Nesiophasma sobesonbaii, Hennemann & Damastra & Damaledo & Cumming & Tirant, 2023

Hennemann, Frank H., Damastra, Garda Bagus, Damaledo, Davis Marthin, Cumming, Royce T. & Tirant, Stéphane Le, 2023, Nesiophasma sobesonbaii n sp a new giant stick insect from the island of Timor Indonesia Insecta Phasmatodea, Faunitaxys 11 (20), pp. 1-13 : 1-13

Nesiophasma sobesonbaii n. sp.

( Fig. 1-7 )

ZooBank: http://zoobank.org/ 45EBF9BB-7B35-4D9E-BD4D-4512443B14DB

Holotype, ♀, ex Zucht F. Hennemann 2022 (F1-Gen.), Herkunft: Indonesien, West Timor, Provinz East Nusa Tenggara, Nekamese Dist., Desa Oemasi SE of Kupang , 14.IV.2021, leg. Davis Marthin Damaledo [ IMQC, ex coll. FH].

Paratype, ♂, Indonesia, West Timor, Prov. East Nusa Tenggara, District Nekamese, Oemasi, Desa Oemasi SE of Kupang, 7.III.2021, leg. Davis Marthin Damaledo [ IMQC].

Paratype, ♀, Indonesia, West Timor, Prov. East Nusa Tenggara, District Nekamese, Oemasi, Desa Oemasi SE of Kupang, 7.III.2021, leg. Davis Marthin Damaledo [ IMQC].

Paratypes, 36 eggs, Indonesia, West Timor, Prov. East Nusa Tenggara, District Nekamese, Oemasi, Desa Oemasi SE of Kupang, 14.IV.2021, leg. Davis Marthin Damaledo [coll. FH, No. 1311-E].

Paratypes, 3 ♂♂, 6 ♀♀, 30 eggs: ex Zucht F. Hennemann 2022 (F1- Gen.), Herkunft: Indonesien, West Timor, Provinz East Nusa Tenggara, Nekamese Dist., Desa Oemasi SE of Kupang, 14.IV.2021, leg. Davis Marthin Damaledo [coll. FH, No’s 1311-1 to 19 & E1].

Paratypes, 2 ♂♂, 6 ♀♀: ex Zucht F. Hennemann2023 (F2-Gen.)2023, Herkunft: Indonesien, West Timor, Provinz East Nusa Tenggara, Nekamese Dist., Desa Oemasi SE of Kupang, 14.IV.2021, leg. Davis Marthin Damaledo [coll. FH, No’s 1311-10 to 17] .

Etymology. – This large new species is named in honour of king Sobe Sonbai III. Sobe Sonbai III was a king (keizer) from Timor Island who opposed the Dutch East Indies colonial government until he was arrested in 1907. Sobe Sonbai III was a descendant of Keizer Laurai of the Molo or Oenam Kingdom referred to as the Sonbai or Sonbay. Following the death of Keizer Sonbai in 1885, however, the ‘empire’ collapsed. Several states strove to assert their independence and no less than 17 pretenders vied for the keizer’s crown. The eventual winner of that struggle was Sobe Sonbai III, and although he was not accepted by all other Timorese rulers, he was viewed by the Dutch as a serious threat to their authority ( Van Hulstijn 1926:129; Lamster 1945:168; Farram, 2009: 194).

Differentiation. – Females of this new species most closely resemble those of N. sananaense Hennemann, 2021 but differ by the smaller size (body length including subgenital plate <220.0 mm), slightly shorter body segments, fewer but more pronounced teeth of the limbs, shape of the praeopercular organ, and much shorter gonapophyses VIII, that hardly project beyond the apex of the anal segment (projecting by notably more than the length of the anal segment in sananaense ). Males may be separated from all congenerics by the unique colouration, with bodies that are light cream to moderate brown, a head that is mostly white with a faint ochre postocular streak, and the limbs green. Their general morphology resembles N. spinulosum (Brunner v. Wattenwyl, 1907) but differs in the chromatic traits and by a slightly longer median segment which is more than half the length of the metanotum, less numerous but more pronounced teeth on the limbs, and characters of the terminalia such as apically in-curved and hook-like cerci, more broadened anal segment, and a narrower vomer. From the three other known eggs of the genus, Nesiophasma sobesonbaii n. sp. are most similar to N. kuehni (Brunner v. Wattenwyl, 1907) but differ by the somewhat smaller dimensions, comparatively more pronounced ridges and bulges of the capsule surface, more bulging opercular collar, broader micropylar plate that has the outer margin more strongly swollen, as well as the more slender and higher, peg-like capitulum.

Description of ♀ ( Fig. 1 , 3A-D, 6, 7C-D)

Moderately large (body length including subgenital plate 180.0-212.0 mm) and slender for the genus with a long and lanceolate subgenital plate.

Colouration. – General colouration mostly uniformly green ( Fig. 1 A-B, 6D-E, 7C), rarely with drab, brown dorsal mottling on meso- and metanotum andabdominal terga ( Fig.6 A-C, 7D). Upper portion of mesopleurae yellow to light orange with a bright red longitudinal line running along the upper margin ( Fig. 6E ); upper margin of metapleurae yellow to orange with a short red line anteriorly. Pronotum mostly yellowish (greyish in older specimens). Head pale greyish yellow with a faint and washed green postocular streak( Fig. 6E ). Eyesgreenwith afine brown longitudinal medianline.In green specimens the basal three antennomeres are dark green (drab in brown specimens), the following antennomeres are creamish brown and gradually become reddish brown towards the apex; each antennomere has the apical portion somewhat darkened. Lateral inter-segmental membranes of abdominal segments II-VII whitish yellow to pale green (or light cream-coloured in brown specimens). Praeopercular organ with a large dark brown marking close to the posterior margin of abdominal sternum VII. Cerci reddish brown. Gonapophyses and basal inner portion of subgenital plate rusty red ( Fig. 3D ). Basal portion of coxae orange ( Fig. 6C ). Legs a slightly darker green than the body in green specimens, or drab to ochre with a slight orange hue in brown specimens. Bases of profemora rosy red interiorly ( Fig. 1F ), bases of meso- and metafemoradull yellow to buff or occasionally blackish ( Fig. 6C ). Dentations of the front legs dark green, those of the mid and hind legs dark green and tipped with black ( Fig. 1 G-H).

Head ( Fig. 1 C-E). – Elongate-ovoid, with vertex gently rounded and smooth, broadest slightly behind the eyes and gradually narrowing towards the posterior; almost 1.5x longer than wide. Between the bases of antennae are two small impressions that are connected by a shallow furrow. Eyes small, subcircular, their diameter contained about 2.5x in the length of the genae. Antennae reaching to posterior margin of abdominal segment II. Scapus compressed dorsoventrally gently arched towards the exterior and almost 2x longer than wide, pedicellus cylindrical, III narrowing towards apex and almost 2x longer than pedicellus.

Thorax. – Pronotum noticeably shorter and somewhat narrower than head, roughly rectangular with the lateral margins weakly concave and the anterior margin distinctly concave ( Fig. 1C ); a fine longitudinal median furrow throughout the entire length; transverse median sulcus shallow, short and almost straight ( Fig. 1D ). Mesothorax about 5.7x longer than prothorax, about 5.3x longer than wide, constricted anteriorly and gently swollen pre-medially. Metanotum slightly more than half as long as mesonotum, rectangular and 4.5x longer than wide. Meso- and metasternum with a weak longitudinal median keel.

Abdomen ( Fig. 3 A-D). – Abdomen considerably longer than head and thorax combined. Median segment slightly trapezoidal and about half the length of metanotum. Abdominal segments II - V slightly increasing in length, V and VI roughly equal in length and VII about as long as II; II 1.6x and VI almost 2x longer than wide. III is the broadest segment with the following segments gently but gradually narrowing. Terga III-VII somewhat deflexed with lateral margins gently convex. Praeopercular organ formed by a blunt pale purple median swelling near the posterior margin of sternum VII with a wide and weakly indented, granulose area in front, which is marked by a dark reddish-brown marking ( Fig. 3C ). Tergum VIII slightly longer than wide and less than half the length of VII, IX transverse. Anal segment (= tergum X) with the lateral margins roundly excavated near the base of the cerci ( Fig. 3A, D ), the posterior margin distinctly bi-lobed with a deep and narrow median indentation ( Fig. 3B ). Cerci conical and strongly tapered towards a narrow tip and not reaching the apex of the anal segment. Gonapophyses VIII rather short for the genus and just slightly projecting beyond the anal segment ( Fig. 3B ); gently up-curved and inner surface with a deep longitudinal furrow. Subgenital plate long, lanceolate, with basal portion slightly bulging, weakly down-curved in the apical half ( Fig. 3A, D ) and gradually narrowing towards a narrow but blunt tip ( Fig. 3 B-C); projecting over apex of abdomen by about the combined lengths of abdominal terga VII-X.

Legs. – Allmoderatelylong and stocky,profemoraalmost aslongashead, pro- and mesothorax combined, mesofemora notably longer than metathorax, metafemora projecting over posterior margin of abdominal segment IV and metatarsi roughly reaching the tip of the abdomen. All carinae coarsely dentate; teeth of tibiae smaller than those of femora but more numerous and mid and hind legs with dorsal teeth smaller than ventral teeth. The two apical teeth of the two exterior ventral carinae of meso- and metafemora slightly enlarged. Posterodorsal carina of profemora rather serrate with the teeth slightly decreasingin size towardsthe apex.Medioventral carina of all femora indistinctand unarmed ( Fig. 1F, H ). Basitarsi slender.Probasitarsus aslong as tarsomeres, meso- and metabsitarsus somewhat shorter than remaining tarsomeres combined; the latter two with all carinae minutely dentate.

Description of ♂ ( Fig. 2 , 3 E-G, 7A-B)

Medium sized (body length 106.0-110.0 mm) for the genus, shape moderately slender. Entire body smooth and shiny.

Colouration. – General colour of body light creamish to moderate brown or ochre, posterior margin of abdominal terga chestnut brown. Pronotum with a greenish hue and upper portions of meso- and metapleurae medium green. Meso- and metasternum with a faint dark green marking posteriorly. Head mostly white to light cream and with a faint greenish ochre postocular streak ( Fig. 7B ). Eyes light olive with a fine brown longitudinal median line. Basal three antennomeres dark green, the following dark greyish olive and from the median portion of the antennae onwards gradually transition to reddish brown. Anal segment somewhat lighter colour than preceding terga and with a slight greyish hue. Vomer greyish dark green and with the apex brown. Legs plain green with the outer basal portion of the profemora dark green and the bases of the meso- and metafemora dark orange to brown.All dentations dark brown.

Head ( Fig. 2 B-D). – Elongate-ovoid, almost 1.6x longer than wide and broadest at the eyes, genae narrowing and vertex gently rounded and wholly smooth. Frons between the bases of antennae with two small but distinct impressions and a small, shallow pit near each compound eye. Eyes large, circular in outline and strongly projecting, their diameter contained a little less than 1.7x in length of genae. Antennae long and filiform, reaching to the anterior of abdominal segment V. Basal three segments similar to the ♀♀ but scapus straight.

Thorax. – Pronotum basically as in ♀♀ and roughly 1.4x longer than wide ( Fig. 2D ). Mesothorax slender and elongate, slightly widened posteriorly, about 7.25x longer than pronotum and almost 12x longer than wide. Metanotum approximately half the length of mesothorax with anterior and posterior portion weakly widened and roughly 5.6x longer than wide. Mesosternum weakly tectate medio-longitudinally. Tegmina vestigial (length <1.0 mm).

Abdomen. – Abdomen excluding median segment longer than head and thorax combined. Median segment noticeably narrowed medially with posterior margin notably wider than anterior margin, about 3x longer than wide and somewhat less than half the length of metanotum. Segments II - VII gradually decreasing in length, II about 1.8x longer than median segment and 5x longer thanwide, VIIlessthanthree-fifths the length of II androughly 3.5x longer than wide. All slightly constricted medially. Sterna II - VII smooth. Tergum VIII about half as long as VII and gradually widened towards posterior, dorsal distinctly trapezoidal. IX slightly shorter, much narrowed medially and with anterior margin somewhat broader than posterior margin. Anal segment (= tergum X) scarcely longer than wide, about as long as IX with the lateral surfaces slightly convex sub-basally; the posterior margin is broadly concave, and the outer corners obtusely rounded ( Fig. 3E - F ). Ventrally the posterior margin is densely set with small reddish brown denticles (= thorn pads; Fig 3G ). Poculum small and moderately convex, cucullate ( Fig. 3E ) with the posterior margin broadly rounded and somewhat labiate; reaching about two-thirds the wayalong tergum IX ( Fig. 3G ). Vomer slender and gradually narrowing towards a pointed and gently dorsallycurving terminal hook; the ventral surface is smooth and with a shallow medio-longitudinal furrow on the basal portion, the base otherwise is biglobose ( Fig. 3G ). Cerci obtuse, somewhat compressed laterally, gently in-curved with the apex acute and distinctly in-curved and hook-like; notably projecting over the posterior margin of the anal segment ( Fig. 3E - F ).

Legs. – All long and slender, with all carinae dentate; teeth less distinct but more numerous on the tibiae and those of the meso- and metafemora somewhat increase in size towards the apex of femur with the most apical tooth the largest and slightly arched ( Fig. 2E ). Profemora longer than head, pro- and mesothorax combined, mesofemora slightly longer than pro- and mesothorax combined, metafemora reaching to posterior margin of abdominal segment V and metatibiae projecting considerably over apex of abdomen. Medioventral carina of all femora weakly developed and unarmed. Tarsi elongate and slender (probasitarsus in particular), probasitarsus longer than remaining tarsomeres, meso- and metabasitarsi longer than following three tarsomeres combined and with a few small teeth on the two exterior ventral carinae.

Variability. – Both sexes show only slight variability in size as well as the development and number of teeth on the extremities. While ♂♂ show no chromatic variation, ♀♀ occur in a green and a drab or light brown colour form. Among specimens observed in their natural habitats in Timor, only the ♀ from Mainina, Lautem District was brown (fig. 6A), while all other encountered specimens were green. Captive breeding corroborated that drab or brown specimens are notably rarer than the usual green form. In captivity in Europe all seven ♀♀ of the F1-generation were green and only two of the six ♀♀ of the F2-generation were brown. One specimen had the body fawn dorsally, greenish ventrally and the legs green, thus representing an intermediate between the green and brown colour forms.

Description of nymphs

Newly emerged nymphs have a body length of 18 mm.Their body is yellowish to moderate green in colour with only the anal segment and lateral portions of the pronotum brown. The head bears a fine brown postocular streak. The front legs are mostly brown with small dark yellow speckles while the mid and hind legs are rather light apple green with three brown transverse bands on each femur and tibia. Eyes dark brown. Antennae brown with some faint lighter annuli. Later instars of both sexes are moderate to dark green throughout the entire nymphal development with only the subgenital plate brownish. It is interesting to note that from 2 nd instar onwards ♀♀ have a transverse, brown swelling on posterior margin of abdominal tergum V, which disappears with the final ecdysis. The sexes can be distinguished from the 3 rd instar on.

Description of egg ( Fig. 3 H-I)

Fairly small, general colour light greyish to mid brown; the raised portions are somewhat darker and greyer than the pale ochre indented

areas. Capsule elongate-ovoid, barrel-shaped about 2x longer than wide, the ventral surface and lower region of dorsal surface with an indistinct and obtuse longitudinal bulge. Capsule surface minutely granulose and covered with an irregular wide-meshed network of broad obtuse ridges. The lowered interjacent areas each have a distinct central impression. Opercular collar strongly swollen. Polar area weakly indented and dark grey in colour.Micropylar plate spearhead-shaped,notably less than half the length of capsule with lower portion strongly narrowed, the inner portion dark greyish brown.Outer portion of the plate is bulging and the outer margin dark orange. Micropylar cup small, bowl-shaped, and placed just above the constricted posterior portion of the capsule. Median line impressed, almost reaching to the polar area and on both sides bordered by an unevenly shaped longitudinal bulge. Operculum almost circular, flat and with the outer margin weakly swollen; greyish/ mid brown. Capitulum an irregularly shaped, elongate and peg-like projection, that projects by about one-fifth the length of the capsule; colour dark blackish brown basally and turning to dark orange towards the apex. Measurements [mm]: Overall length 4.2-4.3, length 3.5-3.6, width 1.8-1.9, height 2.1-2.2, length of micropylar plate 1.5.

Remarks & biology. – A captive reared F1 generation ♀ is chosen as the holotype because the two wild specimens are damaged and incomplete.

This species was found in dry semi-forested areas mixed with grassland and tall bushes in Nekamese, Oemasi Village, East Nusa Tenggara Province ( Fig. 5 ). In the Lautem and Oecussi-Ambeno districts of Timor-Leste however, it was found in primary forest with lush and varied vegetation lower vegetation and trees that reach 45 m in height. This latter habitat is considerably more humid with annual rainfall of 2000-4000 mm. In its natural habitat feral guava-trees ( Psidium guayava , Myrtaceae ) appear to be the most common host plant although this is not a native plant species in Timor. However, until N.sobesonbaii is found on any other native plant species the true native host plant remains unknown.At present,the species is known to also feed on mango ( Mangifera indica , Anarcadiaceae) and magenta cherry ( Syzygium paniculatum , Myrtaceae ).

In captivity in Europe, oak ( Quercus spp. , Fagaceae ), bramble ( Rubus fruticosus , Rosaceae ) and eucalyptus ( Eucalyptus spp. Myrtaceae ) were readily accepted as alternative food plants by newly hatched nymphs and throughout the entire life cycle. Also, elm ( Ulmus minor , Ulmaceae ), robinia ( Robinia pseudoacacia , Fabaceae ), and hazel ( Corylus avellana , Betulaceae ) have been accepted by nymphs but long-term use has not been conducted (pers. comm. with Daniele Canali, Rome, Italy). Newly hatched nymphs feed very well on St. John’s Wort ( Hypericum patulum , Hypericaceae ) which apparently improves the survival rates during the first instar (pers. comm. with Tim Bollens).Eggs are flicked away singularly by the adult ♀♀ and an average of 3- 5 eggs is produced per day per ♀.At temperatures of 22-25°C eggs hatch after about four months. Nymphs are fast growing, sturdy and at the temperatures mentioned reach maturity after no more than four months, ♂♂ usually developing slightly faster than ♀♀. A large and well-ventilated cage and medium humidity of 60-80% with a daily spray of water have proven to provide appropriate climatic conditions for a good nymphal development and successful ecdysis. While the F1-generation was very sturdy with few losses among the nymphs, the F2-generation has proven very difficult to maintain with immense losses during the first nymphal instar and frequent losses of nymphs throughout the proceeding stages. This might relate to the use of alternative foodplants in captivity but this hypothesis cannot be evaluated, since too little guava was available for experimental series in breeding conditions in Europe. It has also been observed that every kind of change of the climatic circumstances or breeding cage directly resulted in losses of 30-50% of the nymphs.

Adults and nymphs are very difficult to handle. If disturbed they will frequently drop to the ground and behave extremely hectically, rolling on the ground and after a while of maintaining this awkward behaviour walking away quickly to climb the next host plant. Nymphs especially shed limbs easily if a leg is grasped by a predator or the uncareful breeder.

Distribution ( Fig. 4 ). – Endemic to the Island of Timor and apparently widespread throughout the island. So far recorded from the following three localities: 1) SW-Timor, Prov. East Nusa Tenggara, District Nekamese, Oemasi, Desa Oemasi SE of Kupang, 400 m. 2) NE-Timor Timor Leste, District Lautem, Malahara, Mainina, 500 m. 3) NE-Timor, Timor Leste, District Oecussi-Ambeno, Nibesi, 500 m.

Figures

Fig. 1. Female of Nesiophasma sobesonbaii n. sp. A. HT, dorsal view [IMQC, ex coll. FH]. B. HT, lateral view [IMQC, ex coll. FH]. C. Head and prothorax in dorsolateral view [FH]. D. Head and prothorax in dorsal view [FH]. E. Head and prothorax in ventral view [FH]. F. Right profemur in ventral view [FH]. G. Left mesofemur in posterolateral view [FH]. H. Left mesofemur in ventral view [FH].

Fig. 2. Male of Nesiophasma sobesonbaii n. sp. A. PT, dorsolateral view [FH, No. 1311-8]. B. PT, head and prothorax in dorsolateral view [FH]. C. Head and prothorax in dorsal view [FH].D. Head and prothorax in ventral view [FH]. E. Apical portion of right mesofemur in posterolateral view [FH].

Fig. 3. Terminalia and egg of Nesiophasma sobesonbaii n. sp. A. Terminalia of ♀ in lateral view [FH]. B. PTerminalia of ♀ in dorsal view [FH]. C. Terminalia of ♀ in ventral view [FH]. D. Terminalia of ♀ in lateral view, showing details of inner genitalia [FH]. E. Terminalia of ♂ in lateral view [FH]. F. P Terminalia of ♂ in dorsal view [FH]. G. Terminalia of ♂ in ventral view [FH]. H. Egg in dorsal view [FH, No. 1311-E]. I. Egg in lateral view [FH, No. 1311-E].

Fig. 4. Distribution and records of Nesiophasma sobesonbaii n. sp. (CopyrightWikimedia Creative Commons (GFDL, CC-BY, PD). Mats Halldin,CC BY-SA 3.0 (original file slightly adjusted):https://de.m.wikipedia.org/wiki/Datei:East_Timor_map_mhn.jpg)

Fig. 5. A-B. Natural habitat of Nesiophasma sobesonbaii n. sp. at Desa Oemasi SE of Kupang (400 m), Nekamese District, Province East Nusa Tenggara.

Fig. 6. Live Nesiophasma sobesonbaii n. sp. A. ♀ (brown form) at Kupang on guava (Psidium guajava (Myrtaceae). B. ♀ (brown form) with mating ♂ on its back (captive reared). C. Ventral view of metathorax of brown captive reared ♀ showing the orange coxae. D. Typical green ♀ (captive reared). E. Lateral view of head, pro- and mesothorax of green ♀ showing the red stripe of the mesopleurae (captive reared).

Fig. 7. Live Nesiophasma sobesonbaii n. sp. ♂ (captive reared). B. Closeup of head and prothorax of ♂ (captive reared). C. Green ♀, closeup of head and thorax (Captive reared). D. ♀ brown colour form (captive reared).