Bugs and Fungus

[kbdsyd]

Hi all.
I was wondering if there is a general 'rule of thumb' regarding winter prep for orchids with regard to fungus prevention/bug prevention.
I have a range of orchid species from a range of genera, and I'm not sure
a) if I just spray the lot with any old fungicide
b) if I need t be cautious and selective in my product choice/dilution (as with fertiliser requirements . . .)
c) if I need be concerned with bugs in Sydney(Australia) in winter
For the latter, baring in mind I live on the 6th floor of an apartment block with a completely tiled terrace.
I have seen crickets wandering about at night (I assume here that they don't harm the orchids) and have also seen tha obligatory Sydney cockcroach too.
Any help/suggestions greatly appreciated!
Keir