1949] 
W erner — Epicauta 
97 
and in body size so that unusual specimens might be 
overlooked in the field. 
When one examines the distribution of the four species 
in Arizona, a region well-known for its diversity of habitat 
and life zones, he gets some clue as to the possible reasons 
for segregation. E. maculata, ranging across the Great 
Plains and even as far east as Ohio, extends its range 
westward south of the Rockies onto the Colorado Plateau, 
just north of the Arizona AVhite Mts., where it is quite 
abundant, feeding on the leaves of a species of Amaran- 
thus and Salsola. It also reaches the plateau to the north 
of the Huachuca Mts., where it is likewise abundant and 
feeds on the same or similar plants. On this plateau 
and nearby it is taken occasionally on Solanum elceagni- 
folium. The specimens on this plant tend toward smaller 
spots and more luteous pubescence than most populations 
and may represent a separate race. A series collected by 
Mr. Parker at Phoenix was feeding on Kallstrcemia. It 
does not seem to differ from normal specimens from other 
parts of the range. 
The record of E. nor mails is not as complete. It is 
found from the Rockies to the Sierras and seems to range 
farther north than maculata. It has been taken in the 
Chiricahua and Huachuca Mts. and at Willcox. No food 
plant records had been kept for these specimens. The 
Willcox series was mixed with maculata but no attempt 
had been made to segregate by food plant or exact locality. 
It seems possible that normalis usually is found at higher 
altitudes than its near relatives. Extensive collecting on 
the plateau in 1948 did not produce any specimens. 
E. no gales has turned up only in or near the Santa Cruz 
river valley and it is quite evident that it must have a 
more extended range in the adjacent part of Mexico. The 
other species have not been taken in this valley. 
The occurrence of the fourth species, E. bispinosa, on 
the plateau north of the Huachuca Mts. in an area where 
E. maculata also occurs abundantly, would be quite in- 
explicable were it not for some observations made at the 
time it was taken. Both species were abundant at a road- 
side stop 10 miles east of Sonoita. Maculata was feeding 
