ABSTRACT
The complexity of the species of Heliconius is double: food of the caterpillar, Passiflora spp., food of the adult. Plants are at the base of all plant-animal food chains, but only in some groups does this interdependence become symbiotic or even pseudosymbiotic. Many lycaenid caterpillars are myrmecophilous, reared by ants and even brought within the nests by the ants themselves. Species of Danaidae, on the contrary, obtain from their host plants not only the cardenolids, toxic to predators, but also the pheromone precursors. A species of Danaus, fed on cabbage, loses its emetic agents and becomes edible, something that birds would learn rapidly if this happened in nature. The diversity of tropical species is due to climatic conditions, permanent and optimal, which allowed development of the great diversity of phytophagous insects as well as the plants on which they feed.
