Trychopeplus thaumasius Hebard, 1924

Hennemann, Frank H. & Conle, Oskar V., 2024, Studies on Neotropical Phasmatodea XXVI: Taxonomic review of Cladomorformia tax. n., a lineage of Diapheromerinae stick insects, with the descriptions of seven new genera and 41 new species (Phasmatodea: Occidophasmata: Diapheromerinae), Zootaxa 5444 (1), pp. 1-454 : 290-293

publication ID	https://doi.org/ 10.11646/zootaxa.5444.1.1
publication LSID	lsid:zoobank.org:pub:5DE4A9DD-99F7-4E23-AD50-58DC491BB75E
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treatment provided by	Plazi
scientific name	Trychopeplus thaumasius Hebard, 1924
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Trychopeplus thaumasius Hebard, 1924 View in CoL

( Figs. 80A, 80C–E View FIGURE 80 , 124 View FIGURE 124 )

Trychopeplus thaumasius, Hebard, 1924: 148 View in CoL , pl. 6: 8 & 9 (♀).

Ott1, 1978: 78.

Zompro, 2001: 230.

Otte & Brock, 2005: 339.

Brock & Büscher, 2022: 515.

= Trychopeplus ortho-lamellatus Campos, 1926: 15 View in CoL , pl. (♀). syn. n.

Otte & Brock, 2005: 339.

Brock & Büscher, 2022: 515.

Diagnosis. Females (the only sex known) are readily seperated from the other two known species by the much larger size. They are similar to T. laciniatus ( Westwood, 1874) from Central America but differ by the generally smoother dorsal body surface (metanotum, median segment and abdominal terga in particular), unarmed pronotum ( Fig. 80D View FIGURE 80 ), having the dorsal excrescences of the mesonotum rather foliaceous with entire margins (multi-dentate in laciniatus ), relatively larger foliaceous lateral appendages of abdominal tergum III, larger lobes of the extremities, which have their marginal projections more rounded, and slender cerci, which are not thickened apically.

Description. ♀ ( Fig. 80A View FIGURE 80 ): The very detailed original description provided by Hebard (1924) and description of the synonymous T. ortholamellatus by Campos (1926) are sufficient and make a re-description needless. However, since the colouration of both specimens was based on the discoloured dried type specimens a description of the colouration based on photographs of live specimens taken by Andreas Kay ( Figs. 124A–D View FIGURE 124 ) appears desirable. General colour of body various shades of green with the dorsal portions of the posterior section of the mesonotum, entire metanotum and abdominal terga greyish dull brown. Head green with the cephalic lobes orange apically; antennae with the basal three antennomeres green and the remaining ones black. Pronotum pale creamish green with the lateral portion dark brown. Anterior half of mesonotum with a faint brown medio-longitudinal streak and metanotum with a conspicuous pale creamish to whitish green V-shaped marking. The large ventral meso- and metafemoral lobes and lateral lobes of the abdominal terga with irregular brown and black maculations.

Comments. The ♀ holotype of T. ortholamellatus Campos was stated to be deposited in this author’s collection (coll. Prof. F. Campos) but unfortunately could not yet be located. Hence, it must be presumed lost. Careful comparison of the original description and illustration of the specimen provided by Campos (1926: 17) and taking the great intraspecific variability of Hebard’s T. thaumasius into account leaves no doubt that it is a synonym (syn. n.). Examination of photographs of several live specimens of T. thaumasius from differernt localities in Ecuador and Colombia, show this species to show a great deal of intraspecific variability and all distinguishing features mentioned by Campos appear to lie within the range of variability of this species. Coniderable variability is basically seen in all appendages and excrescences of the head, body and extremities, including the large ear-like lobes of the head, lobate mesonotal excrescences, lateral appendages of the meso- and metapleurae, lateral lobes of abdominal terga II–VIII as well as the teeth and lobes of all legs. The still undescribed ♂♂ and eggs are only known from photographs.

Specimens from Colombia, listed as T. laciniatus (Westwood) by Conle et al. (2011: 57) appear to be this species.

Table 69. Measurements of Trychopeplus spp.

* apex of subgenital plate missing. Campos (1926: 17) cited 119.0 mm for the HT of the synonymic T. ortholamellatus .

5.25. Genus Xylodus Saussure, 1859

( Figs. 6D View FIGURE 6 , 81–82 View FIGURE 81 View FIGURE 82 , 83H–J View FIGURE 83 , 94B View FIGURE 94 , 104F View FIGURE 104 )

Type-species: Xylodus adumbratus Saussure, 1859: 62 (= C. ceratocephalus Gray, 1835 ), by original monotypy

Xylodus Saussure, 1859: 62 View in CoL .

Kirby, 1904: 357.

Redtenbacher, 1908: 425. (As a synonym of Cladomorphus Gray, 1835 )

Bragg, 2001: 627.

Zompro & Brock, 2003: 6. (Re-established as a valid genus)

Otte & Brock, 2005: 344.

Hennemann & Conle, 2007a: 3.

Hennemann & Conle, 2010: 103.

Brock & Büscher, 2022: 547.

Cladomorphus, Kirby, 1904: 357 View in CoL .

Otte & Brock, 2005: 94 (in part).

Phibalosoma, Westwood, 1859: 71 , pl. 36: 2 (in part).

Redtenbacher, 1908: 425 (in part).

Description. ♀, ♂ ( Figs. 81–82 View FIGURE 81 View FIGURE 82 ): Medium-sized (body length ♂♂ 115.0 mm, ♀♀ incl. subgenital plate 148.0– 150 mm) stocky Cladomorphini with short and stocky legs that have most of their carinae deflexed. ♀♀ wingless, ♂♂ with short tegmina and well-developed alae. Colouration of ♀♀ lichenose, consisting of various shades of white, grey, ochre and brown; ♂♂ generally with less white and grey colouration than ♀♀. Head globose with vertex strongly convex, raised and armed with a pair of crenulate, laterally compressed, auriform lobes; otherwise set with a few paired conical tubercles and granules ( Figs. 82G–H View FIGURE 82 ). No ocelli. Eyes very large and projecting more than hemispherical in ♂♂, their diameter about equal to length of genae; notably smaller in ♀♀. Antennae fairly strong and slightly compressed dorsoventrally; reaching to posterior margin of median segment in ♂♂ and about three-quarters the way along mesothorax in ♀♀. Scapus strongly compressed dorsoventrally with the lateral margins roundly deflexed (♀♀ in particular). Scapus oval in cross-section and much shorter than pedicellus, antennomere III longer than pedicellus, IV transverse and the following gradually increasing in length. Pronotum narrower than head, rectangular and with the transverse median sulcus shallow; surface granulose. Mesothorax in ♂♂ 3.7x longer than pronotum, slender and of uniform width; in ♀♀ only 3.4x longer than pronotum, slightly widened towards the posterior and somewhat swollen medially. Mesonotum with a fine medio-longitudinal carina; in ♂♂ irregularly set with black node-like granules; in ♀♀ slightly gibbose and with an obtusely tubercular, strumose swelling pre-medially and a small median swelling at posterior margin, the surface unevenly rugose and sparsely granulose. Meso- and metapleurae and sterna irregularly set with black node-like granules in ♂♂; unevenly rugose and weakly tubercular in ♀♀. Metanotum of ♀♀ rectangular and about 1.3x longer than wide with the posterior margin distinctly swollen and obtusely raised medially. Tegmina of ♂♂ strongly narrowed in basal portion, the apical half obtusely angular and the central hump fairly distinct. Alae projecting over posterior margin of abdominal segment V. Median segment in ♂♂ much longer than metanotum, in ♀♀ about equal in length to metanotum. Abdominal segments II–VII uniform in width, in ♂♂ at least 2.5x longer than wide and gradually decreasing in length, in ♀♀ II–V increasing and VI–VII decreasing in length with VI the longest segment and 1.7x longer than wide. All terga with an obtuse longitudinal median carina (slightly rugose and with weakly indicated longitudinal carinae in ♀♀), tergum V with a tri-carinae transversely scale-like excrescence at posterior margin ( Figs. 82C–E View FIGURE 82 ) and VI with a much smaller posteromedian protuberance. Praeopercular organ of ♀♀ prominent and formed by two triangular, acutely tooth-like lobes at posterior margin of sternum VII ( Fig. 82A View FIGURE 82 ). Terminalia of ♀♀ ( Fig. 82C View FIGURE 82 ): Three terminal terga strongly shortened and their combined length hardly more than length of tergum VII. All obtusely tectate longitudinally, IX and X almost 2x higher than long. Cerci very small and obtuse, almost fully hidden under anal segment. Gonoplacs conspicuously enlarged, ovate and somewhat spatulate in outline and laterally compressed and carinate, projecting beyond posterior margin of anal segment. Gonapophyses VIII elongated and their distinctly upcurved apex projecting notably beyond apex of subgenital plate ( Fig. 82A View FIGURE 82 ). The subgenital plate very strongly and acutely keeled longitudinally ansd projecting beyond apex of abdomen roughly by length of anal segment; apex rounded and the upper margins somewhat undulate. Terminalia of ♂♂ ( Fig. 6D View FIGURE 6 , 82D–F View FIGURE 82 , 94B View FIGURE 94 ): Tergum VIII trapezoidal and widened towards the posterior. Anal segment shorter than IX with an obtuse longitudinal median keel and narrowed towards the posterior; the posterior margin somewhat swollen, with a shallow median indention and set with very minute denticles ventrally. Epiproct very small. Cerci cylindrical, straight and slightly projecting beyond posterior margin of anal segment. Vomer large, elongate and somewhat tapered towards the apex, which has two short terminal hooks; ventral surface with a deep medio-longitudional furrow ( Figs. 6D View FIGURE 6 , 94B View FIGURE 94 ). Poculum bulgy, rounded cup-shaped and with a long spatulate apical protrusion that extends beyond anal segment by more than the combined length of the three terminal terga ( Figs. 82D–F View FIGURE 82 ). Legs fairly short and stocky with all carinae distinct and the outer ventral carinae of the protibiae and the mid and hind legs in particular deflexed (more strongly towards the apex). Anterodorsal carina of profemora weakly undulate, the posteroventral carinae of the protibiae strongly lamellate and undulate in ♀♀. Posterodorsal carina of meso- and metatibiae with a prominent dentiform apical lobe and the two outer ventral carinae occasionally with a tooth pre-medially. Meso- and metatibiae with a distinct medio-dorsal lobe. Tarsi very short, the basitarsi at best as long as following two tarsomeres combined and with a rounded dorsal lobe.

Differentiation. Very similar and possibly the sister-taxon of Cladomorphus Gray, 1835 . It may however be distinguished by: the smaller size; more robust body; more prominent and crenulate cephalad horns of the vertex and relatively shorter mesothorax of both sexes, which is less than 2x the length of the head and pronotum combined (>2x in Cladomorphus ). Females also differ by the dorsomedially swollen mesonotum, relatively shorter abdominal terga VIII–X and subgenital plate, conspicuously enlarged gonoplacs ( Fig. 82A View FIGURE 82 ) and much more undulate and lamellate carinae of the mid and hind legs. The short mesothorax resembles Hirtuleius Stål, 1875 but the prominent cephalad horns of both sexes, as well as the strongly undulate mid and hind legs and shorter, undulate subgenital plate of ♀♀ as well as the long apical appendix of the poculum of ♂♂ readily distinguish Xylodus from that genus.

Comments. Saussure (1859: 62) described Xylodus to contain the Brazilian X. adumbratus Saussure, 1859 . Redtenbacher (1908: 425) interpreted Xylodus as a synonym of Phibalosoma (= Cladomorphus Gray, 1835 ) and correctly synonymised the type-species X. adumbratus with Cladomorphus ceratocephalus Gray, 1835 . Zompro & Brock (2003: 6) did not accept Redtenbacher’s synonymy of the genus and re-established Xylodus on the basis that the morphology of the genitalia was “strikingly different” from that of Cladomorphus . However, the differences in genital morphology postulated by Zompro & Brock (2003: 6) are based on the fact that the holotype of X. adumbratus is a penultimate instar ♀ nymph and genital features are not fully developed in immature insects ( Fig. 81D View FIGURE 81 ). The only differences in the genital morphology of the ♀♀ if compared to Cladomorphus are the relatively shorter abdominal terga VIII–X, slightly shorter subgenital plate and more strongly enlarged gonoplacs ( Fig. 82C View FIGURE 82 . Zompro & Brock (2003) also made no mention of the synonymy of X. adumbratus established by Redtenbacher (1908: 427), who synonymised it with C. ceratocephalus and described the ♂ based on a specimen in the collection of ZMUH. This synonymy was also omitted by Otte & Brock (2005) and in the key to the genera of New World anreolate taxa presented by Zompro (2004b), which does not mention the ♂ of Xylodus . Examination of the ♀ holotype of Phibalosoma michaelis Redtenbacher, 1908 in the collection of NHMW ( Figs. 81A–B View FIGURE 81 ) has proven this to represent the same distinctive and fairly variable species, hence it is here synonymised with C. ceratocephalus (syn. n.). Thus, Xylodus is a monotypic genus.

Careful examination of the type specimens of all three species and the ♂ in ZMUH reveals other features that distinguish C. ceratocephalus ( = adumbratus , = michaelis ) from C. phyllinus , the type-species of Cladomorphus . Actually, the relatively shorter subgenital plate and dorsomedially more swollen mesonotum used as distinguishing features in the key presented by Zompro (2004b: 141) distinguish this species from representatives of Cladomorphus , but if compared to the adult insects both features are merely seen to be more strongly developed in the immature holotype of X. adumbrates ( Fig. 81D View FIGURE 81 ). The more prominent, crenulate cephalad swellings of the vertex, which were used for distinguishing Xylodus from Cladomorphus in the provisional key presented by Hennemann & Conle (2010: 103), and relatively shorter mesothorax of both sexes of Xylodus are the only features that allow a sufficient distinction between Xylodus and Cladomorphus . The conspicuous apical appendix of the poculum is shared by both genera, which indicates very close relation between Xylodus and Cladomorphus , however the basal portion of the poculum is more fornicate in Xylodus . Eggs unknown.