THE MOUTH PARTS, OR BEAK. 
53 
The upper lip is comparatively short, and serves its normal purpose 
as a covering- for the adjacent parts of the mouth. What correspond 
to the short, powerful biting jaws of gnawing insect- are in the Cicada 
greatly elongated and thread like, and brought together to form a sort 
of piercing and sucking apparatus, which is inclosed in the greatly 
elongated lower lip. The latter is three-jointed and deeply grooved 
above so as to be almost tubular, and acts as a support and sheath for 
the piercing seta like jaws, and also assists in conveying the liquids 
from the point of contact with the plant to the month cavity. The long 
lower lip just described is the piercing beak in popular belief, yet in 
Fig. 22.— Hea<l and prothorax of Cicaila. lateral view, with parts separated t<> show .structure: T. a, 
clypeua, b and e, labium, J. epipharynx: I . same from beneath: II, mandible, a. base, b. sheath for 
seta, c, mandibular seta, e . muscular base of latter: III. maxilla with parts similarly lettered: IV. 
labium, with three joints as follows, a. submentum. b, mentum. c. lignla; the hypopharynx. is shown 
at d, from side, d . from above, and d , from beneath: V, prothorax (author's illustration). 
point of fact it never enters the tissues of the plant, the puncture being 
made solely by the line, stiff, needle-like jaws or seta-, which can be 
projected at will by the insect with great force from the tip of the beak. 
(See figs. 20, 21, and 22.) 
In the periodical Cicada no food is taken in the adult winged stage 
as a rule. Some observers insist that the females, which arc longer 
lived than the males, pierce certain plants and sustain themselves on 
plant juices, but this is certainly in very small amount and is not con 
lirmed by the majority of observers. (See p. 72.) The male is very short 
lived and certainly never feeds, and taken altogether, therefore, the 
feeding by the emerged insect is insignificant in amount and not of 
practical importance. Throughout the long adolescent period, how- 
ever, comprising the larval and pupal existence of the insect under 
