Castiarina keyzeri Barker, new species (Figs 1 g, 2 d)

Type material: Holotype male, S.A.: Googs track: Yumbarra Conservation Park: 50.7 km NE of Kalanbi: 31°32’ 59” S. 133°55’ 51.1”E. Elevation 54m., 1.xi.2004. On flowers of Grevillea pterosperma. A. Sundholm, R. de Keyzer, A. Scott, SAMA I 21 705. Allotype female, S.A.: Googs track: Yellabinna Regional Reserve: 54.2 km NE Kalanbi: 31°31’ 6.6” S. 133°56’ 28.2” E. Elevation 116 m, 1.xi.2004. On flowers of Grevillea pterosperma. A. Sundholm, R. de Keyzer, A. Scott, SAMA I 21 706.

Paratype female, S.A.: Googs track: Yellabinna Regional Reserve: 55.3 km NE Kalanbi: 31°30’ 44.2” S. 133°56’ 44.2” E. Elevation 130 m, 1.xi.2004. On flowers of Grevillea pterosperma. A. Sundholm, A. Scott, R. de Keyzer, ASSA.

Size: Holotype 10.7 x 3.7 mm. Females 11.2 x 3.9 mm.

Description. Colour: Head dark blue with coppery reflections. Antennomeres: 1–2 dark blue; 3–11 bronze. Pronotum dark blue with coppery reflections. Scutellum dark blue. Elytra orange with following black markings with blue reflections: narrow basal margin; pre­medial spot on suture, in one specimen also a spot over humeral callus on each elytron; post­medial fascia reaching margin, narrowly connected along suture to pre­apical mark covering apex and spines. Ventral surface dark blue. Legs: femora dark blue; tibiae light blue dorsally, dark blue ventrally; tarsomeres light blue dorsally.

Shape & sculpture. Head punctured, broad median sulcus, moderately produced mouthparts. Antennomeres: 1– 4 obconic; 5–11 triangular. Pronotum punctured, small basal fovea extending to middle as glabrous line, anterior margin straight, basal margin bisinuate, laterally rounded out from base, widest before middle, rounded and narrowed to apex. Scutellum scutiform, medially indented, without punctures. Elytra punctate­striate, 9th interval from suture prominent along whole length from base to apex, laterally angled outwards from base, rounded at humeral callus, concave, rounded post­medially and narrowed to bispinose apex, marginal spine acute, space between it and minute sutural spine rounded and indented, apices slightly diverging. Ventral surface punctured, short sparse setae. S7 truncate both sexes. Legs: males, 2nd & 3rd legs pulvilli on tarsomeres 1–3 replaced with double median spines.

Aedeagus: Wedge­shaped (Fig. 1 g).

Remarks. This species is a typical member of the C. sexplagiata (Gory) species group, all males of which have wedge­shaped genitalia and modified structures on the tarsomeres of the 2nd and 3rd legs. The only other member of this group found on the flowers of Eremophila scoparia on the Eyre Peninsula is Castiarina vanderwoudae (Barker) which is a much smaller yellow and black species.

Distribution. Specimens have only been collected in a small area north of Ceduna, South Australia.

Etymology. The species is named after R. de Keyzer, Sydney.