Larval snapshot

There's been a caterpillar out there these past two mornings, working its way through the immature milkweed pods. It's not a parsleyworm (in other words, not a future black swallowtail butterfly). This one is striped, but doesn't have those yellow bumpy spots. It has two tall black bristles in front and two short black bristles in back. When there's time, the caterpillar-identification squad must get on the trail. Can this possibly be a monarch? That's what the guess would be except that it seems so late.