The above butterfly dived numberous times down to the sitting butterfly. Don't know if it was aggesive behaviour or an attemp to mate with it ( even when it was a different species ),
It's not a strange behaviour, but the mating behaviour of all Heliconius and most diurnal butterflies. Always the one that flutter above and make quick approachs is the male while the one sitting is the female, with wings spread and abdomen raised for indicate receptiveness and spread pheromones.
Are you sure that they're different species? They looks like it (for example H. erato looks good for the male and H. melpomene for the female), but given that most Heliconius species have morphs mimicking every other Heliconius species (and other similar genus) with overlapping ranges (mullerian mimicry), I'm not enough brave for affirm that they're different species...
Anyway, interspecific mating in Heliconius is common in captivity - even developping to adult hybrids is not rare.
They can bee inded different species, I'm not saying that they aren't. It's just that I don't know if they are the same species or different, because each species have multiple form that mimic other forms of other species. Better explained with an image:
Here, the three butterflies of the top row are the same species, Heliconius erato, and the three in the lower row are a different species, Heliconius melpomene. But each form of erato mimic a form of melpomene and vice versa!. This happen at much bigger scale with many species, some of them having dozens of subspecies and forms each one mimicking a different butterfly!
