THE MILKWEED BUTTERFLY 
4i 
Imago. The wing expanse varies from 100 mm. to 115 mm. 
in both sexes. Sexual difference is distinct. On the second 
median nervure of the hind wing in the male is a conspicuous 
patch of black androconial scales. The markings are usually 
broader in the female, but there is no black patch on the 
hind wing. 
The ground colour is deep amber, the neuration black, the 
margins of both wings broadly banded with black, enclosing 
two rows of white spots. The apical portion of the fore wing 
is clouded with black, and has four pale amber spots and 
five smaller white markings along the costa, also some white 
markings on the costa of the hind wing. The under side is 
similar in pattern and markings to the upper side, except 
that the marginal white spots are larger, and there are 
additional white spots at the base of the hind wing. The 
apex of the fore wing and ground colour of the hind wing 
are oclireous-yellow, inclining to buff. The head, thorax and 
abdomen are black, spotted with white ; the legs and antennae 
are also black. 
Life of Imago. Probably the life of this powerful butterfly 
is from six to eight weeks. 
Aberration. Aberration is chiefly in the development of 
the white spots, several being sometimes absent; also at times 
the spots are asymmetrical. In some specimens the apical 
space between the amber spots and marginal dots is almost 
entirely black; the amber spots are occasionally replaced by 
white. 
