For the April instalment, a few new species have been added to the collection to be seen in the Butterfly House in addition to the regular species. El Bosque Nuevo, the Costa rica butterfly farm that supplies us, has at least 70 species available, so the collection manager likes to ring the changes occasionally to keep things interesting for the annual members who visit regularly.
First, off, we have two new species of Owl butterfly. Largest and most richly coloured of the owls is the Yellow-Edged Giant Owl, Caligo atreus. Like the Pale Owl we have had from the beginning, it has a cryptically coloured underside enlivened by a single large eye spot. I presume that the difference in underside colour means it rests in different locations by preference in the wild to the rather greyer Pale owl, but I have not found any studies to confirm this – one of the many considerations that need researching. Most knowledge of butterflies is extremely superficial beyond bare descriptions and location data, and this is a subject that could well repay studies in the wild or in butterfly houses. My impression from Bristol is that they like to rest closer to the ground than Pale Owls, but this may be a constraint of their surroundings. Like their relatives, Yellow-Edged Giant Owls are long lived as adults – some at least seem to reach close to 50 days. The foodplant is various Banana and Heliconia species.
The other Owl butterfly we have has only just emerged, so I am not sure of the lifespan. The Tamarind Owl Opsiphanes tamarindi is a half-sized version of a Giant owl with a more plainly patterned underside. It seems to fly differently to Giant Owls, being much more active and a faster flyer. Caligo species prefer to fly at dawn or dusk, but the activity period of Tamarind owls may be different. The foodplant is as for the Caliogo species.
We have also added two new species of Swallowtail butterfly. The Red-spotted Swallowtail Papilio anchisaides feeds on Citrus, so the red spots (usually a sign of a distasteful species) may be mimicry of a more toxic species. Mimicry rings, especially in the tropics, can involve numerous species, including butterflies, moths, wasps, flies, beetles and other groups, all mimicking each other and some of which are toxic and others just pretending to be, so disentangling the network of imitation can be very difficult. Almost certainly toxic is the Green-celled Cattleheart, Parides childrenae, which feeds as a larva on Aristolochia. This plant contains numerous toxins which are retained into the adult butterfly, and most Aristolochia-feeders worldwide have various warning patterns. Unlike the owl butterflies, which feed on fruit juices as adults, the swallowtails visit flowers.
Finally, we have a new species of Pierid, the Orange-barred Sulphur Phoebis philea. Another flower-feeder, it seems to like to rest well off the ground if possible here at the Butterfly house. The foodplant of the larva is Cassia.
Coming up, a new species in Twilight World and then a survey of the waterfowl we have here at Bristol.
(images from wikipedia, bugguide, encyclopedia of life)