Book Festival

I shall be doing two events at the Edinburgh Book Festival on Friday 28 August, the first at 3.00 in the RBS Main Theatre about my new biography of William Golding, and the second with Sebastian Barry in the Scottish Power Studio Theatre, about Faber & Faber's 80 years of publishing.
Re Beekeping. Does anyone have experience of Apiguard for countering varroa? I'm using it for the first time this year as I read that the varroa mite has become immune to Apistan, which I have used till now.