FIRST DESCRIPTION OF A MALE CASTIARINA INSCULPTA (CARTER, 1934) (COLEOPTERA: BUPRESTIDAE), A THREATENED TASMANIAN JEWEL BEETLE

Abstract

Current knowledge of Castiarina insculpta (Carter) in Tasmania is reviewed, and the adult male and its genitalia are described and illustrated.

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FIRST DESCRIPTION OF A MALE CASTIARINA INSCULPTA
(CARTER, 1934) (COLEOPTERA: BUPRESTIDAE),
A THREATENED TASMANIAN JEWEL BEETLE
KAREN RICHARDS and CHRIS P. SPENCER*
65 Sinclair Avenue, Moonah, Tasmania 7009.
Abstract
Current knowledge of Castiarina insculpta (Carter) in Tasmania is reviewed, and the adult male and
its genitalia are described and illustrated.
Keywords: Tasmanian Central Highlands, aedeagus, Miena Jewel Beetle
Introduction
Castiarina insculpta (Carter, 1934) was originally collected in the yingina/Great
Lake region of Tasmania by Critchley Parker in 1934. It was formally described in
that year (Carter, 1934) based on the single female specimen obtained. By 2010,
six dead female C. insculpta specimens were recognized, but it was not until
2013 that multiple live C. insculpta were discovered and a substantial increase
in knowledge of the species’ biology ensued (Bonham et al. 2013, Spencer and
Richards 2014, Richards and Spencer 2016, 2017, 2020).
Twenty described species of Castiarina Gory and Laporte, 1838 occur in
Tasmania, although four are unlikely to be permanent residents. Seven species
are endemic to the state and three are purported to be rare (Cowie 2001). Two
of the endemic species, C. insculpta and C. virginea (Erichson, 1842), belong
to the C. rectifasciata species group which Barker (2006) founded on structural
similarities. They are readily separated from each other by the angle of the
marginal elytral spines, and other characters. Castiarina insculpta was listed as
extinct under the Tasmanian Threatened Species Protection Act 1995, but further
specimens discovered in the mid 2000’s led to a review of its status. In 2008 the
species was down-listed to endangered (Threatened Species Section 2021).
Several suspected male C. insculpta specimens were collected by the authors
between 2013 and 2020, plus three denite males, each with their aedeagus
everted. The conrmed males come from two locations in Tasmania’s Central
Highlands. They comprise two drowned specimens recovered from Lake Ada
in January 2017, and one specimen found in the Lake Augusta sand dunes in
January 2019. This paper provides the rst description and images of a male
specimen and aedeagus of C. insculpta.
Abbreviations
KRCPS, joint collection of Karen Richards and Chris P. Spencer, Moonah,
Tasmania (to be deposited in TMAG in near future); NHM, Natural History
Museum, London; TMAG, Tasmanian Museum and Art Gallery, Hobart,
Tasmania.
——————
* Deceased
Australian Entomologist 48 (4): 289–292 (17 December 2021) 289

Castiarina insculpta (Carter, 1934)
(Figs 1, 2)
Stigmodera (Castiarina) insculpta Carter, 1934: 255.
Type material. Holotype ♀, AUSTRALIA, Tasmania, Great Lake, 1934, Critchley Parker
(NHM).
Additional specimens. 1♂, Tasmania, Lake Augusta, 2019, Chris P. Spencer (TMAG
Registration No. F 127265); 1♂, Lake Ada (41°52.977’S 146°28.395’E) January 2017
(KRCPS); 1♂, Lake Augusta sand dunes (41°51.964’S 146°31.148’E) January 2019
(KRCPS). Additional male and female measurements were recorded from Tasmania,
Liawenee (41°53.939’S 146°40.267’E) in February 2021.
Description of male. Measurements in mm: length, 11.0 (11–11.8, mean = 11.52),
width, 4.0 (4.0–4.6, mean = 4.39) mm, (n = 14).
Colour (Fig. 1): Head, pronotum and scutellum metallic green, antennae bronze-
black, mouthparts black. Elytra metallic green with paired yellow markings,
basal fascia rounded medially narrowing anteriorly, small yellow patch on
humeral callus extending along lateral margin, rounded medial patch, post-
Figs 1, 2. Castiarina insculpta. (1) male; (2) aedegus.
1 2
290 Australian Entomologist

medial fascia narrowing to and extending along lateral margin. Ventral surface
metallic green. Legs femora and tibiae metallic green, tarsi bronze-black, setae
silver. Overall colour varies between specimens, ranges from bright metallic blue
to bright metallic green while the yellow markings vary in shape, size, intensity
and coalescence; tarsi vary in colour from bronze-black to metallic green.
Shape and sculpture: Head punctured, median sulcus present, mouthparts short.
Antennomeres 1–3 obconic, 4–11 triangular. Pronotum heavily punctured with
shallow foveae, apical margin projecting medially, basal margin bisinuate, without
basal notch, lateral margin parallel-sided at base, angled outwards then rounded
to widest medially, rounded and narrowed to apex. Scutellum scutiform, at,
without punctures. Elytra striate-punctate, punctures regular and well dened,
ridges carinate, 1 to 4 close, 5 and 6 further apart and more strongly raised,
apex bispinose, marginal spine pointing inwards, sutural spine reduced, margin
between spines deeply concave. Ventral surface nely punctured, mesosternal
process at. S7 truncate.
Aedeagus (Fig. 2): brown-testaceous, elongate, slightly expanding outwards
from basal piece. Parameres rounded at apex. Penis with acute apex, sharp, sides
strongly concave. Apophysis of basal piece moderately wide, rounded at apex.
Description of female: Measurements: holotype ♀, length 12.0, width 4.5 mm.
Additional ♀♀: length (11.2–12.2, mean = 11.66), width (4.2–4.7, mean = 4.52)
mm, (n = 5).
Colour: as for male.
Shape and sculpture: similar to male, but slightly broader. S7 truncate, row of
prominent sensory bristles along hind margin present.
Discussion
The drowned specimens from Lake Ada were disarticulated on discovery and
only their aedeagi were retained.
Barker (2006) included C. insculpta in the rectifasciata group, and while there
are some morphological similarities with the overall aedeagal shape of other
group members, the closest being C. rectifasciata (Saunders, 1868), only two
the seven species occur in Tasmania, the second being C. virginea, the aedeagus
of which is quite dissimilar. As with many Tasmanian buprestid species, the
colour and markings of C. insculpta display plasticity in both sexes. Coalescence
of fascia was observed on several C. insculpta specimens and appeared to be
location-specic. Subsequent visits to this area conrm this to be a site-specic
variation. Given the threatened status of the species, the location is withheld to
protect against illegal targeted collection.
Pre-adult stages are conned to scaly everlasting bush, Ozothamnus hookeri
Sonder (Asteraceae) which is also the main food plant for adults, although they
sometimes feed on blossoms of alpine heath-myrtle, Baeckea gunniana Schauer
(Myrtaceae) (Richards and Spencer 2016, 2017).
48 (4): 289–292 (2021) 291

Acknowledgements
Unfortunately, Chris Spencer passed away shortly after submission of the original
manuscript. I wish to thank the reviewers and editors of Australian Entomologist
for their encouragement and comments on the draft, resulting in a signicantly
improved manuscript.
References
BARKER, S. 2006. Castiarina: Australia’s richest jewel beetle genus. 341 pp. Australian Biological
Resources Study: Canberra.
BONHAM, K., RICHARDS, K., SPENCER, C. P., GROVE, S., REID, C., BYRNE, C., HIRD, D
and THROSSEL, A. 2013. Observations of the Miena Jewel Beetle Castiarina insculpta (Carter
1934) in the summer of 2012–13. Tasmanian Naturalist 135: 104–109.
CARTER, H.J. 1934. Australian and New Guinea Coleoptera. Notes and new species. No III.
Proceedings of the Linnean Society of New South Wales 59: 252–269.
COWIE, D. 2001. Jewel beetles of Tasmania: A eld naturalist’s guide. 40 pp. Tasmanian Field
Naturalists Club: Hobart.
ERICHSON, W.F. 1842. Beitrag zur Insecten-fauna von Vandiemensland, mit besonderer
Berucksichtigung der geographischen Verbreitung der Insecten. Archiv für Naturgeschichte 8: 83–
287, pls 4, 5.
GORY, H.L. and LAPORTE, F.L.N. de C. 1838. Histoire naturelle et iconographie des insectes
Coléoptères. Monographie des Buprestides. Vol. 2, livr. 17–24, genera Stigmodera, Polycesta,
Belionota, Eurybia [genera with separate pagination]. P. Duménil: Paris.
RICHARDS, K. and SPENCER, C. P. 2016. Observations of Castiarina insculpta (Miena Jewel
Beetle) in 2016. Tasmanian Naturalist 138: 66–67.
RICHARDS, K. and SPENCER, C. P. 2017. New distribution and foodplant observations for several
Coleoptera species in the Tasmanian Central Highlands, summer 2017. Tasmanian Naturalist 139:
99–106.
RICHARDS, K. and SPENCER, C.P. 2020. Jewels on re! The Miena Jewel Beetle, Castiarina
insculpta (Carter, 1934) (Coleoptera: Buprestidae), and the 2019 Great Pine Tier re. Tasmanian
Naturalist 142: 35–40.
SAUNDERS, E. 1868. Descriptions of fty new species of the genus Stigmodera. Journal of the
Linnean Society of London. Zoology 9: 460–493.
SPENCER, C.P. and RICHARDS, K. 2014. Did Castiarina insculpta (Miena Jewel Beetle) ride on
the sheep’s back? Tasmanian Naturalist 136: 50–58.
THREATENED SPECIES SECTION, 2021. Listing statement for Castiarina insculpta (Miena Jewel
Beetle). Department of Primary Industries, Parks, Water and Environment, Tasmania.
292 Australian Entomologist