10 



BULLETIN 113, U. S. DEPARTMENT OF AGRICULTURE. 



this stage of the insect. These measurements, arranged numerically, 

 are given in Table III. It is not the writers' opinion that these 

 figures show definitely the number of molts, but they are presented 

 merely for what they are worth. However, a study of Table III 

 seems to warrant the interpretation that there are five instars, or four 

 larval molts. In the last instar considerable variation in the width 

 of the head will be noticed, but as this same variation is found 

 among full-grown larvae taken from their cocoons, they are all con- 

 sidered as belonging to the same stage. 



Table III. — Measurements of width of head of larvv of the lesser hud-moth 

 taken at intervals throughout their development at Benton- Harbor, Mich., 

 in 1913. 



Date. 



Width of 

 head. 



Stage. 



™.r 



Stage. 



Mm. 



First instar. 



April 8 (in hiberna- 

 tion). 



April 18 (in buds) 



May 27 (in cocoon) 



Third molt. 





.12 

 .12 

 .14 

 .15 

 .15 

 .16 

 .16 

 .16 

 .16 

 .16 

 .16 

 .16 

 .16 

 .16 



Mm. 



0.31 



.31 

 .34 

 .35 

 .36 

 .36 

 .38 

 .38 

 .38 

 .41 

 .41 

 .43 

 .43 

 .48 , 



Fourth In- 

 star. 









First molt. 







Fourth molt. 





.19 1 



.19 



.19 



.19 



.20 



.21 



.21 



.21 



.21 i 



Second in- 

 star. 





.56 1 



.57 j 



.57 | 



.59 | 



.60 



.62 



.62 



.64 



.64 



.64 



.66 



.86 



.96 



1.12 

 .60 

 .64 



1.02 

 | 



Fifth instar. 





Second molt. 





.245 ! 

 .245 ! 

 .25 

 .26 

 .275 I 

 .275 ! 



Third instar. 









PUPAL STAGE. 



The first pupae (PI. II, fig. 2) of the lesser bud-moth were found 

 on May 18 under the loose bark on the trunks of young peach trees, 

 incased in their small, white, silken cocoons. The last larvae to 

 pupate in the rearing cages did so on June 16. The average time 

 spent as a pupa is about 19 days, varying, however, from 15 to 30 

 days. 



Table IV is a record kept of isolated larvae, giving dates of pupa- 

 tion and of emergence as adults. 



