Gibbopromachus, 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 : 28-30

Genus Gibbopromachus n. gen.

( Fig. 12 )

Type-species: Pericentrus tripinnatus Redtenbacher, 1998: 352 , by present designation.

Pericentrus Redtenbacher, 1908: 352 (in part).

Brock, 1998: 63.

Hennemann, 1998: 119.

Otte & Brock, 2005: 259.

Neopromachus, Günther, 1938: 58 , 82 (in part).

Diagnosis: ♀ ( Fig.12 ). Fairly small (body length 78.0 mm) and stocky Lonchodinae with very prominent body armature, a strongly swollen mesothorax and a bird-beak like ovipositor. General colour brown with a reddish longitudinal median stripe along most of dorsal body surface. Head and entire body armed with large and strong but obtuse spines of variable sizes ( Figs. 12A–B ). Head slightly longer than wide, globose with the vertex roundly convex and armed with several prominent coronal spines; another strong pair of spines on frons. Antennae slender, reaching to abdominal segment II and consisting of about 35 antennomeres; scapus compressed dorsoventrally and somewhat deflexed laterally, pedicellus cylindrical, following increasing in length, the antennomeres in median section of antennae extremely elongated, the apical ten or so suddenly much shorter. Antennomere XIV with a shiny, knob-like sub-basal dorsal swelling; the elongated median antennomeres with apex thickened and gently curved. Pronotum notably shorter and narrower than head with a prominent, impressed transverse sulcus and at least a pair of strong spines in posterior half. Mesothorax almost 4x longer than prothorax, gently down-curving, very strongly swollen medially with the mesonotum very prominently raised and humped ( Figs. 12A–B ). Mesonotum armed with numerous very strong spines, mesopleurae with a marginal row of strong spines and a strong supra-coxal spine. Metanotum roughly 1/3 the length of mesonotum, about 1.6x longer than wide, almost rectangular and almost 2x longer than median segment; armed with two paired spines. Metapleurae principally like mesopleurae. Meso- and metasternum with several strong but short, paired spines. Abdomen longer than head and thorax combined. Median segment somewhat transverse. Segments II – VI decreasing, VII and VIII increasing in length. Terga II and VII with four spines, III – VII with the lateral margins deflexed into a large, almost semi-circular lobe and armed with six spines ( Fig. 12A ). All terga with a fine, longitudinal median carina. Sterna with paired spines, VII with Preopercular organ formed by two obtusely rounded swellings ( Fig. 12E ). Terga VIII and IX with an obtuse posteromedian hump. Anal segment strongly narrowed and declining in lateral aspect ( Fig. 12C ), the apex strongly elongated into a very long and straight, lanceolate projection (apex broken in the unique holotype, Fig. 12D ). Cerci very small, conical and gently compressed dorsoventrally. Epiproct very small, triangular and also concealed under apical projection of anal segment. Subgenital plate convex, strongly keeled longitudinally, bulgy in median portion ( Fig. 12 C ) and with apex elongated into a lanceolate projection, that is not reaching the apex of the anal segment; apex obtusely angular ( Fig. 12E ). Legs long and moderately slender, profemora a little longer than mesothorax, mesofemora slightly shorter than mesothorax and metafemora reaching to abdominal segment VI. Profemora strongly compressed and curved basally. All femora trapezoidal in cross-section, distinctly carinate and on two outer carinae and posterodorsal carina with a prominent triangular lobe sub-apically. Medioventral carina obtuse. All tibiae slender and longer than corresponding femora, unarmed except for a distinct, rounded sub-basal lobe on medioventral carina. Basitarsi long and slender, somewhat longer than combined length of all remaining tarsomeres .

Egg ( Figs. 12F–G ): The unique egg available from the ovipositor of the holotype of G. tripinnatus (Redtenbacher, 1908) n. comb. lacks the operculum. Moderately sized (length 3.5 mm), ovoid about 1.7x longer than wide, notably higher than wide and oval in cross-section; the polar end slightly narrowed. Capsule surface minutely and evenly punctured, slightly glossy. General colour flecked with dull ochre and mid brown. Micropylar plate very elongate with anterior half parallel-sided and posterior half gently widened; covering more than ¾ the length of capsule. Micropylar cup small but well defined and placed some distance off posterior end in a narrow posteromedian gap of plate. Median line almost obsolete.

Differential diagnosis: Numerous morphological characters suggest close relation to the principally New Guinean genus Neopromachus Giglio-Tos, 1912 , which also has a few representatives on the very eastern islands of Wallacea (e.g. Aru Islands) but east of Weber’s line; this is mainly the prominent spination of the head and body, as well as the bird-beak like secondary ovipositor of ♀♀. Females of this new genus, the only sex known, however differ from those of Neopromachus by the laterally lobed abdominal terga II–VII, strongly swollen and gibbose mesonotum, angular apex of the subgenital plate ( Fig. 12E ), considerably longer basitarsi that are longer than the corresponding remaining tarsomeres taken together and extremely elongated median antennomeres. Moreover, the egg is more ovoid and notably less elongate than all known eggs of Neopromachus . Within the Sulawesian fauna, the beak-like ovipositor resembles Paramanduria n. gen., but the strong body armature, more globose head, strongly swollen mesonotum and lateral lobes of the abdominal terga readily distinguish this new genus. The strong body armature resembles Acanthomenexenus Brock & Hennemann, 2009 , but Gibbopromachus n. gen. readily differs from that genus by the morphology of the terminalia.

Comments: The true relationships of this striking new genus are still not fully known and require knowledge of the still unknown ♂♂. Redtenbacher (1908: 352) originally placed this species in the genus Pericentrus Redtenbacher, 1908 , which however is not closely related and geographically restricted to northern India and Bhutan. A discussion of and redescription of Pericentrus was presented by Hennemann, Conle & Zhang (2008: 51), who already assumed close relation to Neopromachus Giglio-Tos, 1912 .

Etymology: The name is a combination of “ gibbus ” (lat. = hump) and “ promachus ” from the visually very similar looking genus Neopromachus Giglio-Tos, 1912 . Masculine.

Distribution: Sulawesi (endemic).

Species included:

1. Gibbopromachus tripinnatus (Redtenbacher, 1908: 352) [ Pericentrus ]. HT, ♀: Coll. Br. v. W., Celebes, Dr. Sarasin; Lowu Mtne c. 700 m; Pericentrus 3-pinnatus Redt.; det. Redtenb. Pericentrus tripinnatus [NHMW, No. 713]. n. comb.

Distribution: NE-Sulawesi, Prov. Sulawesi Utara, Mount Lowu 700m [NHMW]; NE-Sulawesi, Minahasa, Gunung Sudara summit [NHMB].

Genus Hermagoras Stål, 1875

( Figs. 13 , 68A )

Type-species: Lonchodes personatus Bates, 1865: 336 , pl. 44: 7 [= H. foliopeda (Olivier, 1792) ], by subsequent designation of Kirby, 1904: 322.

Comments: This genus has five known species on Borneo and is represented throughout the southeastern regions of Wallacea by the type-species H. foliopeda (Olivier, 1792) . On Sulawesi it is represented by one species, which was formerly regarded a subspecies of H. foliopeda but is here raised to species level. The distinction between Hermagoras and the morphologically very similar Mnesilochus Stål, 1877 presented by Seow-Choen (2016: 279) is partly based on a misinterpreted character and is clarified in the comments on Mnesilochus below.

Figures

FIGURE 12. Gibbopromachus tripinnatus (Redtenbacher, 1908) n. gen., n. comb., A–E ♀, holotype [NHMW], F–G egg extracted from ovipositor of holotype (operclum missing) [NHMW]: A. Habitus in dorsal view; B. Habitus in lateral view; C. Terminal abdominal segments in lateral view; D. Terminal abdominal segments in dorsal view; E. Terminal abdominal segments in ventral view; F. Egg, dorsal view; G. Egg, lateral view. © 2019 Natural History Museum Vienna, NOaS Image Collection / H. Bruckner.

FIGURE 13. Hermagoras celebensis (Hennemann, 1998) n. stat.: A. ♀ (AT), lateral view [MNHU, No. 7917]; B. ♀ (AT),dorsal view [MNHU, No. 7917]; C. ♂ (HT), lateral view [MNHU, No. 7916]; D. ♂ (HT), lateral view [MNHU, No. 7916]; E. ♂ from Luwu, dorso-lateral view [NHMB]; F. Apical half of abdomen of ♂ from Luwu, lateral view [NHMB]; G. Terminal abdominal segments of ♂ from Luwu, dorsal view [NHMB]; H. Terminal abdominal segments of ♂ (HT), lateral view [MNHU, No. 7916]; J. Metanotum and median segment of ♂ from Luwu, dorso-lateral view [NHMB].

FIGURE 68. Live insects from Bogani Nani Wartabone National Park, Gorontalo Province, Northern Sulawesi (all © Pavel Kirillov). A. ♂ of Hermagoras celebensis (Hennemann, 1998); B. ♂ of an as yet undescribed species of Asceles Redtenbacher, 1908; C. ♀ of an undescribed species of Asceles Redtenbacher, 1908, close to A. rufescens Redtenbacher, 1908 and possibly the opposite sex of the ♂ shown in figure B. D. ♀ of an undescribed species of Neoclides Uvarov, 1940 showing remarkable twiglike camouflage; E. ♀ of the same Neoclides species seen in figure D, which is the only record of this genus from Sulawesi.