Caterpillars of the
Cactoblastis moth have been effective in reducing the populations of introduced prickly pear but they haven't eradicated the pest. The road sides between Goondiwindi and Miles are infested with cactuses, both well-established and newly-growing. Neighbouring farm land is largely free of prickly pear. Not through
Cactoblastis, I suspect, but in the same way that farm land is largely free of anything over half a metre tall