Jan. 5, 1924 
45 
The Argus Tortoise Beetle 
LARVA 
The larva (fig. i, b; PI. 1, A, b; B) may be described as follows: 
Head prominent, dark brown, outline of basal half semicircular; eyes small, black; 
mandibles prominent, darker brown, width of head about 1.6 millimeters; surface 
with numerous short bristles. Thoracic plate nearly twice as long as wide, each half 
irregularly pentagonal. Body dull light yellow, strongly marked with numerous 
dark brown, nearly tuberculate spots; its form, including thorax, robust, less than 
twice as long as wide, somewhat depressed, armed with long prominent lateral spines, 
14 on each side as follows: 4 thoracic, first pair directed forward and upward above 
head, second pair at acute angles and semierect and two pairs at right angles; 8 abdom¬ 
inal spines, slightly curving upward at apex, 2 anal spines erect. Each spine wide at 
base and light colored in basal half with strong lateral spines, apical half acuminate, 
black. Dorsum of abdominal segments each with two rows of transversely rounded 
oblong tubercles, those of first three segments largest, size diminishing posteriorly. 
Anal segment with well defined dark brown plate about twice as long as wide, ter¬ 
minating in a long proleg rounded at apex. The feci-fork is usually held slanting back 
from the body and rarely vertical or over it. 
Lower surface with a median row of 5 small, rounded, longitudinal brown spots on 
segments 2 to 6, 6 to last with transverse dark-brown marks, growing stronger to last 
segment, posterior third more or less marked with dark brown. Legs long and stout, 
dark brown, blackish when folded. 
Length of full-grown larva without feci-fork 7 millimeters (about inch), width 
4.5 millimeters. 
Fig. 2.—Eggs of the argus tortoise beetle: a. Mass of eggs, attached to leaf; b, c, individual eggs before and 
after hatching. 
PUPA 
The pupa (fig. 1, c, d; PI. 1, A, c) is pale yellow, marked with dark brown, becoming 
nearly black toward the time of transformation to adult. The surface is nearly covered 
with a pale bluish bloom or waxy secretion resembling a mold, a peculiar covering not 
often seen in any other group of beetles. The ventral surface is somewhat flattened 
and the dorsal surface is convex. The thorax projects strongly at each side, being a 
little wider than the widest abdominal segment. It is armed apically with two short 
spinous processes in the proximal third. The antennal sheaths and legs are robust, 
the posterior pair being about as long as the elytral sheaths. The body is armed on 
each side with five long and strong black-tipped spines similar to those of the larva, the 
first pair situated about the midafle of the body. The first two pairs are subequal in 
length and the remaining pairs decrease in length posteriorly. There are also two 
pairs of short unicolorous spines toward the apex. The cast skin of the larva with its 
spines is rolled up in a mass at the posterior extremity. 
Length 8 millimeters, width 4.5 millimeters. 
DISTRIBUTION 
The Argus tortoise beetle is a native species inhabiting, a large portion 
of the United States. It also occurs in Canada. The species does not 
appear to be recorded from Mexico, but several related species occur 
there. The known distribution, including what at present are con¬ 
sidered varieties, is shown in Figure 3. 
