There are nowhere near as many pest bugs in Australia as in the USA for whatever reason. I have found that keeping a very clean garden and mulching with compost keeps most bugs away. We have a species called Cabbage Moth which like to eat all brassica's so we use insect netting over all of those crops. It equates to a 20% shade cloth.

We kangaroos and rabbits everywhere here which require the equivalent of deer fencing with smaller gauge fencing at the bottom for the rabbits. Koalas can climb over and come through but they don't eat vegetables.