Fly trap.

I checked on the olive fly traps. This fly (mosca olearia) lays an egg in the olives and the larve ruin them from june till harvesting, which in our area is best from mid october to mid november.
The trap is made,  as you can see, of a plastic bottle containing fresh sardines,  water and ammonia.
There are four 3/4mm holes and bright yellow marks, which attract the flies. 
Imagine the terrible stink of sardines and routine flies.
They seem to be working fine so far as I  can't see any of the characteristic, black dots that mark the fly entry point.
The trees desperately need some rain, without which, there is a risk of the olives being shed.
It is too hot for comfort here at the moment. 37C and a few degrees less at home, thanks to a breeze from the sea.