Cydno (Heliconius cydno)
The Cydno is a striking, common longwing butterfly of butterfly gardens. In the wild, you have a good chance of seeing this beautiful butterfly if you visit such Caribbean slope national parks as Tortuguero, Braulio Carrillo, Arenal, and Cahuita.
In flight, the large white wing tips of this smallish Heliconid butterfly contrast with the dark wings and body. When the Cydno rests with its wings spread open, a close look reveals a velvety indigo coloration in the wings. When feeding, the Cydno holds its wings closed and upright to reveal two dark red lines on the lower parts of the undersides of each wing. Like most Heliconid butterflies, this species also occurs with others that closely resemble it. In Costa Rica, one of its most similar mimics is the Sapho Longwing. This species can usually be separated from the Cydno with a close look at the lower parts of the underwings; the Sapho lacks the red markings.
Behavior in Costa Rica
In Costa Rica, the Cydno flutters through the upper understory of forests in search of the orange and red flowers that it typically feeds from. Whether seen in the dim forest interior or in forest gaps, the bold wing pattern of this species seems to beg for attention. The Cydno can afford to be seen because, like other Heliconids, it is poisonous and unpalatable to birds. Like most Heliconids, it also has other Heliconid species that mimic its appearance such as the Sapho Longwing. The form of mimicry involved is known as Mullerian mimicry whereby both species are actually toxic but somehow benefit in having very similar coloration.
Habitat and distribution in Costa Rica
The Cydno is a butterfly of the wet rainforests of the Caribbean slope. It can be found inside the forest, along streams, and will feed from flowers that occur in treefall gaps and other forest edge habitat. In Costa Rica, this beautiful species occurs from the lowlands to wet cloud forest such as that found in Tapanti National Park.