44 6 
The Moths and Butterflies 
three or four white spots appear; in some specimens the hind wings have 
a narrow broken border of scarlet on the under side. 
Of the yellows, or sulphurs, the most familiar in the eastern states is 
Eurymus philodice, the clouded sulphur, expanding i| to 2 inches; the 
wings are pale sulphur-yellow with black outer borders and with a discal 
black spot on each fore wing and orange spot on each hind wing; in the 
female the black border of the fore wings is very broad and contains five or 
six irregular yellow spots. Similar in pattern, but with the ground color of the 
wings bright orange instead of pale yellow, is the orange-sulphur, E. eury- 
theme, common through all the West. Both of these species are polychro¬ 
matic and polymorphic, that is, show marked variation in ground color and 
in size, some individuals called albinos being white, some called negros 
being suffused with blackish; some are very small, others unusually large. 
A variety of names has been given to some of these aberrations because 
of their regular appearance under certain seasonal conditions. The longi¬ 
tudinally striped green larvae of both species feed on clover. Another com¬ 
mon sulphur in the southern and western states is the dog-face, large with 
pointed-tipped front wings and the yellow color of these wings so outlined 
by the black base and broad border as to produce a rough likeness to a dog’s 
head seen in profile; a small discal black spot serves as the eye. The south¬ 
ern species is Zerene ccesonia (PI. V, Fig. 10), the Pacific coast species Z. eury- 
dice. The caterpillars, which are green with a whitish longitudinal stripe and 
a transverse dark line on each segment, feed on various Leguminosae. Another 
common southern and western species is Terias nicippe , the black-bordered 
orange (PL XI, Fig. 2), whose larvae feed on cassia. A striking species 
is the cloudless sulphur, Catopsila eubule , the largest of the Pierids, expand¬ 
ing 2\ inches; it occurs in the southern and southwestern states, its larva 
feeding on cassia. At the other extreme in size is the dainty sulphur, 
Nathalis iole , (PI. V, Fig. 7), the smallest member of the family, expanding 
but 1 inch; it has the same range and food habits as the cloudless sulphur. 
In the western states occur seven or eight species of the pretty little 
Pierids known as orange-tips; only one species, Synchloe genutia (PI. XI, 
Fig. 3), is found in the east. All are small and most of them are readily 
distinguished by the characteristic orange-colored apex of the fore wings 
as shown in the colored figure of genutia. S. sara, with two named varie¬ 
ties, reakirtii and sara , is the commonest western species. The larvae of 
the orange-tips, so far as known, feed on Cruciferae. 
Perhaps the most striking and admired of all familiar insects are the 
great swallowtail butterflies. They have an easy, half-fluttering, half-soar¬ 
ing flight; their unusual size and their black and yellow (or greenish-white) 
tiger-like markings make them so conspicuous that they are fascinatingly 
apparent to the most casual observers. Twenty-one different swallowtail 
