86 
THE PERIODICAL CICADA. 
the soil, facilitating its climbing trees or other objects; in other words, 
covering the periods between the hatching and entering the soil and 
between the emergence of the pupa and the disclosure of the imago. 
During its long subterranean life, however, these long, slender tarsi, 
being distinctly in the way in 
digging in the earth and of no 
service, become rudimentary 
with the first molt and nearly dis- 
appear in the subsequent larval 
stage. They reappear in the first 
pupal stage, but in this and the 
subsequent pupal stage, while 
the insect is still below the soil, 
they are folded back along the 
tibiae, so as to be practically func- 
tiouless (see fig. 40), and are only 
unfolded and brought into serv- 
ice after the pupa has emerged 
from the ground. 
The more detailed description 
of the different stages which fol- 
lows will facilitate the easy 
recognition of any particular 
stage. The chief points to be 
considered in determining both 
the age of the larva and whether 
or not it belongs to the periodical 
species are the measurements of 
the corresponding parts of the 
legs and antenna 1 , but particularly the variation in the structure of 
the peculiar comb like organ which is found on the apical margin of the 
front femora, together with the important differences in the hairy 
covering of the body and legs. 
TECHNICAL DESCRIPTION OF THE DIFFERENT STAGES. 
First larval stage. — The newly hatched larva (fig. 3ti, a) is about 1.8 
mm. long from tip of head to the extremity of the abdomen, is rather 
slender and of a nearly uniform thickness throughout, presenting, how- 
ever, the general characteristics of the later larval stages. The body is 
clothed with numerous scattering long hairs. The general color is 
creamy white, with prominent, deep red, almost black, eye spots. The 
antennae, beak, and legs are, relatively with other stages, very large in 
comparison with the size of the body. The anterior femora are developed 
in general as in the later stages, though lacking the comb-like organ 
and the minute second subapical tooth which appears in the fourth stage, 
and the first tooth from apex is somewhat more pointed than in later 
stages. The anterior tibia are also more slender and the mandible-like 
Fig. 3C— First larval stage : o, newly hatched larva ; 
b, antenna of same: c, larva eighteen mouths old: 
d, enlarged anterior leg of same (original). 
