Great fleas have little fleas upon their backs to bite 'em
Jonathan Swift wrote:
"So, Nat'ralists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller yet to bite 'em,
And so proceed ad infinitum"
Which is often rendered in the Augustus De Morgan re-write:
"Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on"
So the Ixora plant by my door here on Nevis has Green Scale (and green aphids) attacking it, and the Green Scale insects have parasitoids in the wasp family Encyrtid attacking them, and so on...