Introduction
The Ithomiini comprises of 376 known species, although it is likely that at least another 30 will be discovered in the near future. All are confined to the neotropical region. Ithomiines are unpalatable to birds, and are consequently mimicked in appearance by many other species. These include other unpalatable species ( Müllerian mimics ), not only from the Ithomiinae but also from several other butterfly families. There are also a large number of edible species ( Batesian mimics ) which have evolved similar patterns. Birds have the ability to memorise butterfly patterns and so learn to avoid eating noxious species, but are also fooled into ignoring similarly marked edible species.
Ithomiines are characterised by having small eyes, slender abdomens and long drooping antennae that lack distinct clubs. Males have a plume of long androconial scales or “hair pencils” on the costa of their hindwings. These are hidden from view when the butterflies are at rest, but are displayed when the wings are held open during courtship. Other Ithomiine characteristics include a very slow and deep wing beat, and a preference for inhabiting the darkest recesses of the forest understorey.
There are basically 2 types of Ithomiine. The first type are the black and orange-banded “tigers”, many of which are mimicked by other species due to their unpalatability to birds. The second type are the “glasswings”, recognised by their translucent wings and prominent venation. Many genera contain examples of both types, and in some cases an individual species may produce adults of both forms according to location.
The genus Hyalyris comprises of 13 species, which can be recognised by their distinctive venation, and by the broad black margins with which are prominent white submarginal spots. Some species have simple patterns like that of latilimbata, antea and mestra; but others including excelsa, coeno, schlingeri and oulita have conspicuous orange patches on the hindwings.
There are 13 known species in the genus Hyalyris, of which 10 are found in Peru.
Habitats
Hyalyris mestra is found in mid elevation cloudforest on the eastern Andes, at altitudes between about 500-1200m. It can be found flying along shady forest trails, or in full sunshine along forest edges. Populations tend to be highly localised.
Lifecycle
The eggs are white. They are laid in batches of up to 80 beneath leaves of Solanum ( Solanaceae ) growing along forest edges. The caterpillars are gregarious. They feed diurnally on the leaf tissue, leaving the midrib and veins intact. When fully grown they are black above and whitish below, with translucent green prolegs. The chrysalis is golden, smooth, and shaped like a raindrop.
Adult behaviour
Hyalyris mestra is usually seen singly, and flies in open sunlight at the edges of clearings, and along forest trails, where it nectars at Eupatorium and other flowers.
Males sequester pyrrolizidine alkaloids from Heliotropium, Tournefourtia, Myosotis ( Boraginaceae ), Eupatorium, Neomiranda and Senecio ( Asteraceae ). These chemicals confer toxic qualities to the butterflies which deter bird attacks. The chemicals are also used in the production of pheromones used to entice females into copulation.