotum, structurally very similar to male but comparatively larger and more finely granulose; alae modified into a gearwheel-like pars stridens. Mesopleurae with a row of blunt tubercles on each side along lateral margins (13/13 tubercles on left/right sides, respectively). Metapleurae with a longitudinal row of variously-sized blunt tubercles, which are stronger towards the median part of mesopleurae and more homogeneous on metapleurae. Meso-and metasternum rugulose and weakly tuberculate.
Legs ( fig. 1). Generally as in male, but relatively longer and more robust. Abdomen (figs. 6-7). Tegument thin and weakly sclerotized. Median segment basically rectangular, 1.5 times longer than wide and 2.2 times longer than metanotum, similar in structure to the latter; anterior margin strongly concave, lateral margins shallowly concave, posterior margin shallowly convex. Segments II-VII quite homogeneous in size and shape, 1.0-1.3 times longer than wide, with segments I, VI and VII slightly shorter; subcylindrical in dorsal view, each with a pair of small, blunt tubercles near posterior margin, which are progressively larger along abdomen; lateral margins essentially straight. Segment VIII in dorsal view with lateral margins divergent backwards, with a pair of blunt tubercles near posterior margin.  Segment IX subrectangular but bulky in dorsal view, 1.5 times shorter than VIII, with a pair of strong tubercles near the posterior margin (left one bifurcate, right one larger). Segment X (anal segment) laterally moderately expanded, sloping down posteriorly and strongly carinated; lateral margins convex to angulose, distal half of lateral margins with three crenulations on each side. Epiproct (supra-anal plate) very well developed, 1.3 times longer than wide, conspicuously exposed, narrowly paraboloid and remarkably tectiform, with dorsal carina very strong; lateral margins serrate, with edges covered by minute setiferous tubercles. Cerci very short and conical. Sternites II-VII rugose, with small granules scattered. Preopercular organ very well-developed, heavily sclerotized, dark, strongly raised and with surface coarsely rugose, shaped like a transverse hourglass, i.e., anterior and posterior margins V-notched, lateral margins shallowly convex. Operculum (subgenital plate) not projecting beyond tip of abdomen, i.e., much shorter than epiproct, lanceolate in ventral view; anterior and lateral margins shallowly convex, posterior margin sharply subtriangular, lateral edges covered by minute setiferous tubercles.  Variation. Coloration is essentially identical in all six types; the few minor differences observable are all artifacts of preservation. Live individuals exhibit the same basic coloration and pattern, but it is much more vivid and sharply contrasting ( fig. 9). Both males measure about 38 mm, but total length in females range from 45.20-53.85 mm (tab. 1). Female and male paratypes ( fig. 9) show some minor variations in sculpture of head and body, i.e., slight differences in amount, density and size of cuticular tubercles.
Eggs (figs. 8). Capsule fusiform, elongate-slender (5.0 times longer than wide) and straight. Surface smooth and coriaceous, i.e., without any relevant sculpturing such as spines, granules, wrinkles or filaments. Capitulum digitiform, elongate-slender (3.8 times longer than wide), shaped variably from straight to curved downwards. Operculum round, with surface coarsely and irregularly rugose. Micropylar plate lanceolate, very long and narrow (4.47 times longer than wide and essentially half the capsule length), with anterior portion paraboloid and posterior portion W-shaped. Centre of micropylar plate faintly rugose. Micropylar cup very distinct, located just at posterior region of micropylar plate. Polar area with a few distinct teeth.
Coloration. Fresh eggs are irregularly variegated with dark olivaceous brown and pale silver-gray. After alcoholic preservation, it changes to light brown and the dark pattern conspicuously fades. Measurements  Distribution. Known only from type locality (see genus section and figure 10). Taking into account the great homogeneity of relief, soil and vegetation across the highest peaks of Guamuhaya Massif, this species is expected to be more widespread there.
Ecological notes. Despite intensive searches during daytime, all specimens of Guamuhaya prodita n. gen, n. sp. were found exclusively at night. Most of them were detected on peripheral twigs of a single bush (Pilea sp., Urticaceae), except two males and a female walking on a concrete sidewalk about 200 m away, near the meteorological station.
This species was collected only at the mountaintop, where the cloud forest vegetation is shorter and sparser due to the strong wind incidence ( fig. 11). Repeated searches just a few meters below in the taller and deeper rainforest, were unsuccessful.
In August 2015, two mating pairs were found together on the same plant. Females never simply dropped the eggs, but instead attached them to vertical surfaces such as plant stems or house walls. Eggs were always attached to the substratum all along the ventral surface of the capsule.
Pico San Juan (1,140 m a.s.l.) is the highest peak of the Guamuhaya Massif and by extension, also of the central region of Cuba (fig. 10). The primary vegetation is still well preserved, montane rainforest and cloud forest (Capote & Berazaín, 1984). The climate is temperate by day and in summer months, but cold at night and in winter. Teruelphasma (2). The lower left inset shows the Guamuhaya mountains in detail, with the precise type-locality of Guamuhaya prodita n. gen., n. sp. Figure 11. Pico San Juan, type-locality of Guamuhaya prodita n. gen., n. sp.: a) from a north-facing perspective; b) from a south-facing perspective. See the concrete sidewalk and low bushes on the roadside, where the type-series was collected.

General remarks
Two additional adult males were collected on 19-27/February/2015 by the present author and T. M. Rodríguez, but both were originally preserved dry-pinned and latter unfortunately destroyed by a collection pest. These two specimens were found at night, walking on a concrete sidewalk.
The new genus described herein is remarkable for its very peculiar combination of morphological characters, but otherwise it is undoubtedly a member of Teruelphasmini. It is evident in the shared possession of the same unique type of complex stridulatory organ (with identical plectrum and pars stridens), size and shape of metanotum, structure of male and female genitalia, sculpture and carination of body and legs, and, also for the obscure condition of the gula (see detailed discussion below).
It is crucial to discuss here about the gula in Teruelphasmini. When the tribe was diagnosed according to its (then) single genus Teruelphasma, it was regarded as absent (Yong, 2017: 228), but the discovery of Guamuhaya n. gen. and the recent acquisition of additional material and literature has forced to reconsider this statement. Actually, the presence or absence of gula cannot be defined with certainty in any genus of the tribe, because the separation of this plate from adjacent cervix is not clearly delimited.
Unfortunately, although repeatedly used as a diagnostic character in recent taxonomic revisions such as that on Cladomorphinae by Hennemann et al. (2016), usually the gula is only briefly mentioned and no images are provided. But the few contributions where it has been illustrated, the gula is depicted as a wellsclerotized plate with precisely defined margins that allow a clear-cut distinction from the adjacent, soft membranose cervix (e.g., see Bradler, 1999: figs. 2a,b,c, andBuckley et al., 2008: figs. 3a,b,c).
As depicted by Yong (2017: fig 2c), both sexes of Teruelphasma possess the cuticle of the entire body so thick and heavily sclerotized that the whole ventral surface of head surrounded by the submentum, genae and probasisternum (which by definition must include the cervix and a gula if present), is also largely hardened and covered by granulation and minute setiferous tubercles. There is a narrow transverse suture where the predicted separation between gula and cervix is expected to occur (more evident in female due to heavier sclerotization and armature), but it is not a true membranose split and thus, it cannot be interpreted categorically as such.
And as depicted in fig. 2c of the present paper, both sexes of Guamuhaya n. gen. possess the cuticle of the whole body very thin and poorly sclerotized, including the ventral surface of the head. In males, the area surrounded by the submentum, genae and probasisternum is membranose and paler, thus, it may be interpreted as lacking a gula. But in females, it is as sclerotized and dark as the rest of the head and again there is a narrow transverse suture where the predicted separation between gula and cervix is expected to occur, but as in Teruelphasma, it is not a true split.
Although not categorically, it seems now pertinent to regard the gula as apparently present in both sexes of Teruelphasma and in female Guamuhaya n. gen. only, until more detailed studies can be made on this subject, e.g., SEM imaging.
The great dissimilarity in cuticle sclerotization and armature between the two known genera of Teruelphasmini represents a classic example of high differential adaptation to opposite, yet extreme ecological conditions. On one end, the thick, heavily sclerotized and spinose tegument of Teruelphasma is a well-known adaptation to the aridity of the hot, dry coastal desert where it occurs, in response to the critical need of reducing water-loss and avoid desiccation. And the reverse is true for Guamuhaya n. gen., which inhabits a temperate and very humid montane rainforest and in turn has developed a thin, poorly sclerotized and almost unarmed tegument.
With the addition of the new genus to Teruelphasmini, it becomes necessary to reevaluate and introduce minor updates to the tribe diagnosis:  Size very small to medium for the subfamily (body length: males 29-38 mm, females 42-54 mm including subgenital plate), body moderately slender, with sexual dimorphism subtle to well-marked: male always much smaller and more slender than female, and occasionally also with different body shape (cylindrical in male, fusiform in female). Metanotum short, noticeably wider than long. Both sexes micropterus, with tegminae and alae extremely reduced and strongly modified into a complex stridulatory organ (plectrum + pars stridens). Entire body surface rugose, sharply spinose to blunt tuberculate, and with dense cover of minute setiferous tubercles always present but variable in extension. Gula apparently present in female, absent or present in male. Sensorial area absent. Legs unarmed and distinctly carinate, medioventral carina of meso-and metafemora distinct; probasitarsus very short, dorsally rounded to vestigially angulose, but lacking any dorsal carinae and lobes.
As seen from above, the unexpected discovery of this second genus has actually strengthen the definition of Teruelphasmini, especially because it occurs in completely opposite ecological conditions. This allowed to corroborate the validity of the characters originally selected to justify the tribe-rank separation made by Yong (2017) on the basis of the (then) single known genus, by revealing that essentially all these characters were correctly judged and not the result of a single, extreme ecological adaptation by Teruelphasma. Moreover, it also made possible to describe the first eggs of this tribe. The distribution of Teruelphasmini remains endemic from Cuba, but now includes two monotypic genera widely disjunct in a humid mountaintop and a coastal desert of the central and eastern regions of the island, respectively ( fig. 10). This could indicate that this tribe is a very ancient and formerly widespread lineage of the Cuban phasmid fauna, which nowadays has become represented only by isolate, relict remnants. Or conversely, it could suggest that it is a diverse group of multiple micro-endemic taxa adapted to very specific ecological conditions, which still remain largely undiscovered.