23 



leaving the egg at the surface. She would then turn immediately and 

 devour the egg. After that, seeming conscious of her failure and 

 aware of the cause of it, she would proceed to find and enlarge some- 

 what the cavity j)reviously made. When this was completed she would 

 attempt to place another egg therein. The second attempt was usu- 

 ally successful, but in one or two cases a female was seen to fail several 

 times, and in moi-e than half of these cases she ate the eggs, as has 

 been described. 



PERCENTAGE OF EGGS THAT HATCH. 



Definite records were not kept upon this point, but in the many 

 hundreds of eggs followed during these observations very few failed 

 to hatch, though some were much slower in embryonic development 

 than were others laid at the same time and by the same female. It 

 is the writers' general impression that less than 1 per cent of the eggs 

 are infertile or fail to hatch. 



THE LARVA. 



DESCRIPTION. 



The young larva, upon hatching from the egg, is a delicate, white, 

 legless grub of about 1 mm. {,,\ inch) in length. Except for the 

 brown head and dark-brown mandibles, the young larva is at first as 

 inconspicuous as the egg from which it came. As it feeds and grows 

 it continues to enlarge a place for itself in the square or boll until 

 the food supply has become exhausted or the vegetable tissues 

 are so changed as to be unsuitable for food. By this time, as a rule, 

 the interior of the square has been almost entirelj^ consumed and the 

 larval castings are spread thickly over the walls of the cavity (PL 

 III, fig. 15). This layer becomes firmly compacted by the frequent 

 turning of the larva as it nears the end of this stage. In the cell 

 thus formed occur the great changes from the legless grub to the fully 

 formed and perfect beetle (PI. I, figs. 7, 8, and '.)). 



Throughout this stage the bod}^ of the larva preserves a ventrally 

 curved crescentic form (PI. Ill, fig. 1(3). The color is white, modi- 

 fied somewhat by the. dark color of the body contents, which show 

 through the thinner, almost transparent, portions of the body wall. 

 The dorsum is strongly wrinkled or corrugated, while the venter is 

 quite smooth. The ridges on the dorsum appear to be formed largely 

 of fat tissue. After becoming full-grown the larva ceases to feed, 

 the alimentary canal becomes emptied, and both the color and form 

 of the larva are slightly changed. The dark color disappears from 

 the interior and is replaced by a creamj^ tint from the transforming 

 tissues within. The ventral area becomes flattened, and the general 

 curve of the body is less marked. Swellings may be seen on the sides 

 of the thoracic region, and when these are very noticeable pupation 

 will soon take place. 



