158 



species of the genus is the first joint above the elbow of the an- 

 tenna which is longer than the second. 



In the four years during which I have watched this insect 

 the beetles have always appeared on the chestnut trees early in 

 August, or about two weeks after chestnut blossoms disappear 

 normally from the trees. By the middle of August they are 

 usually abundant and may be found collected about the young 

 chestnut burs. From the middle to the 25th of the month, or, 

 at about the time the tender kernel begins to form in the nut, 

 egg-laying begins and is continued for a period of from five to 

 seven weeks. As the fall advances the beetles gradually decrease 

 in numbers, the last of the generation disappearing late in Octo- 

 ber, often, not until several severe frosts have occurred. I have 

 found two adults on the trees as early as August 8th and one 

 year collected several from open chestnut burs on October 26th. 

 These are my earliest and latest seasonal records of finding the 

 adults. 



The following table shows the dates and progress of the 

 transformation from larvae to adults of over a hundred indi- 

 viduals under perfectly natural conditions. The table shows the 

 state of development in which the insects were found at seven 

 different times during the summer in the soil beneath bearing 

 chestnut trees. 



TABLE SHOWING DEVELOPMEENT OF LARGER CHESTNUT WEEVIL. 



Date. Larvae. Pupae. Adults. Remarks. 



July 1 18 (Pupation not begun.) 



July 8 10 5 (Pupation begun.) 



July 26 31 11 8 (Pupae beginning to change to adults.) 



Aug. 1 12 9 (All pupae changed to adults.) 



Aug. 10 29 4 (Adults leaving ground.) 



Aug. 23 16 (All adults out of ground.) 



Aug. 28 13 (All adults out of ground.) 



The above records were obtained in 1906. There seems to 

 be some variation in the time the insects mature and leave the 

 ground in different years but this variation is not great. The 

 table indicates that the change from larva to pupa begins about 



