ORTHOPTERA. 



189 



Fig. 266. —Mlcrocentrwm retinervis ovipositing. 



each side so as to form an edge. This operation is accompanied by a sudden, nervous 

 shake of the body from side to side, and lasts sometimes but two or three minutes, 

 sometimes more than ten. When the 

 operation is accomplished to her satis- 

 faction, she clutches with her front feet 

 the stem to be used, and anchors the 

 middle and hindmost feet for the most 

 part upon contiguous leaves or branches, 

 and often quite wide apart. Then, if 

 she has her head in an upward direc- 

 tion (for it seems to be immaterial to 

 lier whether the eggs are placed from 

 below up or vice versa), she begins at 

 the lower end of the lower portion of 

 the twig, and, after fretting it anew 

 with her jaws and measuring and feel- 

 ing it over again and again with her 

 palpi, as if to assure herself that all is 

 as it should be, she slowly — with much 

 apparent effort, and not without letting 

 it partly fall several times — curls the 

 abdomen under until the lower edge of the ovipositor is brought between the jaws and 

 the palpi, by which it is grasped and guided to the right position. It is then Avorked 

 slightly up and down for from four to six minutes — all the time guided by the jaws — 

 while a shiny viscid fluid is given out apparently from the ovipositor. Finally, after a 

 few seconds' rest or suspension of this work, the egg gradually rises, and, as it passes be- 

 tween the ovipositor, turns so that one end appears almost simultaneously, from between 

 the convex edge, with the other from the lower tip, of the blade. The egg adheres to 

 the roughened bark in an oblique position. It is at first almost black and highly var- 

 nished, but it acquii-es its normal gray color within eight or ten hours. After the egg is 

 placed the abdomen is straightened out, and the insect rests for a few moments, soon, 

 however, to resume her efforts and repeat the like performance, in every particular, except 

 that the second egg is placed on the opposite side of the twig and a little above the 

 first one. The third egg is pushed in between the top of the first one and the twig, 

 the fourth between the top of the second, and so on, one each side, nlternately. Thus 

 these eggs are not laid, as we might naturally imply, one over the other, but, rather, 

 one under the other; i. e., each succeeding pair having their ends thrust in between i 

 the tops of the preceding pair, the teeth at the end of the ovipositor lielping to crowd 

 the end into place. 



" The number of eggs laid at one time varies from two to thirty, the first batches 

 containing more than those deposited later in the season. Each female produces from 

 one hundred and fifty to two hundred, or perhaps more, and I have known them to 

 lay on the edge of a leaf, or of a piano-cover, or a long piece of cord. 



" These eggs, as already remarked, are rather flat when laid, but become more 

 swollen, so that they have a narrower look as they approach the period in springs 

 During the early part of May the embryo larva — which lies straight in its egg, com- 

 pletely filling it, with the legs bent up as in a pupa, and the long antennae curling 

 around them — attains its full development, and after hours of tedious contracting 



