218 



AGRICULTURE ON THE PACIFIC SLOPE 



the season. They 

 feed on the leaf by 

 sucking its juices, 

 and thus produce 

 white spots ; the 

 leaves often turn 

 yellow and fall off. 

 Only when there 

 are a great many of 

 them do they do 

 much damage. A 



P art f 



FIG. 125.-Vine hopper; the empty skin out 



of which it has just crept (seen on the left) can be CaUght by 

 is smaller than the insect. (Enlarged.) 



means of a hopper 



cage (described in Bulletin 192, mentioned below). 

 Spraying is also useful. (California Experiment Sta- 

 tion, Bulletins 116 and 192, 1897, 1907.) 



FRUIT THRIPS 



This very tiny insect, which is only about half as 

 as a plant louse, spends eleven months of the year 

 underground. It comes out when the fruit trees begin 

 to blossom and feeds upon the flower buds. It attacks 

 the inside of flower buds and sucks out the juices so 

 that they do not open. It damages especially the 

 pears and -prunes. No good remedy is known^ 



A different sort of thrips attacks onions and beans, 



