Common Oressinoma

Behavior

The butterflies are usually encountered singly, or in two's and three's. They are active only in cloudy weather or weak hazy sunlight. Males perch on sedges or ferns, often for long periods, but remain alert at all times. If disturbed they dart up rapidly, but then lazily descend to resettle on foliage a short distance away. Both sexes feed at rotting fruit and decomposing fungi.

Courtship takes place in late morning. The perching male flies up to intercept a passing female, hovering above her ( probably while disseminating pheromones ) until she settles. At this point the pair face each-other, and the male leans forward to press his antennae against hers, while vibrating his wings. If receptive, the female allows him to manoeuvre alongside her to copulate.

Habitat

Oressinoma typhla breeds in pre-montane rainforest and cloudforest habitats on both sides of the Andes at elevations of between about 1200-2400 metres. In Costa Rica it breeds at lower altitudes, between about 700-1700 metres. The butterfly is localised in distribution, occurring near streams, or in association with swampy areas where the larval foodplants grow.

Reproduction

The eggs are pale shining green, spherical, and laid singly on the foodplant. The fully grown larvae are green, with a rough texture, with dark green longitudinal lines along the back and sides. They feed nocturnally on Cyperus ( Cyperaceae ).