214 



Marvels of Insect Life. 



legs for crawling through the earth, but in later life, when the soft hind- 

 body has grown fat, they cannot do much in this direction, but lie with 

 the body doubled up, and eat such roots as are within reach. It can content 

 itself with the roots of grass or corn, but if the farmer is growing mangold- 

 wurzel or beet above its birthplace, the white-grub, as it is called, will destroy 

 the crop. They moult several times during the three or four years in which 

 they assiduously work for the farmer's ruin, and when they feel they have accom- 

 plished all they can, they retire into deeper earth and hohow out an oval cell, in 

 which they become chrysalids. The period of the grub stage varies in different 

 parts of Europe according to the geographical position. In Britain it is about 

 four years, in Central Europe three years, and in Northern Europe five years. 



I'hoto by] 



[H. Bastin. 



C (K KLHAl-EK ItRI 1', 



That the protected underground life and the interminable meal of roots agrees with this grub is manifest. After three or four years 

 of feeding they attain almost to the size shown here, and are so plump that their legs are of little use c.\cept for holding their food 

 whilst they gnaw at it. 



In a series of dry summers, when the roots are not so succulent, the period 

 will be lengthened. 



We occasionally experience what local devastation this grub can cause in our 

 own country, but it is scarcely worth mentioning when compared with what it 

 has effected in other countries. There are plenty of statistics available giving the 

 amount of damage done in various places at divers times, and the quantities by 

 weight and count of the cockchafers that have been caught and killed where a 

 resolute war has been waged against them. Thus in the years 1857, i860, and 1862, 

 the crop of beet in the department of I'Aisne (France) was sixty per cent, below the 

 average yield of years when there were few cockchafers in the ground, and the 

 reduction was attributable solely to the ravages of the white-grub. Again, in 

 1866, the authorities of the dcpartm.ent of the Seine- Inferior estimated the loss 



