Red Postman

That's the usual way: Accumulation of toxins in caterpillars, together with some warning colors makes the caterpillar AND later the buttefly unpalatable for birds. There are actually some moths which produces as adults also toxins out of amico acids (for example Zygaenidae). But most of the toxins in Lepidoptera are built in the caterpillar. All these mechanism and mimicry seem at first sight quite easy to understand, if you go deeper in the topic you see that it is an extraordinarily complex and amazing matter. Any technique provided by one species will usually have a counterpart on the other side of another species.

Cool!
Question, H. melpomene produces its own poison or it keeps it from the larval stage? Because i've read that some butterflies keeps the venom from the plants they ate when they were caterpillars as a deffensive system. Is this the case? Or there is no butterflies who produce venom?

Yes, if you feel bad afterwards, you got Heliconius melpomene, if you feel fine Heliconius erato. Both are mimicrying each other. Heliconius melpomene is the poisenous one, Erato Longwing is pretending beeing poisenous, too, which is not the case.

Taste it? Really?

Or you can taste it.

Freshly captured Melpomene smells of fried-rice and Erato from Wytch-hazel (Hamamelis virginiana).

Smell them? Really? How so? That's new to me

It is the only way! Or you smell them...

Thanks bayucca, i have finally learned to distinguish this from H. melpomene rosina... I have to look at the white stripe, actually is not really hard to identify them with a good ventral view