BLUEBERRY INSECTS IN MAINE, 255 



larvae were common in all stages from those just hatched to 

 some ready to leave the berries. On September lo they v^ere 

 decidedly less numerous and there were but few small maggots. 

 About 30 puparia were obtained from material collected on 

 July 30, 1913, and on Septem'ber 5 of that year maggots were 

 still common in all stages. The season 191 3 was more normal 

 than 1914, which was decidedly backward, and this doubtless 

 explains the discrepancy in the records. In 191 5 larvae in all 

 stages were found to be common on August 25 and 26. 



Judging from measurements of the chitinous rasping hooks 

 there are three larval instars. About one-fifth caudad there is a 

 pronounced articulation, and measurements were made from 

 the base of this angle to the tip of the terminal portion. In a 

 recently hatched maggot this measurement was .035 mm., and 

 in the succeeding instars .0625 mm. and .iix mm. (although in 

 the two latter cases there was variation from .055 to .070 and 

 from .090 to .120). The size of the larva offers absolutely no 

 criterion as to the size of the hooks. 



The writer has reared only a few larvae under such conditions 

 that he was sure as to the exact number of days passed in the 

 berry. One maggot which hatched August 18, 1914, was in the 

 third instar on August 24, and formed its puparium on Sevj- 

 tember 2. Two which hatched August 26, 1914, were in the last 

 instar on September 2, were apparently full grown September 

 7, left their berries Sepember 8, and formed puparia September 

 9. One which hatched August 28, 1914, was in the second in- 

 star on September 2, and in the last instar on September 8; the 

 puparium was formed on September 14. One which was in the 

 second instar on August 26, 19 14, was in the last instar on 

 September 2 and formed its puparium on September 7. 



These records indicate that the larva spends on the average 

 about 14 days in the berry and that the period spent during the 

 last instar is nearly as long as the time of the two preceding in- 

 stars together. 



Although when the maggots are small, an infested berry can- 

 not be distinguished by sight from a sound one, in any case, 

 even when the larvae are very small, fruit which has been at- 

 tacked can easily be determined by the touch, for it feels soft 

 and mushy, and this is the surest external indication of attack 

 from Rhagoletis. The pulp becomes red and stringy and by the 



