BLUEBERRY INSECTS IN MAINE. 2^3 



they are most abundant from July 13 until about July 24, occur- 

 ring, however, through the rest of the month. 



From his data and observations the writer would infer that 

 each instar lasts about a week, except the fourth which (includ- 

 ing the prepupal period) extends over 10 days, and that conse- 

 quently 30 or 31 days is a fair estimate of the average length of 

 the larval life. The majority hatch about June 22 and pupate 

 from July 23 to July 30. 



The pupa. This insect does not leave the berry in order to 

 pupate, but the pupa is formed in the same little cavity in whicli 

 the larva lived. The young pupa is pure white, with transparent 

 legs and wings.' It is able to move rather freely when disturbed. 

 The cast larval skin usually adheres to the tip of the abdomen. 

 Two days before emerging the beak, coxae, and femoro-tibial 

 joints are brownish. About 24 hours before emergence, these 

 parts are darker brown and the tips of the elytra appear dark; 

 12 hours before, in addition the dorsal part of the prothorax is 

 brownish, and the eyes are black. The beak, head and pro- 

 thorax of the newly emerged beetle are dark brown, the eyes 

 deep black, the legs white except for the dark brown femoro- 

 tibial joints and the black tarsi; the abdomen is practically white, 

 the elytra are soft and colorless, and the wings are not yet 

 folded beneath them. The legs are at first closely appressed to 

 the body. The pupa lies with the ventral side uppermost and 

 the adult remains on its back for several hours. The weevil 

 stays in its cavity within the berry until the cuticula becomes 

 fully hardened and colored, a matter of some 24 hours. Often 

 the pupal skin is caught on the end of the beak which is used in 

 pushing off the old cuticula. 



Only once was the writer able to determine the pupal period 

 exactly. From a pupa formed on July 20, 1914, the adult beetle 

 emerged on July 29 and was fully colored on July 30. Less 

 definite observations would indicate that 9 days might safely be 

 considered the normal time spent as a pupa. Reckoning tliq 

 duration of the egg stage as 5 days, the period of larval life as 

 31. and the pupal instar as 9, gives 45 days as the average length 

 of the period of development. 



Adults. The adults began to emerge in mid- July and emer- 

 gence continued a month or more. Below is given in tabulated 

 form the emergence of adults in 1913 and 1914. 



