You may someday wander down a road in the American Tropics and see Julia butterflies clustered along the way in hundreds and thousands, sipping at the damp places, or rising in glittering orange clouds into the air. If you try to catch one, however, it suddenly turns into a demon of action, storming away through the air like a frightened hummingbird. Watch a Julia flitting along the edges of the woods and sometime you may see the butterfly it mimics, a similar-looking Heliconian. The Heliconian is poisonous, but the Julia is not. However, birds leave the Julia along because they think it too is poisonous. The peculiar thing is that usually, the non-poisonous Julia is much more common than the poisonous butterfly it mimics.
Another difference between the Julia and one it mimics is that the Julia has a much stronger flight and widely roams over miles of the country while the other butterfly is usually found only along the edges of woods and is a poor flier. It almost seems as though the Julia has become such a swift flier that it no longer needs the protection of looking like something poisonous to eat.
The caterpillars have long, branching spines and live on leaves of the Passion Flowers, which are common along many a tropical American road.
This great butterfly, often almost three and a half inches in wingspread, has brilliant red spots glowing on its underwings against a delicate Japanese blue color so strangely lovely that the design looks almost like a scene from fairyland. In spite of its exquisite beauty, it likes to alight on such dirty things as dog dung and other manure or decaying material left along a roadway. It may even drink the juices of rotting animal bodies, as it is frequently found upon them, apparently thoroughly enjoying itself.
1 to 1 1/2 inch wingspread. This soft-colored little skipper can be told from others by the dark veins and peculiar mark on the fore-wings and the bright yellow-orange of the under-sides of the hind wings. The females are much larger than the males and have more dark markings.
Once people in America took many of these easily reared silk moths, in which the caterpillars spin beautiful silken cocoons, and tried to use them to raise silk for sale. It was possible to produce fine silk all right, but they found that the cost of American labor was so much higher than Oriental labor for producing this silk that it was impossible to compete. So the attempt was abandoned.
Wherever streams come down out of mountains, wherever the willows grow, but particularly in the western parts of North America, the Cerise Sphinx wings its way in the dusk of evening or early morning to the flowers of the evening primrose and other flowers with deep throats. It uncurls its long, long tongue, longer by far than that of a bee or wasp or even a butterfly, and finds precious nectar in the heart of the deepest flower. Sometimes it visits gardens in a city, and then you may see it shoot around the corner of the building, fast as a hummingbird, hover above a flower with buzzing wings and dip down with its tongue for the delightful sweets.