THE PECAN NUT CASE-BEARER 9 



TIME OF PUPATION OF OVERWINTERING LARV.E AND LENGTH OF SPRING-BROOD 



PUPAL PERIOD 



Investigations show that the time of pupation of the overwintering 

 larvae is variable. Records for 1916 give April 24 as the earliest date 

 of pupation, and the latest as May 12; while for 1917 pupae were 

 forming in rearing cages from April 19 to May 1. During the season 

 of 1917 overwintering larvae were observed in the field after May 1, 

 showing that insectary records do not actually indicate the complete 

 period at which transformation to pupae occurs. Before making any 

 generalization on the time of pupation, more extensive data are de- 

 sirable, as observations have been confined to a limited number of 

 individuals. 



During 1916 and 1917 the length of the pupal period of the spring 

 brood was determined for 19 individuals, as shown in Table 5: 



Table 5. — Length of pupal period of spring-brood pupse of the pecan nut case- 

 bearer, Monticello, Fla., 1916 and 1917 ' 



1916 



Num- 

 ber of 

 indi- 

 viduals 



Date of 

 pupation 



May 11. 

 May 13. 

 May 14. 

 May 15. 

 May 16. 

 May 17. 

 May 18. 

 May 19. 



do.. 



May 23. 



Average for 12 individuals. 



Apr. 24.. 

 Apr. 28.. 

 May2... 

 May4._ 

 May 5.. 

 May6_. 

 May 7.. 

 do- 

 May 8... 

 May 12. 



Date of 

 emergence 



Days as 

 pupa 



1917 



Num- 

 ber of 

 indi- 

 viduals 



Date of 

 pupation 



Apr. 19... 

 Apr. 20... 

 Apr. 28... 



do.... 



Apr. 29... 

 Apr. 30... 

 May 1... 



Date of 

 emergence 



May 2.. 

 May3._ 

 May 14. 

 May 16. 

 Mayl7. 

 do- 



May 16. 



Average for 7 individuals. 



Days as 

 pupa 



15.85 



TIME OF PUPATION AND LENGTH OF PUPAL PERIOD OF THE FIRST AND SECOND 



BROOD PUP^E 



Of the first-brood larvae under observation that transformed to 

 pupae during 1914 the first pupated June 9, and during 1916 and 

 1917 the first pupae appeared June 5 and June 2, respectively. Pupa- 

 tion continued in 1916 until June 29 and in 1917 until July 2, while 

 in 1914 the last pupa for insectary material was recorded on June 19. 

 It should be stated, however, that larvae under natural conditions 

 were probably pupating for a week or 10 days later than pupation 

 records for 1914 indicate, as it was determined on June 20 from field- 

 collected material that only 85 per cent of the larvae had pupated. 

 These records are given in Table 6. 



The second-brood larvae transform to pupae during the latter half 

 of July and the greater part of August. The time of pupation for a 

 number of individuals of the second brood is also given in Table 6. 

 These records, however, do not represent the entire period of 

 pupation for the second brood, as only a limited number of trans- 

 forming larvae were under observation during some seasons. 



