Ramulus torajanus, Hennemann, 2021

Hennemann, Frank H., 2021, Stick insects of Sulawesi, Peleng and the Sula Islands, Indonesia- a review including checklists of species and descriptions of new taxa (Insecta: Phasmatodea), Zootaxa 5073 (1), pp. 1-189 : 84-88

Ramulus torajanus n. sp.

( Figs. 34 , 35C–D )

HT, ♂: S-Sulawesi, Prov. Sulawesi Selatan, Tana Toraja, Rantepao 700 m, leg. Tajuddin X.1995 – II.1996 [ ZSMC, ex coll. FH] .

PT, 12 ♂♂, 1 ♀, 1 ♀ (penultimate instar), 2 ♂♂ (penultimate instar), 1 egg: S-Sulawesi, Prov. Sulawesi Selatan, Tana Toraja, Rantepao 700 m, leg. Tajuddin X.1995 – II.1996 [ FH, No’s 1064-3 to 18, E] .

PT, 2 ♂♂: S-Sulawesi, Prov. Sulawesi Selatan, Tana Toraja, Strasse von Rantepao nach Palopo km23, ca. 800 m, leg. F. Hennemann 13.–18.VIII.1995 [coll. FH, No’s 1064-1 & 2] .

Etymology: Named to honour the Toraja, an ethnic group indigenous to the central highland of South Sulawesi, the Tana Toraja regency in the province Sulawesi Selatan.

Differentiatial diagnosis: Very similar and closely related to the sympatric R. globosicaput (Brunner v. Wattenwyl, 1907). Both sexes differ by the avaraging larger size, more slender shape, relatively longer legs and smaller ventral sub-apical teeth oft he meso- and metafemora of both sexes. Males differ by the more or less plain brown head ( Figs. 34K–L ; green with dark markings in globosicaput , Figs. 29L–M ), contrasting dark brown three terminal abdominal segments and longer, more slender hemi-terga of the anal segment ( Fig. 34F ). Females can be distinguished by the more elongate and less globose head which only bears small dark markings, longer anal segment that has the posterior margin more deeply and narrowly incised medially and larger epiproct ( Fig. 34D ). The eggs readily differ from those of R. globosicaput by the larger size, more slender and less strongly sculptured capsule surface and less distinct dorsal projection of the operculum ( Figs. 35C–D ). Males also strongly resemble those of R. melanurus n. sp. but differ by the less globose head (almost spherical in melanurus , Fig. 30C ), brownish scapus and pedicellus, not black three terminal abdominal segments, somewhat broader and shorter hemi-terga of the anal segment ( Fig. 34F ) and lack of a posteromedian hump on abdominal terga V and VI.

Description: The colouration is described from dried specimens only. Unfortunately, the unique ♀ is damaged, having the head capsule and abdomen squashed laterally and lacking the left antenna. Hence, the morphology of the eyes cannot be described because they are pushed into the head capsule.

♀ ( Fig. 34A ). Of average size for the genus (body length 122.0 mm), form slender, body surface entirely smooth and very slightly shiny, the head fairly globose and unarmed, the subgenital plate strongly keeled longitudinally and roughly reaching apex of abdomen and the legs unarmed. General colour various shades of dull ochre with the abdomen somewhat lighter in colour and yellowish. Genae usually dark brown to black in portion anterior to the eyes. Pronotum with two closely placed, parallel, longitudinal black streaks along median line. Lateral surfaces of thoracic segments and the posterior portions of the abdominal terga irregularly marbled with dark brown or black. Abdominal terga IX and X and posterior half of subgenital plate almost entirely blackish brown. Head ochre and with distinct longitudinally directed black markings on genae, behind the eyes and posteromedially; two very conspicuous short black lateral stripes in median portion of vertex.Anterior portion of genae and upper half of mandible black. Eyes dark reddish brown. Antennae dark brown. Legs faintly annulated with ochre and mid brown, the ochre bands on both sides bordered by a narrow dark brown band; apical portion of all femora dark brown.

Head: Strongly globose, ovoid and about 1.3x longer than wide, broadest at eyes; vertex rounded and smooth. Frons with two very shallow indentions. Antennae 1.3x longer than head and pronotum combined, consisting of 25 antennomeres. Scapus strongly flattened dorsoventrally with the outer lateral margin very weakly rounded and the interior lateral margin straight, somewhat narrowed towards the base and 3x longer than wide. Pedicellus a little more than 1/3 the length of scapus, cylindrical. III much longer than pedicellus, the following antennomeres gradually decreasing in length, only the two terminal ones considerably longer than preceding; terminal antennomere longest of all.

Thorax: Pronotum shorter and much narrower than head, roundly rectangular in dorsal aspect with the sub-anterior portion slightly narrowed; about 1.4x longer than wide. Transverse median sulcus strongly pronounced, deeply impressed, straight in the median portion with the outer portions bent towards the anterior; expanding over entire width of segment. Meso- and metanotum with a very fine and indistinct longitudinal median line. Mesothorax about 2.8x longer than head and pronotum combined and almost 1.5x longer than metanotum. Metanotum about 6x longer than wide.

Abdomen: Median segment indistinctly trapezoidal with the posterior margin slightly wider than the anterior margin, its length contained about 6.2x in that of metanotum. Abdomen excluding median segment notably longer than head and complete thorax combined. All abdominal segment roughly uniform in with but sub-equal in length; II about 3x longer than median segment and 3.2x longer than wide; II–IV increasing in length, V–VI slightly decreasing and VII as long as VI; IV–VI on average 3.6x longer than wide. Preopercular organ almost obsolete and merely represented by a very weakly swollen and shiny posteromedian area on sternum VII ( Fig. 34E ). Tergum VIII about ¾ the length of VII, IX about 1/3 the length of VIII. Anal segment tectiform longitudinally, longer than IX, about 1.5x longer than high and slightly narrowed in the apical portion; posterior margin with a very deep and narrow incision and the posterolateral angles obtusely angular ( Fig. 34D ). Epiproct fairly large, longer than wide, tectinate longitudinally, triangular and notably projecting beyond anal segment ( Fig. 34D ). Cerci not visible in the unique specimen at hand. Gonapophyses VIII enlarged, broadened and shovel-shaped, gonapophyses IX slender, straight and about equal in length ( Fig. 34C ). The gonoplacs filiform, gently up-curving and roughly reaching to apex of gonapophyses. Subgenital plate elongate, strongly convex and keeled longitudinally, the ventral margin almost straight over most of the length and gradually bent upwards only in the apical portion; the dorsal margins bent downwards apically; roughly reaching to apex of epiproct ( Fig. 34C ).

Legs: All long and slender with all carinae covered by fine, black setae. Anterodorsal carina of profemora with a few small but acute denticles and 4–5 minute denticles present on posterodorsal carina of meso- and metafemora. A single but fairly distinct black sub-apical tooth on the well defined medioventral carina of the meso- and metafemora ( Fig. 34J ). Both dorsal carinae of metatibiae with a few minute teeth in apical portion. Profemora slightly longer than head, pro- and mesothorax combined, mesofemora a little longer than mesothorax, metafemora reaching about 2/3 the way along abdominal segment V and metatibiae slightly projecting beyond apex of abdomen. Basitarsi very long, slender and notably longer than combined length of remaining tarsomeres (probasitarsi in particular).

♂ ( Fig. 34B ). Medium-sized (body length 84.8–99.5 mm), very slender and fairly typical for the genus with a moderately globose head. Body and head plain ochraceous or orange light to mid brown, the three terminal abdominal segment dark brown. Legs usually coloured like body but often with a faint greenish wash and sometimes apple green with only the apex of the femora and tibiae brownish. Antennae black with the basal two segment coloured like head and body. Eyes dark reddish brown.

Head: Sub-globose, ovoid, slightly longer than wide, broadest at the eyes and somewhat narrowed towards the posterior; vertex gently convex, smooth ( Figs. 34K–L ). Two small and shallow impressions between bases of antennae. Eyes very large and projecting more than hemispherically; their diameter contained almost 1.7x in length of genae Antennae slightly longer than head, pro- and mesothorax combined and just not reaching to apex of profemora; consisting of 25 antennomeres; length relations generally as in ♀♀ but all antennomeres relatively much longer. Scapus compressed dorsoventrally and slightly narrowing towards the base, about 2.5x longer than wide; pedicellus cylindrical and a little less than ½ the length of scapus.

Thorax: Pronotum shorter and somewhat narrower than head; shape generally as in ♀♀ with the pre-median portion slightly narrowed and the post-median portion somewhat expanded; 1.5x longer than wide. The longitudinal medina line distinctly impressed in the anterior half. Mesothorax very elongate and slender, about 3.5x longer than head and pronotum combined and almost 1.3x longer than metanotum.

Abdomen: Median segment slightly trapezoidal and roughly as long as wide, very slightly narrowing towards the anterior and its length contained about 8.5x in that of metanotum. Abdomen excluding median segment a little longer than head and complete thorax combined. Segment II 2.8x longer than median segment, and equal in length to III–V; these on average 5x longer than wide. VI–VII noticeably decreasing in length with VII only 3/5 the length of II. All of uniform width and weakly constricted medially. Tergum VIII widening towards the posterior, widest of all segments and about 2/3 the length of VII, IX very slightly shorter and very weakly narowing towards the posterior; both terga with the lateral margins gently deflexed and rounded and with a well pronounced and acute mediolongitudinal carina. Anal segment 1.75x longer than IX very strongly tectiform and split; basic shape of apical half of hemi-terga roughly triangular in lateral aspect, the basal portion much broader with the dorsal surface straight and the ventral margin weakly rounded ( Fig. 34F ); apex blunt, swollen and slightly incurving with the interior surface armed with several minute denticles ( Fig. 34G ). Cerci short, fairly slender, somewhat nattowed towards the apex and gently in-curving ( Fig. 34H ). Poculum small, scoop-shaped and with the posterior margin narrowed and slightly tapered; roughly reaching to posterior margin of abdominal tergum IX ( Fig. 34A ).

Legs: All very long and slender; unarmed except for a very small sub-apical tooth on medioventral carina of meso- and metafemora. Profemora almost 1.3x longer than head, pro- and mesothorax combined, metafemora reaching about half way along abdominal segment VII and metatibiae projecting strongly over apex of abdomen. Basitarsi very long and very lender, probasitarsus 2.2x longer than combined length of remaining tarsomeres, meso-and metabsitarsus about 1.5x longer than remaining tarsomeres combined.

Variability: The variability of ♀♀ can not be described since so far only one specimen is known. As usual for the genus, ♂♂ are very constant and do not show any noteworthy variability other than in size and colouration of the legs. While most specimens at hand have the legs coloured like to body and with just a very faint greenish wash, three specimens have the legs distinctly apple green with only the apex of all femora and tibiae brownish.

Eggs ( Figs. 35C–D ): Large, very elongate and slender, 3.7x longer than high and only 1.54x higher than wide. Capsule in lateral aspect slightly unevenly narrowing towards the anterior, the lateral surfaces roughly parallelsided. Entire capsule surface fairly even and very minutely granulose, partially and sparsely set with small peg-like scattered tubercles. Polar-area with a wide and obtusely angular indention. Lateral surfaces with a medio-longitudi-nal furrow that is least pronounced in the median portion and posteriorly terminates in a very prominent and deep, roughly oval impression; the entire furrow but the posterior impression in particular covered densely covered with wart-like, tuberculose swellings. The raised ventral portion of the lateral surface with a longitudinal line of minute tubercles. Dorsal and ventral surfaces each with an obtuse, tuberculose medio-longitudinal bulge that is on both sides marked by a shallow longitudinal furrow; these terminating in an obtuse protrusion at polar-area. Micropylar plate very indistinctly bordered with the outer margin difficult to determine; bilobed and consisting of two roughly oval sections that expand somewhat on the lateral surfaces of capsule. Micropylar cup, a semi-circular swelling positioned in posteromedian gap of plate. Median line short but distinctly raised and well identifiable. Colour plain greyish ochre, the tuberculose swellings with a yellowish hue. Measurements [mm]: Length (including operculum) 8.0, length 7.4, width 1.3, height 2.0, length of micropylar plate 1.5.

Comments: Hennemann (1998: 115) erroneously regarded the type-specimens of this new species as lying within the range of intraspecific variability of R. globosicaput (Brunner v. Wattenwyl, 1907). Careful re-examination of the holotype of R. globosicaput in NHMW and comparison with the specimens at hand have however shown these to represent two distinct species.

Distribution: So far only known from the central Tanah Toraja highlands of South Sulawesi

Figures

FIGURE 29. Ramulus globosicaput (Brunner v. Wattenwyl, 1907): A. ♀, dorsolateral view [coll. FH, No. 0303-2]; B. ♀, dor- solateral view [coll. FH, No. 0303-1]; C. Terminal abdominal segments of ♀ seen laterally [coll. FH, No. 0303-1]; D. Terminal abdominal segments of ♀ seen dorsally [coll. FH, No. 0303-2]; E. Terminal abdominal segments of ♂ seen laterally [coll. FH, No. 0303-4]; F. Terminal abdominal segments of ♂ seen dorsally [coll. FH, No. 0303-4]; G. Terminal abdominal segments of ♂ seen ventrally [coll. FH, No. 0303-4]; H. Head with antennae and prothorax of ♀ in dorsal view [coll. FH, No. 0303-2]; J. Head with antennae and prothorax of ♀ in dorsal view [coll. FH, No. 0303-3]; K. Head and prothorax of ♀ in lateral view [coll. FH, No. 0303-2]; L. Head with antennae and prothorax of ♂ in dorsal view [coll. FH, No. 0303-4]; M. Head with antennae and prothorax of ♂ in lateral view [coll. FH, No. 0303-4].

FIGURE 30. Ramulus melanurus n. sp. ♂, holotype [MNHU]: A. Habitus, dorso-lateral view; B. Terminal abdominal segments seen laterally; C. Head and prothorax seen laterally.

FIGURE 34. Ramulus torajanus n. sp.: A. ♀ (PT), lateral view [coll. FH, No. 1064-3]; B. ♂ (PT), lateral view [coll. FH, No. 1064-4]; C. Lateral view of terminal abdominal segments of ♀ (PT) [coll. FH, No. 1064-3]; D. Dorsal view of terminal abdominal segments of ♀ (PT) [coll. FH, No. 1064-3]; E. Ventral view of terminal abdominal segments of ♀ (PT) [coll. FH, No. 1064- 3]; F. Lateral view of terminal abdominal segments of ♂ (PT) [coll. FH, No. 1064-2]; G. Dorsal view of terminal abdominal segments of ♂ (PT) [coll. FH, No. 1064-2]; H. Ventral view of terminal abdominal segments of ♂ (PT) [coll. FH, No. 1064-2]; J. Apex of right mesofemur of ♀ (PT) seen intero-laterally [coll. FH, No. 1064-63]; K. Head and prothorax of ♂ (PT) in dorsal view [coll. FH, No. 1064-5]; K. Head and prothorax of ♂ (PT) in dorsal view [coll. FH, No. 1064-5]; L. Head and prothorax of ♂ (PT) in dorso-lateral view [coll. FH, No. 1064-8].

FIGURE 35. Ramulus spp., eggs: A. R. globosicaput (Brunner v. Wattenwyl, 1907), dorsal view [coll. FH, No. 0303-E]; B. R. globosicaput (Brunner v. Wattenwyl, 1907), lateral view [coll. FH, No. 0303-E]; C. R. torajanus n. sp., dorsal view (PT) [coll. FH, No. 1064-E]; D. R. torajanus n. sp., lateral view (PT) [coll. FH, No. 1064-E]; E. R. togianense n. sp., dorsal view (PT) [coll. FH, No. 0733-E]; F. R. togianense n. sp., lateral view (PT) [coll. FH, No. 0733-E]; G. R. pelengense n. sp., dorsal view (PT) [coll. FH, No. 0790-E]; H. R. pelengense n. sp., lateral view (PT) [coll. FH, No. 0790-E];