52 



MASS. EXPERIMENT STATION BULLETIN 353 



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sf.-^ ' :t. 



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Japanese Beetle 



1. Grub. Greatly enlarged. 



2 and 3. Pupae, bottom and top views. Greatly enlarged. 



4. Adult beetle. Greatly enlarged. 



5. Injured elm leaves. 

 Courtesy, Robert L. Coffin. 



The newly deposited eggs are elliptical, translucent, creamy-white, and about 

 1/16 inch in diameter. After being in the ground a week they swell to twice this 

 size and become almost round. 



The newly hatched grub is about 1/16 inch long. When mature it is about 1 

 inch long and creamy-white in color. It is normalh curled into a U-shaped posi- 

 tion, the posterior portion being broadly rounded and slightly swollen. It re- 

 sembles the grub of the June beetle but may be distinguished from it by a V- 

 shaped arrangement of spinelike hairs on the hindmost abdominal segment, and 

 by other characters which can only be distinguished by microscopic examination. 



The pupa is similar to the grub in color and te.xture but, having all the adult 

 appendages closely appressed to its sides, has the general form of an adult. 



