184 Bugs, Cicadas, Aphids, and Scale-insects 
with the natural reddish green of the uninjured bark. With the second 
moult the females do not change materially from 
their former appearance, retaining the pale-yellow 
color with a number of transparent spots around 
the edge of the body. The sucking-bristles are 
extremely long, two or three times the length of the 
body of the insect. 
“About twenty days after birth the male insect 
transforms to the true pupa. With the first moult 
the shed larval skin is retained beneath the scale 
as in the case of the female; with the later moult- 
ings the shed skins are pushed out from beneath 
the scale. The scale, after the second moult, pre¬ 
sents on the inside two longitudinal ridges run¬ 
ning from one end to the other, touching the sides 
of the pupa, and which apparently enable the 
insect to move backward or forward and assist the imago in pushing itself 
out. 
“The true pupa is pale yellow, sometimes purplish, darkened about 
the base of the abdomen. The head, antennae, legs, wing-pads, and style 
are well formed, but almost colorless. . . . 
“From four to six days later, or from twenty-four to twenty-six days 
from birth, the males mature and back out from the rear end of their 
scales, having previously, for a day or two, remained practically developed, 
but resting under the scale. They seem to issue chiefly by night or in 
the evening. 
“The mature male (Fig. 252) appears as a delicate two-winged fly-like 
insect with long feelers and a single anal style projecting from the end of 
the body; orange in color, with a faintly dusky shade on the prothorax. 
The head is darker than the rest of the body, the eyes are dark purple, and 
the antennae, legs, and style are smoky. The wings are iridescent with 
yellow and green, very faintly clouded. 
“Thirty days from birth the females are full grown and the embryonic 
young may be seen within their bodies, each enclosed in a delicate mem¬ 
brane. At from thirty-three to forty days the larvae again begin to make 
their appearance. 
“The adult female, prior to the development of the young, measures 
one millimeter in length and a little less in breadth, and is pale yellow with 
transparent spots near the margin of the body (Fig. 252). 
“The length of a generation is determined by the female, and, as shown 
by the above record, covers a period of from thirty-three to forty days. Suc¬ 
cessive generations were followed carefully throughout the summer, and 
h 
Fig. 252.—The San 
Jose scale, Aspidiotus 
perniciosus. a , male; 
b, adult female. 
(Much enlarged.) 
