Psyche 
[September 
1 68 
of the second molt. The third instar has the head, anal region, and 
prolegs a dull orange color and body uniformly green. 
The body is covered by sparse hair. The larva is about 14 mm 
long at the third molt. The fourth instar (Fig. i-D) is uniformly 
dark green throughout the head, body, anal region, and prolegs. The 
head and body are covered by a dense down of short red hairs. The 
head is now noticeably wider than the body, which tapers towards 
the anal region. At the time of the fourth molt, the larva is about 
20 mm long. The fifth (final) instar (Fig. i-E) is very similar to 
the previous instar, but the head is gray-green and the spiracles are 
bordered in red. Both head and body retain the dense reddish down 
seen in the previous instar. The larva measures about 28 mm in 
length by pupation. 
Until the day preceding eclosion, the elongate pupa (Fig. i-F) 
remains light green; after this, the pupa darkens and the wing-pat- 
tern becomes visible (Fig. i-G). The pupa is about 21 mm long. 
Sexual dimorphism in wing coloration is pronounced; Fig. i-H 
shows the dorsal and ventral aspects of a female. The large light 
dorsal forewing areas are yellow in females and white in males (and 
reduced), and the distal series of three small spots of the female are 
cream. In the female, the large light area on the dorsal surface of 
each hindwing is bright yellow, while in the male this area is larger 
and whitish. Ventral markings of both sexes are remarkably similar. 
The forewing length of wild-caught (10 individuals) adults is 
29.4 ± 1.2 mm. It should be emphasized that the lighter dorsal 
regions of the wings are not creamy-white, which is characteristic of 
D. virgo. The wings of females bear a yellow color very similar to 
that of a sympatric ithomiid, Oleria zelica pagasa (see below). 
As commonly noted in butterflies, developmental time is strongly 
affected by whether larvae feed on young or old leaves (Table 1). 
The leaves of the larval host plant are of two kinds : ( 1 ) tough, 
older green leaves, and (2) soft, young red leaves at the apex of the 
plant. Eggs are found in the field on both kinds of leaves, but 
usually not on older leaves when young leaves are present on an in- 
dividual plant. The individual host plants studied at Cuesta Angel 
did not have young leaves during the study period, whereas exten- 
sive flushes of young leaves were found on several individual plants 
at Bajo la Hondura, but only after the middle of July. Individuals 
reared on young leaves of I. pittieri complete development sooner 
than individuals reared on older leaves (Table 1). This effect of 
leaf age is significant, as indicated by a / test (P<0.05). The in- 
dividuals used to measure this effect were obtained from eggs seen 
