In article , Franz Heymann
writes
You have a point. I mentioned the use of Cactoblastis cactorum to
clear the prickly pears out of the Little Karoo. After the job was
done, there were rumours floating around that the insect had started
turning its atention to pumpkin fields. I don't know whether that
threat ever materialised.

There was the whole rabbit/opuntia thing in Oz - I can't remember
whether the rabbits were introduced control the opuntias or vice versa,
but either way it didn't afterwards look to be such a good idea.

--
Kay
"Do not insult the crocodile until you have crossed the river"