Costa Rica is home to approximately 1500 different species of butterflies. Biologists classify butterflies within the Class of Insecta (having 6 legs), Order Lepidoptera, a name originating from ancient Greek, “lepis” (scale) and “pteron” (wing). There are six Families of butterflies and the blue morpho belongs in the largest Family, Nymphalidae with approximately 6,000 species world-wide. The Genus Morpho, has 29 different species with 147 subspecies.

The blue morpho is among the largest butterflies in Costa Rica (or in the world) and is an iconic species with its iridescent blue wings. Butterfly wings can be intricately colored. Their wings have scales on them with two coloration types. One type is that the scales contain different colored pigments where the color is from an organic chemical compound. In the case of the blue morpho the scales actually lack color and are made of nanoparticles which refract light (refraction refers to the bending of light) to give the iridescent blue.

Entomologists speculate that the iridescent color of the blue morpho is one adaptation to ward off birds’ attacks which is the main way butterflies die. It also makes the butterfly look larger than it really is. The adult blue morpho do not visit flowers, but rather is attracted to rotting fruit using their proboscis to suck juices for nourishment.

The first stage of the life cycle, after mating, is the egg. When the egg hatches, a caterpillar emerges which the second stage. The food plant for most butterflies are leaves. Usually the female lays eggs on the plants that are the preferred food plant and the caterpillars on emerging immediately start to eat and grow. Caterpillars have an external skeleton or exoskeleton. As they eat and grow, they outgrow the exoskeleton then shed it in a process known as molting. The caterpillar attaches to a stem or leaf using silk and sheds its exoskeleton. The new soft exoskeleton can expand as the caterpillars eat and the process is repeated again. Caterpillars have five growth instars; the first instar emerges out of the egg. The fifth and final instar when the caterpillar has completed eating turns into a chrysalis or pupa.

In the chrysalis, metamorphosis occurs where the chemicals of the caterpillar are reformed into that of the mature butterfly. The exact nature of metamorphosis is not thoroughly understood and is one area of intense interest and study by entomologists. The pupal stage of the blue morpho is approximately 14 days. The adult butterflies emerge and expand the wings. The expansion is the result of the butterfly pumping body fluids into the veins of the wings which takes about 30 to 45 minutes.

The blue morpho caterpillars feed on plants in the pea family, Fabaceae, with 670 genera and approximately 20,000 species. They are widely distributed as trees, shrubs, and vines. The fruits they produce are known as legumes.

The adults then mate, and the cycle starts over. The total life cycle is reported to be approximately 115 days.