Marpesia crethon, male, Rio Madre de Dios, Peru – Adrian Hoskins
Introduction
The genus Marpesia is confined largely to the neotropical region, but is closely allied to the Mapwing and Maplet butterflies ( Cyrestis & Chersonesia ) of the Oriental region.
Daggerwings are similar in wing shape to Swordtails and Swallowtails ( Papilionidae ), but the latter have 6 legs whereas Marpesia and all other Nymphalidae genera have only 4 legs. Another feature to look for is the antennae. In all Papilionids these are recurved at the tip, but in Marpesia they are straight. In total there are 17 Marpesia species, all with the same wing shape as crethon except for petreus which has 2 tails on each hindwing and a deeply scalloped outer margin to it’s forewing.
Marpesia crethon, male, Rio Madre de Dios, Peru – Adrian Hoskins
This species can be confused with orsilochus, but in the latter the white spots on the forewing are absent, replaced with a thin white line. It can also be confused with merops which has the white spots but lacks the white bands.
Marpesia crethon occurs in Colombia, Venezuela, Surinam, Ecuador, Brazil, Peru and Bolivia.
Marpesia crethon, males, upperside and underside, Rio Madre de Dios, Peru – Adrian Hoskins
Habitats
This is a lowland rainforest species occurring at elevations between about 100-500m.
Lifecycle
I have no data relating to crethon, but the following characteristics are applicable in general to the genus Marpesia : The eggs are white or yellowish, and laid singly on the foliage of trees and shrubs in the family Moraceae – including Ficus, Chlorophora, Brosimum and Artocarpus. The fully grown caterpillars are very colourful, typically marked with red and / or yellow spots and stripes. There is a single row of unbranched, recurved spines along the back, and the head is adorned with a pair of very long wavy spines. They feed diurnally and rest on the upper surface of leaves. The pupae are typically pale in colour, marked with blackish spots or blotches, and have wiry filaments projecting from the back of the abdomen and from the head.
Marpesia crethon, male, Rio Madre de Dios, Peru – Adrian Hoskins
Adult behaviour
Males are usually encountered in threes and fours when visiting wet sand or mud to imbibe mineral laden moisture. In hot weather they are extremely active, darting and skipping from place to place, and rarely settling for more than 2 or 3 seconds. The wings are occasionally fanned or held erect, but normally they are spread flat immediately after the butterfly has settled.
Females are elusive, spending most of their lives in the forest canopy, but in overcast weather will sometimes descend to settle on foliage along forest trails.
Marpesia crethon, Satipo, Peru – Adrian Hoskins