A plague on your Yellow Box!

I have mentioned the infestations of Plague Soldier Beetles (Chauliognathus lugubris) in a few posts, most recently this one.  This afternoon I noticed the heavy blossom load on the huge ( perhaps 30m high, estimated to be >200 years old) Yellow Box (Eucalyptus meliodora) tree in our lawn.

Then my eye strayed down to the branches above the daisies featured in the earlier post.  Hooley, and also Dooley!  There were masses of beetles up there.

This next shot gives a closer view of one of the dark masses of beetles.

I am intrigued that thus far there doesn't seemed to be anything predating the beetles.  Perhaps they are so widespread that birds and other insects cannot keep up with the work?  It seems that at present the beetles are restricted to the lower levels of the tree, perhaps up to 10m above the ground.

By 30 January the number of beetles  in the tree had declined somewhat but there were still masses on the daisies and lawn underneath the tree.  In the middle of the afternoon on the 31st - by which time a strong breeze had arisen - I noticed that all the beetles had gone.  No idea why.  From talking with an entomologist it appears the insects are rather like an Australian saying about wombats: "Eats, roots, shoots and leaves.".  Generally after the breeding activity they die, but I can find no trace of the corpses.