YES THEY ARE SO GOOD I LOVE THEM. The only carnivorous species of butterfly caterpillar in North American is the Harvester (Feniseca tarquinius). It’s a small lycaenid that feeds on woolly aphids as a caterpillar. Since they are carnivorous they can complete the caterpillar stage in as little as 8 days. Some of the caterpillars will cover themselves in the carcasses of their prey to hide from predators. Sometimes the caterpillars are protected by ants because they mimic the chemicals of the aphids that attract ants. The chrysalis kinda looks like a monkey head. Adults actually don’t visit flowers but feed on aphid honeydew, poop, and sap!
And then there are also carnivorous moth caterpillars. The ones I am most familiar with are native to Hawaii because as a child I used to watch and rewatch a documentary on the native wildlife of Hawaii and there was a sequence with them! They’re several species in the Geometrid genus
Eupithecia (Common name: Pugs). These caterpillars mimic twigs and they pounce on their prey when hairs on their backs are triggered! These caterpillars had been known to science since the 1880s but it wasn’t untill the 1970s that the carnivorus behavior was observed. They metamorphose into small drab colored moths.
Here is one of the adult species (Eupithecia orichloris)
There is also a species of case bearing moth (
Cosmopterigidae: Hyposmocoma molluscivora) on Hawaii that traps snails in silk webbing and eats them alive as caterpillars. Pretty cool huh?