By themselves......no insects needed.

But why do peas need protection? We have never had any insect attack on ours.

The only reason I have put netting over mine on my allotment is to keep the sparrows and pidgeons off as they seem to like the leaves, but as the other two have said no problem with insect attack

Many thanks for the replies.
I used to use Sybol 2 which worked very well, but it's run out.
This year (in Leicestershire) the pea moth on my allotment caused me to scrap much of my crop.
Next year, it will be a previously unused part of my allotment (for peas), plus the mesh.

OK, Dave, never had this problem.