Monarchs or not...???

Siiggghhh... i surely do not have the heart to kill them.... but i do hope my Ascepia incarnata..which has only been planted a few months and yet to bloom as such...will survive this attack.  Google informed that Asclepias are food for Monarch Butterfly caterpillars.... and will be able to survive despite having been gobbled up by the caterpillars.... i really really do hope that will be the case here... but am not sure whether these are really Monarch Butterfly caterpillars or the caterpillars of some other butterfly....????