Dimorphodes sarasini Redtenbacher, 1908

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 : 99-100

Dimorphodes sarasini Redtenbacher, 1908 rev. stat.

( Fig. 39 )

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.

Sellick, 1998: 223.

Dimorphodes prostasis sarasini, Günther, 1934b: 88 .

Günther, 1938: 82.

Brock, 1998: 55.

Hennemann, 1998: 123.

Otte & Brock, 2005: 129.

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, ♂ (pen-ultimate instar nymph): Coll. Br. v. W., Celebes Dr. Sarasin; det. Redtenb. Dimorphodes bellicosus [NHMW, No. 728]. (Synonymised by Günther, 1934b: 88)

Günther, 1935: 15.

Otte & Brock, 2005: 129.

Further material: 1 ♂: Celebes, Latimodjong Geb. Oeroe 800 m, G. Heinrich 8.1930 [ MNHU] ; 1 ♀: Sarasin 28.I.– 1. II .1895, Luwu, Flachland, Goran-Djaladja , Centr. - Cel. [ MNHU] ; 3 ♀♀, 1 ♂, eggs: Indonesia, Central Sulawesi, Lore Lindu N.P., 13.–20. VIII .1993 [coll. AJH] ; 5 eggs: S-Sulawesi, Sulawesi Tengah, Lore Lindu N.P., leg. A.J.E. Harman 13.–20. VIII .1993 [coll. FH, No. 1318-E].

Differential diagnosis: Males of this species are well recognized amongst the Sulawesian members of the genus by having developed alae with a well developd fan, that are notably longer than the tegmina. Females differ from the three other known Sulawesian species by the larger size (body length> 85.0 mm). The anterior pair of spines on abdominal terga III–V is shared with ♀♀ of D. celebensis but the latter species has an additional anterior pair of spines on tergum II, is more stocky in shape and also has strong paired spines on the mesonotum.

Eggs ( Figs. 39A–B ): Medium sized for the genus. Capsule sub-spherical in shape, slightly higher than wide, about 1.2x longer than wide and slightly oval in cross-section. Entire capsule surface densely but unevenly granulose to rugulose and covered with several very irregularly shaped, shallowly raised areas; these most pronounced on dorsal surface and around micropylar plate. Anterior margin of capsule weakly inflated. Micropylar plate pearshaped, with posterior portion 1.75 wider than anterior end and about 1.9x longer than width of posterior portion. Surface sculptured like capsule and with an obtuse medio-longitudinal bulge. Micropylar cup distinct, bowl-shaped with a blunt swelling anteriorly and placed in posteromedian gap of plate. Median line fairly distinct but short and not reaching to polar end of capsule. Operculum almost circular, roundly convex and with a distinct, conical capitulum in centre, which has a distinct central pit on top and the lateral surfaces with some obtuse, longitudinal ridges. General colour of capsule mid brown with the raised portions and the opercular collar greyish ochre. Micropylar plate slightly lighter in colour than capsule with the outer margin dark brown. Colour of operculum like that of capsule, the apical portion of the capitulum ochraceous. Measurements [mm]: Length including capitulum 4.6, length 3.9, width 3.3, height 3.5, length of micropylar plate 2.6.

Comments: Günther (1934b: 88) regarded D. sarasini as a subspecies of the type-species D. prostasis Westwood, 1859 from the Aru islands in the very southestern Wallacea. This taxon however so strongly differs from typical D. prostatsis in various morphological characters that valid species status appears more than justified. Therefore, D. sarasini is here reinstated as a valid species (rev. stat.). Features that readily separate D. sarasini from D. prostasis are: the much shorter alae, which only reach to abdominal tergum II (V or VI in prostasis ) and prominent paired anterior spines of abdominal terga II–V of ♂♂ as well as the distinct spines on the vertex and pronotum, much more distinct anterior pair of spines of abdominal terga II–V and lack of conspicuously enlarged lobes on the meso- and metafemora of ♀♀.

The four specimens from Lore Lindu National Park in the personal collection of Allan J.E. Harman (Essex, U.K.) prove that Günther (1934b: 88) was correct when he synonymised D. bellicosus Redtenbacher, 1908 as the opposite sex of D. sarasini . For providing stability of this synonym the unique adult ♂ specimen in the collection of NHMW is here selected as the lectotype .

The three ♀♀ from Lore Lindu National Park are all rather plain dark brown in colour and have the anterior pair of spines of the mesonotum more pronounced than the holotype and ♀ from Luwu in the collection of MNHU. The latter specimen was originally recorded from NHMB and is yellowish ochre in colour with various dark brown markings all over the head, body and legs ( Fig. 39E ). In addition to the specimen in MNHU Günther (1938: 82) recorded a second ♀ from the same locality in the collection of SMTD, but this specimen was not examined for the present study .

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

Figures

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).