temperature sensitive?

[Rebecca Jolly]

     A colleague (without internet access) was chatting to me and 
     wanted to know the answer to the following:
     
     Assuming that butterflies need warmth to fly, presumably moths 
     require less warmth (as generally they are night-flying).  Are 
     moths temperature sensitive?  At what temperature do they cease 
     to fly?  What is the minimum temperature?
     He has just reared some death's-head hawkmoths (Acherontia 
     atropos) and I think this has sparked his interest!
     
     If anyone can comment I would be very grateful as I am unable to 
     answer his questions myself!
     Thanks
     Rebecca