I would venture to say that collecting with a net is the easiest method, followed by a killing jar with ethyl-acetate. The bug must not get wet and should be removed from the killing jar as soon as it is dead and transferred to a glassine envelope or homemade folded square of parchment paper with its wings folded. They should be frozen in a sealed plastic container as soon as possible.
We can arrange for pick up or some other method of delivery...but we'll cross that bridge if and when we get to it! Anybody else have a "method" for capturing butterflies?!
Thanks, Mary Beth