Introduction
The Pyrginae, popularly known as Flats or Spreadwings, are a cosmopolitan subfamily distributed across temperate and tropical habitats throughout the world. In the Americas there are 990 species.
About 580 species are placed within the tribe Pyrgini.
The genus Quadrus is closely allied to Pythonides, Eracon and Sostrata. These genera comprise of small species sharing the characteristic Pyrgine wing shape and a peppering of metallic blue scales overlaid on a dingy brown ground colour. They also have a series of small transparent windows on the forewings which has a different configuration in each genus. In total there are about 45 species in this group of genera, 11 of which are placed in Quadrus.
Most Quadrus species are common and widespread, occurring throughout the Amazon and Andes, although a few such as the Mexican francesius have more restricted ranges.
Quadrus cerialis is found from Panama to Bolivia.
Habitats
This species occurs in rainforest, cloudforest and humid deciduous forest habitats at altitudes between sea level and about 1400 metres.
Lifecycle
The lifecycle appears to be unrecorded. Generally, Pyrgine butterflies lay their eggs singly on either the upperside or underside of leaves. The caterpillars are typically dull green or brownish, with thin longitudinal lines along the back and sides, and with black shiny heads. They feed typically on low growing herbaceous plants, but some feed on the leaves of bushes or trees. The pupae are usually dark and smooth, with the wing cases in a contrasting tone or colour. They are normally formed within silken tents formed by spinning together the leaves of the foodplant.
Adult behaviour
The butterfly is usually encountered singly, or occasionally in two’s or three’s, and is active mainly in hazy sunshine or early in the morning. In hot weather it retires to the shade of the forest, occupying light gaps where the sunlight filters through leaves. It periodically basks on the upper surface of tree foliage at a height of about 2-3 metres, interspersed with longer periods spent at rest beneath leaves with wings outspread.