Phasmotaenia virgea, 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 : 33-37

Phasmotaenia virgea n. sp.

[ Figs. 41–47 , 53 , 59 , 60 ]

HT, Ƥ: New Georgia, Solomon Is., 20.V. 1963, R.W. Paine, N 4; Brit. Mus., 1967-404; BMNH(E) # 845349 (BMNH).

PT, Ƥ: Munda: XII. 60, Host Plant unknown, Type, R.W. Paine, H; Solomon Is: Munda XII. 1969 R.W. Paine; Pres by Com[…]nst Ent B M 1962 I; BMNH(E) # 845351 (BMNH).

PT, 3: Solomon Is: Munda, 20.V.1963, R.W. Paine, B.M. 1965-21; BMNH(E) #845350 (BMNH).

Diagnosis: Very similar to P. australe (Günther, 1933) but distinguished by: the much more elongate body and relatively longer body segments; more slender and elongate legs and less globose head of both sexes; more slender not considerably swollen mesothorax; tuberculose mesonotum; spinulose mesopleurae; black anal fan of the alae; dorsally dentate meso- and metafemora and distinct bi-dentate apical lobe on the anteroventral carina of the mesofemora of ƤƤ ( Fig. 47 ); as well as the relatively shorter alae; more distinct but less numerous granules of the mesonotum; lack of the distinctive white anterior margin of the tegmina, and differently shaped anal segment of 3 ( Fig. 46 ). The eggs differ from those of P. a u s t r a l e by the relatively longer micropylar plate and distinctive, flat cone-shaped pseudo-capitulum ( Fig. 53 ).

Etymology: The specific name virgea is derived from the Latin “ virga ” (= twig) and refers to the slender and twig-like body of this new species.

Description: Ƥ ( Fig. 41 ): Large (body length 172.0– 172.5 mm, incl. subgenital plate 181.0–182.0 mm), very slender and elongate species for the genus (body width at abdominal tergite V 6.0 mm) with a just gently swollen, minutely tuberculose mesothorax, well developed tegmina (8.1–8.5 mm) and alae (9.7–10.6 mm), a black anal fan, and a moderately long subgenital plate.

Colouration: General colour of body and legs ranging from mid green (HT) to greenish pale brown or sepia (PT). The PT has most parts of the body become black during the preservation, since the specimen was not eviscerated. Tegmina and costal region of alae green to olive with a brownish wash in the central portion. Anal region of alae black. Gonapophyses straw to pale brown. Spines of the extremities with the points black, the apical lobe on the posteroventral carina of the mesofemora dark brown. Three terminal tarsomeres mid to dark brown. Eyes ochraceous or reddish brown. Antennae dull green or olive, antennomeres II–V dark brown ventrally.

Head: Sub-globose, oval in dorsal aspect, broadest just behind the eyes and about 1.3x longer than wide; vertex gently convex and smooth. Eyes of moderate size, circular and projecting hemispherically; their length contained about 2.5x in that of cheeks. Antennae just not reaching posterior margin of mesonotum and consisting of 30 segments. Scapus dorsoventrally compressed, roundly rectangular in dorsal aspect and some 1.6x longer than wide. Pedicellus roughly half the length of scapus, round in cross-section and slightly longer than wide. III a little longer but more slender than pedicellus, IV very short. V–XIV increasing in length, remaining tarsomeres elongate and of roughly equal length.

Thorax: Pronotum slightly shorter and narrower than head, roughly rectangular and about 1.6x longer than wide. Surface with a slightly impressed longitudinal median line, transverse median depression distinct, widely V-shaped and almost reaching to lateral margins of segment. Mesothorax elongate and 5.4–5.5x longer than pronotum, the anterior 1/3 slightly constricted, then very gently swollen and the posterior half roughly parallel-sided. Mesonotum with a rather decided longitudinal median carina and on both sides set with several spiniform tubercles, which are irregularly arranged in two longitudinal rows; another row of small tubercles parallel along lateral margins. Metanotum slightly longer than wide and smooth. Meso-and metapleurae with a longitudinal ridge or carina, on the mesopleurae set with a row of 15–20 spiniform tubercles. Meso- and metasternum sparsely and irregularly granulose. Tegmina well developed, reaching some ¾ the way along metanotum and just covering base of alae (length 8.1–8.5 mm); shape scale-like, constricted at the base and the central hump shallow. Alae very slightly longer than tegmina (9.7–10.6 mm) and reaching a little more than half the way along median segment.

Abdomen: Median segment 1.4x longer than metanotum, gently widened towards the posterior and smooth. Segments II–VI roughly of uniform width, all parallel-sided, the tergites smooth. II longer than median segment, 1.8x longer than wide and shorter than III–VI but equal in length to VII. III–VI equal in length and about 2x longer than wide. VII slightly narrower than previous and almost 2.5x longer than wide. All sterna smooth, praeopercular organ formed by a small, wart-like median structure near posterior margin of sternum VII. Tergite VIII about half as long as VII, 1.5x longer than wide and gently constricted at the anterior. IX about half the length of VIII and roughly quadrate in dorsal aspect. Anal segment a little longer than IX, slightly tectiform and with a very small posteromedian indention; posterolateral angles slightly elevated and rounded ( Fig. 44 ). Supraanal plate small, roundly triangular and projecting over posterior margin of anal segment. Cerci small, round in cross-section and tapered towards a pointed apex, finely bristled. Lower gonapophyses very elongate, filiform and ± reaching ¾ the way along the extending part of the subgenital plate, the apex slightly widened and up-curving. Upper gonapophyses projecting by a little less than the length of anal segment, apex pointed. Subgenital plate strongly keeled in basal portion and projecting over apex of abdomen by about the combined length of tergites IX–X, apex narrow and ± pointed ( Fig. 43 ).

Legs: All moderately long and slender. Profemora longer than mesonotum, mesofemora about ¾ the length of mesonotum, metafemora reaching some ¾ along abdominal segment VI and metatarsi not reaching to anal segment. Anterodorsal and posteroventral carinae of profemora each armed with 20–25 acute serrations, a few more minute teeth are present in the compressed basal portion of the posteroventral carina. Anteroventral carina minutely serrate, posterodorsal carina smooth. Medioventral carina distinct and set with several rather distinct spines, which strongly decrease in size towards base of femur. Ventral carinae of protibiae minutely serrate, dorsal carinae smooth. Dorsal and two outer ventral carinae of meso- and metafemora distinctly and rather regularly dentate, the teeth much small on the dorsal carinae although. Anteroventral carina with a distinct, triangular, bi-dentate lobe near the apex. Medioventral carina distinct and set with ± 10 rather prominent spines. Meso- and metatibiae distinctly and acutely serrate ventrally, just sparsely and minutely dentate on dorsal carinae. Probasitarsus elongate, slender and a little longer than following three tarsomeres combined, meso- and metabasitarsus about as long as the following three tarsomeres combined; ventral carinae minutely denticulate.

33 ( Fig. 42 ): Rather large (body length 110.4 mm), very slender and elongate for the genus (body width at abdominal tergite V 1.9 mm), with a sparsely, but rather acutely granulose mesonotum, well developed alae (46.7 mm) and long, slender legs.

Colouration: General colour of body an irregular mix of various shades of brown with a slight greenish wash on the head, pronotum and abdomen; head paler than rest of body. Mesonotum with the lateral margins very dark brown and the granules dull green. Tegmina green with a bold, but poorly defined brown posteromedian marking, in front with a creamish white centeral longitudinal stripe which terminates just before tha base of tegmen. Costal region of alae green with the anterior portion broadly brown, anal region transparent with a very slight yellowish wash. Profemora with base pale green, otherwise pale brown with irregular darker brown mottling. Meso- and metafemora each with three dark brown transverse bands, the most basal one faint, the apical one very distinct and broadest. Eyes greyish brown and irregularly marbled with green. Antennae greyish mid brown, the scapus and pedicellus cream.

Head: Generally as in ƤƤ but eyes more prominent, projecting hemispherically and their length contained only about 2x in that of cheeks. Antennae consisting of 24 segments and reaching to posterior metanotum. Otherwise as in ƤƤ.

Thorax: Pronotum generally as in ƤƤ but distinctly narrower than head, smooth. Mesothorax very elongate, almost 7x longer than pronotum and slightly widened at the posterior. Mesonotum with a very fine longitudinal median carina and sparsely set with rather distinct and acute granules. Mesopleurae with a longitudinal median carina, which is set with a row of small granules. Mesosternum sparsely and minutely granulose, metapleurae and metasternum unarmed. Metanotum about 1.3x longer than wide. Tegmina scaleshaped, constricted basally and just not reaching posterior margin of metanotum; central hump small but distinctly roundly conical. Alae slightly projecting over posterior margin of abdominal tergite IV.

Abdomen: Median segment slightly longer than metanotum, about 2.5x longer than wide, smooth. Segments II–VII equal in width and parallel-sided. II longer considerably longer than median segment and longer than III–VII. III–VI roughly equal in length and about 6x longer than wide. VII about 2/3 the length of VI. All tergites smooth except for a ± distinct longitudinal bulge along lateral margins. Sernites II–VII very slightly tectiform and sparsely set with very minute granules. Tergites VIII–X with two blunt longitudinal carinae. VIII a little more than half the length of VII and very slightly widened at the posterior. IX about ¾ the length of VIII, 1.5x longer than wide and tectiform; roughly parallel-sided. Anal segment about half the length of IX, the dorsal surface with a fine longitudinal median carina. Posterior margin with a wide and flat angulate excavation ( Fig. 46 ), the posterolateral angles slightly swollen and with three minute teeth intero-ventrally. Cerci of moderate size, round in cross-sectio, straight and with the apex slightly club-like. Vomer broadly triangular with the apex acute and straight. Poculum rather small, scoop-shaped, with a longitudinal median keel in posterior portion and just not reaching posterior margin of tergite IX ( Fig. 45 ).

Legs: All long and slender. Profemora about as long as combined length of head, pro- and mesonotum, mesofemora slightly shorter than mesonotum, metafemora reaching about half way along abdominal segment IV and metatarsi reaching apex of abdomen. Armature generally as in ƤƤ but less distinct and mesofemora without a sub-apical lobe on the two outer lower carinae. Probasitarsus very elongate, slender and longer than remaining tarsomeres combined; all carinae unarmed. Meso- and metabasitarsi longer than remaining tarsomeres combined, slender and unarmed.

Eggs ( Fig. 53 ): One egg (PT) could be extracted from the ovipositor of the Ƥ PT and served for the description here presented.

Medium-sized, ovoid, capsule longer than wide and slightly oval in cross-section. Capsule surface very minutely rugulose and strongly shiny. Micropylar plate distinctly raised above surface of capsule, elongate and a little more than 2/3 the length of capsule. The median portion roundly elevated, the anterior and posterior portions gradually narrowed; anterior apex rounded, posterior apex rather pointed. Micropylar cup very small, rounded and placed somewhat below centre of plate. Operculum slightly oval, flat and in the centre with a large and gently conical, disc-like pseudo-capitulum, which almost covers the entire operculum. Surface of pseudo-capitulum smooth. General colouration of capsule reddish mid brown with most of the surface irregularly furnished with pale cream, washed markings. Micropylar plate cream with the central portion brown. Operculum greyish brown, the pseudo-capitulum pale straw.

Measurements [mm]: length (incl. operculum) 4.2, length 3.9, width 2.1, height 2.5, length of micropylar plate 2.9.

Distribution ( Fig. 60 ): Solomon Islands. So far only known from north-eastern New Georgia Island (Munda).

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 41 – 47. Phasmotaenia virgea n. sp. 41. Habitus of Ƥ HT (BMNH, No. 845349). [Photo by P. D. Brock, © BMNH]; 42. Habitus of 3 PT (BMNH, No. 845350). [Photo by P. D. Brock, © BMNH]; 43. Ƥ apex of abdomen (lateral view); 44. Ƥ apex of abdomen (dorsal view); 45. 3 apex of abdomen (lateral view); 46. 3 apex of abdomen (dorsal view); 47. Mid leg of Ƥ HT (anterolateral view).

FIGURES 48 – 58. Eggs of Phasmotaenia spp. in dorsolateral view. 48. Phasmotaenia australe (Günther, 1933), Central Malaita Id., Kwara’ae Province (culture-stock); 49. Phasmotaenia australe (Günther, 1933), Central Malaita Id., Kwara’ae Province (culture-stock); 50. Phasmotaenia australe (Günther, 1933), Central Malaita Id., Kwara’ae Province (culture-stock); 51. Phasmotaenia australe (Günther, 1933), Central Malaita Id., Kwara’ae Province (culture-stock, after incubation on damp vermiculite); 52. Phasmotaenia australe (Günther, 1933), from Maramasike (coll. FH, No. 0513 - E 1); 53. Phasmotaenia virgea n. sp., PT (BMNH); 54. Phasmotaenia guentheri n. sp., PT (BMNH); 55. Phasmotaenia lanyuhensis (Huang & Brock, 2001) (coll. FH, No. 0610 - E); 56. Phasmotaenia laeviceps (Hennemann & Conle, 2006), PT (RMNH); 57. Phasmotaenia salomonense n. sp., PT (SMTD); 58. Phasmotaenia spinosa n. sp., PT (coll. FH, No. 0602 - E).