Phobaeticus mucrospinosus, Hennemann & Conle, 2008

Hennemann, Frank H. & Conle, Oskar V., 2008, Revision of Oriental Phasmatodea: The tribe Pharnaciini Günther, 1953, including the description of the world's longest insect, and a survey of the family Phasmatidae Gray, 1835 with keys to the subfamilies and tribes (Phasmatodea: " Anareolatae ": Phasmatidae), Zootaxa 1906, pp. 1-316 : 167-169

Phobaeticus mucrospinosus spec. nov.

( Figs. 105, 255, 328, 387)

HT, ♀: Mus. Leiden, P. t. Stolz, Solok Borenl., Febr. 1914; Pharnacia spec. ignota K. Günther det. 1956 ( RMNH) .

PT, 3 eggs (removed from abdomen of HT): same data as HT ( RMNH) .

Diagnosis: This new species is related to Ph. serratipes ( Gray, 1835) from Peninsular Malaysia and Sumatra, the Sumatran Ph. sobrinus Brunner v. Wattenwyl, 1907 and perhaps Ph. chani Bragg spec. nov. from Borneo. ♀♀ (the only sex known) however easily distinguished from these and all other members of the genus by the three distinct and conspicuously dagger-like spines in the basal quarter of the posteroventral carina of the mesofemora.

Etymology: The name mucrospinosus refers to the characteristic ventral armature of the mesofemora and is a combination the two Latin words “ mucro ” (= dagger) and “ spinus ” (= spine).

Description: ♀♀ ( Fig. 105): The unique ♀ in RMNH is in poor condition and incomplete. Apart from showing damage caused by parasites, the complete antennae, both fore legs, and last four tarsomeres of the meso- and metatarsi are broken off and missing.

Very long (body length 233.0 mm) and slender species (maximum body width 5.0 mm) with a short subgenital plate. General colour of the body creamish mid brown with a few white spots on metanotum, median segment and abdominal tergites II–III. Head more yellowish brown than rest of body and with several faint dark longitudinal lines. Legs pale brown to straw and becoming lighter towards the bases of the femora. Dagger-like ventral spines of the mesofemora and enlarged teeth of the tibiae and metafemora dark brown. Eyes reddish mid brown.

Head: Oval, 1.3x longer than wide, broadest at the eyes and distinctly narrowed towards the posterior; vertex almost flat. Posterior margin slightly angulate and convex medially. Vertex with a dark faint coronal line in front which terminates near the centre of head capsule and two dark longitudinal slightly converging lateral lines; the outer ones shorter. Between the eyes with a large transversely triangular, gently raised area. A transverse impression between the bases of the antennae. Eyes small and projecting hemispherically from head capsule; their length contained 2.4 in that of cheeks.

Thorax: Pronotum narrower but almost as long as head, slightly widening towards the posterior; 1.6x longer than wide. Anterior margin raised and follow by a distinct transverse furrow. Median transverse depression deep, gently curved but just not reaching lateral margins of segment. Mesothorax more than 3x longer than head and pronotum combined, mesonotum parallel-sided except for being very slightly broadened at the posterior. Median line dark brown, very faint. Metanotum about half the length of mesonotum, parallelsided, 4.4x longer than wide. Meso- and metasternum with a very fine and slightly raised longitudinal median line.

Abdomen: Median segment slightly shorter than metanotum, posterior margin broader than anterior margin, slightly constricted medially. Segments II–V slightly increasing in length, VI about as long as V, II less than 2.5x, VI almost 4x longer than wide. VII slightly shorter and narrower than previous, about 3x longer than wide. Tergites II–IX with a blunt posteromedian tubercle; this most prominent on V and VI. Praeopercular organ moderately developed and formed by two small, blunt spiniform tubercles at posterior margin of sternum VII. Tergite VIII considerably narrower but almost as long as VII, 5x longer than wide, strongly convex and parallel-sided. IX a little more than 1/3 the length of VIII, strongly convex and broadened in posterior half. Anal segment slightly shorter than IX, parallel-sided, with a fine longitudinal median carina and a small roughly semi-circular posteromedian notch; the posterolateral angles truncate. Supraanal plate very small, tapered towards apex and with a fine median keel. Cerci very small, slightly laterally compressed and gently up-curving. Subgenital plate longitudinally keeled and roughly reaching to posterior margin of anal segment (apex broken in the HT, Fig. 255).

Legs: Mid and hind legs long and slender with all carinae minutely spinose. Mesofemora about as long as mesothorax, metafemora reaching to posterior margin of abdominal segment V and metatibiae slightly projecting over apex of abdomen. Medioventral carina of meso- and metafemora indistinct and set with 10–15 minute spines. Posteroventral carina of mesofemora with three prominent, long (3.3 mm, 4.0 mm and 2.6 mm), basally constricted and conspicuously dagger-like spines in basal quarter of femur (Fig. 328). Metafemora with two needle-like sub-basal spines on same carina. Posterodorsal carina of meso- and metatibiae with a broad, triangular tooth near the middle (very indistinct on metatibiae) and raised into a rounded, dentate lobe at the apex. Medioventral carina of the meso and metatibiae with a flat, triangular spine about one third of the base of tibia (very indistinct on metatibiae). Metabasitarsus elongate, all carinae minutely dentate.

Eggs: Three eggs (PT) could be extracted from the abdomen of the HT. They are however in a rather early stage of development and do not show any specific structures which would allow a confirmed differentiation from the eggs of other species in the genus. Hence only a very brief characterization and measurements are provided.

Of moderate size, globose, almost as wide as long and oval in cross-section. Micropylar plate oval, longer than wide, about half the length of capsule and with a median notch posteriorly. Operculum oval, slightly convex and with an irregularly cone-shaped capitulum. Greyish mid brown.

Measurements [mm]: length (including capitulum) 4.7, length 3.5, width 3.0, height 3.4, length of micropylar plate 2.2.

Comments: ♂ unknown.

Distribution (Fig. 387): Eastern Sumatra (Solok).

Number of specimens examined: 1