230 BUTTERFLIES 



must go to the tropics to see the culmination of what nature 

 has done in painting the outstretched membranes of 

 butterfly wings with gorgeous colors. The great butterfly 

 tribes that swarm in tropical forests seldom reach our tem- 

 perate clime, and even when they do they are likely to 

 show only a suggestion of the splendid size and rich color- 

 ing to be seen farther south. The Zebra butterfly 

 {Heliconius charitonius) belongs to one of these tropical 

 tribes. It shows its affinities by its coloring and the 

 curious shape of its wings. In most of our northern but- 

 terflies, the wings are about as long as they are wide, but 

 in the tropical family, Heliconidae, they are very much 

 longer than wide. This gives the insect an entirely 

 different look from our common forms so that one recog- 

 nizes it at once as a stranger within our gates. Indeed, it 

 does not penetrate far into our region, being found com- 

 monly only in Florida and one or two other neighboring 

 states, its principal home being in tropical America. 



The Zebra butterfly is well named. Across the brown- 

 ish black wings there runs a series of yellow stripes, three 

 on each front wing and one on each hind wing, with a sub- 

 marginal row of white spots on each of the latter. The 

 under surface is much like the upper, except that the color- 

 ing is distinctly paler. It is very variable in size : some 

 specimens may be but two and a half inches across the 

 expanded wings, while others are four inches. {See plate, 

 page 22 1^.) 



The Zebra caterpillars feed upon the leaves of the pas- 

 sion flower. When full grown they are about an inch and 

 a half long, whitish, more or less marked with brownish 

 black spots arranged in transverse rows, and partially 

 covered with longitudinal rows of barbed black spines. 



