Phasmatidae Leach, 1815

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 : 94-95

Family Phasmatidae Leach, 1815 s. str.

Subfamily -

Tribe -

Genus Dimorphodes Westwood, 1859

( Figs. 38–39 )

Type-species: Dimorphodes prostasis Westwood, 1859: 81 , pl. 34: 4–5, by original monotypy.

Comments: The taxonomy of the genus Dimorphodes is much confused. Günther (1934b: 87) attempted a reorganisation which basically reduced the known diversity to five valid species with all the other known taxa either regarded as subspecies of D. mancus Bates, 1865 and D. prostasis Westwood, 1859 or synonymised. The genus is badly in need of a revision and without any doubt many of the taxa regarded as subspecies by Günther are in fact valid species. As a first step towards a rearrangement the two known Sulawesian taxa are here reinstated as valid species and removed from subspecies status. Redtenbacher (1908: 366) recorded D. mancus Bates, 1865 from Sulawesi based on specimens in the collection of NHMW, however no Sulawesian specimens are present in this nor in any other collection. Thus, this record must be regarded as erroneous.

Distribution: New Guinea and Wallacea.

Species recorded from Sulawesi:

1. Dimorphodes celebensis Redtenbacher, 1908: 367 . rev. stat.

Comments: For type-data see below. The egg is described for the first time below.

Distribution: S-Sulawesi, Prov. Sulawesi Selatan, Gunung Lompobatang, Loka [NHMW]; S-Sulawesi, Prov. Sulawesi Selatan, Gunung Lompobatang, 1100 m [MNHU]; S-Sulawesi, Prov. Sulawesi Selatan, Lembang, Maros [coll. FH].

2. Dimorphodes elegans n. sp.

Distribution: Central Sulawesi, Prov. Sulawesi Selatan, Luwu [NHMB]; Central Sulawesi, Prov. Sulawesi Se-latan, Lake Poso [NHMB]; S-Sulawesi, Prov. Sulawesi Selatan, Gunung Bawakaraeng “Bua Kraeng” [ZMPA]; Central Sulawesi, Prov. Sulawesi Selatan, Luwu, Boran Djaladja, lowland [SMTD].

3. Dimorphodes epidicus (Günther, 1935: 5, pl. 1: 3 (♀ )). HT, ♀: Tanke Salokko 1500 m; S-O. Celebes, Meng-koka-Geb., 1.1932, G. Heinrich; Typus [ MNHU]. n. comb .

Comments: This tiny species was described from a unique and incomplete ♀ HT in MNHU. Already at the time of description the specimen lacked both front legs, all tarsi and most of the left antenna. Subsequently, also the entire abdomen got lost. Günther (1935: 5) originally placed this species in the genus Menexenus but in a final amendment on page 29 of the same publication stated it should really belong in the genus Pachymorpha because of the short antennae that only consist of 17 segments and are no more than twice the length of the head. Examination of the specimen however clearly places epidicus in Dimorphodes , being a rather typical member of that genus in most anatomical aspects but remarkably small (body length 32 mm according to Günther, 1935: 5).

Distribution: SE-Sulawesi, Mengkoka Mountains, Gunung Tanke Salokko [MNHU].

4. Dimorphodes sarasini Redtenbacher, 1908: 367 . HT, ♀: Luwu; Coll. Br. v. W. Celebes, Dr. Sarasin; det. Redtenb. Dimorphodes sarasini ; Dimorphodes sarasini Redt. [NHMW, No. 732]. rev. stat.

= Dimorphodes bellicosus Redtenbacher, 1908: 365 . LT, ♂ (by present designation): Pic von Bouthain; Coll. Br. v. W., Celebes, Sarasin; det. Redtenb. Dimorphodes bellicosus ; Dimorphodes bellicosus Redt. Type [NHMW, No. 728]; PLT, ♂ (penultimate instar nymph): Coll. Br. v. W., Celebes Dr. Sarasin; det. Redtenb. Dimorphodes bellicosus [NHMW, No. 728]. (Synonymised by Günther, 1934b: 88)

Distribution: S-Sulawesi, Prov. Sulawesi Selatan, Luwu [NHMW, MNHU]; Sulawesi [NHMW]; S-Sulawesi, Prov. Sulawesi Selatan, Gunung Latimojong, Rantemario, Uru 800 m [MNHU]; Central Sulawesi, Prov.Su-lawesi Tengah, Lore Lindu National Park [coll. AJH, coll. FH].

Keys to the Sulawesian species of Dimorphodes

♀♀

1. Body length <60.0 mm; pronotum and abdominal terga without paired anterior spines.............................. 2

- Body length> 60.0 mm; pronotum spinose and abdominal terga III–V with a prominent pair of spines near anterior margin. 3

2. Very small (body length <40.0 mm) and stocky; mesonotum 2x longer than wide............................ epidicus

- Larger (body length> 45.0 mm) and slender species; mesonotum 3x longer than wide..................... elegans n. sp.

3. Very large (body length> 90.0 mm) and slender species; mesonotum 3x longer than wide and without distinct median and lateral spines; no distinct anterior pair of spines on abdominal tergum II ( Fig. 39E )............................ sarasini

- Smaller (body length <70.0 mm) and more stocky species; mesonotum 2.5x longer than wide and all over armed with prominent spines; abdominal tergum II with a distinct pair of spines near anterior margin.......................... celebensis

♂♂ *

1. Body length> 50.0 mm; tegmina and alae present; pronotum and abdominal terga III–V with prominent paired spines..... 2

- Smaller (body length <35.0 mm); apterous; pronotum and abdominal terga unarmed...................... elegans n. sp.

2. Alae vestigial and concealed by tegmina (length> 2.0 mm); abdominal tergum II with a very prominent anterior pair of spines....................................................................................... celebensis

- Alae developed, much longer than tegmina and reaching to abdominal tergum II ( Fig. 39C ); tergum II unarmed ( Fig. 39D )................................................................................................ sarasini

* ♂♂ of D. epidicus (Günther, 1935) are not known

Figures

FIGURE 38. Dimorphodes elegans n. sp. [NHMB]: A. ♀ (HT), dorso-lateral view; B. ♀ (HT), lateral view; C. ♀ (HT), dorsal view; D. ♂ (PT), lateral view; E. ♂ (PT), dorsal view; F. Head, prothorax and anterior portion of mesothorax of ♀ (HT) seen laterally; G. Head, prothorax and anterior portion of mesothorax of ♂ (PT) seen laterally; H. Terminal abdominal segments of ♂ (PT) in lateral view; J. Terminal abdominal segments of ♀ (HT) in dorsal view; K. Terminal abdominal segments of ♀ (HT) in ventral view.

FIGURE 39. Dimorphodes sarasini Redtenbacher, 1908 rev. stat.: A. Egg, dorsal view [coll. FH, No. 1318-E]; B. Egg, lateral view [coll. FH, No. 1318-E]; C. ♂ (LT of synonym D. bellicosus Redtenbacher, 1908), dorsal view [NHMW, No. 728]; D. ♂ (LT of synonym D. bellicosus Redtenbacher, 1908), lateral view [NHMW, No. 728]; E. ♀ from Luwu, dorsal view [MNHU]; F. Terminal abdominal segments of ♀ (HT) in lateral view [NHMW, No. 732]; G. Terminal abdominal segments of ♂ (LT of synonym D. bellicosus Redtenbacher, 1908) in lateral view [NHMW, No. 728]. (Figs. C–D, F–G © Paul D. Brock).