226 I.N SECT TRANSFORMATIONS. 



defoliated by them ; and Salisbury says, the leaves of 

 the oaks in Richmond Park were so eaten by them, 

 that scarcely an entire leaf was left. But it is in their 

 previous larva state that they are most destructive, as 

 we shall see by tracing their history. 



The mother cockchafer, when about to lay her eggs, 

 digs into the earth of a meadow or corn-field to the 

 depth of a span, and deposits them in a cluster at 

 the bottom of the excavation. Rosel, in order to 

 watch their proceedings, put some females into glasses 

 half-filled with earth, covered with a tuft of grass, 

 and a piece of thin muslin. In a fortnight, he found 

 some hundreds of eggs deposited, of an oval shape 

 and a pale yellow colour. Placing the glass in a 

 cellar, the eggs were hatched towards autumn, and 

 the grubs increased remarkably in size. In the fol- 

 lowing May they fed so voraciously that they required 

 a fresh turf every second day ; and even this provmg 

 too scanty provender, he sowed in several garden- 

 pots a crop of peas, lentils, and salad, and when the 

 plants came up, he put a pair of grubs in each pot ; 

 and in this manner he fed them through the second 

 and third years. During this period they cast their 

 skins three or four times, going for this purpose 

 deeper into the earth, and burrowing out a hole where 

 they might effect their change undisturbed ; and they 

 do the same in winter, during which they become 

 torpid and do not eat. 



When the grub changes into a pupa, in the third 

 autumn after it is hatched, it digs a similar burrow 

 about a yard deep ; and when kept in a pot, and 

 prevented from going deep enough, it shows great 

 imeasiness and often dies. The perfect beetle comes 

 forth from the pupa in January or February ; but it 

 is then as soft as it was whilst still a grub, and does 

 not acquire its hardness and colour for ten or twelve 

 days, nor does it venture above ground before May, 



