If my old (out of date taxonomy wise) book is correct it could be Dryadula phaetusa a single species of which is placed in the sub family Heliconiiane .
larvae feed on passiflora species and butterfly is attracted to red yellow and white Flowers. C. America.
Or Dryas iulia which is much the same as the above, but sometimes lacks the black markings. central and tropical S. America and USA
Thanks dean. We'd been calling them 'julias' as shorthand but weren't sure if they genuinely were. Costa Rican butterfly guides these days go straight from glossy pamphlet to multi-volume textbook with nothing in between, sadly!
