110 DISEASES OF CROPS. 



potash, and nitrogen (eitter in the form of nitrate of soda 

 or ammonium sulphate). Farmers should bear in mind 

 an old saying attributed to Arbuthnot, that " he who 

 sows his grain upon sand will have many a hungry belly 

 before his harvest." When soils are properly manured, 

 healthy and vigorous crops are the result. Such crops 

 are better capable of battling with the various destructive 

 insects than those grown upon impoverished or poor soils. 



The Cockchafer (M. vulgaris), one of the largest 

 of the British Coleoptera} has already been described as 

 a pest of grasses. The larvse also feed upon the roots of 

 wheat and other cereal crops, often causing a considerable 

 amount of damage. 



The Corn Moth {Tinea granella) is found abun- 

 dantly in granaries in June and July, " when it lays its 

 eggs upon each grain. The young larvse, when hatched, 

 eat their way into the interior of the grain and feed in 

 concealment upon its substance ; but when this portion of 

 food is consumed, each larva unites three or four grains 

 together with a web, so as to form a little habitation, in 

 the interior of which it feeds." T. granella belongs to 

 the same tribe as the common clothes-moth. 



The Wheat Flour Moth (Ephestia kuhniella) has 

 only been known in England about three years. " In 

 1887 the caterpillars of this moth did great harm in some 

 large stores in London, and in 1888 the attack established 

 itself in a wheat-flour steam-mill in the north of England. 

 The great harm caused is by reason of the caterpillars 

 ' felting ' up the meal or flour by the quantity of web 

 which they spin in it. . . . This clogs the mill appa- 



' The Eev. Canon Fowler, M.A., P.L.S. (of Lincoln) informs the 

 author that, at least, 100,000 species of the Coleoptera are known. 



