OVIPOSITION AND ITS EFFECT ON THE PLANT. < 5 
the apple among the fruit trees. Any plant which presents itself is, 
however, accepted, often herbaceous ones and occasionall; ens, 
although the sticky resinous sap of the latter stems to be distasteful 
to these insects. Xo careful, complete list of plants in which they ovi- 
posit lias been made, although several observers have made rather 
extensive lists, notably Mr. Butler and Mr. Davis, the latter having 
observed the Cicadas laying their eggs in between seventy and eighty 
trees, bushes, and herbaceous plants on Staten Island in L 894, and 
states also that he had evidently not nearly reached the limits of plants. 
In some cases even the large petioles of plants, like the horse-chestnuts, 
had been oviposited in. A list of plants could be given which have 
been put on record, but it would have but little value, as in every dis- 
trict in which they appear they will oviposit in practically all plants 
which come their way. with the exception of pines, as already stated, 
which are ordinarily exempt. 
That they are not very choice in this matter is shown by a case of 
faulty instinct reported by Mr. Hunter Nichols, who observed a female to 
alight on the iron rod of a bridge and attempt to insert her eggs, even 
extruding them to the number of seven, some of whichremained attached 
to the rod and the others falling to the ground. Other similar eases of 
error on the part of the insect are noted by Mr. Davis. In one instance 
a female had attempted to insert her eggs in the very hard stem of 
catbriar (Smilax rotund) folia) and in another place had thrust her 
ovipositor entirely through the stem of a plant only to hud that it was 
hollow. 
The part of the plant selected for a receptacle for the eggs is almost 
invariably the twigs of the previous year's growth. When larger limbs 
are chosen, as occasionally happens, the female evinces her dislike for 
them by constructing only a nest or two instead of the long series of 
slits which are usually characteristic of her work on limbs of newer 
growth. 
RESULT TO THE PLANT OF OVIPOSITION. 
The effect on the plant of the cutting of the smaller twigs by the 
female in depositing her eggs has been often described, and is apt to 
be especially noteworthy and disastrous in the ease of such favorite 
trees as the oak. hickory, and apple, and in the case of the latter, espe- 
cially in young orchards surrounded by woods, or in recent clearings. 
(See tig. 30.) The weakening of the twigs by the punctures causes many 
of them to be partly broken otf by the winds, and the brown, withered 
leaves are conspicuous for the remainder of the summer. Many oH the 
twigs break otf entirely and tall to the ground, and the general twig 
pruning which results is often of considerable extent, giving the for- 
ests, as sometimes described, a gloomy appearance, or as though 
scorched by tire, from the number of the extremities of twigs thus 
injured. With large shade trees, and particularly trees in forests, 
the damage is not often excessive, and the recovery is usually complete, 
