METHOD OF INSERTING THE EGGS. ~ 109 
METHOD OF INSERTING THE EGGS. 
The work of the female Cicada in inserting her eggs is an interesting 
subject for study, and so little does she mind the presence of an 
observer that the operation can be closely watched without her exhib- 
iting any alarm. The position taken is almost invariably with the 
head upward or directed toward the tip of the branch, the work being 
steadily prosecuted in that direction. When her course is interfered 
with by the occurrence of side shoots, instead of moving to one side 
or the other she reverses her position and thus extends her row of 
punctures in a straight line completely to the base of the intervening 
shoot. The branch selected is ordinarily of a size which the female 
can surround and clasp firmly with her legs to give her the strong 
attachment necessary to enable her to force her ovipositor into the 
woody tissues. 
The exact method of making the egg fissure and depositing the eggs 
has hitherto, in the 
main, been either 
very briefly referred 
to, or the actions of 
the insect have been 
inaccurately — inter- 
preted. The descrip- 
tion of this process, 
hitherto generally ac- 
cepted and quoted, 
is that given by Doc- 
tor. Harris, substan- 
Cc 
tially as follows: Fig. 44.—Egg nest of the periodical Cicada: a, recent puncture, front 
ae view; 5, same, surface removed to show arrangement of eggs, from 
Raising her body above; c, same, side view; d, egg cavity exposed after eggs are 
somewhat above the removed, and showing the sculpture left by the ovipositor. All 
enlarged (after Riley). 
twig, the point of her 
ovipositor is brought to bear on the bark at an angle of 45 degrees, 
and is thrust slowly and repeatedly into the bark iia wood, the two 
lateral saws working in alternation. When fully inserted he instru- 
ment is pried upward by a motion of the abdomen, raising and loosen- 
ing in this way little fibers of wood which, remaining attached, form 
a sort of covering for the egg fissure or nest. The cutting normally 
extends nearly to the pith or about one-twelfth of an inch in depth, 
and is continued until space is made to receive from ten to twenty 
eggs. After preparing the egg nest as described, the female moves 
back to the point of commencement and again abaeste | in her oviposi- 
tor, using the two side pieces as grooves or channels to convey the 
eggs into the twigs, where they are placed in pairs, separated by a 
central tongue of woody fiber, which has been left undisturbed, and 
which is wider at the bottom than at the top. Two eggs having been 
