CODLING MOTH IN NORTHWESTERN PENNSYLVANIA. 85 



Larval life in the cocoon. — Cage records were kept relative to the 

 time of leaving the fruit and the time of pupation of 52 individual 

 larvae. This period includes the time for the making of the cell and 

 the so-called post-larval stage, which consists of an inactive period 

 of one or two days, when the larva undergoes structural changes 

 previous to pupation. A definite time limit for the post-larval stage 

 can hardly be given, since this is a gradual change, which leads up to 

 pupation. In Table XXII the larval life of the cocoon has been 

 referred to under the making of the cocoon, as this constitutes the 

 main activity of the larva during this period, but it also included 

 the post-larval stage. The summary of the larval life in the cocoon, as 

 recorded in Table XXIII, agrees in a striking manner with the 

 records obtained by Mr. E. L. Jenne a in Arkansas in 1908. For 

 North East, Pa., the average was 7.09 days, the maximum 19 days, 

 and the minimum 3 days. Mr. Jenne's records show an average of 

 7.2 days, maximum 19 days, and minimum 3 days. In instances 

 where the entire period previous to pupation has been recorded to 

 last only three days, it is very probable that the larvae, when dis- 

 turbed in the process of making the cocoons, abandoned the first 

 cocoons and made new ones. The period, therefore, appears shorter, 

 as no record was kept of the time required in making the first cocoon. 



FIRST-BROOD PUP^E. 



Time of pupation. — From infested apples, collected in an orchard 

 July 8, mature larvae emerged July 10 which pupated July 16. From 

 the band material pupae were obtained a few days later and were 

 observed in abundance throughout the period. The last pupation 

 occurred in the cages August 27. These late-appearing pupae, how- 

 ever, failed to develop, moths emerging only from larvae that pupated 

 not later than August 19. 



Length of first-brood pupal stage. — Of 95 pupae of the first brood, 

 the average duration of the stage was 12.5 days, ranging from 6 to 

 22 days. (See Table XX.) The records for the individual pupae 

 are given in Table XVIII, with a summary in Table XIX, showing 

 variations observed in the length of the stages during the entire 

 period when pupae were found. 



a U. S. Dept. Agr., Bur. Ent., Bui. 80, Part I. 



