4 



CIRCULAR 2 3 7, U. S. DEPARTMENT OF AGRICULTURE 



that the ordinary sprays have on the beetle. The beetle is controlled 

 mostly by the prevention of feeding, and the term " protection " or 

 " control " in this circular therefore refers to the repelling effect 



Figure 3. — Diagrammatic representation of the annual life cycle of the Japanese beetle 



of the spray deposits on the plant rather than to the destruction of 

 large numbers of beetles. Some feeding does occur, but unfortu- 

 nately only about 30 per cent of the beetles which feed on the 







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Figure 4. — Unsprayed and well-sprayed foliage. This figure illustrates the deposit 

 on foliage which is necessary to control the Japanese beetle 



poisoned plant consume a toxic dose. The majority of beetles in 

 the vicinity of sprayed foliage are repelled before alighting. 



Thoroughness and timeliness of application of the sprays are more 

 important in the control of this insect than is the ingredient used 



