My Wisteria (Pale Pink Japanese) is currently getting devoured by some sort of insect. 6 months old. we tried some insect sprays and they just turned the leaves yellow and did more damage than good.

Do you live in Australia? Your photo doesn't show much (Stems, boards..). Have you seen these insects? Can you send a photo?

I googled Geelong...
Also googled kudzu bugs in Geelong...
Couldn't tell whether you have them yet.

I wish the Chinese wisteria here looked like that.

I also googled pink Japanese wisteria aggressiveness...
It's a thug.
Rather than dumping poison on this future problem.... Look around and see if you can't find a more appropriate vine.
If nothing else.... Try planting runner beans.

Sorry I can't help, but... If its a bug, you're gonna have to catch them in the act and get some pictures.

In the future, never put poison on the plant, when you have no idea what the problem is.

Do you have leaf cutter ants there?

Hi, we found some small caterpillars which are logically the culprit. Any tips on the best way to persuade this little vine eaters to move on?
All help appreciated!