Castiarina testudocaput Hutchinson & Allsopp, 2022

Hutchinson, Paul M. & Allsopp, Peter G., 2022, Two new species of Castiarina Gory and Laporte, 1838 (Coleoptera: Buprestidae: Stigmoderini) from Australia, Zootaxa 5099 (4), pp. 485-495 : 486-489

Castiarina testudocaput Hutchinson & Allsopp , sp. n.

( Figs. 1–7 )

Zoobank urn:lsid:zoobank.org:pub:9BBEBB36-8403-4F23-902E-B3AB4F9D00B2

Type material. Holotype male: AUSTRALIA: Queensland: Turtle Head Is. Cape York, Qld. Aust. [10.92°S, 142.67°E] 24.Feb.2005 Shoichi Mizuno ( WAM).

Allotype female ( WAM) and paratype female ( PMH), same data as holotype; 4 male paratypes, Turtle Head Island , 17.i.2005, Shoichi Mizuno ( QM, registration numbers T250628–31); 5 male and 10 female paratypes, Turtle Head Island , 7.iii.2005, Shoichi Mizuno (1 male, 1 female PMH; 4 males, 9 females QM, registration numbers T250636–48); 3 male and 1 female paratypes, Turtle Head Island, 11.iii.2005, Shoichi Mizuno ( QM, registration numbers T250632–35).

Description ( Figs. 1–5 ). Size. Holotype, 11.8 mm x 4.9 mm ( Figs. 1–3 ). Allotype, 12.4 mm x 4.9 mm ( Figs. 4–5 ). Paratypes, 11.5–13.2 mm x 4.2-5.0 mm.

Colour. Head green-blue with coppery reflections. Antennomeres blue with green reflections. Pronotum blue, with green reflections laterally. Scutellum purple-green. Elytra yellow-orange with the following blue markings with green and purple reflections: narrow basal margin; pre-medial fascia expanded anteriorly covering humeral callus, posterior portion reaching margin; post-medial fascia reaching margin; spade-shaped mark covering preapex; apex and spines, all joined along suture; margin post-medially broadly red. Ventral surface of male metallic green, sternites 3–7 red-brown; female metallic green. Legs metallic green. Setae silver.

Shape and sculpture. Head shallowly punctured, with shallow median sulcus, mouthparts moderately long. Antennomeres 1–3 obconic, 4–11 triangular. Pronotum closely punctured, anterior margin projecting apically, basal margin weakly bisinuate, large medial basal puncture, laterally parallel sided at base, rounded to widest pre-medially then linear convergent to pre-apex and then rounded to anterior margin. Scutellum scutiform, impunctate. Elytra punctate-striate, intervals noticeably convex, intervals 5 and 6 densely punctate, laterally angled outwards from base, rounded and widest at humeral callus, concave, rounded post-medially, rounded and narrowed to bispinose apex, spines acute, marginal larger than sutural, margin rounded and indented between spines. Ventral surface shallowly punctured, moderately dense, flat setae. S 7 weakly rounded in male, rounded in female.

Aedeagus. Parameres divergent linear from basal piece, widest pre-apically then rounded at apex, apical part dorso-ventrally flattened; penis apex acutely rounded with pre-apical lateral expansions.

Diagnosis. This species keys to and conforms to the morphological characters of the Castiarina haswelli species group ( Barker 2006). This group contains three other species from the eastern Queensland and eastern New South Wales. Determined specimens of C. haswelli (Carter, 1916) and C. sexualis (Carter, 1929) were examined. No specimens of C. denmanensis Barker, 2004 were available to us, but viewing was not warranted as its colour pattern (Baker, 2006, Plate 4f) is distinctly different from that of C. testudocaput sp. n. All specimens of C. testudocaput sp. n. are consistent and differ from the description of C. denmanensis in Barker (2004) as follows: in elytral pattern by the red margin restricted to the posterior half (posterior three-quarters in denmanensis ), pre-medial and post-medial fascia reaching margin without a red barrier (not in denmanensis ), pre-medial fascia not enclosing a yellow basal area (enclosed in denmanensis ) with all yellow spots directed to the middle; legs green ventrally (purple in denmanensis ). In addition, the type localities of the two species are separated by more than 2500 km and have different climates and vegetation (Denman is at 32.38°S, 150.68°E and has a Köppen-Geiger climate classification of Cfa (humid subtropical)).

Castiarina testudocaput sp. n. appears similar to C. haswelli (Carter, 1916) with the elytra of both with red margins (lacking in C. sexualis (Carter, 1929) ( Barker 2006, Plate 4d)). It differs from C. haswelli in having the pre-medial fascia reaching the margin, and the red margin restricted to apical half (complete except interrupted by a post-medial fascia in C. haswelli ( Barker 2006, Plate 4e)). The male genitalia has the penis acutely rounded, whereas it is pointed in the other members of the group.

The key to the Castiarina haswelli species group ( Barker 2006: 50) can be modified as follows to accommodate C. testudocaput sp. n.:

1 Elytral margins wholly or partly red...................................................................... 2

- Elytral margins not red............................................................ C. sexualis (Carter, 1929)

2 Pre-medial fascia reaching margin, red margin restricted to apical half ( Figs. 1, 4 ).................................................................................................. C. testudocaput Hutchinson & Allsopp , sp. n.

- Pre-medial fascia not reaching margin, red margin not restricted to apical half ( Barker 2006, Plates 4e,f)................ 3

3 Abdomen blue in females.......................................................... C. haswelli (Carter, 1916)

- Abdomen metallic in females.................................................... C. denmanensis Barker, 2004

Etymology. The name refers to the type locality and is derived from the Latin testudo for turtle and caput for head. It is to be treated as a noun in apposition.

Habitat and behaviour. All known specimens are from Turtle Head Island, near the tip of Cape York Peninsula, northern Queensland ( Fig. 7 ). The area has a Köppen-Geiger climate classification of Aw (tropical savanna) and most of the island is covered with vine forest ( Fig. 6 ). Adults were collected on Styphelia sp. prob. ruscifolia (R.Br.) Spreng and Styphelia yorkensis (Pedley) Hislop, Crayn & Puente-Lelièvre (sensu Crayn et al. 2020; Ericaceae ) ( Fig. 6 ) during the middle of the ‘wet’ season.

Figures

FIGURE 6. Vegetation of Turtle Head Island, Queensland, the collection locality of Castiarina testudocaput sp. n. The plants in the lower right are Styphelia (probably) ruscifolia (left) and Styphelia yorkensis (right). © Shoichi Mizuno.

FIGURE 7. Known distribution in northern Queensland of Castiarina testudocaput sp. n. (red triangle), and in southern Western Australia of Castiarina notocrux sp. n. (yellow squares).

FIGURES 1–5. Castiarina testudocaput sp. n. 1–3 Holotype male. 1, dorsal view; 2, ventral view; 3, aedeagus, dorsal view. 4–5, Allotype female. 4, dorsal view; 5, ventral view.