WHY BUTTERFLIES AND MOTHS
HAVE BEAUTIFUL COLORS
Some butterflies are dingy, others uniform, but in contrast to moths the majority are beautifully colored. This is especially the case with tropical forms. How the colors are variegated and contrasted in spots and bands, how the hues are embellished by metallic shimmer, every one knows; what exactly the color means is, however, still obscure. A few general facts may be first noticed: (1) The color is in many cases subject to variation—it cannot be said to be absolutely constant for a species; (2) in some instances, at any rate, it is influenced by external conditions, for different forms at different periods of the year, is known in many kinds; (3) sometimes the color and markings, especially of the under surface of the wings, are obviously of use for the protection of the resting butterfly; (4) in some cases this protective adaptation is so pronounced as to deserve to be called mimicry; (5) in many cases the coloring is in direct connection with the physical constitution of the species, and is usually most marked in the males.
CHIEF CLASSES OF
BUTTERFLIES
Of the families representing more than five thousand species, the chief are the following:
(1) Nymphalidæ, the largest, containing between four and five thousand species. They have a relatively simple type of coloration, and are interesting because of their disposition to mimic other species. They are distasteful to birds. They include the red admiral, the tortoise-shells, the peacock, and so on, as well as the fritillaries and the purple emperor. In it are also included the remarkable leaf butterflies in which the under surface, in shape, color and markings, closely resemble a dead leaf, while the upper surface is brightly colored. On alighting only the under surface is visible.
(2) The Erycinidæ is represented by the Duke of Burgundy fritillary.
(3) The Lycænidæ include the “blues,” so commonly seen flitting near the ground along muddy roads, so called from the color of the upper surface, but many are also copper, white and yellow.
(4) The Pieridæ include the white cabbage butterflies. They are remarkable for the prevalence of white, yellow, and orange colors, and for the fact that these tints are due to uric acid, or derivatives of this substance, stored in the wings as a pigment.
(5) The Papilionidæ, or swallow-tails, contain perhaps the most beautiful forms. The females are strikingly different from the males, and though larger, do not display the same beauty of coloration. The members of the family are widely distributed.
(6) The family Hesperidæ, or skippers, includes insects very different from other butterflies, both in structure and habits. The adults have in many cases a very rapid but jerky method of flight, and the larvæ in their habits resemble moths rather than butterflies.