Phasmotaenia bukaense, Hennemann, Frank H. & Conle, Oskar V., 2009

Hennemann, Frank H. & Conle, Oskar V., 2009, Studies on the genus Phasmotaenia Navás, 1907, with the descriptions of five new species from the Solomon Islands, a revised key to the species and notes on its geographic distribution (Phasmatodea: “ Anareolatae ”: Phasmatidae s. l.: Stephanacridini), Zootaxa 2011, pp. 1-46 : 15-17

Phasmotaenia bukaense n. sp.

[ Figs. 16–20 , 59 , 60 ]

HT, Ƥ: Südsee-Exp. Wolf 1909, Buka. D., Salom. I., 29.8.0 9, 40. (SMFM). PT, 1 egg (removed from ovipositor of HT): Same data (SMFM).

Diagnosis: ƤƤ, the only sex known, are similar to P. australe ( Günther, 1933) and P. godeffroyi ( Redtenbacher, 1908) from the Carolines. From the first species they differ by: the strongly reduced tegmina and alae (length <1.0 mm; presence of eight distinctly enlarged tubercles on the mesonotum; pair of posteromedian carinae on abdominal tergite VI; deep posteromedian excavation of the anal segment ( Fig. 18 ), dorsally unarmed profemora, and presence of several dorsal teeth in the basal half of the meso- and metafemora. The eggs differ from those of P. australe by the plain brown colouration of the capsule and longer micropylar plate. With P. godeffroyi ƤƤ share the strongly reduced tegmina and lack of alae but they can be distinguished from this species by: the more stout body and relatively shorter body segments; strongly swollen mesothorax; unarmed mesopleurae; broadly rounded posteromedian excavation of the anal segment, and more globose head.

Etymology: Named after the type-locality, Buka Island north of Bougainville.

Description: Ƥ ( Fig. 16 ): Medium sized (body length 153.5, including subgenital plate 160.5 mm), rather robust (maximum body width at abdomen 10.4 mm) species with a strongly swollen mesothorax, strongly reduced tegmina and alae and a moderately long, apically tapered subgenital plate (25.6 mm).

Colouration: General colour of body and legs plain drab to yellowish brown (may be due to preservation in ethanol), supraanal plate, apices of femora, tibiae and all tarsomeres dark brown to black. Scales of tegmina and alae mid brown. Eyes yellowish pale brown. Leg armature black. Antennae pale brown with the apical border dark brown and ventral surface of antennomeres I–IV black.

Head: Globose, vertex gently rounded and smooth, broadest just behind the eyes and about 1.25x longer than wide. Between the bases of the antennae with a shallow, oval impression. Posterior portion of vertex with a short impressed median line. Antennae almost reaching posterior margin of mesonotum (apices broken in the HT). Scapus almost 1.5x longer than wide, rectangular in dorsal aspect and dorsoventrally compressed. Pedicellus cylindrical, longer than wide and about half the length of scapus. III as long as pedicellus, IV ½ the length of III, V 2x longer than IV, the remaining antennomeres strongly increasing in length towards apices of antennae.

Thorax: Pronotum shorter and slightly narrower than head, roughly rectangular and about 1.4x longer than wide. Median line distinctly impressed over complete length of segment. Median transverse depression dark brown and distinct, gently curved but not reaching lateral margins of segment. Mesothorax some 4.5x longer than pronotum, constricted at the anterior, strongly swollen pre-medially and slightly narrowing in posterior half. Mesonotum in anterior portion with two longitudinal rows of four distinct but blunt tubercles, and a longitudinal row of small granules along lateral margins. Metanotum just a little longer than wide. Mesopleurae and metapleurae with a blunt longitudinal carina and sparsely granulose. Meso- and metasternum very sparsely and irregularly set with granules. Tegmina and alae strongly reduced and rudimentary (length <1.0 mm).

Abdomen: Median segment a little longer than metanotum, ca. 1.4x longer than wide, unarmed. Segments II–VI roughly of equal width and length, 1.3–1.4x longer than wide. Tergites II–V each with a small pair of posteromedian granules, otherwise smooth. VI posteromedially with two short, roughly parallel carinae, which increase in size towards the posterior. VII slightly shorter than previous and only 1.2x longer than wide. Sternites II–VII smooth. Praeopercular organ formed by two small, shallow humps near posterior margin of sternum VII. VIII slightly shorter than VII, just a little longer than wide and constricted in anterior half. IX transverse and about 2/3 the length of VII. Anal segment almost as long as VIII, posterior margin with a deep, rounded median excavation; posterolateral angles narrowed ( Fig. 18 ). Supraanal plate distinct, roundly triangular, longitudinally carinate dorsally and well projecting over apex of anal segment. Cerci elongate, slender, round in cross-section and narrowed towards the apex; about half as long as anal segment. Lower gonapophyses elongate, slightly broadened and up-curving apically, projecting over apex of abdomen by the combined length of tergites IX–X and almost reaching tip of subgenital plate. Subgenital plate moderately elongate and projecting over abdomen by slightly more than the combined length of tergites IX and X, strongly keeled and convex in basal portion, then gradually narrowed towards a rounded apex ( Fig. 17 ).

Legs: All moderately long and slender. Profemora almost as long as pro- and mesonotum combined, mesofemora shorter than mesonotum, metafemora reaching to posterior of abdominal segment IV and metatarsi reaching tip of abdomen. Posteroventral carina of profemora with about 24 very minute serrations and medioventral carina spinose, remaining carinae smooth. Posteroventral carina of protibiae densely but very minutely serrate, other carinae smooth. Probasitarsus very elongate and longer than remaining segments combined, ventral carinae serrate. Two outer ventral carinae of meso- and metafemora with 12–16 teeth of moderate size; the two apical teeth on the anteroventral carina of the mesofemora enlarged and slightly lobelike. Medioventral carina distinct and set with 11–14 minute spines. Basal half of anterior carinae dentate, the apical half smooth. All ventral carinae of meso- and metatibiae serrate, dorsal carinae smooth. Meso- and metabasitarsi slightly longer than following two tarsomeres combined, ventral carinae minutely serrate.

Eggs ( Figs. 19–20 ): One fully developed egg (PT) could be removed from the ovipositor of the HT.

Medium-sized, ovoid, capsule longer than wide and slightly oval in cross-section. Capsule surface smooth and moderately shiny. Micropylar plate elongate and almost as long as capsule, anterior 2/3 slender and gradually widening towards a roundly elevated sub-median portion, posterior end tapered. Micropylar cup small, rounded and placed in posterior half of plate. Operculum slightly oval, flat and in centre with a large, slightly conical, disc-like pseudo-capitulum, which almost covers the entire operculum. Pseudo-capitulum with a central impression and surface tuberculose. General colouration of capsule plain mid brown, micropylar plate and pseudo-capitulum pale straw.

Measurements [mm]: length (incl. operculum) 3.9, length 3.6, width 2.0, height 2.5, length of micropylar plate 3.2.

Comments: 3 unknown. It may well be that this new species turns out merely as a subspecies of P. australe ( Günther, 1933) once more material, including the unknown 3 becomes available.

Distribution ( Fig. 60 ): So far only known from Buka Island, north of Bougainville.

Ƥ, HT (SMFM)

Body (incl. subgen. pl.) 160.5 Body 153.5 Head 9.8

Pronotum 7.0

Mesonotum 32.5 Metanotum 8.4

Median segment 10.0 Subgenital plate 25.6 Profemora 37.0 Mesofemora 26.3 Metafemora 33.0 Protibiae 40.0 Mesotibiae 26.3 Metatibiae 34.9 Antennae> 40.0

Figures

FIGURE 59. Geographic distribution of Phasmotaenia Navás, 1907 with the concrete records indicated by red spots.

FIGURE 60. Distribution of Phasmotaenia spp. in the Solomon Islands.

FIGURES 16 – 20. Phasmotaenia bukaense n. sp. 16. Habitus of Ƥ HT (SMFM); 17. Apex of abdomen of Ƥ from Central Malaita Id., Kwara’ae Province (lateral view) [scale = 5 mm]; 18. Apex of abdomen of Ƥ from Central Malaita Id., Kwara’ae Province (dorsal view) [scale = 5 mm]; 19. Egg (dorsal view) [scale = 1 mm]; 20. Egg (lateral view) [scale = 1 mm].