Castiarina notocrux 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 : 489-493

Castiarina notocrux Hutchinson & Allsopp , sp. n.

( Figs. 7–20 )

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Type material. Holotype male: AUSTRALIA: Western Australia: 38–39 km S [south of] Coolgardie, 11.October.2020, M. Powell, on Eucalyptus platycorys flws [flowers] ( WAM).

Paratypes: 1 female, Lake Seabrook (strandline) [30.99°S, 119.60°E] West. Aust. 4.Feb.2006 P. Hutchinson | Castiarina dead lake edge ( WAM) ; 1 female: G.G. BURNS Bonnie Rock [30.53°S, 118.37°E] W.A. 9 SEPT. 1987 | G.G. BURNS COLLECTION COL-71860 | G63 ( MV, image examined) ; 1 female, 19 km W [west of] Coolgardie [30.98°S, 120.96°E], Western Australia, 20 October 2020, M. Powell, on Leptospermum flowers ( MP) .

Description ( Figs. 8–17 ). Size (widest at elytra post-medially). Holotype, 13.9 mm x 5.4 mm. Paratypes, 13.3 mm x 5.0 mm; 16.3 mm x 6.3 mm; 16.8 mm x 16.1 mm.

Colour (holotype). Head blue, antennae blue with golden reflections. Pronotum vivid blue medially, red laterally. Scutellum vivid blue. Elytra orange medially on margins and apically red, with the following vivid blue markings: narrow basal margin; post-medial fascia not reaching margin; pre-apical mark covering apex and spines all marks connected along suture. Ventral surface dark blue, sternites red laterally and posterior sternite entirely dull red. Legs with femora blue, tibiae blue with green reflections, tarsomeres green. Setae silver.

Shape and sculpture. Head shallowly punctured medially, deeply punctured elsewhere, broad median sulcus with narrow deep groove on frons, mouthparts moderately long. Antennomeres 1–3 obconic, 4–11 triangular. Pronotum deeply punctured, dense medially, sparser laterally, anterior margin projecting medially, basal margin weakly bisinuate, laterally widest in basal half, tapering to apex. Scutellum caudiform, impunctate. Elytra punctate-striate, intervals not raised, laterally angled outwards from base, rounded at humeral callus, linear and slightly divergent and rounded post-medially (where at widest), rounded and narrowed to bispinose apex, with pointed and conical marginal spine, sutural spine smaller, margin rounded and indented between spines. Ventral surface densely punctured, sparse, short, round setae. S 7 weakly rounded in male, rounded and slightly pointed in female.

Aedeagus (not extracted, partially protruding on holotype): Parameres parallel apically and rounded at apices, apical part dorso-ventrally flattened; penis apex acutely rounded.

Diagnosis. Colours of live collected buprestids often fade after death ( Barker, 2006) and saltlake-collected specimens have the added impacts of highly saline water and sun affecting the colour. Hence, the holotype shows vibrant blue and orange on the dorsal surface ( Fig. 8 ), whilst the paratype from Lake Seabrook that was dead when collected has the blue sections almost black and the orange sections a dull yellow ( Figs. 18–19 ) Both, however, have the same general patterning.

This species keys to and conforms to the morphological characters of the Castiarina amabilis species group ( Barker 2006). Determined specimens of the other three species of the group, C. amabilis ( Gory & Laporte, 1838) , C. maculicollis (Carter, 1916) and C. armata (Thomson, 1879) , have been examined.

Castiarina notocrux sp. n. differs from C. armata and C. maculicollis in colour and patterning of unweathered specimens; head, pronotum medially and ventral surface blue and red (head, pronotum medially black, ventral surface black and yellow in C. armata and C. maculicollis ) and the elytra bear a post-medial fascia (absent in C. armata and C. maculicollis ). It is most similar to C. amabilis but differs in the following: humeral calli non-maculated and post-medial fascia present (humeral callus vittae present and post-medial fascia absent in C. amabilis ).

Castiarina notocrux sp. n. superficially resembles C. carnabyi ( Barker, 1979) ( C. analis species group) also from Western Australia but can be distinguished by: presence of elytral apices armed with spines and post-medial fascia not reaching margin (elytral spines absent in C. carnabyi , post-medial fascia reaching margin ( Barker 2006, Plate 11g )).

The key to the Castiarina amabilis species group ( Barker 2006: 98) can be modified as follows to include C. notocrux sp. n.:

1 Dorsal surface with red and blue markings................................................................. 2

- Dorsal surface yellow with black markings................................................................ 3

2 Elytra with post-median fascia and humeral calli non-maculated ( Figs. 8 , 15 ).... C. notocrux Hutchinson & Allsopp , sp. n.

- Elytra without post-median fascia and humeral calli maculated ( Barker 2006, Plate 11e)..................................................................................................... C. amabilis ( Gory & Laporte, 1838)

3 Pronotum with a medial, oval, black mark ( Barker 2006, Plate 11c)...................... C. maculicollis (Carter, 1916)

- Pronotum with a medial, elongate, black mark ( Barker 2006, Plate 11a).................... C. armata (Thomson, 1879)

Etymology. Named for its known range with Southern Cross, Western Australia at its centre, its association with the Koora Retreat Centre (Anglican Church of Australia), and for the ‘inverted cross’ on the elytra. It is to be treated as a noun in apposition.

Habitat and behaviour. Allen Sundholm detected in the records for C. amabilis in Atlas of Living Australia an anomalous specimen collected by Gordon and Joy Burns on 9 September 1987 at Bonnie Rock, which is well inland of the expected distribution of C. amabilis . Allen suspected it was misidentified and he contacted Ken Walker (MV) asking for images of this specimen; these allowed Allen to immediately recognised it as an undescribed species that is described here. Apart from type series, a further specimen only known from a photograph was taken at Koora Retreat Centre [31.26°S, 120.02°E] (Allen Sundholm personal communication). All specimens were recorded in the vicinities of Southern Cross and Coolgardie, Western Australia ( Figs. 7 , 20 ). The area is close to the 300 mm isohyet and has a Köppen-Geiger climate classification ( Beck et al. 2018) bordering Bsk (cold semi-arid) and Csa (hot-summer Mediterranean). Adults have been collected on the flowers of Eucalyptus platycorys and Leptospermum sp. , both Myrtaceae .

Figures

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 8–11. Holotype male of Castiarina notocrux sp. n. 8, dorsal view; 9, ventral view; 10, lateral view; 11, label.

FIGURES 12–14. Holotype male of Castiarina notocrux sp. n. 12, head, dorsolateral view; 13, aedeagus, dorsal view; 14, aedeagus ventral view.

FIGURES 15–17. Paratype female of Castiarina notocrux sp. n. from 19 km west of Coolgardie. 15, dorsal view; 16, ventral view; 17, label.

FIGURES 18–19. Weathered paratype female of Castiarina notocrux sp. n. from Lake Seabrook. 18, dorsal view; 19, ventral view.

FIGURE 20. General view of Lake Seabrook, Western Australia, the collection locality of a paratype of Castiarina notocrux sp. n.