you can suck em up in the vacuum cleaner then dump it real fast before they start to smell...
or knock them off into a cup of water with a tsp of dish soap in it. they will drown in 30 or so seconds and not stink.
they have been dormant all winter and now they are coming out to eat your orchids bec there isnt anything else to eat. I dont think orchids would have been their 1st choice if you had something else for them to chew on. They prefer fruits and berries.