Butterflies of the Amazon and Andes
Blue Doctor
Rhetus periander  CRAMER, 1777
subfamily - RIODININAE
Rhetus periander, Rio Claro, Colombia  Adrian Hoskins
Butterflies in the genus Rhetus are noted for their short palpi, and for having a beautiful blue sheen across the upper surface of the wings. Rhetus are closely allied to Ancyluris and have a very similar wing shape. In Ancyluris however there is a blue iridescence on the underside of the wings, but not on the upperside.
There are 3 Rhetus species, of which periander is the commonest and most widespread. The others are arcius, which is paler, with longer, thinner tails; and dysonii, in which the pink markings on the hindwings are of a different configuration.
Rhetus periander, Satipo, Peru  Adrian Hoskins
Rhetus periander is usually found singly or in very low numbers, in the vicinity of streams or rivers. It can be also be found along tracks through primary or disturbed rainforest or cloudforest habitats. The butterfly occurs at elevations between 0-1800m, and flies throughout the year.

Rhetus periander, Satipo, Peru  Adrian Hoskins
The larval foodplants are unknown. The eggs of other Rhetus species are white, and laid singly on stems or leaf axils.
Rhetus periander, Satipo, Peru  Adrian Hoskins
Adult behaviour

Males can be seen perching under leaves at a height of between about 3-8m above ground in the early morning. Later in the morning, presumably after mating has taken place, they often descend to ground level to imbibe at wet mud. After first settling they are skittish and take flight instantly if disturbed, but after a while they overcomes their nervousness and will sometimes remain in one spot for several minutes. Males are attracted mainly by mineral salts, but will also visit carrion - I once observed one feeding on the juices of a dead tarantula in Venezuela!

Both sexes are attracted to Eupatorium flowers, and also nectar at Inga, Croton and Cordia.

Rhetus periander, male, Satipo, Peru  Adrian Hoskins


Contact  /  About me

Butterfly-watching holidays

Trip reports

UK latest sightings

Frequently asked questions

Strange but true !

Taxonomy & Evolution



Enemies of butterflies

Survival strategies

Migration & dispersal

Habitats - UK / Palaearctic

Habitats - Tropical rainforests

Butterfly world census

Butterflies of the World :

British Isles


Amazon & Andes

North America

temperate Asia


Indian subcontinent

Malaysia & Borneo

Papua New Guinea

Australia & N.Z.

Insects of Britain & Europe

Insects of Amazonia

Moths of the Andes

Saturniidae - Silkmoths

Caterpillars of the World

Butterfly Photography

Recommended Books



Code of practice

Copyright - text & images

Copyright - text & images






All photographs, artwork, text & website design are the property of Adrian Hoskins ( unless otherwise stated ) and are protected by Copyright. Photographs or text on this website must not be reproduced in part or in whole or published elsewhere without prior written consent of Adrian Hoskins / learnaboutbutterflies.com

Site hosted by Just Host