The black-veined golden butterfly larvae first break off the veins of the venomous milkweed plant to allow the venom to flow out, and then feed into the whole leaf  Under normal circumstances, the venom inside the milkweed plant is basically completely drained after the veins are broken, even if there is a trace of residue, it will not pose a threat to the larvae
Black-veined golden butterfly larvae use this method to feed poisonous milkweed plants until they mature
Larvae have many ways to deal with the venom of poisonous plants. Therefore, poisonous plants are a food source for many kinds of larvae.