Well Dumpy, To give you an explanation for each one of those would take all day. So instead I'll point you here [info.webcrawler.com]
You'll find a lot (not all) of your answers there. Others are personal bots or the module bots for scripting language utilities. A couple you have there are new and you are going to have to do some digging to get the scoop on. A couple of them are site rippers designed to steal content or emails.
xyro_(firstname.lastname@example.org) has ben catching my eye lately - they seem to be crawling inktomi results You could read about them here [inria.fr] . I'm not sure if anything is going to come from all their crawling.