Spinisternum castaneipictus Willemse, 1966

Ünal, Mustafa, 2009, Spinisternum castaneipictus Willemse, 1966 (Orthoptera: Tettigoniidae: Conocephalinae) from Papua New Guinea, with description of the male and remarks on the relationship, Zootaxa 2055, pp. 61-68 : 62-67

Spinisternum castaneipictus Willemse, 1966

( Figs. 1–17 )

Spinisternum castaneipictus: Willemse, 1966 , Publ. Natuurh. Genoot. Limburg, 16: 13. Spinisternum castaneipictus: Otte, 1997 , Orth. Spec. File, 7: 37

Description of male: Fastigium of vertex ( Figs. 1 , 14 ) short and narrow, 1.5 times shorter and 1.9 times narrower than antennal scape; compressed laterally; slightly narrowed to apex in dorsal view; separated from fastigium of frons with a thin incision, in frontal view slightly widened to apex. Antennae filiform, at least twice as long as body. Eye ( Figs. 1 , 14 ) small, its vertical diameter 1.3 times shorter than the distance between eyes on vertex; almost as wide as antennal scape in frontal view. Labrum small, not covering mandibles completely; distal teeth of mandibles visible under labrum ( Figs. 1 ). Face slightly convex. Pronotum ( Figs. 2, 3 , 13, 14 ) with two distinct tranverse sulci, typical sulcus deep; Hind margin of paranota distinctly raised over the thoracic auditory spiracle; anterior margin of pronotum slightly concave, posterior margin strongly convex; prozona raised, convex in lateral view; metazona almost straight, prolonged backwards; pronotum 1.3 times longer than wide and twice as long as its height. Tegmina ( Figs. 2, 3 , 13, 14 ) greatly reduced, reaching end of first abdominal tergite, apex narrowly rounded; stridulatory apparatus fully concealed under pronotum. Thoracic auditory spiracle elliptical, 2.3 times longer than wide, visible under raised hind margin of paranota in posterior view. Fore coxa ( Fig. 13 ) with a large downcurved dorsal spine; middle and hind coxa with a short and broad distinct ventral tooth. Outer side of fore femur with 5–6, inner side with 6 ventral spines, in other male inner side with 5–6 spines. Middle femur with 6 outer and 2 inner proximal ventral spines, in other male inner side with 1–2 ventral spines. Hind femur with 9–10 ventral spines on outer side, with 2 ventral spines on inner side distally, in other male with 3 inner spines distally. All tibia with ventral spines on both sides. Dorsal surface of femora, fore and middle tibia without spines. Hind tibia with dorsal spines on each side; with 2 dorsal and 4 ventral apical spurs. Outer and inner genicular lobes of fore and middle femora ( Figs. 13, 14 ) with one distinct spiniform tooth, inner one sharper and longer than outer one; genicular lobe of hind femur with 2 sharp spines on each side. Prosternum ( Fig. 17 ) with 2 long U-shaped spines. Mesosternum ( Fig. 17 ) with a long spiniform tooth at posterior end of lateral margin, anterior end rounded. Metasternum ( Fig. 17 ) with 2 short blunt teeth on lateral margin, anterior tooth low and sharper, distinctly separated by a deep split; posterior tooth blunt conical; lateral margin between two tooth rounded collar-like. Last abdominal tergite ( Fig. 4 ) short, only little longer than 9th tergite, 2.2 times broader than long, posterior margin with a shallow and broad rounded incision. Cercus ( Fig. 6, 7 ) stout with 2 inner arms, basal part cylindrical, after second inner arm slightly narrowed to apex; apex blunt, narrowly rounded; base with a long, slender, S-shaped and downcurved inner arm, pointed with a short tooth; middle part with a larger, bird-shaped, main inner arm, pointed with a large tooth like a bird-beak. Subgenital plate ( Fig. 5 ) longer than wide, posterior margin with a very shallow rounded incision, styli longer than the depth of posterior incision.

Female: Head and pronotum as in male. Tegmina ( Figs. 15, 16 ) narrow, 1.7 times longer than wide, reaching slightly beyond end of first abdominal tergite, in other female reaching 1/3 of second abdominal tergite; slightly overlapping; distinctly narrowed at apex. Thoracic auditory spiracle as in male. Fore femur with 5 outer and 4–5 inner spines ventrally; outer side of middle femur with 5–6, inner side with 1–2 ventral spines; other characteristics of legs including genicular lobes as in male. Last abdominal tergite (Fig. 9) very short, almost half of 9th abdominal tergite, in other female slightly longer; posterior margin with a small, triangular median incision. Cercus (Fig. 9) long, slightly incurved; basal part broad, its apical part strongly and sharply narrowed; strongly pointed at apex. Subgenital plate (Figs. 10, 11) with a large side sclerite; short and broad, 2.4 times broader than long, excluding its side sclerite; posterior margin strongly downcurved, with a wide rounded median incision. Ovipositor (Figs. 12, 15) almost half of body length, 1.4 times longer than pronotum and 1.6 times shorter than hind femur; just after its base narrow, widened in middle part; its apical part strongly and sharply narrowed and distinctly upcurved.

Color (dry specimens): Body dull brown and black. Face yellowish brown, with brown or reddish brown vertical bands; above fronto-clypeal sulcus with 2 oval light spots. Labrum of lighter color, yellow in holotype, in others yellowish brown. Teeth of mandibles black. Antenna brown with sparse irregular dark rings. Pronotum bicolored, dorsal surface reddish brown, lateral lobes dark brown or black. Tegmina dark brown, costal margin black, anal margin light brown. Fore and middle femora reddish or blackish brown; fore femur with short light spots on outer surface in male; basal part of hind femur dark reddish brown in male, black in female, its apical part of lighter color. Abdominal tergites black in male, dark reddish brown in female, with a broad light brown median band on dorsal surface, excluding male last tergite. Male last tergite dark brown. Cerci pale greenish brown in both sexes. Subgenital plate greenish brown in male and reddish brown in female. Sternites milky yellowish brown. Basal part of ovipositor dark brown and black, its apical part light reddish brown.

Measurements (mm): Length of body: male 26–27.2, female 27–30.8; pronotum: male 9.9–10.2, female 9.7–10.2; tegmina (visible part): male 4.5–4.7, female 5–6; hind femur: male 20.4–20.2, female 22.1–23; ovipositor: 13.9–14.5.

Material examined: New Guinea (NE), Busu R., E. of Lae, 100 m, Sept. 14, 1955, 1 female (holotype) (leg. J.L. Gressitt); New Guinea (NE), Baindep. Salawaket Range, 1260 m, Sept. 16, 1956, 1 female nymph (paratype) (leg. E.J. Ford); New Guinea (NE), Sepalakambang, Salawaket Range, 1920 m, IX.11.1956, 1 female (paratype) (leg. E.J. Ford) (all in BM); D.N. Guinea, Kap König Wilhelm, 2 males, 2 females (no more data) (all in MNCN).

The original label data of the new specimens is: D.N. Guinea, Kap König Wilhelm. D.N. Guinea (formerly probably reads ‘Deutsch Neu Guinea’ the former German colony in the North East of New Guinea at times when ‘König Wilhelm’ was the German King) (pers. commun. Dr. Sigfrid Ingrisch). Deutsch Neu Guinea is currently, Papua New Guinea.

Diagnosis and remarks. Spinisternum castaneipictus is recognizable by the shape of thoracic sterna, male cercus, titillators, last tergite, female subgenital plate and ovipositor. However it was not easy to determine its genus. I had first identified it as Anthracites . But, I have seen that there are very close genera which may include this species. Dr. Ingrisch stated regarding some genera of the Oriental Agraeciini : “Without a severe revision of the genera it is not possible to be certain about the right genus” that he has in mind (pers. commun.). I place this species in Spinisternum which is recogniseable by the raised and dentate thoracic sterna (especially meso- and metasterna). Other species in related genera are compared below.

Spinisternum castaneipictus is different from Spinisternum insularis Willemse, 1942 on the basis of the structure of mesosternum (with one tooth at posterior end of lateral margin, but in S. insularis with one tooth in the middle of lateral margin), the shape of subgenital plate (much broader than long, but in S. insularis it is about as long as broad), the shape of supra anal plate (triangular in S. insularis ), the shape of ovipositor, the shorter tegmina, the longer pronotum, hind femur and ovipositor. It is very different from Spinisternum palauensis Vickery & Kevan, 1999 on the shape of male cercus, subgenital plate, pronotum, female subgenital plate, ovipositor and the longer tegmina.

Spinisternum castaneipictus is also similar to Anthracites Redtenbacher on the basis of habitus, the shape of pronotum, tegmina and ovipositor. Males have the last tergite similar to that of A. nigrifrons Karny, 1912 but differing in the shape of the circus and titillators. The pronotum, subgenital plate of both sexes, darker body color and distinctly larger size are distinctive.

The male characteristics of S. castaneipictus are very different from those of A. femoralis Dohrn, 1905 such as the shape of the last abdominal tergite, cercus, subgenital plate, measurements and coloration (female of A. femoralis is unknown). S. castaneipictus has the ovipositor similar to A. tibialis Karny, 1931 , the males’ last tergite and subgenital plate are less similar. But, the male cercus, pronotum and the tegmina of both sexes, shorter clypeus, female subgenital plate, coloration and the measurements except ovipositor are different. The male pronotum and last tergite and measurements are similar to A. rufus Ingrisch, 1998 . But it differs by the shape of male cercus, titillators, shorter clypeus and coloration.

A. geniculatus Dohrn, 1905 is known only from one female and the brief description ( Dohrn, 1905). There are no illustrations of the species either in the literature or on data bases. However, according to the description of A. geniculatus , S. castaneipictus has a distinctive female subgenital plate, ovipositor, coloration and the larger body size. A. discolateralis Karny, 1931 and A. humeralis Karny, 1931 are only known from females. The female of S. castaneipictus is very different from both of those species in the shape of the subgenital plate, the ovipositor, the shorter clypeus, and the measurements and coloration.

There are more superficial similarities with the following species. S. castaneipictus is similar to Nicsara insulana Willemse, 1966 , known from females, in the general shape of pronotum and ovipositor. But, the very much shorter tegmina (reaching hind knee in N. insulana ) and the shape of subgenital plate of the female are very different. It is closer to Heminicsara jacobii Karny, 1912 in the general shape of head and pronotum and a minor degree, the titillators and ovipositor. But, the other characteristics such as the shorter tegmina (reaching half of hind femur in H. jacobii ), the shape of male cercus, last abdominal tergite, subgenital plate of both sexes are different. S. castaneipictus is different from Gonatacanthus griffinii Karny, 1911 in the shape of male pronotum (metazona not prolonged backwards in G. griffinii ), the structure of fastigium of vertex (narrow triangular, prolonged between antennal scapes, broader at base and longer than scapus in G. griffinii ), the presence of male tegmina and the shape of male subgenital plate.

The main generic character of Spinisternum is the structure of meso- and metasterna, with spiniform projections ( Willemse, 1942). But, some species of Anthracites have similar sterna and have no other distinct characters. Therefore, for better understanding the separate state of Spinisternum and Anthracites , the type species of the both genera, Spinisternum insularis Willemse, 1942 and Anthracites nitidus Redtenbacher, 1891 should be compared which has never been done.

Figures

FIGURES 1 – 5. Male of Spinisternum castaneipictus: 1, head frontal view; 2, pronotum and tegmina from above; 3, ditto lateral view; 4, last abdominal tergite from above; 5, subgenital plate and last sternite. Scales 1 mm.

FIGURES 6 – 8. Male of Spinisternum castaneipictus: 6, cercus dorsal view; 7, ditto internal view; 8, titillators. FIGURES 9 – 12. Female of Spinisternum castaneipictus: 9, last tergite and cerci from above; 10, subgenital plate, ventral view; 11, ditto posterior view; 12, ovipositor. Scales 1 mm.

FIGURES 13 – 17. Male and female of Spinisternum castaneipictus: 13, male lateral view; 14 ditto dorsal view; 15, female lateral view; 16, ditto dorsal view; 17, projectings of pro-, meso- and metasterna in male.