[Glyn]

I noticed last night that I had quiet allot of black fly on my raspberry leaves, I was going to build a fruit cage around them but would debris netting be ok to use if not what sort of netting would be best to keep them out?

[mumofstig]

The only thing that would keep out blackfly would be enviromesh, expensive stuff, but then how would your fruit get pollinated if the bees can't get to it

[corynsboy]

I think fruit cages are meant to keep out anything bigger than a bee. 

You'll always get bugs.  Find a good spray that works for you and fits in with the philosophy of the way that you want to grow. 

The price of home grown fruit is eternal vigilance! 

[Rowan]

i'll sceond the above comments, i used a simple black netting from Homebase, beas were fine and everything pollenated really well, birds can't get in...........

Apart form a magic one that was in there the other morning trying to get out