Sorry about the double posts- something goes wrong between me and the computer (well doesn't it always?).

Thanks DA for the explanatin. It's a good one and going by the rule of Occam's Razor ie the simplest explanation is usually the best, I prefer to believe in random selection/ evolution rather than the unlikely event of some supreme being making sure wasps learn how to lead cockroaches to their doom in order to impregnate them. Besides isn't good design supposed to ,be simple design, ie the most efficient? Selection wins hands down!