Hi Bob,
Welcome to the forum.
Basically, the whole of Loch Lomondside can be a bit of a midgie hell. As you probably know, any decent breeze keeps the midgies down. As most of the WHW passes through trees by Loch Lomond, the camping spots are pretty sheltered.
Carry a head net, and camp near a pub. ;)
Or go off the way and camp higher.