Phasmotaenia guentheri, 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 : 18-21

Phasmotaenia guentheri n. sp.

[ Figs. 21–26 , 54 , 59 , 60 ]

Phasmotaenionema australe Günther, 1933: 155 , figs. 1–4 (in part – only the three paratypes from Makira Island).

HT, Ƥ + 1 egg (ex ovipositor): Salomonen, Kira-Kira (Makira), I. 1929, leg. E. Paravicini; Typus; Phasmotaenionema australe K. Günther det. (MNHU) [PT of Phasmotaenionema australe Günther, 1933 ].

PT, 2 ƤƤ: Salomonen, Kira-Kira (Makira), I. 1929, leg. E. Paravicini; Phasmotaenionema australe K. Günther det. (NHMB) [PT’s of Phasmotaenionema australe Günther, 1933 ].

PT, Ƥ + 1 egg (ex ovipositor): Solomones, San Cristoval, Huni, R. south Camp. 4, 15.8.65, Roy. Soc. Exped., BM 1966- 1; BMNH(E) #845039 and BMNH(E) #845040 (BMNH).

PT, Ƥ: Solomones, San Cristoval, Huni, R. south Camp. 4, 15.8.65, Roy. Soc. Exped., BM 1966 - 1; BMNH(E) # 845038 (BMNH).

PT, 1 egg (ex ovipositor of Ƥ BMNH(E) #845039): Solomones, San Cristoval, Huni, R. south Camp. 4, 15.8.65, Roy. Soc. Exped., BM 1966-1; BMNH(E) #845040 (BMNH).

PT, Ƥ (penultimate instar nymph): Solomones, San Cristoval, Narahito R., 28 M, 1965, "on felled tree", Roy. Soc. Exped., BM 1966-1; BMNH(E) #845041 (BMNH).

PT, Ƥ: Solomon Is., Yarikora, T.C. Whitemore VII. 1963, Brit. Mus. 1966-55; BMNH(E) # 845041 (BMNH).

PT, Ƥ: „South-Sea Islands“;BMNH(E) #845041 (BMNH).

Diagnosis: ƤƤ are similar to P. godeffroyi (Redtenbacher, 1908) from the Carolines and P. australe (Günther, 1933) from the Solomon Islands, but at once differ from both species by the much shorter gonapophyses which do not project over the apex of the anal segment ( Figs. 25–26 ) and black longitudinal median stripe on the pronotum. From the first species ƤƤ furthermore differ by: the larger body size; more globose head and much longer, lanceolate, apically pointed and tri-dentate subgenital plate ( Fig. 26 ), and dentate dorsal carinae of the mid and hind legs. From P. australe ƤƤ differ by: the less globose head; more slender and less swollen mesothorax; much smaller, vestigial tegmina and lack of alae ( Figs. 23–24 ), as well as the apically tri-dentate subgenital plate ( Fig. 26 ).

Etymology: Named in honour of Klaus Günther, a well known German entomologist, who included some specimens of this species in his type-series of Phasmotaenia australe (Günther, 1933) .

Description: Ƥ ( Figs. 21–22 ): Large (body length 140.0– 172.5 mm, incl. subgenital plate 155.0–189.0 mm), moderately slender and elongate species (body width at abdominal tergite V 7.0–8.0 mm) with a gently broadened mesothorax, very small and vestigial tegmina (1.3–3.2 mm), a long lanceolate, apically tri-dentate subgenital plate, and very short gonapophyses which hardly project over the posterior margin of the anal segment.

Colouration: General colouration of body and legs variable and ranging from straw (HT, Fig. 21 ), over greyish mid brown (PT from Yarikora) to dark reddish brown (PT’s from San Cristoval, Fig. 22 ), more rarely green (PT from “South-Sea Islands” in BMNH). Pronotum with a distinctive black longitudinal median stripe, which is broadest at anterior margin, gradually narrows towards the posterior and terminates just before the posterior margin. Spines of the extremities with the points black. Antennae pale orange to dark brown. Eyes dark reddish brown.

Head: Sub-globose, roundly rectangular in dorsal aspect, broadest at the eyes and about 1.3x longer than wide. Vertex almost flat and irregularly set with a variable number of small but pointed tubercles. A few small granules present on the cheeks. Inter-ocular portion gently raised. Eyes of moderate size, circular and projecting hemispherically; their length contained almost 3.5x in that of cheeks. Antennae reaching about half way along metanotum. Scapus dorsoventrally compressed, roundly rectangular in dorsal aspect and roughly 1.5x longer than wide. Pedicellus about half as long as scapus, round in cross-section and narrowing towards the apex. III slightly longer than pedicellus, IV shorter than III, following antennomeres first increasing, then decreasing in length towards apex of antennae.

Thorax: Pronotum about as long and broad as head, roughly1.3x longer than wide and very slightly narrowed medially. Surface very sparsely granulose. Anterior margin gently raised, the transverse median depression distinct, gently curved and spanning about half the width of segment. Longitudinal median impression very distinct. Mesothorax almost 4.5x longer than pronotum, the anterior 1/3 constricted, the posterior 1/3 roughly parallel-sided and broader than anterior 1/3, the median portion gently swollen. Mesonotum with a very faint longitudinal median carina and irregularly set with numerous small but pointed granules. A broad longitudinal stripe of numerous but very minute granules along lateral margins. Metanotum roughly quadrate and sparsely granulose. Mesopleurae with a longitudinal row of ± 10 small, pointed tubercles (indistinct in the HT); a few small tubercles also present in anterior half of metapleurae. Mesosternum sparsely granulose and with a fine, slightly raised longitudinal carina along lateral margins. Metasternum unarmed. Tegmina very small and vestigial (length 1.3–3.2 mm), ovate and very slightly projecting over posterior margin of mesonotum. Alae lacking.

Abdomen: Median segment indistinctly longer than metanotum. Surface of median segment and tergites II–IV very sparsely and minutely granulose; remaining tergites unarmed. Segments II–VI roughly of equal width and roundly rectangular. II and III of equal length, about 1.2x longer than wide and slightly longer than median segment. III–V very slightly increasing in length. VII as long as VI but considerably narrower, parallel-sided and about 2x longer than wide. Praeopercular organ formed by a small median granule at posterior margin of sternum VII. Tergite VIII about 3/4 the length of VII, 1.3x longer than wide and gently narrowed towards the posterior. IX 2 /3 the length of VIII and roughly quadrate in dorsal aspect. Anal segment longer than IX, narrowed towards the posterior and with a distinct longitudinal median keel. Posterior margin with a distinct, roundly triangular median excavation ( Fig. 25 ). Supraanal plate acutely triangular with a pointed apex and considerably projecting over posterior margin of anal segment. Cerci small, sub-cylindrical and tapered in apical portion with the apex narrow, finely bristled. Gonapophyses short and not projecting over the apex of anal segment. Subgenital plate strongly keeled longitudinally, roundly convex and bulgy in basal portion and projecting over the apex of abdomen by at least the combined length of tergites VIII–X. Apex pointed and ± tri-dentate ( Fig. 26 ).

Legs: All long and slender with all carinae except dorsal carinae of protibiae dentate. Profemora considerably longer than mesonotum, mesofemora about ¾ the length of mesonotum, metafemora ± reaching posterior margin of abdominal segment IV and metatibiae almost reaching apex of anal segment. Anteroventral carina of mesofemora occasionally with a ± distinct and triangular, dentate sub-apical lobe (one of the PT’s in BMNH). Otherwise without any conspicuously enlarged teeth or lobes. Spines of the medioventral carina of the femora distinct. Probasitarsus elongate and about as long as following three tarsomeres combined. I–III each with a ± distinct, rounded apical lobe (very faint in the HT). Meso- and metabasitarsi about as long as the following three tarsomeres combined, the outer ventral carinae minutely denticulate.

Variation: Apart from the size and colouration, variation is seen in the number and size of the granules and tubercles of the head and thorax, shape of the apex of the subgenital plate and size of the tegmina. The HT lacks a dentate sub-apical lobe on the anteroventral carina of the mesofemora, whereas it is very prominent in one of the Ƥ PT’s from Huni in BMNH. The Ƥ from Yarikora merely has two enlarged sub-apical teeth. The tegmina are below 1.5 mm in e.g. the HT and one of the PT’s from Huni in BMNH but quite well developed, scale-like and some 3.2 mm in the second PT from Huni ( Figs. 23–24 ).

Eggs ( Fig. 54 ): One egg each could be extracted from the ovipositor of the HT in MNHU and one of the Ƥ PT’s from Huni in BMNH. Both eggs widely correspond to each other but show differences in the colour of the capsule, thus indicating variability of the colouration.

Medium-sized, ovoid, capsule longer than wide and slightly oval in cross-section; dorsally more convex than ventrally. Capsule surface very minutely granulose and strongly shiny. Anterior margin slightly downcurving near dorsal mid-line of capsule. Micropylar plate elongate and about 2/3 as long as capsule, the anterior 3/4 slender and gradually widening towards a round elevation in the posterior ¼, posterior end tapered and rather acute. Outer margin of plate distinct and raised. Micropylar cup small, rounded and placed some 1/3 away from the posterior end of plate. Operculum slightly oval, with a raised outer rim and a central knob-like pseudo-capitulum; dorsal surface of pseudo-capitulum deeply pitted. General colouration of capsule pale to mid cream all over but to a variable degree furnished with washed brown markings. Micropylar plate reddish mid brown with the outer margin darker. Operculum black with the central pseudo-capitulum dark orange.

Measurements of the egg removed from the Ƥ HT [mm]: length (incl. operculum) 3.9, length 3.5, width 2.1, height 2.3, length of micropylar plate 2.7.

Comments: 3 unknown.

Distribution ( Fig. 60 ): Solomon Islands. Appears to be endemic to San Cristobal Island (Huni, Kirakira, Yarikora & Narahito).

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 21 – 26. Phasmotaenia guentheri n. sp. 21. Habitus of Ƥ HT (MNHU); 22. Habitus of Ƥ PT (BMNH, No. 845038) [Photo by P. D. Brock, © BMNH]; 23. Tegmina and alae of Ƥ PT (BMNH, No. 845039); 24. Tegmina and alae of Ƥ PT (BMNH, No. 845038); 25. Ƥ apex of abdomen (lateral view); 26. Ƥ apex of abdomen (dorsal 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).