Soldier butterflies, sometimes called Tropical Queens, were a new species for Brian. They're kind of a cross between Monarchs and Queens, all of which host on milkweed. However Soldiers are very picky about their host plant. They don't eat true milkweed and will die from it. Brian was really stressed when he was unable to get them their proper host, Honeyvine Milkweed (Cynanchum laeve). Luckily, he got them to eat Fringed Twinevine (Sarcostemma cynanchoides), but the resulting butterflies that emerged yesterday were slightly in the small range for their species. Nevertheless, they look perfect and he's happy with them.
I have never seen a Soldier. In Texas they just occur in the Lower Rio Grande Valley where their host milkweed exists. Here are a few of the Soldiers as larva.
And here is one of his Soldier pupa (top) next to a Monarch pupa.
He's still waiting anxiously for his precious Ornythion Swallowtail to emerge from its pupa (lower). Soon, maybe tomorrow. Here it is beside a Western Giant Swallowtail pupa (upper).