On a sunny afternoon, this Jewel beetle (probably Temognatha variabilis, subfamily Buprestinae) scrambled along the middle of our driveway. Quite a big beauty!
What I, at first sight, thought to be attempts to become airborne again (a laborious undertaking for such a big, heavy insect), turned out to be scraping movements it (she!) made with the end of the abdomen, presumably to lay eggs.
She didn’t get anywhere on that hard surface, but didn’t appreciate a softer, sandy spot, to which I carried her, and buzzed off.
The next day, I watched a similar (the same?) beetle fly in tight spirals up around the trunk of a large tree, down again and then it disappeared straight into the opening of one of our possum nestboxes. Is she going to lay eggs in there?
Further remarks on sand-scraping by female Temognatha. Peterson (1996) observed Temognatha chalcodera (a WA species) laying single eggs on the trunks of its Allocasuarina host plant, then completely coating each egg with a dome-shaped cap of sand; the sand was previously collected into the extended ovipositor from the soil surface. Williams et al. (2024) also report sand-scraping by Temognatha variabilis, ‘with individuals moving backwards and forwards over the soil surface for periods [of more than] 10 minutes, each with the ovipositor extended and the tip of the abdomen bent downwards’. (Bibliographic references can be provided on request.)
Thank you, Kimberi, for that very interesting information! We have seen the sand-scraping behaviour in other beetles, too.
This is a female Temognatha regia, a North Queensland relative of T. variabilis. I don’t know what she is doing in your video, but I doubt she is laying eggs, as the larvae are wood borers and eggs are normally deposited on the bark of the host plant. However, I believe the behaviour (i.e. dragging the abdomen in sand) has been recorded in the literature – I will try to find the publication.