saw fly on red currants

I used to have a terrible time with sawfly until I learnt that saw fly are attracted to redcurrants and gooseberries by scent.Two years ago, armed with this knowledge, I planted garlic all around the base of my currents. I may regret saying this but so far no sawfly since. The scent of the garlic masks that of the currants so the saw fly cannot find them, or so my theory goes. I would love to know if anyone else has tried this.