Austrodontura castletoni Naskrecki & Bazelet, 2011, n. sp.
Creators: name: Naskrecki, Piotr
name: Bazelet, Corinna S.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Phaneropteridae
Austrodontura
Austrodontura castletoni

description: Austrodontura castletoni n. sp.
(Figs. 2 A–K, 3)
Type locality. REPUBLIC OF SOUTH AFRICA: Eastern Cape, Silaka Nature Reserve (nr. Port St. John’s), forest nr. chalet 18 (31°39'12.7''S, 29°30'30.6''E), 58 m, 15–20.i.2011, coll. P. Naskrecki & C. Bazelet—male holotype (SAMC)
Diagnostic description (male, except where specified). General characteristics as for the genus, diagnostic characters listed below. This species can be distinguished from its congener by the development of the tegmina, which in both sexes are only about as long as wide and shorter than the pronotum (Figs. 2 B, D); the presence of at most 5 small stridulatory files on the female right tegmen (Fig. 2 J), and the spacing of stridulatory teeth in the male, which are distinctly less densely spaced in the proximal (closer to the posterior margin of the tegmen) end (Fig. 2 K).
Thorax. Lateral carinae of pronotum sharply defined, nearly straight when seen from above (Fig. 2 B); ratio of pronotum length to its minimum width (as measured between lateral carinae) at most 1.4 in male and 1.2 in female (Fig. 2 D). Lateral lobe about 1.7 times as long as high, its posterior edge nearly straight.
Legs. Front tibia with dorsal anterior dorsal margin with 0–1, posterior one with 3–4 minute spines; both ventral margins armed with 3–4 minute spines. Genicular lobes of mid femur always unarmed. Apex of hind tibia with 1 pair of dorsal and 2 pairs of ventral spurs.
Wings. Tegmen shorter pronotum, about as long as wide, broadly truncated apically (Fig. 2 H); stridulatory file weakly bent, 1.6–1.7 mm long, 0.1 mm wide, with 65–70 teeth; teeth on proximal end of file thicker and less densely spaced than on distal end (Fig. 2 K). Female tegmen as long as wide, truncated apically (Fig. 2 I) and not reaching posterior margin of 1st abdominal tergite; posterior margin of tegmen with 3–5 short stridulatory files nearly perpendicular to M; each file with 3–8 small, peg-like teeth (Fig. 2 J).
Abdomen. Subgenital plate with narrowly triangular incision at most as deep as 1/4 of plate (Fig. 2 E); female subgenital plate widely triangular, broadly rounded apically (Fig. 2 F).
Coloration. Coloration straw green (Figs. 2 A, C), antennae brown, concolorous; antennal scapus without markings; face pale green. Pronotum green with distinct, narrow black stripes bordered with brown along lateral carinae; tegmen with distinct dark brown patches, with costal area green, lighter than rest of wing. Legs green; hind femur green, upper half often dark brown; abdominal sterna without markings; abdominal terga green with minute dark dots; subgenital plate without markings; ovipositor green.
Measurements (7 males, 6 females). body: male 16.3–18 (17.5±.7), female 19.5–22 (20.6±1.1); pronotum: male 3.5–4 (3.8±.2), female 4–4.9 (4.4±.4); tegmen: male 3.5–3.9 (3.7±.2), female 3–3.2 (3.1±.1); hind femur: male 18.1–20 (18.9±.7), female 18.3–20.5 (19.3±.7); ovipositor: 4–5 (4.7±.4) mm.
Material examined (44 specimens). Republic of South Africa: Eastern Cape, Transkei Distr., Silaka Nature Reserve (nr. Port St. John’s), forest nr. chalet 18, elev. 58 m (31°39'12.7''S, 29°30'30.6''E), 15–20.i.2011, coll. P. Naskrecki & C. Bazelet — 11 females, 16 males, 2 nymph females (incl. holotype, 25 paratypes) (ANSP, SAMC, TMSA); Silaka Nature Reserve (nr. Port St. John’s), main trail, elev. 158 m (31°39'7.8''S, 29°30'5''E), 16–20.i.2011, coll. P. Naskrecki & C. Bazelet— 9 females, 4 males, 1 nymph female (paratypes) (ANSP, MCZ, SAMC).
Etymology. This species is named in honor of the artist Gavin Castleton.
Remarks. A. casteltoni was found to be abundant in forest edge habitats of the coastal scarp forest within the small Silaka Nature Reserve near Port St. John’s. Forests in this reserve are some of the last remaining fragments of the once more widespread forests of the Transkei Coastal Belt, which exhibit exceptionally high levels of botanical endemism and are biogeographically ancient (Mucina and Rutherford 2006). The katydids were found, often in densities of 3–5 individuals/m2, on herbaceous vegetation at shaded edges of the forest and on lower branches of Acacia karroo Hayne. Multiple individuals were observed feeding on buds and bark of A. karroo, both during the day and at night. Individuals of A. castletoni were are also seen frequently on the invasive plant Lantana camara L., but no feeding on this plant was observed.
Male stridulation was recorded only at night, beginning at around 21:00. The sound produced by the males was entirely within the ultrasonic range, and no energy was detected below 25 kHz, as measured by the Petersson D200 ultrasound detector; the highest range of the call reached 120 kHz, but we were unable to detect its uppermost limit due to the limitations of the equipment. At 26°C the male call consisted of a series of 3–8 short (0.206–0.735 sec) echemes, usually followed by a single longer echeme lasting 1.25– 5.0 s; each echeme consisted of short syllables lasting 0.028– 0.042 s (± 0.0032, n=30) (Fig. 3). Conspecific males present in the vicinity of the caller often began calling in the second half of the long echeme of the principal caller. We were unable to obtain an unambiguous recording of a female, but single, ultrasonic ticks were later found between several calls of the males, and the presence of distinct stridulatory files on the right tegmen of the female suggests that this species engages in courtship duetting.
description: Published as part of Naskrecki, Piotr & Bazelet, Corinna S., 2011, A revision of the South African katydid genus Austrodontura Fontana & Buzzetti (Orthoptera: Tettigoniidae: Phaneropterinae), pp. 51-59 in Zootaxa 2873 on pages 56-58, DOI: 10.5281/zenodo.204801