Lacks white scale-hair patches on the elytra.
This species was not reported from SA until I collected it in the northern Mt Lofty Ranges in 2011, and subsequently in the Barossa Ranges, Adelaide Hills and on Kangaroo Island. Its breeding stages came to light in 2020 when A.M.P. Stolarski collected a larva on Eyre Peninsula and I found a pupa in the Adelaide Hills, both of which I reared to adult stage.
Specimens from the NL Region tend to have less colourful and more subdued markings than those from elsewhere. The single KI specimen is unusual in having the pronotum with punctulate rather than striate sculpturing as in all other specimens seen. Nevertheless, DNA barcode sequencing (mitochondrial CO1) groups it together with specimens from NL and very close to a sample from NSW.
Occurrences in MU region are confined to the eastern edge of the Mt Lofty Ranges.
The gall-making habit of this species was first recognised in August 2021. The distinctive stem collar galls which persist and are readily detected on its host plants of family Rhamnaceae reveal this this species' wide distribution and abundance, which otherwise, if based on adult captures only, might appear to be rather rare.
Legend | records | count of breeding adults, pupae and larvae |
sites | count of major sites (unique 10 km grid cells +/- some distinct approximate localities) |
* | indicates alien (non-native) plant occurrences, either wild or planted (the species may be alien in SA, or native in parts of its SA range) |
adult | live = extracted alive; dead = extracted dead as intact or fragmentary remains; ex billet = reared and emerged from stored sections of host; ex pupa = reared from sampled pupa |
pupa | extracted pupa; pupa ex larva = reared pupa from larva |
larva | extracted larva (any stage including prepupa) |
gall (only) | hatched or unhatched gall identified by form and position rather than contents |
Plant names in green are hyperlinked to a matching host species page with plant photos. |
Golden Wattle Acacia pycnantha is well established as a major adult host plant in the northern and southern Mt Lofty Ranges. The single occurrence on the Melaleuca may be incidental, but the one on Spyridium parvifolium is notable, as that species is also a larval host.
The breeding records are established by individuals reared from two plant species: Spyridium parvifolium and Cryptandra setifera, supported by consistent associated larvae and gall morphology. The two larval host plant species are quite different in form, but are both in the family, Rhamnaceae. Both genera are widespread across the range of D. aurocyanea, with Cryptandra being more prevalent in the northern Mt Lofty Ranges sites which is where the greatest numbers of beetles have been found in SA. Further breeding records are needed to ascertain the degree of specificity to the Rhamnaceae, and whether a wide range of genera and species of that family are used, as is the case for Anilara subcostata.
Pupation occurs in the centre of quite narrow stems, with the pupal cavity occupying most of the diameter of the hard woody stem core. The first adult to be reared came from a prepupa in a stem and the surrounding collar gall was initially thought to be coincidental. Discovery of more specimens, showed that the larvae are always associated with collar galls. The younger stages feed and tunnel in the relatively soft and moist outer ring of gall tissue, before the final instar larva tunnels into the hard inner woody stem core to pupate.