54 



MASS. EXPERIMENT STATION BULLETIN 353 



greens. Egg laying continues until about mid-August. One to 4 eggs are de- 

 posited, usually at night, in holes 2 to 4 inches deep. The beetles feed during the 

 day. They may be seen feeding on plants until early fall although the peak of 

 the feeding season occurs in late July or early August. The eggs hatch about 2 

 weeks after they are laid. The larvae then feed on the smaller plant roots. They 

 often grow to be about % to 1 inch long before cold weather. The grubs usually 

 feed in the upper 3 inches of the soil, but as winter approaches they go deeper 

 to hibernate. 



POINTS AT WHICH JAPANESE BEETLES 

 HAVE BEEN FOUND UP TO AND INCLUDING 

 THE YEAR 1935. 



^B AREA CONTINUOUSLY INFtSTED BY NATURAL SPREAD. 

 IV ail LOCALIZED COLONIES OR POINTS OF MINOR OCCURRENCE. 



Courtesy, Bur. Ent, and Plant Quarantine, U. S. Dept. Agr. 



Control. The Japanese beetle is not an easy insect to control. For best results 

 the cooperative efforts of all persons living in a region of infestation are essential. 

 In Japan where the beetle is native, it is not an important pest, probably because 

 favorable host plants are limited there and native parasites help to hold it in 

 check. The United States Government is introducing the more promising of 

 these parasites to help control the beetle in this country'. 



Protecting the foliage. — To protect shade trees from defoliation by the adult 

 beetles it is necessary to keep a coating of poison on the leaves just before and 

 throughout the fl>ing season of the beetles. The protection is obtained primarily 

 by repelling the beetles rather than by poisoning them. For this purpose a spray 

 composed of 6 pounds of acid lead arsenate with 4 pounds of wheat flour or IJ^ ■ 

 pints of light pressed fish oil added to 100 gallons of water is recommended. ■ 

 In case it is not desirable to use lead arsenate, a spray composed of 3 pounds of 

 aluminum sulfate and 20 pounds of hydrated lime in 100 gallons of water may be 

 used. Where the beetles are abundant it may be necessary to repeat the spray 



