Guinea fowl would help, we already have abundance of wild birds, plenty of small birds that hunt insects, plenty of dung beetles to reduce the available food for buffalo flies. Lots of frogs and reptiles.

Rarely see house flies or blowflies. Fruit flies weren't an issue this year.

My suspicion is that some of the neighbours are using an insecticide that local buffalo flies have built up resistance to, along with the feral cattle that live in the nearby national parks being untreated creating a refuge for buffalo fly.