12 



BULLETIIT 352, V. S. DEPAETMENT OF AGEICULTUEE. 



Total feeding period. — A total of 227 larvae were carried through 

 the entire feeding period from hatching to entrance into the ground. 

 Table IV contains the data obtained. These data were obtained 

 during the period from August 5, when the first one hatched, to 

 September 5, when the last one entered the ground. 



Table IV. — Total feeding jyeriod of larvx of the cherry leaf-heetle, North East, Pa., 1915. 



Number of 

 individuals. 



Total feeding 

 period. 



j Number of 

 individuals. 



! 



Total feeding 

 period. 



3 



49 

 113 

 36 



7 

 7 



Days. 

 ■ 10 



11 



12 



13 



14 



15 



1 1 



2 



: 5 



2 



Days. 

 16 

 17 

 IS 

 20 



227 1 1 12. 33 



1 Average. 



PERIOD IN GROUND. 



"?% 



Fig 8.— Tue(.aerr\ leaf-beetle 

 Pre pupal lar^ a (Original ) 



The pupal cell is nearly spherical and about 5 mm. in diameter. 

 It is from a fourth to a half mch below the surface. Within it the 

 insect passes through the transformations from 

 larva to pupa and from pupa to adult. The 

 larva lies for several days curled up as shown 

 in figure 8 before transforming to the pupa. 



Data on the dates of transformation of the 

 laiwa are difficult to obtain, since this neces- 

 sarily involves the breaking up of the pupal 

 cell, and such data as were obtained are based 

 on but few individuals. 



Prepupal period. — In a lot of larvae that 

 entered the ground on August 5 daily exammation showed that the 

 first one pupated on August 1.3, or 8 days later. On the same daj- 

 1 pupa was found among larvse that entered the ground on August 

 6, giving a prepupal period of 7 days. One out of 3 laiwse that 

 entered the ground on August 7 had pupated 7 days later, on 

 August 14. Larvae that entered the ground on September 4 and 

 5, when the weather was much warmer than in August,' required 

 only 5 days to pupate. 



Pupal period. — In the August lots just mentioned the first trans- 

 formation to the adult stage took place 9 days after the first pupa- 

 tion, while in the September lots the pupal period was only 7 or 8 

 days. In a lot which entered the ground on August 22 the first one 

 pupated on September 10, 19 days later. Unfortunately, the pre- 

 pupal period for these was not determmed, but as that period was 

 passed during the very cold days of late August, it was undoubtedly 

 longer than in the earlier and later lots, and the pupal period was 

 probably close to 11 days in length. 



