Butterflies for collections

[Terry Fluke]

I'm new to this list, and I was just wondering, what do lepidopterists
exactly do?  Is it study moths and butterflies?  Or do you collect
butterflies ect. for collections and/or retail  to other collectors?  If it
is retail sales, are they dead or alive when you collect them.  If they are
alive when you collect them, and another collector wants them for their
collection, do you have to kill them or do you just wait till they naturely
expire?
Just curious.

Terry