Mid August is very early in the Buprestid season. It’s generally late August through to early March in southern Australia. It also depends a bit on whether winter lingers through August and when the warmth returns at the beginning of Spring. That can certainly impact Buprestid emergences.
@MarkH thanks for that advice. :-) It was mid September and possibly the end of their season last year. Allowing 4 weeks, it could be from mid August, then possibly. I don't live near Red Hill, so getting when they are in flower will help with narrowing that timing, too, potentially.
Hi Korinne, if you look at around the same time of year that you found the last one that is likely your best chance. Although some species can emerge over a few consecutive months buprestids generally emerge over 2-4 weeks at the same time each year. Good luck!
So I'm set up with a long handled net to go and look this year (thank you cicada scientist on iNaturalist last year who bought me one so I could see whether I could get cicadas at Bungonia for him). I've also sent an email to Red Hill Regenerators asking whether they might forward to their members the request to let me know when eucalypts are in flower to make it easier to time looking.