ROTJNDHEADED APPLE-TREE BORER. 15 



PERIOD OF PUPATION. 



At French Creek, W. Va., practically all the individuals pass 

 through the pupal stage during the period from April 15 to May 15, 

 although the time of pupation and the duration of the stage depend 

 very much on weather conditions. The earliest pupa was found in the 

 field April 12, 1913, and the latest May 20, 1915, although undoubtedly 

 a few may sometimes occur before and after these dates. In the 

 locality mentioned, the entire pupal period for any one year has not 

 been found to extend over 30 days, the pupal stage for a single 

 individual averaging about 20 days. All transforming individuals 

 were found in the pupa stage at Demorest, Ga., on May 1, 1915 ; at 

 Winthrop, Me., on June 17, 1916; and at Munising, Mich., on June 

 20, 1917. 



As has been stated, the pupse are sensitive to temperatures, warm 

 weather accelerating and cold weather retarding the changes. After 

 transforming to the adult stage the beetles usually remain within 

 the pupal chamber from 5 to 10 days, the length of this period, too, 

 depending on weather conditions. 



THE ADULT. 



The adult (PL VI, C; VIII, C) is a handsome, elongate beetle, the 

 males averaging 15 mm. in length and the females 20 mm. The 

 back is cinnamon brown with two broad white stripes extending the 

 full length of the body; the front of the head and underparts are 

 silvery white and the legs and antennae gray, changing to brownish 

 at the extremities. The antennae of the males are slightly longer 

 than the body and those of the females slightly shorter than the 

 body. 



In escaping from the wood the beetles gnaw round exit holes 

 through the bark at the upper end of the pupal chamber, the holes 

 ranging from 5 to 8 mm. in diameter, the larger ones being those 

 from which females issue (PL VII, D). 



PERIOD OF ACTIVITY OF BEETLES. 



The statements of other investigators regarding the length of time 

 that the beetles of the roundheaded apple-tree borer are on the 

 wing indicate that in some places this period may be of longer 

 duration than in any of the localities where the present writer has 

 made observations. Becker (14), in the summary of his paper, says 

 that in the Ozarks pupation begins in the latter part of March and 

 may continue until the middle of June, and on another page speaks 

 of larvae that pupated as late as July 11, the inference being that 

 this was under normal conditions. The beetles are said by the same 

 author to be on the wing in the Ozarks from the third week of April 



