The bee issue is already being studied intensely because it's of vital importance to agriculture. Most of our crops are pollinated by bees, and if we lose their services we'll be in deep doo doo. Just a couple of weeks ago there was an announcement of a new US government policy to help protect bee populations:
http://www.npr.org/sections/thetwo-way/ ... ollinatorsThe article mentions that neonicotinoid pesticides in particular are thought to be a contributing factor to the collapse of bee populations. Neonic pesticides are OK for use with organic crops as well as conventional because nicotine is natural. Yum, nicotine. Roundup is NOT a neonic pesticide, in fact it's not a pesticide at all. It's an herbicide, designed to kill weeds not bugs or anything that feeds on bugs.
The butterfly situation probably isn't being studied as intensely, but anything that benefits bees is likely to benefit butterflies too. The loss of winter habitat in Mexico is a huge problem for the monarchs, so even if we plant lots of milkweed up here it might not help too much.