Brugmansia

Hi

I have a Brugmansia which I have potted from a cutting this year. It was growing well indoors so I moved it to the greenhouse. Within days something was eating the holes in the leaves. Then I saw what looked like a white web or residue round the top of the centre stem and young leaves waiting to open. As the plant grew and the leaves opened it looks as though a pest has eaten the top off the centre stem and most of the young leaves. I am left with a healthy plant which hasn't grown to a 'Y' yet with off shoots at the trunk and growing nodules off the trunk. Does anybody have any ideas what caused the problem and how I manage to get the plant to grow and produce flowers now that the top of the centre stem has gone?