Anteros acheus (Stoll, 1781)
The acheus caterpillars were found feeding on a common species of Miconia, a Melastomataceae near Villavicencio, Colombia. I noticed the feeding damage on a young plant and found a shelter formed by a curled piece of leaf. Inside was a fuzzy yellow caterpillar with a red collar.
The red collar turned out to be balloon setae, organs of uncertain use but possibly for ant-mediation.
The caterpillar body color is translucent light green, the setae are light yellow and the balloon setae are mixed red and white. The caterpillar above is about 12mm.
A loose cocoon is spun off the food plant and the shed larval skin is somehow expelled to the outside of the cocoon. The pupa is translucent green and is capable of movement, it wiggles the abdomen when annoyed. This movement of the abdomen causes the shed balloon setae to move back and forth, possibly being used as a predator decoy to deflect an attack away from the pupa.
The pupa stage lasts 8 days, the above photo is the day before eclosion.
A beautiful adult Anteros acheus. The Anteros occasionally move their hind wings up and down, so the black protruding scales on the hind wing may be predator decoys like the wing filaments of the Lycaenidae.