THE HABITS OF THE LARVA AND PUPA. 91 
facts lose much of their significance when it is remembered that any 
vegetation, even annual, as of* farm crops, would supply ample root 
growth for the Cicada larva during the growing period of summer, and in 
the colder months they undoubtedly lie dormant in their earthen cells. 
Perhaps the first writer to point out and demonstrate the true 
method of feeding of the larva and pupa of this insect in their under- 
ground existence was Miss Morris, of Germantown, Pa. That the 
Cicada larva' and pupae pierce small roots with their sucking beaks 
and feed on the juices of the plant, as do other plant-feeding Bemip- 
terous insects, as their normal, if not their sole method of subsisting 
was fully proven by her investigation, and has been confirmed repeat- 
edly in the diggings made by the writer, and there can no longer be 
any possibility of doubt in the matter. In practically every case, in 
the writer's experience, where the cell in which the larva rested was 
taken out in condition for examination a small root, one sixteenth to 
three-sixteenth inch in diameter, was found to border usually the 
upper end of the cell, and in several instances larva' were found with 
their beaks so securely embedded in the root that they were not easily 
loosened. In other instances the roots showed unmistakable signs of 
having been punctured by the slight swelling and reddish discolora- 
tion beneath the bark. 
The root-feeding habit can best be witnessed in light, rich soils, and 
in the plantings of the brood of 1889 under oak trees on the Depart- 
ment grounds, the soil beneath these trees was so thickly inhabited 
that between the depths of and 12 inches every spadeful of earth 
would throw out numbers of the larva 1 , and a most excellent opportu- 
nity was afforded for the study of their habits. In hard, packed soils, 
perhaps scantily supplied with roots, the difficulty of getting out the 
cells in perfect condition is such that one might easily be led into 
error, and the comparative rarity of the larva' in such soils adds fur- 
ther to the difficulty of determining their feeding habits. 
It is for this reason, I have no doubt, that the opinion has obtained 
in some quarters that the larva' subsist not on the roots of plants, but 
on the nourishment obtained from the surface moisture of the roots, or 
the general moisture of the earth, which might be supposed to con- 
tain more or less nutrient material arising from the decomposition of 
the vegetable matter. That the moisture of the surrounding soil may, 
and doubtless does, supply the very delicate, thin skinned larva' and 
pupae with a certain amount of liquid by absorption through the skin 
may be admitted, and in fact when the larva' are taken from their nat- 
ural surroundings and exposed to the air they very rapidly dry and 
shrivel. Larva' are doubtless occasionally found in cells away from 
roots, and this may be explained by the fact of their being at that 
time either undergoing one of their long resting or hibernating periods, 
which may be of frequent occurrence in such an extremely long lived 
species, or they may be burrowing in search of roots on which to subsist. 
