180 INSECTS INJURIOUS TO STAPLE CROPS, 



as, and is still, an important enemy of fruit-trees, more 

 especially on the Pacific coast and in the Western States, 

 but also in other sections of the country. The most 

 injury seems to have been done to clover in the Central 

 States as far south as Tennessee, though it has suffered 

 somevi^hat even in the East. 



When attacked by the mite the leaves of the clover or 

 fruit-trees become yellow and have a sickly appearance, as 



Fig. 99. — The Clover-mite {Bryobia pratensis). 



if affected with a fungous disease. Especially upon the 

 upper sides of the tender leaves of clover the juices are 

 extracted over irregular areas, looking more or less like 

 the burrows of some leaf-mining larvae. Owing to the 

 small size of the mites they may be doing considerable 

 damage to the foliage and yet remain unnoticed; but in 

 the egg stage the pest is much more readily detected and 



