I asked a local nursery guy about this as I had similar problems, though on a a relatively small scale. He had no experience of brewing hops, but had personal experience of ornamental hops, which are obviously very similar. He suggested going out at night with a torch to see if you can catch the...
I note you didn't get much of a response to your query about growing hops in Brisbane. I am moving to Gold Coast soon and wondered how you're going with this. I have had a couple of hops in this season (in Ballarat, Vic) which have grown like weeds and are now forming small cones - looking good...