Nesiophasma giganteum Hennemann, Le Tirant & Purwanto, 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 : 106-113

Nesiophasma giganteum Hennemann, Le Tirant & Purwanto n. sp.

( Figs. 40A–C , 41A , 42 , 44B–C , 45A–C & N , 46A & J–L , 47A–B )

HT, ♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Bulagi District , Alul village near Bulagi, XII.2011 [ IMQC] .

PT, 9 ♀♀: E-Sulawesi, Prov. Sulawesi Tengah, Banggai-Islands , W-Peleng Island, Bulagi District , Alul village near Bulagi, XII.2011 [ IMQC] .

PT, 2 ♂♂: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Buko District , btw. Tatendeng village and Eben village 400–550 m, IX.2011 [ IMQC] .

PT, 3 ♀♀, 2 eggs (ex ovipositor): O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln, Peleng Island , 2008, via S. Suzuki (Ja-pan) 2009 [coll. FH, No’s 0656-1 to 3, E1] .

PT, 3 ♂♂, 5 ♀♀, 10 eggs: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Bulagi District , Alul village near Bulagi, XII.2011 [coll. FH, No’s 0656-4 to 11, E2] .

PT, 7 ♂♂, 10 ♀♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Buko District , btw. Tatendeng village and Eben village 400-550 m, IX.2011 [coll. FH, No’s 0656-12 to 28] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25.VIII.2018, leg. A. Brata [coll. FH, No’s 0656-29 to 30] .

PT, 13 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ IMQC] .

PT, ♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ CMN] .

PT, ♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ LEMQ] .

PT, ♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ MNHN] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ MNHU] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ NHMB] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ NHMUK] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ RMNH] .

PT, 2 ♀♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII .2018, leg. A. Brata [ SMFM] .

PT, 2 ♀♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Buko District , btw. Tatendeng village and Eben village 400–550 m, IX.2011 [ IRSN] .

PT, 2 ♀♀: Coll. R.I.Sc.N.B., Indonesia: Peleng Isl. , III.2019 , local collector [IRSN].

PT, 2 ♀♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Buko District , btw. Tatendeng village and Eben village 400–550 m, IX.2011 [ NHMW] .

PT, 6 ♀♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai Ids., W-Peleng Island, Buko District , Tinanasu, VI.2016 [coll. OC, No’s 0544-1 to 6] .

PT, 2 ♀♀: O-Sulawesi, Prov. Sulawesi Tengah, Banggai-Inseln , W-Peleng Island, Buko District , btw. Tatendeng village and Eben village 400-550 m, IX.2011 [coll. OC, No’s 0544-7 & 8] .

PT, ♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII.2018, leg. A. Brata [coll. AB] .

PT, ♀: Indonesia: E-Peleng Island, Tinangkung Utara , near Luksagu village, 1–25. VIII.2018, leg. A. Brata [coll. RTC] .

PT, 2 ♂♂, 4 ♀♀: E-Sulawesi, Prov. Sulawesi Tengah, Banggai-Islands , W-Peleng Island, Bulagi District , Alul village near Bulagi, VI.2020 [coll. EB].

Etymology: The name (giganteus lat. = huge, giant, enormous) refers to the very large size of this new species, which is the so far largest known representative of the genus Nesiophasma and together with N. plateni ( Dohrn, 1910) from the Sangihe and Talaud Islands may be regarded as the longest of all insects of Wallacea.

Differential diagnosis: Females of this gigantic new species most closely resemble those of N. sananaense n. sp. ( Figs. 40D–F , 41B ) from Sanana, Sula Islands by the more stocky appearance, longer antennae that reach as far back as abdominal segment II (median segment only in sananaense ), shorter and less lanceolate subgenital plate ( Figs. 45A–C ), less prominent tubercle of the Preopercular organ ( Fig. 45C ), and differently shaped anal segment, which has the posterior lobes broader and more angular ( Fig. 45B ). From those of N. spinulosum (Brunner v. Wattenwyl, 1907; Fig. 43C ) from the Selayar Islands south of Sulawesi these ♀♀ readily differ by the much larger size and more slender shape, parallel-sided abdominal terga II–VII, more globose head and slender not dorsally lobed probasitarsus. From the similarly large N. plateni ( Dohrn, 1910; Figs. 43A–B ) ♀♀ differ by being more stocky in shape with comparatively shorter and stronger legs, as well as having the subgenital plate considerably shorter (projecting over apex of abdomen by less than combined length of three terminal abdominal terga; Figs. 45A–C ). Males are very similar to those of N. turbans (Brunner v. Wattenwyl, 1907; Fig. 44A ) from Minahasa, N-Sulawesi but differ by the slightly smaller size, more stocky shape with relatively shorter body segments, legs and tarsi, as well as the less curved cerci and differently shaped vomer ( Fig. 46J ). The eggs are similar to those of N. kuehni (Brunner v. Wattenwyl, 1907) from Pulau Romang but differ by being slightly more elongate and having the ventral keel of the capsule less distinct ( Figs. 47A–B ).

Description: The colouration of ♀♀ is described from pictures of live specimens kindly provided by Edy Bhaskara ( Indonesia) and specimens reared by Hari Purwanto, that of the ♂♂ based only on preserved specimens.

♀ ( Figs. 40A–C , 41A ). Very large (body length including subgenital plate 251.0–301.0 mm) and moderately stocky for the genus with a fairly long and lanceolate subgenital plate. General colouration ranging from very pale whitish grey over various shades of mid grey and ochre to dark greyish brown ( Fig. 42A ), more rarely with a slight greenish hue (e.g. HT, Fig. 41A ); paler specimens with more distinct brown speckles and mottling all over the head body and legs. Lateral surfaces of meso- and metanotum as well as meso- and metapleurae in particular with dark brown to black mottling. Genae as well as lateral surfaces of abdominal tergum II and III in anterior half with dark mottling or a cluster of dark speckles. Paraprocts, gonoplacs and gonapophyses dull red ( Fig. 42D ). Legs with irregular annulations formed by dark speckles. Antennae greyish brown with basal portion black ventrally. Eyes pale ochre.

Head: Ovoid, moderately globose with vertex gently rounded and smooth ( Fig. 45N ), broadest a slight distance behind the eyes; about 1.4x longer than wide. Between the bases of antennae with a short but distinct and slightly curved furrow. Eyes small and their length contained about 3x in that of genae. Antennae reaching about half way along abdominal segment II. Scapus compressed dorsoventrally, pedicellus cylindrical, III narrowing towards apex and almost 2x longer than pedicellus.

Thorax: Pronotum shorter and notably narrower than head ( Fig. 45N ), rectangular and with a longitudinal median furrow over entire length; transverse median sulcus moderate, very short and straight. Mesothorax about 5.3x longer than prothorax, about 4.5x longer than wide and gently swollen pre-medially (fig. 42C). Metanotum more than half the length of mesonotum, rectangular and 3x longer than wide. Meso- and metasternum with a very weak longitudinal median keel.

Abdomen: Abdomen considerably longer than head and complete thorax combined. Median segment roughly quadrate and a little more than 1/3 the length of metanotum. Abdominal segments II–VI slightly increasing in length, II 1.6x and VI almost 2x longer than median segment; on average 1.7x longer than wide. IV and V broadest segments, the remaining ones gently but gradually narrowing. Terga III–VI somewhat deflexed with lateral margins very gently convex. Preopercular organ formed by a blunt black tubercle some distance off the posterior margin of sternum VII ( Fig. 45C ). Tergum VIII slightly longer than wide, IX transverse. Anal segment slightly tectiform longitudinally, the lateral margins with a large and deep angular excavation near the base of cerci ( Fig. 45A ), the posterior margin with a very deep but narrow median incision and the lateral portions each forming an obtuse angular lobe ( Fig. 45B ). Cerci strongly conical, strongly constricted towards a very pointed tip and not reaching apex of anal segment. Gonapophyses VIII projecting considerably over posterior margin of anal segment but not reaching apex of subgenital plate ( Figs. 42A–B ); gently up-curving and the inner surface with a deep longitudinal furrow. Subgenital plate long, lanceolate, bulgy in basal portion, weakly down-curving ( Fig. 45A ) in apical half and gradually narrowed towards a narrow but blunt tip; projecting over apex of abdomen by at least the length of abdominal terga IX and X combined ( Figs. 45A–C ).

Legs: All moderately long and stocky, profemora longer than mesothorax, mesofemora reaching to posterior margin of abdominal segment II, metafemora projecting over posterior margin of abdominal segment IV and metatarsi roughly reaching tip of subgenital plate. All carinae dentate; teeth of tibiae smaller but more numerous. Both posterior carinae of profemora distinctly serrate. Medioventral carina of all femora indistinct, that of profemora unarmed and that of meso- and metafemora just sparsely armed with minute spines. The two apical teeth of the two outer ventral carinae of meso- and metafemora notably enlarged. Basitarsi slender. Probasitarsus as long, meso- and metabsitarsus somewhat shorter than remaining tarsomeres combined; the latter two with all carinae minutely dentate.

♂ ( Figs. 44B–C ). Medium sized (body length 139.5–153.0 mm), shape moderately slender for the genus. Entire body smooth and very slightly shiny. General colour apple green to dull greenish brown. Genae with a very faint, broad dark postocular streak; the vertex and lower portion of genae ± yellow ( Fig. 42E ). Posterior portion of poculum pale cream ( Fig. 42F ). Legs coloured like body with the apex of all femora and tibiae as well as of all tarsomeres blackish brown; leg armature black. Antennae ochre to greyish mid brown with the basal quarter black ventrally. Eyes greyish brown ( Fig. 42E ).

Head: Moderately globose, almost 1.4x longer than wide and broadest at the eyes, genae narrowing and vertex very gently rounded and smooth. Eyes very large, circular in outline and strongly projecting, their length contained a little less than 2x in that of genae. Antennae long and filiform, reaching to posterior of abdominal segment IV. Basal three segments as in ♀♀.

Thorax: Pronotum notably shorter and much narrower than head, rectangular in outline, the transverse median sulcus moderately developed, almost straight and not reaching lateral margins of segment; about 1.7x longer than wide ( Fig. 46K ). Entire surface with a fine but distinct impressed longitudinal median line. Mesothorax very slender and elongate, very slightly widened posteriorly, about 8x longer than pronotum and almost 18x longer than wide. Metanotum a little less than half the length of mesothorax with anterior and posterior portion gently widened. Meso-and metaststernum very indistinctly tectinate longitudinally.

Abdomen: Abdomen excluding median segment longer than head and complete thorax combined. Median segment gently narrowed medially and about 4x longer than wide and somewhat less than 1/3 the length of metanotum. Segments II–VII slightly decreasing in length, II about 1.8x longer than median segment and 6.3x longer than wide, VII a little more than 3/5 the length of II and roughly 4.5x longer than wide. All slightly constricted medially. Sterna II–VII all very slightly tectinate longitudinally. Tergum VIII about 2/3 the length of VII and gradually widened towards posterior, IX slightly shorter, narrowed medially and with anterior margin broader than posterior margin. Anal segment slightly tectinate longitudinally, almost as long as IX and slightly broadening towards posterior; the anterior portion roundly swollen laterally, the posterior margin broadly concave ( Figs. 42G , 46A ) and the outer corners bluntly rounded, somewhat downward directed, swollen and minutely dentate ventro-interiorly ( Fig. 46J ). Poculum small and moderately convex, roundly cup-shaped ( Fig. 42F ) with the posterior margin broadly rounded ( Fig. 46J ); reaching about half way along tergum IX. Vomer roundly triangular, about 1.5x longer than wide, the ventral surface convex and fairly smooth, the basal portion broadly rounded, the apical portion distinctly narrowed and terminating in a single, strong and up-curving black hook ( Fig. 46J ). Cerci obtuse, round in cross-section, very gently in-curving and notably projecting over posterior margin of anal segment ( Fig. 42F ).

Legs: All very long and slender, with all carinae minutely and densely dentate; teeth less distinct but positioned narrower to each other on tibiae. Profemora longer than head, pro- and mesothorax combined, mesofemora slightly longer than mesothorax, metafemora reaching to posterior margin of abdominal segment V and metatibiae projecting considerably over apex of abdomen. Medioventral carina of all femora well defined and armed with a row of minute spines. Tarsi elongate and slender (probasitarsus in particular), basitarsi 1.3x longer than remaining tarsomeres combined, meso- and metabasitarsi with a few minute teeth on ventral carinae.

Eggs (47A–B): Medium sized, general colour greyish mid brown. Capsule elongate-ovoid, about 2x longer than wide, the ventral surface and lower region of dorsal surface with an indistinct blunt longitudinal keel. Capsule surface strongly sculptured; all over covered with an irregular network of broad raised ridges and very minutely granulose. Polar area gently flattened if seen in lateral aspect. Micropylar plate spearhead-shaped, less than half the length of capsule with lower portion strongly narrowed; the inner portion dark brown. Outer margin of plate bulging and of same colour as capsule. Micropylar cup small, bowl-shaped and placed just above the constricted portion of capsule. Median line impressed and almost reaching to polar area. Operculum almost circular and brown. Capitulum irregularly conical and morel-like, colour slightly darker than capsule. Measurements [mm]: Overall length 5.1–5.4, length 4.1–4.3, width 2.0–2.1, height 2.6–2.7, length of micropylar plate 1.9–2.0.

Comments: Together with N. plateni ( Dohrn, 1910) this new species is the longest insect known to occur in Wallacea. It is apparently endemic to the island of Peleng, the largest of the Banggai Islands positioned east of Sulawesi and is distributed throughout the lowland regions of the island. Its host plants are the Gamal tree ( Gliricidia sepium , Fabaceae ) and cashew tree ( Anacardium occidentale , Anacardiaceae ) but it is occasionally also found feeding in guava ( Psidium guayava , Myrtaceae ). In captivity it feeds well on guava and breeding attempts in Europe have shown also bramble ( Rubus fruticosus , Rosaceae ) and salal ( Gautheria shallon , Ericaceae ) to be accepted as alternative food plants. Eggs are flicked away by the adult ♀♀ singularly and an average of 3– 5 eggs is produced per day and ♀. At average temperatures of 25°C eggs hatch after about five months. Newly hatched nymphs have a body length of about 18.0 mm and are bright apple green with the tip of the abdomen brown and the legs dark brown with contrasting white annulae. Nymphs are green throughout their entire development with ♀♀ getting their final grey or brown colouration only by the final ecdysis.

Distribution: Endemic to the Island of Peleng, Banggai Islands Regency (Bulagi District, Alul village near Bulagi; Tinangkung Utara District, near Luksagu village 60 m; Buko District, Tatendeng village 400–550 m; Buko District, Eben village 400–550 m).

Figures

FIGURE 40. Nesiophasma spp., ♀♀: A. N. giganteum n. sp. ♀ (PT) from Tinanasu, Buko District, dorsal view [coll. FH, No. 0656-6]; B. N. giganteum n. sp. ♀ (PT) from Tinanasu, Buko District, dorso-lateral view [coll. FH, No. 0656-6]; C. N. giganteum n. sp. ♀ (PT) from Luksagu village, Tinangkung Utara, dorso-lateral view [coll. FH, No. 0656-29]; D. N. sananaense n. sp. ♀ (PT), dorsal view [coll. FH, No. 0822-1]; E. N. sananaense n. sp. ♀ (PT), dorso-lateral view [coll. FH, No. 0822-1]; F. N. sananaense n. sp. ♀ (PT), dorso-lateral view [coll. FH, No. 0822-2].

FIGURE 41. Nesiophasma spp., ♀♀, holotypes: A. N. giganteum n. sp. ♀ (HT) from Alul village, Bulagi District, dorsal view [IMQC] (© René Limoges, IMQC); B. N. sananaense n. sp. ♀ (HT), dorsal view [IRSN] (© Jérôme Constant, IRSN).

FIGURE 42. Nesiophasma giganteum n. sp., live captive reared insects. A. ♀, dark brown variety; B. ♀, common pale variety; C. Close up head, pro- and mesothorax of ♀ in dorsal view; D. Close up of terminalia of mating couple; E. Head, pro- and mesothorax of ♂; F. Terminalia of ♂ in lateral view; G. Terminalia of ♂ in dorsal view. (Figs. A–B © Edy Bhaskara; Figs. C–G © Hari Purwanto).

FIGURE 43. Nesiophasma spp., ♀♀: A. N. plateni (Dohrn, 1910) ♀ (LT), dorsal view [ZMPA]; B. N. plateni (Dohrn, 1910) ♀ (LT), dorso-lateral view [ZMPA]; C. N. sananaense n. sp. ♀ (PT), dorsal view [coll. FH, No. 0822-1]; C. N. spinulosum (Brunner v. Wattenwyl, 1907) ♀ (HT of N. eremothocus Günther, 1934), dorsal view [MNHU]; D. N. kuehni (Brunner v. Wattenwyl, 1907) ♀ (LT) [NHMW, No. 309].

FIGURE 44. Nesiophasma spp., ♂♂: A. N. turbans (Brunner v. Wattenwyl, 1907) ♂ [IRSN] © Jérôme Constant, IRSN; B. N. giganteum n. sp. ♂ (PT) from Tinanasu, Buko District, dorso-lateral view [coll. FH, No. 0656-10]; C. N. giganteum n. sp. ♂ (PT) from Tinanasu, Buko District, dorsal view [coll. FH, No. 0656-10]; D. N. oligarches (Günther, 1935) ♂ (HT), dorsolateral view [MNHU].

FIGURE 45. Nesiophasma spp., ♀♀: A. N. giganteum n. sp., terminal abdominal segments of ♀ (PT) seen laterally [coll. FH, No. 0656-1]; B. N. giganteum n. sp., terminal abdominal segments of ♀ (PT) seen dorsally [coll. FH, No. 0656-5]; C. N. giganteum n. sp., terminal abdominal segments of ♀ (PT) seen ventrally [coll. FH, No. 0656-1]; D. N. sananaense n. sp., terminal abdominal segments of ♀ (PT) seen laterally [coll. FH, No. 0822-3]; E. N. sananaense n. sp., terminal abdominal segments of ♀ (PT) seen dorsally [coll. FH, No. 0822-2]; F. N. sananaense n. sp., terminal abdominal segments of ♀ (PT) seen ventrally [coll. FH, No. 0656-3]; G. N. spinulosum (Brunner v. Wattenwyl, 1907) ♀ (HT of N. eremothocus Günther, 1934), terminal abdominal segments seen laterally [MNHU]; H. N. spinulosum (Brunner v. Wattenwyl, 1907) ♀ (HT of N. eremothocus Günther, 1934), terminal abdominal segments seen dorsally [MNHU]; J. N. spinulosum (Brunner v. Wattenwyl, 1907) ♀ (HT of N. eremothocus Günther, 1934), terminal abdominal segments seen ventrally [MNHU]; K. N. kuehni (Brunner v. Wattenwyl, 1907) ♀ (LT), terminal abdominal segments seen laterally [NHMW, No. 309]; L. N. kuehni (Brunner v. Wattenwyl, 1907) ♀ (LT), terminal abdominal segments seen ventrally [NHMW, No. 309]; M. N. kuehni (Brunner v. Wattenwyl, 1907) ♀ (LT), head and prothorax in dorsolateral view [NHMW, No. 309]; N. N. giganteum n. sp., head and prothorax of ♀ (PT) in dorso-lateral view [coll. FH, No. 0656-5]; O. N. sananaense n. sp., head and prothorax of ♀ (PT) in dorso-lateral view [coll. FH, No. 0822-1]; P. N. plateni (Dohrn, 1910), terminal abdominal segments of ♀ (LT) seen laterally [ZMPA]; Q. N. plateni (Dohrn, 1910), terminal abdominal segments of ♀ (LT) seen dorsally [ZMPA]; R. N. spinulosum (Brunner v. Wattenwyl, 1907) ♀ (HT of N. eremothocus Günther, 1934), N. plateni (Dohrn, 1910), terminal abdominal segments of ♀ (LT) seen ventrally [ZMPA]. Figures P–R © Paul D. Brock / NHMUK.

FIGURE 46. Nesiophasma spp., ♂♂: A. N. giganteum n. sp., terminal abdominal segments of ♂ (PT) seen dorsally [coll. FH, No. 0656-10]; B. N. turbans (Brunner v. Wattenwyl, 1907), terminal abdominal segments of ♂ seen dorsally [IRSN]; C. N. turbans (Brunner v. Wattenwyl, 1907), terminal abdominal segments of ♂ (HT) seen laterally [MNCN]; D. N. turbans (Brunner v. Wattenwyl, 1907), terminal abdominal segments of ♂ (HT) seen ventrally [MNCN]; E. N. oligarches (Günther, 1935), terminal abdominal segments of ♂ (HT) seen laterally [MNHU]; F. N. oligarches (Günther, 1935), terminal abdominal segments of ♂ (HT) seen dorsally [MNHU]; G. N. oligarches (Günther, 1935), terminal abdominal segments of ♂ (HT) seen ventrally [MNHU]; H. N. oligarches (Günther, 1935), head and prothorax of ♂ (HT) seen laterally [MNHU]; J. N. giganteum n. sp., terminal abdominal segments of ♂ (PT) seen ventrally [coll. FH, No. 0656-11]; K. N. giganteum n. sp., head and prothorax of ♂ (PT) seen dorsally [coll. FH, No. 0656-10]; L. N. giganteum n. sp., head and prothorax of ♂ (PT) seen laterally [coll. FH, No. 0656-10].

FIGURE 47. Nesiophasma spp., eggs: A. N. giganteum n. sp., dorsal view [coll. FH, No. 0656-E]; B. N. giganteum n. sp., lateral view [coll. FH, No. 0656-E]; C. N. kuehni (Brunner v. Wattenwyl, 1907), dorsal view (PLT) [NHMW, No. 309]; D. N. kuehni (Brunner v. Wattenwyl, 1907), lateral view (PLT) [NHMW, No. 309]; E. N. plateni (Dohrn, 1910), dorso-lateral view [RMNH]. Figures C–D © 2019 Natural History Museum Vienna, NOaS Image Collection / H. Bruckner.