[Drosophila] RNA yield per fly?

[Chris Jones]

What's the rough yield of total RNA from a single fly? I'm going to be 
doing some comparative experiments with my molecular genetics class and 
need to figure out how many flies to use, which will affect the kinds of 
conditions we can compare.

I've found protocols for preps at various scales, but they don't 
indicate yields. The few estimates of RNA content I've found vary widely 
(the Grey Book cites two studies from the 60s which differ by a factor 
of 6). What has your experience been?

Thanks,

Chris Jones