27-3-2017 VILLA LAPAS, COSTA RICA - CRIMSON PATCH BUTTERFLY (Chlosyne janais)

Chlosyne janais, the crimson patch or janais patch, is a common New World butterfly found from Colombia north through Central America and Mexico to southern Texas, with occasional sightings in southeastern Mexico and northern Texas. The dorsal and ventral wing surface is black with several undulating rows of small white spots on the medial forewings and along all outer wing margins. On each dorsal hindwing is a medial orange-red patch situated anteriorly. The ventral hindwings have a fragmented yellow proximal patch bordered by a thick postmedial band of red that does not reach the wing margins; maximum wingspan is 4.8–6.7 cm.

Adults inhabit the periphery of lowland tropical to subtropical forests, fields, and along streams, where they feed on flower nectar. Reproduction is continuous in the tropics, whereas in temperate areas several broods are produced from July to November. The caterpillars are grey white to green with several transverse rows of fleshly black spines; they feed primarily on acanthus shrubs, especially Anisacanthus wrightii and Odontonema callistachus (in Texas), upon which adult females lay their eggs.

The crimson patch can reach high numbers in the Rio Grande Valley, but the population is periodically killed off by cold snaps; the area is then recolonized by members of the Mexican population. A very similar species is the rosita patch (C. rosita), which is distinguished from the crimson patch by the former's lack of spots on the wing margins.

Adults are found along the forest edge of the tropical forest and the surrounding fields.

In the southern most part of their range there are multiple generations each year and adults can be found year round. In the northern part of their flight range multiple generations still occur, but only between the months of July-November.

Populations of Crimson Patch butterflies can build up in significant numbers. Crimson Patch butterflies are, however, greatly affected by weather conditions and on years with colder than usual temperatures the population often plummets.

The crimson patch can reach high numbers in the Rio Grande Valley, but the population is periodically killed off by cold snaps; the area is then recolonized by members of the Mexican population. A very similar species is the rosita patch (C. rosita), which is distinguished from the crimson patch by the former's lack of spots on the wing margins.

Adults are found along the forest edge of the tropical forest and the surrounding fields.

Males patrol for receptive females. After mating the females lay their eggs in cluster on host plants. Once the eggs hatch, the early instar larvae feed in groups until they reach their fourth instar. The newly formed pupa hangs from plant matter until it emerges.